From bbeb15006af65d371a933fe432bce5078115b9e3 Mon Sep 17 00:00:00 2001
From: Craig Tiller <ctiller@google.com>
Date: Mon, 30 Jan 2023 21:39:11 -0800
Subject: [PATCH] [promises] Server call (#31448)

* add experiment

* allow instantiation

* scratchings

* scratchings

* sniffly

* Automated change: Fix sanity tests

* fix

* fix

* fix

* Automated change: Fix sanity tests

* progress

* change pipe labels to enable server code to be written

* better api

* Automated change: Fix sanity tests

* progress

* [promises] Implementation of deadline for server-based-calls

* compression filter compiles again

* Automated change: Fix sanity tests

* fix

* server tracing fixes

* get client initial metadata

* progress

* progress

* server call surface progress

* Automated change: Fix sanity tests

* move payload

* server-progress

* recv-message-server-connchan

* logging

* fix context-gate

* recv fix@top

* Automated change: Fix sanity tests

* recv close on server

* top termination start

* [promises] Move Empty to be first class

* fixes

* fix

* flow control fix

* got to orphan!

* orphan

* call orphan

* spam cleanup

* fix

* new cancelation semantics

* progress

* large metadata fixes

* fix

* fix

* log

* better logs

* fix-chanz

* logging, necessaryness

* fix typo

* fixes

* fix

* fix

* fix-pipe

* cleanup logging

* fix

* build-fix

* fix

* Automated change: Fix sanity tests

* logging

* Automated change: Fix sanity tests

* Automated change: Fix sanity tests

* better primitive

* Revert "better primitive"

This reverts commit 119b5ee244763a88d2318bc5145065f4940a2295.

* fix

* fix

* trrracing

* Automated change: Fix sanity tests

* get-trailing-metadata

* cancellation

* Automated change: Fix sanity tests

* add transform pipeline to pipe

* add transform pipeline to pipe

* interceptor lists

* new server initial md api into filters

* convert connected_channel

* convert call

* initial promise based filter conversion

* convert promise based filter

* build fixes

* compile fix

* fixes

* fix ordering

* fixes

* check-metadata

* revert later: debug code

* better debug

* fix metadata ordering with messages in promise based filter

* fix ordering problem between batch completion and promise completion

* properly handle failure on receive message path on client

* more debug, fix a repoll bug in pbf

* Automated change: Fix sanity tests

* fixes

* Automated change: Fix sanity tests

* cleanup logging

* fixes

* missing file

* fixes

* logging

* Automated change: Fix sanity tests

* fixes

* convert logging filter

* fix

* Automated change: Fix sanity tests

* fix bad server response test

* Revert "Disable logging test (#32049)"

This reverts commit 5fc92eaeae6f668ba7c2df1024f18ef8c798a319.

* fix

* Automated change: Fix sanity tests

* fix memory leaks, logging

* Automated change: Fix sanity tests

* slice refcount debugging

* asan-canaries

* leak-fix

* leak-fix

* Automated change: Fix sanity tests

* fix

* fix

* fix

* fix

* fix

* Automated change: Fix sanity tests

* fix

* remove mistaken line

* add-comment

* fix refcounting bug

* Automated change: Fix sanity tests

* rename variable

* renames

* bleh

* carry pipe close status from bottom of pipe to top to appease
recv-close-on-server

* backport cancellation

* Revert "carry pipe close status from bottom of pipe to top to appease"

This reverts commit fa33301dcddd01aff52d3bee77b16ffef9466de5.

* fix

* Automated change: Fix sanity tests

* review-feedback

* comment-ordering

* monostate

* renames

* undo-review-feedback

* fix

* review-feedback

* review-feedback

* fix

* review-feedback

* drop debugloc constructor

* interceptor-list-rev-feedback

* interceptor-list-rev-feedback

* pipe test

* review-feedback

* undo-mistaken-change

* Automated change: Fix sanity tests

* pipe error state

* detect send/recv failures and report

* iwyu, build

* fix submodules

* fix

* warning

* cleanup

* Automated change: Fix sanity tests

* fix

* fix for windows

* fix

* null pointer fix

* iwyu

* gen projex

---------

Co-authored-by: ctiller <ctiller@users.noreply.github.com>
---
 BUILD                                         |   15 +-
 CMakeLists.txt                                |  148 +-
 Makefile                                      |    8 +-
 bazel/experiments.bzl                         |    1 +
 build_autogenerated.yaml                      |  259 ++--
 config.m4                                     |    4 +-
 config.w32                                    |    4 +-
 doc/environment_variables.md                  |    1 +
 gRPC-C++.podspec                              |   16 +-
 gRPC-Core.podspec                             |   20 +-
 grpc.gemspec                                  |   12 +-
 grpc.gyp                                      |   12 +-
 package.xml                                   |   12 +-
 src/core/BUILD                                |   95 +-
 .../grpclb/client_load_reporting_filter.cc    |   21 +-
 .../filters/http/client/http_client_filter.cc |   46 +-
 .../message_compress/compression_filter.cc    |  223 ++-
 .../message_compress/compression_filter.h     |   21 +-
 .../filters/http/server/http_server_filter.cc |   49 +-
 .../stateful_session_filter.cc                |   51 +-
 .../chttp2/transport/chttp2_transport.cc      |   32 +
 .../ext/transport/chttp2/transport/internal.h |   14 +-
 .../ext/transport/chttp2/transport/parsing.cc |  135 +-
 .../lib/channel/channel_stack_builder_impl.cc |   15 +-
 src/core/lib/channel/connected_channel.cc     | 1212 ++++++++++++-----
 src/core/lib/channel/promise_based_filter.cc  |  687 ++++++----
 src/core/lib/channel/promise_based_filter.h   |  139 +-
 src/core/lib/event_engine/slice.cc            |    2 +-
 src/core/lib/experiments/experiments.cc       |    4 +
 src/core/lib/experiments/experiments.h        |    9 +-
 src/core/lib/experiments/experiments.yaml     |    8 +
 src/core/lib/gprpp/debug_location.h           |    3 -
 src/core/lib/iomgr/call_combiner.cc           |    8 +-
 src/core/lib/iomgr/closure.cc                 |   27 +
 src/core/lib/iomgr/closure.h                  |    2 +
 src/core/lib/promise/activity.h               |    4 +
 src/core/lib/promise/for_each.h               |   22 +
 src/core/lib/promise/if.h                     |   61 +
 src/core/lib/promise/interceptor_list.h       |  309 +++++
 src/core/lib/promise/intra_activity_waiter.h  |    6 +
 src/core/lib/promise/latch.h                  |   30 +-
 src/core/lib/promise/map_pipe.h               |   32 +-
 src/core/lib/promise/pipe.h                   |  482 ++++---
 src/core/lib/promise/{pipe.cc => trace.cc}    |    5 +-
 src/core/lib/promise/trace.h                  |   24 +
 src/core/lib/promise/try_concurrently.h       |   28 +
 src/core/lib/resource_quota/arena.h           |   90 +-
 src/core/lib/slice/slice.cc                   |    6 +-
 src/core/lib/slice/slice.h                    |   15 +-
 src/core/lib/slice/slice_buffer.h             |    8 +
 src/core/lib/slice/slice_refcount.cc          |   20 +
 src/core/lib/slice/slice_refcount.h           |   26 +-
 src/core/lib/surface/call.cc                  | 1059 ++++++++++----
 src/core/lib/surface/call.h                   |   28 +
 src/core/lib/surface/call_trace.cc            |   28 +-
 src/core/lib/surface/lame_client.cc           |    4 +-
 src/core/lib/surface/server.cc                |  299 +++-
 src/core/lib/surface/server.h                 |    3 +
 src/core/lib/transport/transport.cc           |    7 +-
 src/core/lib/transport/transport.h            |   18 +-
 src/cpp/ext/filters/logging/BUILD             |   11 +-
 src/cpp/ext/filters/logging/logging_filter.cc |  142 +-
 src/python/grpcio/grpc_core_dependencies.py   |    4 +-
 .../fixtures/h2_sockpair_with_minstack.cc     |   15 +-
 test/core/end2end/generate_tests.bzl          |    2 +-
 .../core/end2end/tests/cancel_after_accept.cc |    3 +
 test/core/end2end/tests/grpc_authz.cc         |    1 +
 test/core/end2end/tests/max_message_length.cc |    3 +
 test/core/end2end/tests/no_logging.cc         |    2 +
 test/core/end2end/tests/server_streaming.cc   |   11 +-
 test/core/filters/filter_fuzzer.cc            |   28 +-
 test/core/promise/BUILD                       |   20 +-
 test/core/promise/activity_test.cc            |    4 +-
 test/core/promise/for_each_test.cc            |    1 +
 test/core/promise/if_test.cc                  |   12 +
 test/core/promise/interceptor_list_test.cc    |  144 ++
 test/core/promise/latch_test.cc               |    4 +-
 test/core/promise/map_pipe_test.cc            |    1 +
 test/core/promise/pipe_test.cc                |  262 +++-
 test/core/resource_quota/arena_test.cc        |   45 +
 test/core/slice/slice_test.cc                 |    2 +-
 test/cpp/ext/filters/logging/logging_test.cc  |   10 +-
 tools/doxygen/Doxyfile.c++.internal           |   12 +-
 tools/doxygen/Doxyfile.core.internal          |   12 +-
 tools/run_tests/generated/tests.json          |   24 +
 85 files changed, 4960 insertions(+), 1744 deletions(-)
 create mode 100644 src/core/lib/iomgr/closure.cc
 create mode 100644 src/core/lib/promise/interceptor_list.h
 rename src/core/lib/promise/{pipe.cc => trace.cc} (82%)
 create mode 100644 src/core/lib/promise/trace.h
 create mode 100644 src/core/lib/slice/slice_refcount.cc
 create mode 100644 test/core/promise/interceptor_list_test.cc

diff --git a/BUILD b/BUILD
index 5c11bfe5ffc..aa8b4af6f34 100644
--- a/BUILD
+++ b/BUILD
@@ -1421,6 +1421,8 @@ grpc_cc_library(
         "//src/core:arena",
         "//src/core:arena_promise",
         "//src/core:atomic_utils",
+        "//src/core:basic_join",
+        "//src/core:basic_seq",
         "//src/core:bitset",
         "//src/core:channel_args",
         "//src/core:channel_args_endpoint_config",
@@ -1449,7 +1451,7 @@ grpc_cc_library(
         "//src/core:iomgr_fwd",
         "//src/core:iomgr_port",
         "//src/core:json",
-        "//src/core:latch",
+        "//src/core:map",
         "//src/core:match",
         "//src/core:memory_quota",
         "//src/core:no_destruct",
@@ -1475,6 +1477,8 @@ grpc_cc_library(
         "//src/core:thread_quota",
         "//src/core:time",
         "//src/core:transport_fwd",
+        "//src/core:try_join",
+        "//src/core:try_seq",
         "//src/core:useful",
     ],
 )
@@ -3260,9 +3264,9 @@ grpc_cc_library(
         "grpc_public_hdrs",
         "grpc_trace",
         "promise",
+        "//src/core:activity",
         "//src/core:arena",
         "//src/core:arena_promise",
-        "//src/core:basic_seq",
         "//src/core:channel_args",
         "//src/core:channel_fwd",
         "//src/core:channel_init",
@@ -3270,15 +3274,14 @@ grpc_cc_library(
         "//src/core:context",
         "//src/core:grpc_message_size_filter",
         "//src/core:latch",
-        "//src/core:map_pipe",
+        "//src/core:map",
         "//src/core:percent_encoding",
         "//src/core:pipe",
-        "//src/core:promise_like",
-        "//src/core:seq",
+        "//src/core:poll",
+        "//src/core:race",
         "//src/core:slice",
         "//src/core:slice_buffer",
         "//src/core:transport_fwd",
-        "//src/core:try_concurrently",
     ],
 )
 
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 0951d66112e..a7ece0db6c0 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1015,6 +1015,7 @@ if(gRPC_BUILD_TESTS)
   add_dependencies(buildtests_cxx init_test)
   add_dependencies(buildtests_cxx initial_settings_frame_bad_client_test)
   add_dependencies(buildtests_cxx insecure_security_connector_test)
+  add_dependencies(buildtests_cxx interceptor_list_test)
   add_dependencies(buildtests_cxx interop_client)
   add_dependencies(buildtests_cxx interop_server)
   if(_gRPC_PLATFORM_LINUX OR _gRPC_PLATFORM_POSIX OR _gRPC_PLATFORM_WINDOWS)
@@ -2209,6 +2210,7 @@ add_library(grpc
   src/core/lib/iomgr/buffer_list.cc
   src/core/lib/iomgr/call_combiner.cc
   src/core/lib/iomgr/cfstream_handle.cc
+  src/core/lib/iomgr/closure.cc
   src/core/lib/iomgr/combiner.cc
   src/core/lib/iomgr/dualstack_socket_posix.cc
   src/core/lib/iomgr/endpoint.cc
@@ -2290,8 +2292,8 @@ add_library(grpc
   src/core/lib/load_balancing/lb_policy_registry.cc
   src/core/lib/matchers/matchers.cc
   src/core/lib/promise/activity.cc
-  src/core/lib/promise/pipe.cc
   src/core/lib/promise/sleep.cc
+  src/core/lib/promise/trace.cc
   src/core/lib/resolver/resolver.cc
   src/core/lib/resolver/resolver_registry.cc
   src/core/lib/resolver/server_address.cc
@@ -2369,6 +2371,7 @@ add_library(grpc
   src/core/lib/slice/percent_encoding.cc
   src/core/lib/slice/slice.cc
   src/core/lib/slice/slice_buffer.cc
+  src/core/lib/slice/slice_refcount.cc
   src/core/lib/slice/slice_string_helpers.cc
   src/core/lib/surface/api_trace.cc
   src/core/lib/surface/builtins.cc
@@ -2892,6 +2895,7 @@ add_library(grpc_unsecure
   src/core/lib/iomgr/buffer_list.cc
   src/core/lib/iomgr/call_combiner.cc
   src/core/lib/iomgr/cfstream_handle.cc
+  src/core/lib/iomgr/closure.cc
   src/core/lib/iomgr/combiner.cc
   src/core/lib/iomgr/dualstack_socket_posix.cc
   src/core/lib/iomgr/endpoint.cc
@@ -2971,8 +2975,8 @@ add_library(grpc_unsecure
   src/core/lib/load_balancing/lb_policy.cc
   src/core/lib/load_balancing/lb_policy_registry.cc
   src/core/lib/promise/activity.cc
-  src/core/lib/promise/pipe.cc
   src/core/lib/promise/sleep.cc
+  src/core/lib/promise/trace.cc
   src/core/lib/resolver/resolver.cc
   src/core/lib/resolver/resolver_registry.cc
   src/core/lib/resolver/server_address.cc
@@ -3019,6 +3023,7 @@ add_library(grpc_unsecure
   src/core/lib/slice/percent_encoding.cc
   src/core/lib/slice/slice.cc
   src/core/lib/slice/slice_buffer.cc
+  src/core/lib/slice/slice_refcount.cc
   src/core/lib/slice/slice_string_helpers.cc
   src/core/lib/surface/api_trace.cc
   src/core/lib/surface/builtins.cc
@@ -4402,6 +4407,7 @@ add_library(grpc_authorization_provider
   src/core/lib/iomgr/buffer_list.cc
   src/core/lib/iomgr/call_combiner.cc
   src/core/lib/iomgr/cfstream_handle.cc
+  src/core/lib/iomgr/closure.cc
   src/core/lib/iomgr/combiner.cc
   src/core/lib/iomgr/dualstack_socket_posix.cc
   src/core/lib/iomgr/endpoint.cc
@@ -4481,7 +4487,7 @@ add_library(grpc_authorization_provider
   src/core/lib/load_balancing/lb_policy_registry.cc
   src/core/lib/matchers/matchers.cc
   src/core/lib/promise/activity.cc
-  src/core/lib/promise/pipe.cc
+  src/core/lib/promise/trace.cc
   src/core/lib/resolver/resolver.cc
   src/core/lib/resolver/resolver_registry.cc
   src/core/lib/resolver/server_address.cc
@@ -4528,6 +4534,7 @@ add_library(grpc_authorization_provider
   src/core/lib/slice/percent_encoding.cc
   src/core/lib/slice/slice.cc
   src/core/lib/slice/slice_buffer.cc
+  src/core/lib/slice/slice_refcount.cc
   src/core/lib/slice/slice_string_helpers.cc
   src/core/lib/surface/api_trace.cc
   src/core/lib/surface/builtins.cc
@@ -8288,6 +8295,7 @@ add_executable(chunked_vector_test
   src/core/lib/experiments/experiments.cc
   src/core/lib/gprpp/status_helper.cc
   src/core/lib/gprpp/time.cc
+  src/core/lib/iomgr/closure.cc
   src/core/lib/iomgr/combiner.cc
   src/core/lib/iomgr/error.cc
   src/core/lib/iomgr/exec_ctx.cc
@@ -8302,6 +8310,7 @@ add_executable(chunked_vector_test
   src/core/lib/resource_quota/trace.cc
   src/core/lib/slice/percent_encoding.cc
   src/core/lib/slice/slice.cc
+  src/core/lib/slice/slice_refcount.cc
   src/core/lib/slice/slice_string_helpers.cc
   test/core/gprpp/chunked_vector_test.cc
   third_party/googletest/googletest/src/gtest-all.cc
@@ -10577,6 +10586,7 @@ add_executable(exec_ctx_wakeup_scheduler_test
   src/core/lib/debug/trace.cc
   src/core/lib/gprpp/status_helper.cc
   src/core/lib/gprpp/time.cc
+  src/core/lib/iomgr/closure.cc
   src/core/lib/iomgr/combiner.cc
   src/core/lib/iomgr/error.cc
   src/core/lib/iomgr/exec_ctx.cc
@@ -10585,6 +10595,7 @@ add_executable(exec_ctx_wakeup_scheduler_test
   src/core/lib/promise/activity.cc
   src/core/lib/slice/percent_encoding.cc
   src/core/lib/slice/slice.cc
+  src/core/lib/slice/slice_refcount.cc
   src/core/lib/slice/slice_string_helpers.cc
   test/core/promise/exec_ctx_wakeup_scheduler_test.cc
   third_party/googletest/googletest/src/gtest-all.cc
@@ -11050,6 +11061,7 @@ add_executable(flow_control_test
   src/core/lib/experiments/experiments.cc
   src/core/lib/gprpp/status_helper.cc
   src/core/lib/gprpp/time.cc
+  src/core/lib/iomgr/closure.cc
   src/core/lib/iomgr/combiner.cc
   src/core/lib/iomgr/error.cc
   src/core/lib/iomgr/exec_ctx.cc
@@ -11063,6 +11075,7 @@ add_executable(flow_control_test
   src/core/lib/resource_quota/trace.cc
   src/core/lib/slice/percent_encoding.cc
   src/core/lib/slice/slice.cc
+  src/core/lib/slice/slice_refcount.cc
   src/core/lib/slice/slice_string_helpers.cc
   src/core/lib/transport/bdp_estimator.cc
   src/core/lib/transport/pid_controller.cc
@@ -11119,13 +11132,14 @@ add_executable(for_each_test
   src/core/lib/experiments/experiments.cc
   src/core/lib/gprpp/status_helper.cc
   src/core/lib/gprpp/time.cc
+  src/core/lib/iomgr/closure.cc
   src/core/lib/iomgr/combiner.cc
   src/core/lib/iomgr/error.cc
   src/core/lib/iomgr/exec_ctx.cc
   src/core/lib/iomgr/executor.cc
   src/core/lib/iomgr/iomgr_internal.cc
   src/core/lib/promise/activity.cc
-  src/core/lib/promise/pipe.cc
+  src/core/lib/promise/trace.cc
   src/core/lib/resource_quota/arena.cc
   src/core/lib/resource_quota/memory_quota.cc
   src/core/lib/resource_quota/periodic_update.cc
@@ -11134,6 +11148,7 @@ add_executable(for_each_test
   src/core/lib/resource_quota/trace.cc
   src/core/lib/slice/percent_encoding.cc
   src/core/lib/slice/slice.cc
+  src/core/lib/slice/slice_refcount.cc
   src/core/lib/slice/slice_string_helpers.cc
   test/core/promise/for_each_test.cc
   third_party/googletest/googletest/src/gtest-all.cc
@@ -11478,6 +11493,7 @@ add_executable(frame_test
   src/core/lib/iomgr/buffer_list.cc
   src/core/lib/iomgr/call_combiner.cc
   src/core/lib/iomgr/cfstream_handle.cc
+  src/core/lib/iomgr/closure.cc
   src/core/lib/iomgr/combiner.cc
   src/core/lib/iomgr/dualstack_socket_posix.cc
   src/core/lib/iomgr/endpoint.cc
@@ -11556,7 +11572,7 @@ add_executable(frame_test
   src/core/lib/load_balancing/lb_policy.cc
   src/core/lib/load_balancing/lb_policy_registry.cc
   src/core/lib/promise/activity.cc
-  src/core/lib/promise/pipe.cc
+  src/core/lib/promise/trace.cc
   src/core/lib/resolver/resolver.cc
   src/core/lib/resolver/resolver_registry.cc
   src/core/lib/resolver/server_address.cc
@@ -11580,6 +11596,7 @@ add_executable(frame_test
   src/core/lib/slice/percent_encoding.cc
   src/core/lib/slice/slice.cc
   src/core/lib/slice/slice_buffer.cc
+  src/core/lib/slice/slice_refcount.cc
   src/core/lib/slice/slice_string_helpers.cc
   src/core/lib/surface/api_trace.cc
   src/core/lib/surface/builtins.cc
@@ -13917,6 +13934,77 @@ target_link_libraries(insecure_security_connector_test
 )
 
 
+endif()
+if(gRPC_BUILD_TESTS)
+
+add_executable(interceptor_list_test
+  src/core/ext/upb-generated/google/protobuf/any.upb.c
+  src/core/ext/upb-generated/google/rpc/status.upb.c
+  src/core/lib/debug/trace.cc
+  src/core/lib/event_engine/memory_allocator.cc
+  src/core/lib/experiments/config.cc
+  src/core/lib/experiments/experiments.cc
+  src/core/lib/gprpp/status_helper.cc
+  src/core/lib/gprpp/time.cc
+  src/core/lib/iomgr/closure.cc
+  src/core/lib/iomgr/combiner.cc
+  src/core/lib/iomgr/error.cc
+  src/core/lib/iomgr/exec_ctx.cc
+  src/core/lib/iomgr/executor.cc
+  src/core/lib/iomgr/iomgr_internal.cc
+  src/core/lib/promise/activity.cc
+  src/core/lib/promise/trace.cc
+  src/core/lib/resource_quota/arena.cc
+  src/core/lib/resource_quota/memory_quota.cc
+  src/core/lib/resource_quota/periodic_update.cc
+  src/core/lib/resource_quota/resource_quota.cc
+  src/core/lib/resource_quota/thread_quota.cc
+  src/core/lib/resource_quota/trace.cc
+  src/core/lib/slice/percent_encoding.cc
+  src/core/lib/slice/slice.cc
+  src/core/lib/slice/slice_refcount.cc
+  src/core/lib/slice/slice_string_helpers.cc
+  test/core/promise/interceptor_list_test.cc
+  third_party/googletest/googletest/src/gtest-all.cc
+  third_party/googletest/googlemock/src/gmock-all.cc
+)
+target_compile_features(interceptor_list_test PUBLIC cxx_std_14)
+target_include_directories(interceptor_list_test
+  PRIVATE
+    ${CMAKE_CURRENT_SOURCE_DIR}
+    ${CMAKE_CURRENT_SOURCE_DIR}/include
+    ${_gRPC_ADDRESS_SORTING_INCLUDE_DIR}
+    ${_gRPC_RE2_INCLUDE_DIR}
+    ${_gRPC_SSL_INCLUDE_DIR}
+    ${_gRPC_UPB_GENERATED_DIR}
+    ${_gRPC_UPB_GRPC_GENERATED_DIR}
+    ${_gRPC_UPB_INCLUDE_DIR}
+    ${_gRPC_XXHASH_INCLUDE_DIR}
+    ${_gRPC_ZLIB_INCLUDE_DIR}
+    third_party/googletest/googletest/include
+    third_party/googletest/googletest
+    third_party/googletest/googlemock/include
+    third_party/googletest/googlemock
+    ${_gRPC_PROTO_GENS_DIR}
+)
+
+target_link_libraries(interceptor_list_test
+  ${_gRPC_BASELIB_LIBRARIES}
+  ${_gRPC_PROTOBUF_LIBRARIES}
+  ${_gRPC_ZLIB_LIBRARIES}
+  ${_gRPC_ALLTARGETS_LIBRARIES}
+  absl::flat_hash_set
+  absl::any_invocable
+  absl::function_ref
+  absl::hash
+  absl::type_traits
+  absl::statusor
+  absl::utility
+  gpr
+  upb
+)
+
+
 endif()
 if(gRPC_BUILD_TESTS)
 
@@ -14399,7 +14487,9 @@ endif()
 if(gRPC_BUILD_TESTS)
 
 add_executable(latch_test
+  src/core/lib/debug/trace.cc
   src/core/lib/promise/activity.cc
+  src/core/lib/promise/trace.cc
   test/core/promise/latch_test.cc
   third_party/googletest/googletest/src/gtest-all.cc
   third_party/googletest/googlemock/src/gmock-all.cc
@@ -14646,13 +14736,14 @@ add_executable(map_pipe_test
   src/core/lib/experiments/experiments.cc
   src/core/lib/gprpp/status_helper.cc
   src/core/lib/gprpp/time.cc
+  src/core/lib/iomgr/closure.cc
   src/core/lib/iomgr/combiner.cc
   src/core/lib/iomgr/error.cc
   src/core/lib/iomgr/exec_ctx.cc
   src/core/lib/iomgr/executor.cc
   src/core/lib/iomgr/iomgr_internal.cc
   src/core/lib/promise/activity.cc
-  src/core/lib/promise/pipe.cc
+  src/core/lib/promise/trace.cc
   src/core/lib/resource_quota/arena.cc
   src/core/lib/resource_quota/memory_quota.cc
   src/core/lib/resource_quota/periodic_update.cc
@@ -14661,6 +14752,7 @@ add_executable(map_pipe_test
   src/core/lib/resource_quota/trace.cc
   src/core/lib/slice/percent_encoding.cc
   src/core/lib/slice/slice.cc
+  src/core/lib/slice/slice_refcount.cc
   src/core/lib/slice/slice_string_helpers.cc
   test/core/promise/map_pipe_test.cc
   third_party/googletest/googletest/src/gtest-all.cc
@@ -16016,6 +16108,7 @@ add_executable(periodic_update_test
   src/core/lib/debug/trace.cc
   src/core/lib/gprpp/status_helper.cc
   src/core/lib/gprpp/time.cc
+  src/core/lib/iomgr/closure.cc
   src/core/lib/iomgr/combiner.cc
   src/core/lib/iomgr/error.cc
   src/core/lib/iomgr/exec_ctx.cc
@@ -16024,6 +16117,7 @@ add_executable(periodic_update_test
   src/core/lib/resource_quota/periodic_update.cc
   src/core/lib/slice/percent_encoding.cc
   src/core/lib/slice/slice.cc
+  src/core/lib/slice/slice_refcount.cc
   src/core/lib/slice/slice_string_helpers.cc
   test/core/resource_quota/periodic_update_test.cc
   third_party/googletest/googletest/src/gtest-all.cc
@@ -16153,30 +16247,6 @@ endif()
 if(gRPC_BUILD_TESTS)
 
 add_executable(pipe_test
-  src/core/ext/upb-generated/google/protobuf/any.upb.c
-  src/core/ext/upb-generated/google/rpc/status.upb.c
-  src/core/lib/debug/trace.cc
-  src/core/lib/event_engine/memory_allocator.cc
-  src/core/lib/experiments/config.cc
-  src/core/lib/experiments/experiments.cc
-  src/core/lib/gprpp/status_helper.cc
-  src/core/lib/gprpp/time.cc
-  src/core/lib/iomgr/combiner.cc
-  src/core/lib/iomgr/error.cc
-  src/core/lib/iomgr/exec_ctx.cc
-  src/core/lib/iomgr/executor.cc
-  src/core/lib/iomgr/iomgr_internal.cc
-  src/core/lib/promise/activity.cc
-  src/core/lib/promise/pipe.cc
-  src/core/lib/resource_quota/arena.cc
-  src/core/lib/resource_quota/memory_quota.cc
-  src/core/lib/resource_quota/periodic_update.cc
-  src/core/lib/resource_quota/resource_quota.cc
-  src/core/lib/resource_quota/thread_quota.cc
-  src/core/lib/resource_quota/trace.cc
-  src/core/lib/slice/percent_encoding.cc
-  src/core/lib/slice/slice.cc
-  src/core/lib/slice/slice_string_helpers.cc
   test/core/promise/pipe_test.cc
   third_party/googletest/googletest/src/gtest-all.cc
   third_party/googletest/googlemock/src/gmock-all.cc
@@ -16206,15 +16276,7 @@ target_link_libraries(pipe_test
   ${_gRPC_PROTOBUF_LIBRARIES}
   ${_gRPC_ZLIB_LIBRARIES}
   ${_gRPC_ALLTARGETS_LIBRARIES}
-  absl::flat_hash_set
-  absl::any_invocable
-  absl::function_ref
-  absl::hash
-  absl::type_traits
-  absl::statusor
-  absl::utility
-  gpr
-  upb
+  grpc
 )
 
 
@@ -18768,7 +18830,9 @@ endif()
 if(gRPC_BUILD_TESTS)
 
 add_executable(slice_string_helpers_test
+  src/core/lib/debug/trace.cc
   src/core/lib/slice/slice.cc
+  src/core/lib/slice/slice_refcount.cc
   src/core/lib/slice/slice_string_helpers.cc
   test/core/slice/slice_string_helpers_test.cc
   third_party/googletest/googletest/src/gtest-all.cc
@@ -20162,12 +20226,14 @@ endif()
 if(gRPC_BUILD_TESTS)
 
 add_executable(test_core_event_engine_slice_buffer_test
+  src/core/lib/debug/trace.cc
   src/core/lib/event_engine/event_engine.cc
   src/core/lib/event_engine/resolved_address.cc
   src/core/lib/event_engine/slice.cc
   src/core/lib/event_engine/slice_buffer.cc
   src/core/lib/slice/slice.cc
   src/core/lib/slice/slice_buffer.cc
+  src/core/lib/slice/slice_refcount.cc
   src/core/lib/slice/slice_string_helpers.cc
   test/core/event_engine/slice_buffer_test.cc
   third_party/googletest/googletest/src/gtest-all.cc
@@ -21515,19 +21581,21 @@ add_executable(try_concurrently_test
   src/core/lib/experiments/experiments.cc
   src/core/lib/gprpp/status_helper.cc
   src/core/lib/gprpp/time.cc
+  src/core/lib/iomgr/closure.cc
   src/core/lib/iomgr/combiner.cc
   src/core/lib/iomgr/error.cc
   src/core/lib/iomgr/exec_ctx.cc
   src/core/lib/iomgr/executor.cc
   src/core/lib/iomgr/iomgr_internal.cc
   src/core/lib/promise/activity.cc
-  src/core/lib/promise/pipe.cc
+  src/core/lib/promise/trace.cc
   src/core/lib/resource_quota/arena.cc
   src/core/lib/resource_quota/memory_quota.cc
   src/core/lib/resource_quota/periodic_update.cc
   src/core/lib/resource_quota/trace.cc
   src/core/lib/slice/percent_encoding.cc
   src/core/lib/slice/slice.cc
+  src/core/lib/slice/slice_refcount.cc
   src/core/lib/slice/slice_string_helpers.cc
   test/core/promise/try_concurrently_test.cc
   third_party/googletest/googletest/src/gtest-all.cc
diff --git a/Makefile b/Makefile
index 5f6348a3a64..8c1670e4426 100644
--- a/Makefile
+++ b/Makefile
@@ -1473,6 +1473,7 @@ LIBGRPC_SRC = \
     src/core/lib/iomgr/buffer_list.cc \
     src/core/lib/iomgr/call_combiner.cc \
     src/core/lib/iomgr/cfstream_handle.cc \
+    src/core/lib/iomgr/closure.cc \
     src/core/lib/iomgr/combiner.cc \
     src/core/lib/iomgr/dualstack_socket_posix.cc \
     src/core/lib/iomgr/endpoint.cc \
@@ -1554,8 +1555,8 @@ LIBGRPC_SRC = \
     src/core/lib/load_balancing/lb_policy_registry.cc \
     src/core/lib/matchers/matchers.cc \
     src/core/lib/promise/activity.cc \
-    src/core/lib/promise/pipe.cc \
     src/core/lib/promise/sleep.cc \
+    src/core/lib/promise/trace.cc \
     src/core/lib/resolver/resolver.cc \
     src/core/lib/resolver/resolver_registry.cc \
     src/core/lib/resolver/server_address.cc \
@@ -1633,6 +1634,7 @@ LIBGRPC_SRC = \
     src/core/lib/slice/percent_encoding.cc \
     src/core/lib/slice/slice.cc \
     src/core/lib/slice/slice_buffer.cc \
+    src/core/lib/slice/slice_refcount.cc \
     src/core/lib/slice/slice_string_helpers.cc \
     src/core/lib/surface/api_trace.cc \
     src/core/lib/surface/builtins.cc \
@@ -2009,6 +2011,7 @@ LIBGRPC_UNSECURE_SRC = \
     src/core/lib/iomgr/buffer_list.cc \
     src/core/lib/iomgr/call_combiner.cc \
     src/core/lib/iomgr/cfstream_handle.cc \
+    src/core/lib/iomgr/closure.cc \
     src/core/lib/iomgr/combiner.cc \
     src/core/lib/iomgr/dualstack_socket_posix.cc \
     src/core/lib/iomgr/endpoint.cc \
@@ -2088,8 +2091,8 @@ LIBGRPC_UNSECURE_SRC = \
     src/core/lib/load_balancing/lb_policy.cc \
     src/core/lib/load_balancing/lb_policy_registry.cc \
     src/core/lib/promise/activity.cc \
-    src/core/lib/promise/pipe.cc \
     src/core/lib/promise/sleep.cc \
+    src/core/lib/promise/trace.cc \
     src/core/lib/resolver/resolver.cc \
     src/core/lib/resolver/resolver_registry.cc \
     src/core/lib/resolver/server_address.cc \
@@ -2136,6 +2139,7 @@ LIBGRPC_UNSECURE_SRC = \
     src/core/lib/slice/percent_encoding.cc \
     src/core/lib/slice/slice.cc \
     src/core/lib/slice/slice_buffer.cc \
+    src/core/lib/slice/slice_refcount.cc \
     src/core/lib/slice/slice_string_helpers.cc \
     src/core/lib/surface/api_trace.cc \
     src/core/lib/surface/builtins.cc \
diff --git a/bazel/experiments.bzl b/bazel/experiments.bzl
index bfcbebb19ee..b86d9688824 100644
--- a/bazel/experiments.bzl
+++ b/bazel/experiments.bzl
@@ -25,6 +25,7 @@ EXPERIMENTS = {
         ],
         "core_end2end_test": [
             "promise_based_client_call",
+            "promise_based_server_call",
         ],
         "endpoint_test": [
             "tcp_frame_size_tuning",
diff --git a/build_autogenerated.yaml b/build_autogenerated.yaml
index d656f1b5ba4..a4ad71956d1 100644
--- a/build_autogenerated.yaml
+++ b/build_autogenerated.yaml
@@ -930,25 +930,27 @@ libs:
   - src/core/lib/promise/activity.h
   - src/core/lib/promise/arena_promise.h
   - src/core/lib/promise/context.h
+  - src/core/lib/promise/detail/basic_join.h
   - src/core/lib/promise/detail/basic_seq.h
   - src/core/lib/promise/detail/promise_factory.h
   - src/core/lib/promise/detail/promise_like.h
   - src/core/lib/promise/detail/status.h
   - src/core/lib/promise/detail/switch.h
   - src/core/lib/promise/exec_ctx_wakeup_scheduler.h
-  - src/core/lib/promise/for_each.h
+  - src/core/lib/promise/if.h
+  - src/core/lib/promise/interceptor_list.h
   - src/core/lib/promise/intra_activity_waiter.h
   - src/core/lib/promise/latch.h
   - src/core/lib/promise/loop.h
   - src/core/lib/promise/map.h
-  - src/core/lib/promise/map_pipe.h
   - src/core/lib/promise/pipe.h
   - src/core/lib/promise/poll.h
   - src/core/lib/promise/promise.h
   - src/core/lib/promise/race.h
   - src/core/lib/promise/seq.h
   - src/core/lib/promise/sleep.h
-  - src/core/lib/promise/try_concurrently.h
+  - src/core/lib/promise/trace.h
+  - src/core/lib/promise/try_join.h
   - src/core/lib/promise/try_seq.h
   - src/core/lib/resolver/resolver.h
   - src/core/lib/resolver/resolver_factory.h
@@ -1608,6 +1610,7 @@ libs:
   - src/core/lib/iomgr/buffer_list.cc
   - src/core/lib/iomgr/call_combiner.cc
   - src/core/lib/iomgr/cfstream_handle.cc
+  - src/core/lib/iomgr/closure.cc
   - src/core/lib/iomgr/combiner.cc
   - src/core/lib/iomgr/dualstack_socket_posix.cc
   - src/core/lib/iomgr/endpoint.cc
@@ -1689,8 +1692,8 @@ libs:
   - src/core/lib/load_balancing/lb_policy_registry.cc
   - src/core/lib/matchers/matchers.cc
   - src/core/lib/promise/activity.cc
-  - src/core/lib/promise/pipe.cc
   - src/core/lib/promise/sleep.cc
+  - src/core/lib/promise/trace.cc
   - src/core/lib/resolver/resolver.cc
   - src/core/lib/resolver/resolver_registry.cc
   - src/core/lib/resolver/server_address.cc
@@ -1768,6 +1771,7 @@ libs:
   - src/core/lib/slice/percent_encoding.cc
   - src/core/lib/slice/slice.cc
   - src/core/lib/slice/slice_buffer.cc
+  - src/core/lib/slice/slice_refcount.cc
   - src/core/lib/slice/slice_string_helpers.cc
   - src/core/lib/surface/api_trace.cc
   - src/core/lib/surface/builtins.cc
@@ -2258,25 +2262,27 @@ libs:
   - src/core/lib/promise/activity.h
   - src/core/lib/promise/arena_promise.h
   - src/core/lib/promise/context.h
+  - src/core/lib/promise/detail/basic_join.h
   - src/core/lib/promise/detail/basic_seq.h
   - src/core/lib/promise/detail/promise_factory.h
   - src/core/lib/promise/detail/promise_like.h
   - src/core/lib/promise/detail/status.h
   - src/core/lib/promise/detail/switch.h
   - src/core/lib/promise/exec_ctx_wakeup_scheduler.h
-  - src/core/lib/promise/for_each.h
+  - src/core/lib/promise/if.h
+  - src/core/lib/promise/interceptor_list.h
   - src/core/lib/promise/intra_activity_waiter.h
   - src/core/lib/promise/latch.h
   - src/core/lib/promise/loop.h
   - src/core/lib/promise/map.h
-  - src/core/lib/promise/map_pipe.h
   - src/core/lib/promise/pipe.h
   - src/core/lib/promise/poll.h
   - src/core/lib/promise/promise.h
   - src/core/lib/promise/race.h
   - src/core/lib/promise/seq.h
   - src/core/lib/promise/sleep.h
-  - src/core/lib/promise/try_concurrently.h
+  - src/core/lib/promise/trace.h
+  - src/core/lib/promise/try_join.h
   - src/core/lib/promise/try_seq.h
   - src/core/lib/resolver/resolver.h
   - src/core/lib/resolver/resolver_factory.h
@@ -2552,6 +2558,7 @@ libs:
   - src/core/lib/iomgr/buffer_list.cc
   - src/core/lib/iomgr/call_combiner.cc
   - src/core/lib/iomgr/cfstream_handle.cc
+  - src/core/lib/iomgr/closure.cc
   - src/core/lib/iomgr/combiner.cc
   - src/core/lib/iomgr/dualstack_socket_posix.cc
   - src/core/lib/iomgr/endpoint.cc
@@ -2631,8 +2638,8 @@ libs:
   - src/core/lib/load_balancing/lb_policy.cc
   - src/core/lib/load_balancing/lb_policy_registry.cc
   - src/core/lib/promise/activity.cc
-  - src/core/lib/promise/pipe.cc
   - src/core/lib/promise/sleep.cc
+  - src/core/lib/promise/trace.cc
   - src/core/lib/resolver/resolver.cc
   - src/core/lib/resolver/resolver_registry.cc
   - src/core/lib/resolver/server_address.cc
@@ -2679,6 +2686,7 @@ libs:
   - src/core/lib/slice/percent_encoding.cc
   - src/core/lib/slice/slice.cc
   - src/core/lib/slice/slice_buffer.cc
+  - src/core/lib/slice/slice_refcount.cc
   - src/core/lib/slice/slice_string_helpers.cc
   - src/core/lib/surface/api_trace.cc
   - src/core/lib/surface/builtins.cc
@@ -3703,14 +3711,16 @@ libs:
   - src/core/lib/promise/activity.h
   - src/core/lib/promise/arena_promise.h
   - src/core/lib/promise/context.h
+  - src/core/lib/promise/detail/basic_join.h
   - src/core/lib/promise/detail/basic_seq.h
   - src/core/lib/promise/detail/promise_factory.h
   - src/core/lib/promise/detail/promise_like.h
   - src/core/lib/promise/detail/status.h
   - src/core/lib/promise/detail/switch.h
   - src/core/lib/promise/exec_ctx_wakeup_scheduler.h
+  - src/core/lib/promise/if.h
+  - src/core/lib/promise/interceptor_list.h
   - src/core/lib/promise/intra_activity_waiter.h
-  - src/core/lib/promise/latch.h
   - src/core/lib/promise/loop.h
   - src/core/lib/promise/map.h
   - src/core/lib/promise/pipe.h
@@ -3718,6 +3728,8 @@ libs:
   - src/core/lib/promise/promise.h
   - src/core/lib/promise/race.h
   - src/core/lib/promise/seq.h
+  - src/core/lib/promise/trace.h
+  - src/core/lib/promise/try_join.h
   - src/core/lib/promise/try_seq.h
   - src/core/lib/resolver/resolver.h
   - src/core/lib/resolver/resolver_factory.h
@@ -3878,6 +3890,7 @@ libs:
   - src/core/lib/iomgr/buffer_list.cc
   - src/core/lib/iomgr/call_combiner.cc
   - src/core/lib/iomgr/cfstream_handle.cc
+  - src/core/lib/iomgr/closure.cc
   - src/core/lib/iomgr/combiner.cc
   - src/core/lib/iomgr/dualstack_socket_posix.cc
   - src/core/lib/iomgr/endpoint.cc
@@ -3957,7 +3970,7 @@ libs:
   - src/core/lib/load_balancing/lb_policy_registry.cc
   - src/core/lib/matchers/matchers.cc
   - src/core/lib/promise/activity.cc
-  - src/core/lib/promise/pipe.cc
+  - src/core/lib/promise/trace.cc
   - src/core/lib/resolver/resolver.cc
   - src/core/lib/resolver/resolver_registry.cc
   - src/core/lib/resolver/server_address.cc
@@ -4004,6 +4017,7 @@ libs:
   - src/core/lib/slice/percent_encoding.cc
   - src/core/lib/slice/slice.cc
   - src/core/lib/slice/slice_buffer.cc
+  - src/core/lib/slice/slice_refcount.cc
   - src/core/lib/slice/slice_string_helpers.cc
   - src/core/lib/surface/api_trace.cc
   - src/core/lib/surface/builtins.cc
@@ -5799,6 +5813,7 @@ targets:
   - src/core/lib/experiments/experiments.cc
   - src/core/lib/gprpp/status_helper.cc
   - src/core/lib/gprpp/time.cc
+  - src/core/lib/iomgr/closure.cc
   - src/core/lib/iomgr/combiner.cc
   - src/core/lib/iomgr/error.cc
   - src/core/lib/iomgr/exec_ctx.cc
@@ -5813,6 +5828,7 @@ targets:
   - src/core/lib/resource_quota/trace.cc
   - src/core/lib/slice/percent_encoding.cc
   - src/core/lib/slice/slice.cc
+  - src/core/lib/slice/slice_refcount.cc
   - src/core/lib/slice/slice_string_helpers.cc
   - test/core/gprpp/chunked_vector_test.cc
   deps:
@@ -6797,6 +6813,7 @@ targets:
   - src/core/lib/debug/trace.cc
   - src/core/lib/gprpp/status_helper.cc
   - src/core/lib/gprpp/time.cc
+  - src/core/lib/iomgr/closure.cc
   - src/core/lib/iomgr/combiner.cc
   - src/core/lib/iomgr/error.cc
   - src/core/lib/iomgr/exec_ctx.cc
@@ -6805,6 +6822,7 @@ targets:
   - src/core/lib/promise/activity.cc
   - src/core/lib/slice/percent_encoding.cc
   - src/core/lib/slice/slice.cc
+  - src/core/lib/slice/slice_refcount.cc
   - src/core/lib/slice/slice_string_helpers.cc
   - test/core/promise/exec_ctx_wakeup_scheduler_test.cc
   deps:
@@ -7092,6 +7110,7 @@ targets:
   - src/core/lib/experiments/experiments.cc
   - src/core/lib/gprpp/status_helper.cc
   - src/core/lib/gprpp/time.cc
+  - src/core/lib/iomgr/closure.cc
   - src/core/lib/iomgr/combiner.cc
   - src/core/lib/iomgr/error.cc
   - src/core/lib/iomgr/exec_ctx.cc
@@ -7105,6 +7124,7 @@ targets:
   - src/core/lib/resource_quota/trace.cc
   - src/core/lib/slice/percent_encoding.cc
   - src/core/lib/slice/slice.cc
+  - src/core/lib/slice/slice_refcount.cc
   - src/core/lib/slice/slice_string_helpers.cc
   - src/core/lib/transport/bdp_estimator.cc
   - src/core/lib/transport/pid_controller.cc
@@ -7156,6 +7176,8 @@ targets:
   - src/core/lib/promise/detail/switch.h
   - src/core/lib/promise/exec_ctx_wakeup_scheduler.h
   - src/core/lib/promise/for_each.h
+  - src/core/lib/promise/if.h
+  - src/core/lib/promise/interceptor_list.h
   - src/core/lib/promise/intra_activity_waiter.h
   - src/core/lib/promise/join.h
   - src/core/lib/promise/loop.h
@@ -7164,6 +7186,7 @@ targets:
   - src/core/lib/promise/poll.h
   - src/core/lib/promise/race.h
   - src/core/lib/promise/seq.h
+  - src/core/lib/promise/trace.h
   - src/core/lib/promise/try_seq.h
   - src/core/lib/resource_quota/arena.h
   - src/core/lib/resource_quota/memory_quota.h
@@ -7186,13 +7209,14 @@ targets:
   - src/core/lib/experiments/experiments.cc
   - src/core/lib/gprpp/status_helper.cc
   - src/core/lib/gprpp/time.cc
+  - src/core/lib/iomgr/closure.cc
   - src/core/lib/iomgr/combiner.cc
   - src/core/lib/iomgr/error.cc
   - src/core/lib/iomgr/exec_ctx.cc
   - src/core/lib/iomgr/executor.cc
   - src/core/lib/iomgr/iomgr_internal.cc
   - src/core/lib/promise/activity.cc
-  - src/core/lib/promise/pipe.cc
+  - src/core/lib/promise/trace.cc
   - src/core/lib/resource_quota/arena.cc
   - src/core/lib/resource_quota/memory_quota.cc
   - src/core/lib/resource_quota/periodic_update.cc
@@ -7201,6 +7225,7 @@ targets:
   - src/core/lib/resource_quota/trace.cc
   - src/core/lib/slice/percent_encoding.cc
   - src/core/lib/slice/slice.cc
+  - src/core/lib/slice/slice_refcount.cc
   - src/core/lib/slice/slice_string_helpers.cc
   - test/core/promise/for_each_test.cc
   deps:
@@ -7500,14 +7525,16 @@ targets:
   - src/core/lib/promise/activity.h
   - src/core/lib/promise/arena_promise.h
   - src/core/lib/promise/context.h
+  - src/core/lib/promise/detail/basic_join.h
   - src/core/lib/promise/detail/basic_seq.h
   - src/core/lib/promise/detail/promise_factory.h
   - src/core/lib/promise/detail/promise_like.h
   - src/core/lib/promise/detail/status.h
   - src/core/lib/promise/detail/switch.h
   - src/core/lib/promise/exec_ctx_wakeup_scheduler.h
+  - src/core/lib/promise/if.h
+  - src/core/lib/promise/interceptor_list.h
   - src/core/lib/promise/intra_activity_waiter.h
-  - src/core/lib/promise/latch.h
   - src/core/lib/promise/loop.h
   - src/core/lib/promise/map.h
   - src/core/lib/promise/pipe.h
@@ -7515,6 +7542,9 @@ targets:
   - src/core/lib/promise/promise.h
   - src/core/lib/promise/race.h
   - src/core/lib/promise/seq.h
+  - src/core/lib/promise/trace.h
+  - src/core/lib/promise/try_join.h
+  - src/core/lib/promise/try_seq.h
   - src/core/lib/resolver/resolver.h
   - src/core/lib/resolver/resolver_factory.h
   - src/core/lib/resolver/resolver_registry.h
@@ -7658,6 +7688,7 @@ targets:
   - src/core/lib/iomgr/buffer_list.cc
   - src/core/lib/iomgr/call_combiner.cc
   - src/core/lib/iomgr/cfstream_handle.cc
+  - src/core/lib/iomgr/closure.cc
   - src/core/lib/iomgr/combiner.cc
   - src/core/lib/iomgr/dualstack_socket_posix.cc
   - src/core/lib/iomgr/endpoint.cc
@@ -7736,7 +7767,7 @@ targets:
   - src/core/lib/load_balancing/lb_policy.cc
   - src/core/lib/load_balancing/lb_policy_registry.cc
   - src/core/lib/promise/activity.cc
-  - src/core/lib/promise/pipe.cc
+  - src/core/lib/promise/trace.cc
   - src/core/lib/resolver/resolver.cc
   - src/core/lib/resolver/resolver_registry.cc
   - src/core/lib/resolver/server_address.cc
@@ -7760,6 +7791,7 @@ targets:
   - src/core/lib/slice/percent_encoding.cc
   - src/core/lib/slice/slice.cc
   - src/core/lib/slice/slice_buffer.cc
+  - src/core/lib/slice/slice_refcount.cc
   - src/core/lib/slice/slice_string_helpers.cc
   - src/core/lib/surface/api_trace.cc
   - src/core/lib/surface/builtins.cc
@@ -8701,6 +8733,7 @@ targets:
   build: test
   language: c++
   headers:
+  - src/core/lib/gprpp/construct_destruct.h
   - src/core/lib/promise/detail/promise_factory.h
   - src/core/lib/promise/detail/promise_like.h
   - src/core/lib/promise/if.h
@@ -8769,6 +8802,98 @@ targets:
   - test/core/util/tracer_util.cc
   deps:
   - grpc_test_util
+- name: interceptor_list_test
+  gtest: true
+  build: test
+  language: c++
+  headers:
+  - src/core/ext/upb-generated/google/protobuf/any.upb.h
+  - src/core/ext/upb-generated/google/rpc/status.upb.h
+  - src/core/lib/debug/trace.h
+  - src/core/lib/experiments/config.h
+  - src/core/lib/experiments/experiments.h
+  - src/core/lib/gpr/spinlock.h
+  - src/core/lib/gprpp/atomic_utils.h
+  - src/core/lib/gprpp/bitset.h
+  - src/core/lib/gprpp/cpp_impl_of.h
+  - src/core/lib/gprpp/manual_constructor.h
+  - src/core/lib/gprpp/orphanable.h
+  - src/core/lib/gprpp/ref_counted.h
+  - src/core/lib/gprpp/ref_counted_ptr.h
+  - src/core/lib/gprpp/status_helper.h
+  - src/core/lib/gprpp/time.h
+  - src/core/lib/iomgr/closure.h
+  - src/core/lib/iomgr/combiner.h
+  - src/core/lib/iomgr/error.h
+  - src/core/lib/iomgr/exec_ctx.h
+  - src/core/lib/iomgr/executor.h
+  - src/core/lib/iomgr/iomgr_internal.h
+  - src/core/lib/promise/activity.h
+  - src/core/lib/promise/context.h
+  - src/core/lib/promise/detail/basic_seq.h
+  - src/core/lib/promise/detail/promise_factory.h
+  - src/core/lib/promise/detail/promise_like.h
+  - src/core/lib/promise/detail/status.h
+  - src/core/lib/promise/detail/switch.h
+  - src/core/lib/promise/exec_ctx_wakeup_scheduler.h
+  - src/core/lib/promise/interceptor_list.h
+  - src/core/lib/promise/loop.h
+  - src/core/lib/promise/map.h
+  - src/core/lib/promise/poll.h
+  - src/core/lib/promise/race.h
+  - src/core/lib/promise/seq.h
+  - src/core/lib/promise/trace.h
+  - src/core/lib/resource_quota/arena.h
+  - src/core/lib/resource_quota/memory_quota.h
+  - src/core/lib/resource_quota/periodic_update.h
+  - src/core/lib/resource_quota/resource_quota.h
+  - src/core/lib/resource_quota/thread_quota.h
+  - src/core/lib/resource_quota/trace.h
+  - src/core/lib/slice/percent_encoding.h
+  - src/core/lib/slice/slice.h
+  - src/core/lib/slice/slice_internal.h
+  - src/core/lib/slice/slice_refcount.h
+  - src/core/lib/slice/slice_string_helpers.h
+  - test/core/promise/test_context.h
+  src:
+  - src/core/ext/upb-generated/google/protobuf/any.upb.c
+  - src/core/ext/upb-generated/google/rpc/status.upb.c
+  - src/core/lib/debug/trace.cc
+  - src/core/lib/event_engine/memory_allocator.cc
+  - src/core/lib/experiments/config.cc
+  - src/core/lib/experiments/experiments.cc
+  - src/core/lib/gprpp/status_helper.cc
+  - src/core/lib/gprpp/time.cc
+  - src/core/lib/iomgr/closure.cc
+  - src/core/lib/iomgr/combiner.cc
+  - src/core/lib/iomgr/error.cc
+  - src/core/lib/iomgr/exec_ctx.cc
+  - src/core/lib/iomgr/executor.cc
+  - src/core/lib/iomgr/iomgr_internal.cc
+  - src/core/lib/promise/activity.cc
+  - src/core/lib/promise/trace.cc
+  - src/core/lib/resource_quota/arena.cc
+  - src/core/lib/resource_quota/memory_quota.cc
+  - src/core/lib/resource_quota/periodic_update.cc
+  - src/core/lib/resource_quota/resource_quota.cc
+  - src/core/lib/resource_quota/thread_quota.cc
+  - src/core/lib/resource_quota/trace.cc
+  - src/core/lib/slice/percent_encoding.cc
+  - src/core/lib/slice/slice.cc
+  - src/core/lib/slice/slice_refcount.cc
+  - src/core/lib/slice/slice_string_helpers.cc
+  - test/core/promise/interceptor_list_test.cc
+  deps:
+  - absl/container:flat_hash_set
+  - absl/functional:any_invocable
+  - absl/functional:function_ref
+  - absl/hash:hash
+  - absl/meta:type_traits
+  - absl/status:statusor
+  - absl/utility:utility
+  - gpr
+  - upb
+  uses_polling: false
 - name: interop_client
   build: test
   run: false
@@ -8973,6 +9098,7 @@ targets:
   build: test
   language: c++
   headers:
+  - src/core/lib/debug/trace.h
   - src/core/lib/gprpp/atomic_utils.h
   - src/core/lib/gprpp/bitset.h
   - src/core/lib/gprpp/orphanable.h
@@ -8991,9 +9117,12 @@ targets:
   - src/core/lib/promise/latch.h
   - src/core/lib/promise/poll.h
   - src/core/lib/promise/seq.h
+  - src/core/lib/promise/trace.h
   - test/core/promise/test_wakeup_schedulers.h
   src:
+  - src/core/lib/debug/trace.cc
   - src/core/lib/promise/activity.cc
+  - src/core/lib/promise/trace.cc
   - test/core/promise/latch_test.cc
   deps:
   - absl/meta:type_traits
@@ -9112,6 +9241,8 @@ targets:
   - src/core/lib/promise/detail/switch.h
   - src/core/lib/promise/exec_ctx_wakeup_scheduler.h
   - src/core/lib/promise/for_each.h
+  - src/core/lib/promise/if.h
+  - src/core/lib/promise/interceptor_list.h
   - src/core/lib/promise/intra_activity_waiter.h
   - src/core/lib/promise/join.h
   - src/core/lib/promise/loop.h
@@ -9121,6 +9252,7 @@ targets:
   - src/core/lib/promise/poll.h
   - src/core/lib/promise/race.h
   - src/core/lib/promise/seq.h
+  - src/core/lib/promise/trace.h
   - src/core/lib/promise/try_seq.h
   - src/core/lib/resource_quota/arena.h
   - src/core/lib/resource_quota/memory_quota.h
@@ -9143,13 +9275,14 @@ targets:
   - src/core/lib/experiments/experiments.cc
   - src/core/lib/gprpp/status_helper.cc
   - src/core/lib/gprpp/time.cc
+  - src/core/lib/iomgr/closure.cc
   - src/core/lib/iomgr/combiner.cc
   - src/core/lib/iomgr/error.cc
   - src/core/lib/iomgr/exec_ctx.cc
   - src/core/lib/iomgr/executor.cc
   - src/core/lib/iomgr/iomgr_internal.cc
   - src/core/lib/promise/activity.cc
-  - src/core/lib/promise/pipe.cc
+  - src/core/lib/promise/trace.cc
   - src/core/lib/resource_quota/arena.cc
   - src/core/lib/resource_quota/memory_quota.cc
   - src/core/lib/resource_quota/periodic_update.cc
@@ -9158,6 +9291,7 @@ targets:
   - src/core/lib/resource_quota/trace.cc
   - src/core/lib/slice/percent_encoding.cc
   - src/core/lib/slice/slice.cc
+  - src/core/lib/slice/slice_refcount.cc
   - src/core/lib/slice/slice_string_helpers.cc
   - test/core/promise/map_pipe_test.cc
   deps:
@@ -9706,6 +9840,7 @@ targets:
   - src/core/lib/debug/trace.cc
   - src/core/lib/gprpp/status_helper.cc
   - src/core/lib/gprpp/time.cc
+  - src/core/lib/iomgr/closure.cc
   - src/core/lib/iomgr/combiner.cc
   - src/core/lib/iomgr/error.cc
   - src/core/lib/iomgr/exec_ctx.cc
@@ -9714,6 +9849,7 @@ targets:
   - src/core/lib/resource_quota/periodic_update.cc
   - src/core/lib/slice/percent_encoding.cc
   - src/core/lib/slice/slice.cc
+  - src/core/lib/slice/slice_refcount.cc
   - src/core/lib/slice/slice_string_helpers.cc
   - test/core/resource_quota/periodic_update_test.cc
   deps:
@@ -9774,92 +9910,12 @@ targets:
   build: test
   language: c++
   headers:
-  - src/core/ext/upb-generated/google/protobuf/any.upb.h
-  - src/core/ext/upb-generated/google/rpc/status.upb.h
-  - src/core/lib/debug/trace.h
-  - src/core/lib/experiments/config.h
-  - src/core/lib/experiments/experiments.h
-  - src/core/lib/gpr/spinlock.h
-  - src/core/lib/gprpp/atomic_utils.h
-  - src/core/lib/gprpp/bitset.h
-  - src/core/lib/gprpp/cpp_impl_of.h
-  - src/core/lib/gprpp/manual_constructor.h
-  - src/core/lib/gprpp/orphanable.h
-  - src/core/lib/gprpp/ref_counted.h
-  - src/core/lib/gprpp/ref_counted_ptr.h
-  - src/core/lib/gprpp/status_helper.h
-  - src/core/lib/gprpp/time.h
-  - src/core/lib/iomgr/closure.h
-  - src/core/lib/iomgr/combiner.h
-  - src/core/lib/iomgr/error.h
-  - src/core/lib/iomgr/exec_ctx.h
-  - src/core/lib/iomgr/executor.h
-  - src/core/lib/iomgr/iomgr_internal.h
-  - src/core/lib/promise/activity.h
-  - src/core/lib/promise/context.h
-  - src/core/lib/promise/detail/basic_join.h
-  - src/core/lib/promise/detail/basic_seq.h
-  - src/core/lib/promise/detail/promise_factory.h
-  - src/core/lib/promise/detail/promise_like.h
-  - src/core/lib/promise/detail/status.h
-  - src/core/lib/promise/detail/switch.h
-  - src/core/lib/promise/exec_ctx_wakeup_scheduler.h
-  - src/core/lib/promise/intra_activity_waiter.h
   - src/core/lib/promise/join.h
-  - src/core/lib/promise/loop.h
-  - src/core/lib/promise/map.h
-  - src/core/lib/promise/pipe.h
-  - src/core/lib/promise/poll.h
-  - src/core/lib/promise/race.h
-  - src/core/lib/promise/seq.h
-  - src/core/lib/resource_quota/arena.h
-  - src/core/lib/resource_quota/memory_quota.h
-  - src/core/lib/resource_quota/periodic_update.h
-  - src/core/lib/resource_quota/resource_quota.h
-  - src/core/lib/resource_quota/thread_quota.h
-  - src/core/lib/resource_quota/trace.h
-  - src/core/lib/slice/percent_encoding.h
-  - src/core/lib/slice/slice.h
-  - src/core/lib/slice/slice_internal.h
-  - src/core/lib/slice/slice_refcount.h
-  - src/core/lib/slice/slice_string_helpers.h
   - test/core/promise/test_wakeup_schedulers.h
   src:
-  - src/core/ext/upb-generated/google/protobuf/any.upb.c
-  - src/core/ext/upb-generated/google/rpc/status.upb.c
-  - src/core/lib/debug/trace.cc
-  - src/core/lib/event_engine/memory_allocator.cc
-  - src/core/lib/experiments/config.cc
-  - src/core/lib/experiments/experiments.cc
-  - src/core/lib/gprpp/status_helper.cc
-  - src/core/lib/gprpp/time.cc
-  - src/core/lib/iomgr/combiner.cc
-  - src/core/lib/iomgr/error.cc
-  - src/core/lib/iomgr/exec_ctx.cc
-  - src/core/lib/iomgr/executor.cc
-  - src/core/lib/iomgr/iomgr_internal.cc
-  - src/core/lib/promise/activity.cc
-  - src/core/lib/promise/pipe.cc
-  - src/core/lib/resource_quota/arena.cc
-  - src/core/lib/resource_quota/memory_quota.cc
-  - src/core/lib/resource_quota/periodic_update.cc
-  - src/core/lib/resource_quota/resource_quota.cc
-  - src/core/lib/resource_quota/thread_quota.cc
-  - src/core/lib/resource_quota/trace.cc
-  - src/core/lib/slice/percent_encoding.cc
-  - src/core/lib/slice/slice.cc
-  - src/core/lib/slice/slice_string_helpers.cc
   - test/core/promise/pipe_test.cc
   deps:
-  - absl/container:flat_hash_set
-  - absl/functional:any_invocable
-  - absl/functional:function_ref
-  - absl/hash:hash
-  - absl/meta:type_traits
-  - absl/status:statusor
-  - absl/utility:utility
-  - gpr
-  - upb
+  - grpc
   uses_polling: false
 - name: poll_test
   gtest: true
@@ -10932,12 +10988,15 @@ targets:
   build: test
   language: c++
   headers:
+  - src/core/lib/debug/trace.h
   - src/core/lib/slice/slice.h
   - src/core/lib/slice/slice_internal.h
   - src/core/lib/slice/slice_refcount.h
   - src/core/lib/slice/slice_string_helpers.h
   src:
+  - src/core/lib/debug/trace.cc
   - src/core/lib/slice/slice.cc
+  - src/core/lib/slice/slice_refcount.cc
   - src/core/lib/slice/slice_string_helpers.cc
   - test/core/slice/slice_string_helpers_test.cc
   deps:
@@ -11561,6 +11620,7 @@ targets:
   build: test
   language: c++
   headers:
+  - src/core/lib/debug/trace.h
   - src/core/lib/event_engine/handle_containers.h
   - src/core/lib/event_engine/resolved_address_internal.h
   - src/core/lib/iomgr/port.h
@@ -11571,12 +11631,14 @@ targets:
   - src/core/lib/slice/slice_refcount.h
   - src/core/lib/slice/slice_string_helpers.h
   src:
+  - src/core/lib/debug/trace.cc
   - src/core/lib/event_engine/event_engine.cc
   - src/core/lib/event_engine/resolved_address.cc
   - src/core/lib/event_engine/slice.cc
   - src/core/lib/event_engine/slice_buffer.cc
   - src/core/lib/slice/slice.cc
   - src/core/lib/slice/slice_buffer.cc
+  - src/core/lib/slice/slice_refcount.cc
   - src/core/lib/slice/slice_string_helpers.cc
   - test/core/event_engine/slice_buffer_test.cc
   deps:
@@ -12184,6 +12246,8 @@ targets:
   - src/core/lib/promise/detail/switch.h
   - src/core/lib/promise/exec_ctx_wakeup_scheduler.h
   - src/core/lib/promise/for_each.h
+  - src/core/lib/promise/if.h
+  - src/core/lib/promise/interceptor_list.h
   - src/core/lib/promise/intra_activity_waiter.h
   - src/core/lib/promise/loop.h
   - src/core/lib/promise/map.h
@@ -12192,6 +12256,7 @@ targets:
   - src/core/lib/promise/poll.h
   - src/core/lib/promise/race.h
   - src/core/lib/promise/seq.h
+  - src/core/lib/promise/trace.h
   - src/core/lib/promise/try_concurrently.h
   - src/core/lib/promise/try_seq.h
   - src/core/lib/resource_quota/arena.h
@@ -12212,19 +12277,21 @@ targets:
   - src/core/lib/experiments/experiments.cc
   - src/core/lib/gprpp/status_helper.cc
   - src/core/lib/gprpp/time.cc
+  - src/core/lib/iomgr/closure.cc
   - src/core/lib/iomgr/combiner.cc
   - src/core/lib/iomgr/error.cc
   - src/core/lib/iomgr/exec_ctx.cc
   - src/core/lib/iomgr/executor.cc
   - src/core/lib/iomgr/iomgr_internal.cc
   - src/core/lib/promise/activity.cc
-  - src/core/lib/promise/pipe.cc
+  - src/core/lib/promise/trace.cc
   - src/core/lib/resource_quota/arena.cc
   - src/core/lib/resource_quota/memory_quota.cc
   - src/core/lib/resource_quota/periodic_update.cc
   - src/core/lib/resource_quota/trace.cc
   - src/core/lib/slice/percent_encoding.cc
   - src/core/lib/slice/slice.cc
+  - src/core/lib/slice/slice_refcount.cc
   - src/core/lib/slice/slice_string_helpers.cc
   - test/core/promise/try_concurrently_test.cc
   deps:
diff --git a/config.m4 b/config.m4
index c30182fd782..876ef5c9e36 100644
--- a/config.m4
+++ b/config.m4
@@ -598,6 +598,7 @@ if test "$PHP_GRPC" != "no"; then
     src/core/lib/iomgr/buffer_list.cc \
     src/core/lib/iomgr/call_combiner.cc \
     src/core/lib/iomgr/cfstream_handle.cc \
+    src/core/lib/iomgr/closure.cc \
     src/core/lib/iomgr/combiner.cc \
     src/core/lib/iomgr/dualstack_socket_posix.cc \
     src/core/lib/iomgr/endpoint.cc \
@@ -679,8 +680,8 @@ if test "$PHP_GRPC" != "no"; then
     src/core/lib/load_balancing/lb_policy_registry.cc \
     src/core/lib/matchers/matchers.cc \
     src/core/lib/promise/activity.cc \
-    src/core/lib/promise/pipe.cc \
     src/core/lib/promise/sleep.cc \
+    src/core/lib/promise/trace.cc \
     src/core/lib/resolver/resolver.cc \
     src/core/lib/resolver/resolver_registry.cc \
     src/core/lib/resolver/server_address.cc \
@@ -758,6 +759,7 @@ if test "$PHP_GRPC" != "no"; then
     src/core/lib/slice/percent_encoding.cc \
     src/core/lib/slice/slice.cc \
     src/core/lib/slice/slice_buffer.cc \
+    src/core/lib/slice/slice_refcount.cc \
     src/core/lib/slice/slice_string_helpers.cc \
     src/core/lib/surface/api_trace.cc \
     src/core/lib/surface/builtins.cc \
diff --git a/config.w32 b/config.w32
index 8131eadf4b1..616170f76e2 100644
--- a/config.w32
+++ b/config.w32
@@ -564,6 +564,7 @@ if (PHP_GRPC != "no") {
     "src\\core\\lib\\iomgr\\buffer_list.cc " +
     "src\\core\\lib\\iomgr\\call_combiner.cc " +
     "src\\core\\lib\\iomgr\\cfstream_handle.cc " +
+    "src\\core\\lib\\iomgr\\closure.cc " +
     "src\\core\\lib\\iomgr\\combiner.cc " +
     "src\\core\\lib\\iomgr\\dualstack_socket_posix.cc " +
     "src\\core\\lib\\iomgr\\endpoint.cc " +
@@ -645,8 +646,8 @@ if (PHP_GRPC != "no") {
     "src\\core\\lib\\load_balancing\\lb_policy_registry.cc " +
     "src\\core\\lib\\matchers\\matchers.cc " +
     "src\\core\\lib\\promise\\activity.cc " +
-    "src\\core\\lib\\promise\\pipe.cc " +
     "src\\core\\lib\\promise\\sleep.cc " +
+    "src\\core\\lib\\promise\\trace.cc " +
     "src\\core\\lib\\resolver\\resolver.cc " +
     "src\\core\\lib\\resolver\\resolver_registry.cc " +
     "src\\core\\lib\\resolver\\server_address.cc " +
@@ -724,6 +725,7 @@ if (PHP_GRPC != "no") {
     "src\\core\\lib\\slice\\percent_encoding.cc " +
     "src\\core\\lib\\slice\\slice.cc " +
     "src\\core\\lib\\slice\\slice_buffer.cc " +
+    "src\\core\\lib\\slice\\slice_refcount.cc " +
     "src\\core\\lib\\slice\\slice_string_helpers.cc " +
     "src\\core\\lib\\surface\\api_trace.cc " +
     "src\\core\\lib\\surface\\builtins.cc " +
diff --git a/doc/environment_variables.md b/doc/environment_variables.md
index d2d0ba9e798..f5f10a285f3 100644
--- a/doc/environment_variables.md
+++ b/doc/environment_variables.md
@@ -118,6 +118,7 @@ some configuration as environment variables that can be set.
   - queue_refcount
   - error_refcount
   - stream_refcount
+  - slice_refcount
   - workqueue_refcount
   - fd_refcount
   - cq_refcount
diff --git a/gRPC-C++.podspec b/gRPC-C++.podspec
index adf5330fdb1..cb816108ad5 100644
--- a/gRPC-C++.podspec
+++ b/gRPC-C++.podspec
@@ -907,25 +907,27 @@ Pod::Spec.new do |s|
                       'src/core/lib/promise/activity.h',
                       'src/core/lib/promise/arena_promise.h',
                       'src/core/lib/promise/context.h',
+                      'src/core/lib/promise/detail/basic_join.h',
                       'src/core/lib/promise/detail/basic_seq.h',
                       'src/core/lib/promise/detail/promise_factory.h',
                       'src/core/lib/promise/detail/promise_like.h',
                       'src/core/lib/promise/detail/status.h',
                       'src/core/lib/promise/detail/switch.h',
                       'src/core/lib/promise/exec_ctx_wakeup_scheduler.h',
-                      'src/core/lib/promise/for_each.h',
+                      'src/core/lib/promise/if.h',
+                      'src/core/lib/promise/interceptor_list.h',
                       'src/core/lib/promise/intra_activity_waiter.h',
                       'src/core/lib/promise/latch.h',
                       'src/core/lib/promise/loop.h',
                       'src/core/lib/promise/map.h',
-                      'src/core/lib/promise/map_pipe.h',
                       'src/core/lib/promise/pipe.h',
                       'src/core/lib/promise/poll.h',
                       'src/core/lib/promise/promise.h',
                       'src/core/lib/promise/race.h',
                       'src/core/lib/promise/seq.h',
                       'src/core/lib/promise/sleep.h',
-                      'src/core/lib/promise/try_concurrently.h',
+                      'src/core/lib/promise/trace.h',
+                      'src/core/lib/promise/try_join.h',
                       'src/core/lib/promise/try_seq.h',
                       'src/core/lib/resolver/resolver.h',
                       'src/core/lib/resolver/resolver_factory.h',
@@ -1834,25 +1836,27 @@ Pod::Spec.new do |s|
                               'src/core/lib/promise/activity.h',
                               'src/core/lib/promise/arena_promise.h',
                               'src/core/lib/promise/context.h',
+                              'src/core/lib/promise/detail/basic_join.h',
                               'src/core/lib/promise/detail/basic_seq.h',
                               'src/core/lib/promise/detail/promise_factory.h',
                               'src/core/lib/promise/detail/promise_like.h',
                               'src/core/lib/promise/detail/status.h',
                               'src/core/lib/promise/detail/switch.h',
                               'src/core/lib/promise/exec_ctx_wakeup_scheduler.h',
-                              'src/core/lib/promise/for_each.h',
+                              'src/core/lib/promise/if.h',
+                              'src/core/lib/promise/interceptor_list.h',
                               'src/core/lib/promise/intra_activity_waiter.h',
                               'src/core/lib/promise/latch.h',
                               'src/core/lib/promise/loop.h',
                               'src/core/lib/promise/map.h',
-                              'src/core/lib/promise/map_pipe.h',
                               'src/core/lib/promise/pipe.h',
                               'src/core/lib/promise/poll.h',
                               'src/core/lib/promise/promise.h',
                               'src/core/lib/promise/race.h',
                               'src/core/lib/promise/seq.h',
                               'src/core/lib/promise/sleep.h',
-                              'src/core/lib/promise/try_concurrently.h',
+                              'src/core/lib/promise/trace.h',
+                              'src/core/lib/promise/try_join.h',
                               'src/core/lib/promise/try_seq.h',
                               'src/core/lib/resolver/resolver.h',
                               'src/core/lib/resolver/resolver_factory.h',
diff --git a/gRPC-Core.podspec b/gRPC-Core.podspec
index c5b87c8131b..6e7f4d423e8 100644
--- a/gRPC-Core.podspec
+++ b/gRPC-Core.podspec
@@ -1321,6 +1321,7 @@ Pod::Spec.new do |s|
                       'src/core/lib/iomgr/call_combiner.h',
                       'src/core/lib/iomgr/cfstream_handle.cc',
                       'src/core/lib/iomgr/cfstream_handle.h',
+                      'src/core/lib/iomgr/closure.cc',
                       'src/core/lib/iomgr/closure.h',
                       'src/core/lib/iomgr/combiner.cc',
                       'src/core/lib/iomgr/combiner.h',
@@ -1476,19 +1477,19 @@ Pod::Spec.new do |s|
                       'src/core/lib/promise/activity.h',
                       'src/core/lib/promise/arena_promise.h',
                       'src/core/lib/promise/context.h',
+                      'src/core/lib/promise/detail/basic_join.h',
                       'src/core/lib/promise/detail/basic_seq.h',
                       'src/core/lib/promise/detail/promise_factory.h',
                       'src/core/lib/promise/detail/promise_like.h',
                       'src/core/lib/promise/detail/status.h',
                       'src/core/lib/promise/detail/switch.h',
                       'src/core/lib/promise/exec_ctx_wakeup_scheduler.h',
-                      'src/core/lib/promise/for_each.h',
+                      'src/core/lib/promise/if.h',
+                      'src/core/lib/promise/interceptor_list.h',
                       'src/core/lib/promise/intra_activity_waiter.h',
                       'src/core/lib/promise/latch.h',
                       'src/core/lib/promise/loop.h',
                       'src/core/lib/promise/map.h',
-                      'src/core/lib/promise/map_pipe.h',
-                      'src/core/lib/promise/pipe.cc',
                       'src/core/lib/promise/pipe.h',
                       'src/core/lib/promise/poll.h',
                       'src/core/lib/promise/promise.h',
@@ -1496,7 +1497,9 @@ Pod::Spec.new do |s|
                       'src/core/lib/promise/seq.h',
                       'src/core/lib/promise/sleep.cc',
                       'src/core/lib/promise/sleep.h',
-                      'src/core/lib/promise/try_concurrently.h',
+                      'src/core/lib/promise/trace.cc',
+                      'src/core/lib/promise/trace.h',
+                      'src/core/lib/promise/try_join.h',
                       'src/core/lib/promise/try_seq.h',
                       'src/core/lib/resolver/resolver.cc',
                       'src/core/lib/resolver/resolver.h',
@@ -1651,6 +1654,7 @@ Pod::Spec.new do |s|
                       'src/core/lib/slice/slice_buffer.cc',
                       'src/core/lib/slice/slice_buffer.h',
                       'src/core/lib/slice/slice_internal.h',
+                      'src/core/lib/slice/slice_refcount.cc',
                       'src/core/lib/slice/slice_refcount.h',
                       'src/core/lib/slice/slice_string_helpers.cc',
                       'src/core/lib/slice/slice_string_helpers.h',
@@ -2517,25 +2521,27 @@ Pod::Spec.new do |s|
                               'src/core/lib/promise/activity.h',
                               'src/core/lib/promise/arena_promise.h',
                               'src/core/lib/promise/context.h',
+                              'src/core/lib/promise/detail/basic_join.h',
                               'src/core/lib/promise/detail/basic_seq.h',
                               'src/core/lib/promise/detail/promise_factory.h',
                               'src/core/lib/promise/detail/promise_like.h',
                               'src/core/lib/promise/detail/status.h',
                               'src/core/lib/promise/detail/switch.h',
                               'src/core/lib/promise/exec_ctx_wakeup_scheduler.h',
-                              'src/core/lib/promise/for_each.h',
+                              'src/core/lib/promise/if.h',
+                              'src/core/lib/promise/interceptor_list.h',
                               'src/core/lib/promise/intra_activity_waiter.h',
                               'src/core/lib/promise/latch.h',
                               'src/core/lib/promise/loop.h',
                               'src/core/lib/promise/map.h',
-                              'src/core/lib/promise/map_pipe.h',
                               'src/core/lib/promise/pipe.h',
                               'src/core/lib/promise/poll.h',
                               'src/core/lib/promise/promise.h',
                               'src/core/lib/promise/race.h',
                               'src/core/lib/promise/seq.h',
                               'src/core/lib/promise/sleep.h',
-                              'src/core/lib/promise/try_concurrently.h',
+                              'src/core/lib/promise/trace.h',
+                              'src/core/lib/promise/try_join.h',
                               'src/core/lib/promise/try_seq.h',
                               'src/core/lib/resolver/resolver.h',
                               'src/core/lib/resolver/resolver_factory.h',
diff --git a/grpc.gemspec b/grpc.gemspec
index 4da80f8c12c..5cce81b11c8 100644
--- a/grpc.gemspec
+++ b/grpc.gemspec
@@ -1230,6 +1230,7 @@ Gem::Specification.new do |s|
   s.files += %w( src/core/lib/iomgr/call_combiner.h )
   s.files += %w( src/core/lib/iomgr/cfstream_handle.cc )
   s.files += %w( src/core/lib/iomgr/cfstream_handle.h )
+  s.files += %w( src/core/lib/iomgr/closure.cc )
   s.files += %w( src/core/lib/iomgr/closure.h )
   s.files += %w( src/core/lib/iomgr/combiner.cc )
   s.files += %w( src/core/lib/iomgr/combiner.h )
@@ -1385,19 +1386,19 @@ Gem::Specification.new do |s|
   s.files += %w( src/core/lib/promise/activity.h )
   s.files += %w( src/core/lib/promise/arena_promise.h )
   s.files += %w( src/core/lib/promise/context.h )
+  s.files += %w( src/core/lib/promise/detail/basic_join.h )
   s.files += %w( src/core/lib/promise/detail/basic_seq.h )
   s.files += %w( src/core/lib/promise/detail/promise_factory.h )
   s.files += %w( src/core/lib/promise/detail/promise_like.h )
   s.files += %w( src/core/lib/promise/detail/status.h )
   s.files += %w( src/core/lib/promise/detail/switch.h )
   s.files += %w( src/core/lib/promise/exec_ctx_wakeup_scheduler.h )
-  s.files += %w( src/core/lib/promise/for_each.h )
+  s.files += %w( src/core/lib/promise/if.h )
+  s.files += %w( src/core/lib/promise/interceptor_list.h )
   s.files += %w( src/core/lib/promise/intra_activity_waiter.h )
   s.files += %w( src/core/lib/promise/latch.h )
   s.files += %w( src/core/lib/promise/loop.h )
   s.files += %w( src/core/lib/promise/map.h )
-  s.files += %w( src/core/lib/promise/map_pipe.h )
-  s.files += %w( src/core/lib/promise/pipe.cc )
   s.files += %w( src/core/lib/promise/pipe.h )
   s.files += %w( src/core/lib/promise/poll.h )
   s.files += %w( src/core/lib/promise/promise.h )
@@ -1405,7 +1406,9 @@ Gem::Specification.new do |s|
   s.files += %w( src/core/lib/promise/seq.h )
   s.files += %w( src/core/lib/promise/sleep.cc )
   s.files += %w( src/core/lib/promise/sleep.h )
-  s.files += %w( src/core/lib/promise/try_concurrently.h )
+  s.files += %w( src/core/lib/promise/trace.cc )
+  s.files += %w( src/core/lib/promise/trace.h )
+  s.files += %w( src/core/lib/promise/try_join.h )
   s.files += %w( src/core/lib/promise/try_seq.h )
   s.files += %w( src/core/lib/resolver/resolver.cc )
   s.files += %w( src/core/lib/resolver/resolver.h )
@@ -1560,6 +1563,7 @@ Gem::Specification.new do |s|
   s.files += %w( src/core/lib/slice/slice_buffer.cc )
   s.files += %w( src/core/lib/slice/slice_buffer.h )
   s.files += %w( src/core/lib/slice/slice_internal.h )
+  s.files += %w( src/core/lib/slice/slice_refcount.cc )
   s.files += %w( src/core/lib/slice/slice_refcount.h )
   s.files += %w( src/core/lib/slice/slice_string_helpers.cc )
   s.files += %w( src/core/lib/slice/slice_string_helpers.h )
diff --git a/grpc.gyp b/grpc.gyp
index aac09f741a8..42a1ac2eb33 100644
--- a/grpc.gyp
+++ b/grpc.gyp
@@ -886,6 +886,7 @@
         'src/core/lib/iomgr/buffer_list.cc',
         'src/core/lib/iomgr/call_combiner.cc',
         'src/core/lib/iomgr/cfstream_handle.cc',
+        'src/core/lib/iomgr/closure.cc',
         'src/core/lib/iomgr/combiner.cc',
         'src/core/lib/iomgr/dualstack_socket_posix.cc',
         'src/core/lib/iomgr/endpoint.cc',
@@ -967,8 +968,8 @@
         'src/core/lib/load_balancing/lb_policy_registry.cc',
         'src/core/lib/matchers/matchers.cc',
         'src/core/lib/promise/activity.cc',
-        'src/core/lib/promise/pipe.cc',
         'src/core/lib/promise/sleep.cc',
+        'src/core/lib/promise/trace.cc',
         'src/core/lib/resolver/resolver.cc',
         'src/core/lib/resolver/resolver_registry.cc',
         'src/core/lib/resolver/server_address.cc',
@@ -1046,6 +1047,7 @@
         'src/core/lib/slice/percent_encoding.cc',
         'src/core/lib/slice/slice.cc',
         'src/core/lib/slice/slice_buffer.cc',
+        'src/core/lib/slice/slice_refcount.cc',
         'src/core/lib/slice/slice_string_helpers.cc',
         'src/core/lib/surface/api_trace.cc',
         'src/core/lib/surface/builtins.cc',
@@ -1364,6 +1366,7 @@
         'src/core/lib/iomgr/buffer_list.cc',
         'src/core/lib/iomgr/call_combiner.cc',
         'src/core/lib/iomgr/cfstream_handle.cc',
+        'src/core/lib/iomgr/closure.cc',
         'src/core/lib/iomgr/combiner.cc',
         'src/core/lib/iomgr/dualstack_socket_posix.cc',
         'src/core/lib/iomgr/endpoint.cc',
@@ -1443,8 +1446,8 @@
         'src/core/lib/load_balancing/lb_policy.cc',
         'src/core/lib/load_balancing/lb_policy_registry.cc',
         'src/core/lib/promise/activity.cc',
-        'src/core/lib/promise/pipe.cc',
         'src/core/lib/promise/sleep.cc',
+        'src/core/lib/promise/trace.cc',
         'src/core/lib/resolver/resolver.cc',
         'src/core/lib/resolver/resolver_registry.cc',
         'src/core/lib/resolver/server_address.cc',
@@ -1491,6 +1494,7 @@
         'src/core/lib/slice/percent_encoding.cc',
         'src/core/lib/slice/slice.cc',
         'src/core/lib/slice/slice_buffer.cc',
+        'src/core/lib/slice/slice_refcount.cc',
         'src/core/lib/slice/slice_string_helpers.cc',
         'src/core/lib/surface/api_trace.cc',
         'src/core/lib/surface/builtins.cc',
@@ -1865,6 +1869,7 @@
         'src/core/lib/iomgr/buffer_list.cc',
         'src/core/lib/iomgr/call_combiner.cc',
         'src/core/lib/iomgr/cfstream_handle.cc',
+        'src/core/lib/iomgr/closure.cc',
         'src/core/lib/iomgr/combiner.cc',
         'src/core/lib/iomgr/dualstack_socket_posix.cc',
         'src/core/lib/iomgr/endpoint.cc',
@@ -1944,7 +1949,7 @@
         'src/core/lib/load_balancing/lb_policy_registry.cc',
         'src/core/lib/matchers/matchers.cc',
         'src/core/lib/promise/activity.cc',
-        'src/core/lib/promise/pipe.cc',
+        'src/core/lib/promise/trace.cc',
         'src/core/lib/resolver/resolver.cc',
         'src/core/lib/resolver/resolver_registry.cc',
         'src/core/lib/resolver/server_address.cc',
@@ -1991,6 +1996,7 @@
         'src/core/lib/slice/percent_encoding.cc',
         'src/core/lib/slice/slice.cc',
         'src/core/lib/slice/slice_buffer.cc',
+        'src/core/lib/slice/slice_refcount.cc',
         'src/core/lib/slice/slice_string_helpers.cc',
         'src/core/lib/surface/api_trace.cc',
         'src/core/lib/surface/builtins.cc',
diff --git a/package.xml b/package.xml
index 3f97548e386..8ffbd092a4f 100644
--- a/package.xml
+++ b/package.xml
@@ -1212,6 +1212,7 @@
     <file baseinstalldir="/" name="src/core/lib/iomgr/call_combiner.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/iomgr/cfstream_handle.cc" role="src" />
     <file baseinstalldir="/" name="src/core/lib/iomgr/cfstream_handle.h" role="src" />
+    <file baseinstalldir="/" name="src/core/lib/iomgr/closure.cc" role="src" />
     <file baseinstalldir="/" name="src/core/lib/iomgr/closure.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/iomgr/combiner.cc" role="src" />
     <file baseinstalldir="/" name="src/core/lib/iomgr/combiner.h" role="src" />
@@ -1367,19 +1368,19 @@
     <file baseinstalldir="/" name="src/core/lib/promise/activity.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/promise/arena_promise.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/promise/context.h" role="src" />
+    <file baseinstalldir="/" name="src/core/lib/promise/detail/basic_join.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/promise/detail/basic_seq.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/promise/detail/promise_factory.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/promise/detail/promise_like.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/promise/detail/status.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/promise/detail/switch.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/promise/exec_ctx_wakeup_scheduler.h" role="src" />
-    <file baseinstalldir="/" name="src/core/lib/promise/for_each.h" role="src" />
+    <file baseinstalldir="/" name="src/core/lib/promise/if.h" role="src" />
+    <file baseinstalldir="/" name="src/core/lib/promise/interceptor_list.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/promise/intra_activity_waiter.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/promise/latch.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/promise/loop.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/promise/map.h" role="src" />
-    <file baseinstalldir="/" name="src/core/lib/promise/map_pipe.h" role="src" />
-    <file baseinstalldir="/" name="src/core/lib/promise/pipe.cc" role="src" />
     <file baseinstalldir="/" name="src/core/lib/promise/pipe.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/promise/poll.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/promise/promise.h" role="src" />
@@ -1387,7 +1388,9 @@
     <file baseinstalldir="/" name="src/core/lib/promise/seq.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/promise/sleep.cc" role="src" />
     <file baseinstalldir="/" name="src/core/lib/promise/sleep.h" role="src" />
-    <file baseinstalldir="/" name="src/core/lib/promise/try_concurrently.h" role="src" />
+    <file baseinstalldir="/" name="src/core/lib/promise/trace.cc" role="src" />
+    <file baseinstalldir="/" name="src/core/lib/promise/trace.h" role="src" />
+    <file baseinstalldir="/" name="src/core/lib/promise/try_join.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/promise/try_seq.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/resolver/resolver.cc" role="src" />
     <file baseinstalldir="/" name="src/core/lib/resolver/resolver.h" role="src" />
@@ -1542,6 +1545,7 @@
     <file baseinstalldir="/" name="src/core/lib/slice/slice_buffer.cc" role="src" />
     <file baseinstalldir="/" name="src/core/lib/slice/slice_buffer.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/slice/slice_internal.h" role="src" />
+    <file baseinstalldir="/" name="src/core/lib/slice/slice_refcount.cc" role="src" />
     <file baseinstalldir="/" name="src/core/lib/slice/slice_refcount.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/slice/slice_string_helpers.cc" role="src" />
     <file baseinstalldir="/" name="src/core/lib/slice/slice_string_helpers.h" role="src" />
diff --git a/src/core/BUILD b/src/core/BUILD
index 4ccff69a079..3b71c5dd4ac 100644
--- a/src/core/BUILD
+++ b/src/core/BUILD
@@ -380,6 +380,7 @@ grpc_cc_library(
     hdrs = ["lib/promise/try_concurrently.h"],
     external_deps = [
         "absl/status",
+        "absl/strings",
         "absl/types:variant",
     ],
     language = "c++",
@@ -387,6 +388,7 @@ grpc_cc_library(
         "lib/promise/map_pipe.h",
     ],
     deps = [
+        "activity",
         "construct_destruct",
         "for_each",
         "map",
@@ -395,8 +397,10 @@ grpc_cc_library(
         "promise_factory",
         "promise_like",
         "promise_status",
+        "promise_trace",
         "try_seq",
         "//:gpr",
+        "//:grpc_trace",
     ],
 )
 
@@ -411,9 +415,13 @@ grpc_cc_library(
         "for_each",
         "map",
         "pipe",
+        "poll",
         "promise_factory",
+        "promise_trace",
         "try_seq",
+        "//:gpr",
         "//:gpr_platform",
+        "//:grpc_trace",
     ],
 )
 
@@ -524,6 +532,7 @@ grpc_cc_library(
     language = "c++",
     public_hdrs = ["lib/promise/if.h"],
     deps = [
+        "construct_destruct",
         "poll",
         "promise_factory",
         "promise_like",
@@ -779,14 +788,18 @@ grpc_cc_library(
 
 grpc_cc_library(
     name = "latch",
+    external_deps = ["absl/strings"],
     language = "c++",
     public_hdrs = [
         "lib/promise/latch.h",
     ],
     deps = [
+        "activity",
         "intra_activity_waiter",
         "poll",
+        "promise_trace",
         "//:gpr",
+        "//:grpc_trace",
     ],
 )
 
@@ -811,14 +824,37 @@ grpc_cc_library(
 )
 
 grpc_cc_library(
-    name = "pipe",
-    srcs = [
-        "lib/promise/pipe.cc",
+    name = "interceptor_list",
+    hdrs = [
+        "lib/promise/interceptor_list.h",
+    ],
+    external_deps = [
+        "absl/strings",
+        "absl/strings:str_format",
+        "absl/types:optional",
+        "absl/types:variant",
     ],
+    deps = [
+        "arena",
+        "construct_destruct",
+        "context",
+        "poll",
+        "promise_factory",
+        "promise_trace",
+        "//:debug_location",
+        "//:gpr",
+        "//:grpc_trace",
+    ],
+)
+
+grpc_cc_library(
+    name = "pipe",
     hdrs = [
         "lib/promise/pipe.h",
     ],
     external_deps = [
+        "absl/base:core_headers",
+        "absl/memory",
         "absl/strings",
         "absl/types:optional",
         "absl/types:variant",
@@ -828,10 +864,32 @@ grpc_cc_library(
         "activity",
         "arena",
         "context",
+        "if",
+        "interceptor_list",
         "intra_activity_waiter",
+        "map",
         "poll",
+        "promise_trace",
+        "seq",
+        "//:debug_location",
         "//:gpr",
         "//:grpc_trace",
+        "//:ref_counted_ptr",
+    ],
+)
+
+grpc_cc_library(
+    name = "promise_trace",
+    srcs = [
+        "lib/promise/trace.cc",
+    ],
+    hdrs = [
+        "lib/promise/trace.h",
+    ],
+    language = "c++",
+    deps = [
+        "//:gpr_platform",
+        "//:grpc_trace",
     ],
 )
 
@@ -856,16 +914,20 @@ grpc_cc_library(
     name = "for_each",
     external_deps = [
         "absl/status",
+        "absl/strings",
         "absl/types:variant",
     ],
     language = "c++",
     public_hdrs = ["lib/promise/for_each.h"],
     deps = [
+        "activity",
         "construct_destruct",
         "poll",
         "promise_factory",
+        "promise_trace",
         "//:gpr",
         "//:gpr_platform",
+        "//:grpc_trace",
     ],
 )
 
@@ -1123,6 +1185,9 @@ grpc_cc_library(
 
 grpc_cc_library(
     name = "slice_refcount",
+    srcs = [
+        "lib/slice/slice_refcount.cc",
+    ],
     hdrs = [
         "lib/slice/slice_refcount.h",
     ],
@@ -1130,8 +1195,10 @@ grpc_cc_library(
         "//:include/grpc/slice.h",
     ],
     deps = [
+        "//:debug_location",
         "//:event_engine_base_hdrs",
         "//:gpr",
+        "//:grpc_trace",
     ],
 )
 
@@ -1155,6 +1222,7 @@ grpc_cc_library(
     deps = [
         "slice_cast",
         "slice_refcount",
+        "//:debug_location",
         "//:event_engine_base_hdrs",
         "//:gpr",
     ],
@@ -1169,6 +1237,7 @@ grpc_cc_library(
         "lib/slice/slice_buffer.h",
         "//:include/grpc/slice_buffer.h",
     ],
+    external_deps = ["absl/memory"],
     deps = [
         "slice",
         "slice_refcount",
@@ -1204,9 +1273,13 @@ grpc_cc_library(
 
 grpc_cc_library(
     name = "closure",
+    srcs = [
+        "lib/iomgr/closure.cc",
+    ],
     hdrs = [
         "lib/iomgr/closure.h",
     ],
+    external_deps = ["absl/strings:str_format"],
     visibility = ["@grpc:alt_grpc_base_legacy"],
     deps = [
         "error",
@@ -3514,7 +3587,6 @@ grpc_cc_library(
         "ext/filters/stateful_session/stateful_session_service_config_parser.h",
     ],
     external_deps = [
-        "absl/status",
         "absl/status:statusor",
         "absl/strings",
         "absl/types:optional",
@@ -3523,7 +3595,6 @@ grpc_cc_library(
     deps = [
         "arena",
         "arena_promise",
-        "basic_seq",
         "channel_args",
         "channel_fwd",
         "context",
@@ -3531,12 +3602,12 @@ grpc_cc_library(
         "json",
         "json_args",
         "json_object_loader",
-        "latch",
-        "seq",
+        "map",
+        "pipe",
+        "poll",
         "service_config_parser",
         "slice",
         "time",
-        "try_concurrently",
         "unique_type_name",
         "validation_errors",
         "//:config",
@@ -3574,26 +3645,29 @@ grpc_cc_library(
     ],
     language = "c++",
     deps = [
+        "arena",
         "arena_promise",
         "channel_args",
         "channel_fwd",
         "channel_init",
         "channel_stack_type",
         "closure",
+        "context",
         "error",
         "gpr_atm",
         "grpc_sockaddr",
         "json",
         "json_args",
         "json_object_loader",
-        "latch",
         "lb_policy",
         "lb_policy_factory",
         "lb_policy_registry",
+        "map",
+        "pipe",
+        "poll",
         "pollset_set",
         "ref_counted",
         "resolved_address",
-        "seq",
         "slice",
         "slice_refcount",
         "status_helper",
@@ -3617,7 +3691,6 @@ grpc_cc_library(
         "//:grpc_security_base",
         "//:grpc_trace",
         "//:orphanable",
-        "//:promise",
         "//:protobuf_duration_upb",
         "//:protobuf_timestamp_upb",
         "//:ref_counted_ptr",
diff --git a/src/core/ext/filters/client_channel/lb_policy/grpclb/client_load_reporting_filter.cc b/src/core/ext/filters/client_channel/lb_policy/grpclb/client_load_reporting_filter.cc
index 45e875ba2a6..d9e979b7c43 100644
--- a/src/core/ext/filters/client_channel/lb_policy/grpclb/client_load_reporting_filter.cc
+++ b/src/core/ext/filters/client_channel/lb_policy/grpclb/client_load_reporting_filter.cc
@@ -31,9 +31,11 @@
 #include "src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb_client_stats.h"
 #include "src/core/lib/channel/channel_stack.h"
 #include "src/core/lib/gprpp/ref_counted_ptr.h"
-#include "src/core/lib/promise/latch.h"
-#include "src/core/lib/promise/promise.h"
-#include "src/core/lib/promise/seq.h"
+#include "src/core/lib/promise/context.h"
+#include "src/core/lib/promise/map.h"
+#include "src/core/lib/promise/pipe.h"
+#include "src/core/lib/promise/poll.h"
+#include "src/core/lib/resource_quota/arena.h"
 #include "src/core/lib/transport/metadata_batch.h"
 #include "src/core/lib/transport/transport.h"
 
@@ -61,16 +63,21 @@ ArenaPromise<ServerMetadataHandle> ClientLoadReportingFilter::MakeCallPromise(
     client_stats.reset(*client_stats_md);
   }
 
-  auto* server_initial_metadata = call_args.server_initial_metadata;
+  auto* saw_initial_metadata = GetContext<Arena>()->New<bool>(false);
+  call_args.server_initial_metadata->InterceptAndMap(
+      [saw_initial_metadata](ServerMetadataHandle md) {
+        *saw_initial_metadata = true;
+        return md;
+      });
 
-  return Seq(next_promise_factory(std::move(call_args)),
-             [server_initial_metadata, client_stats = std::move(client_stats)](
+  return Map(next_promise_factory(std::move(call_args)),
+             [saw_initial_metadata, client_stats = std::move(client_stats)](
                  ServerMetadataHandle trailing_metadata) {
                if (client_stats != nullptr) {
                  client_stats->AddCallFinished(
                      trailing_metadata->get(GrpcStreamNetworkState()) ==
                          GrpcStreamNetworkState::kNotSentOnWire,
-                     NowOrNever(server_initial_metadata->Wait()).has_value());
+                     *saw_initial_metadata);
                }
                return trailing_metadata;
              });
diff --git a/src/core/ext/filters/http/client/http_client_filter.cc b/src/core/ext/filters/http/client/http_client_filter.cc
index 7e299e3f2c7..58f9a709024 100644
--- a/src/core/ext/filters/http/client/http_client_filter.cc
+++ b/src/core/ext/filters/http/client/http_client_filter.cc
@@ -40,10 +40,11 @@
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/channel/channel_stack.h"
 #include "src/core/lib/promise/context.h"
-#include "src/core/lib/promise/detail/basic_seq.h"
 #include "src/core/lib/promise/latch.h"
-#include "src/core/lib/promise/seq.h"
-#include "src/core/lib/promise/try_concurrently.h"
+#include "src/core/lib/promise/map.h"
+#include "src/core/lib/promise/pipe.h"
+#include "src/core/lib/promise/poll.h"
+#include "src/core/lib/promise/race.h"
 #include "src/core/lib/resource_quota/arena.h"
 #include "src/core/lib/slice/percent_encoding.h"
 #include "src/core/lib/transport/status_conversion.h"
@@ -118,24 +119,27 @@ ArenaPromise<ServerMetadataHandle> HttpClientFilter::MakeCallPromise(
   md->Set(ContentTypeMetadata(), ContentTypeMetadata::kApplicationGrpc);
   md->Set(UserAgentMetadata(), user_agent_.Ref());
 
-  auto* read_latch = GetContext<Arena>()->New<Latch<ServerMetadata*>>();
-  auto* write_latch =
-      std::exchange(call_args.server_initial_metadata, read_latch);
-
-  return TryConcurrently(
-             Seq(next_promise_factory(std::move(call_args)),
-                 [](ServerMetadataHandle md) -> ServerMetadataHandle {
-                   auto r = CheckServerMetadata(md.get());
-                   if (!r.ok()) return ServerMetadataFromStatus(r);
-                   return md;
-                 }))
-      .NecessaryPull(Seq(read_latch->Wait(),
-                         [write_latch](ServerMetadata** md) -> absl::Status {
-                           auto r = *md == nullptr ? absl::OkStatus()
-                                                   : CheckServerMetadata(*md);
-                           write_latch->Set(*md);
-                           return r;
-                         }));
+  auto* initial_metadata_err =
+      GetContext<Arena>()->New<Latch<ServerMetadataHandle>>();
+
+  call_args.server_initial_metadata->InterceptAndMap(
+      [initial_metadata_err](
+          ServerMetadataHandle md) -> absl::optional<ServerMetadataHandle> {
+        auto r = CheckServerMetadata(md.get());
+        if (!r.ok()) {
+          initial_metadata_err->Set(ServerMetadataFromStatus(r));
+          return absl::nullopt;
+        }
+        return std::move(md);
+      });
+
+  return Race(Map(next_promise_factory(std::move(call_args)),
+                  [](ServerMetadataHandle md) -> ServerMetadataHandle {
+                    auto r = CheckServerMetadata(md.get());
+                    if (!r.ok()) return ServerMetadataFromStatus(r);
+                    return md;
+                  }),
+              initial_metadata_err->Wait());
 }
 
 HttpClientFilter::HttpClientFilter(HttpSchemeMetadata::ValueType scheme,
diff --git a/src/core/ext/filters/http/message_compress/compression_filter.cc b/src/core/ext/filters/http/message_compress/compression_filter.cc
index 69a7f0a25f7..5a84aceefe5 100644
--- a/src/core/ext/filters/http/message_compress/compression_filter.cc
+++ b/src/core/ext/filters/http/message_compress/compression_filter.cc
@@ -21,7 +21,7 @@
 #include <functional>
 #include <initializer_list>
 #include <memory>
-#include <type_traits>
+#include <string>
 #include <utility>
 
 #include "absl/meta/type_traits.h"
@@ -43,17 +43,16 @@
 #include "src/core/lib/compression/compression_internal.h"
 #include "src/core/lib/compression/message_compress.h"
 #include "src/core/lib/debug/trace.h"
+#include "src/core/lib/promise/activity.h"
 #include "src/core/lib/promise/context.h"
-#include "src/core/lib/promise/detail/promise_like.h"
 #include "src/core/lib/promise/latch.h"
-#include "src/core/lib/promise/map_pipe.h"
 #include "src/core/lib/promise/pipe.h"
-#include "src/core/lib/promise/promise.h"
-#include "src/core/lib/promise/seq.h"
-#include "src/core/lib/promise/try_concurrently.h"
+#include "src/core/lib/promise/poll.h"
+#include "src/core/lib/promise/race.h"
 #include "src/core/lib/resource_quota/arena.h"
 #include "src/core/lib/slice/slice_buffer.h"
 #include "src/core/lib/surface/call.h"
+#include "src/core/lib/surface/call_trace.h"
 #include "src/core/lib/transport/metadata_batch.h"
 #include "src/core/lib/transport/transport.h"
 
@@ -158,20 +157,19 @@ MessageHandle CompressionFilter::CompressMessage(
 }
 
 absl::StatusOr<MessageHandle> CompressionFilter::DecompressMessage(
-    MessageHandle message, grpc_compression_algorithm algorithm,
-    absl::optional<uint32_t> max_recv_message_length) const {
+    MessageHandle message, DecompressArgs args) const {
   if (GRPC_TRACE_FLAG_ENABLED(grpc_compression_trace)) {
     gpr_log(GPR_ERROR, "DecompressMessage: len=%" PRIdPTR " max=%d alg=%d",
-            message->payload()->Length(), max_recv_message_length.value_or(-1),
-            algorithm);
+            message->payload()->Length(),
+            args.max_recv_message_length.value_or(-1), args.algorithm);
   }
   // Check max message length.
-  if (max_recv_message_length.has_value() &&
+  if (args.max_recv_message_length.has_value() &&
       message->payload()->Length() >
-          static_cast<size_t>(*max_recv_message_length)) {
+          static_cast<size_t>(*args.max_recv_message_length)) {
     return absl::ResourceExhaustedError(absl::StrFormat(
         "Received message larger than max (%u vs. %d)",
-        message->payload()->Length(), *max_recv_message_length));
+        message->payload()->Length(), *args.max_recv_message_length));
   }
   // Check if decompression is enabled (if not, we can just pass the message
   // up).
@@ -181,11 +179,11 @@ absl::StatusOr<MessageHandle> CompressionFilter::DecompressMessage(
   }
   // Try to decompress the payload.
   SliceBuffer decompressed_slices;
-  if (grpc_msg_decompress(algorithm, message->payload()->c_slice_buffer(),
+  if (grpc_msg_decompress(args.algorithm, message->payload()->c_slice_buffer(),
                           decompressed_slices.c_slice_buffer()) == 0) {
     return absl::InternalError(
         absl::StrCat("Unexpected error decompressing data for algorithm ",
-                     CompressionAlgorithmAsString(algorithm)));
+                     CompressionAlgorithmAsString(args.algorithm)));
   }
   // Swap the decompressed slices into the message.
   message->payload()->Swap(&decompressed_slices);
@@ -194,123 +192,114 @@ absl::StatusOr<MessageHandle> CompressionFilter::DecompressMessage(
   return std::move(message);
 }
 
-class CompressionFilter::DecompressLoop {
- public:
-  explicit DecompressLoop(CompressionFilter* filter, CallArgs& call_args)
-      : filter_(filter),
-        mapper_(PipeMapper<MessageHandle>::Intercept(
-            *call_args.incoming_messages)) {}
-
-  // Once we have a compression algorithm we can construct the decompression
-  // loop.
-  // Returns a promise that resolves to MessageHandle.
-  auto TakeAndRun(grpc_compression_algorithm algorithm) {
-    // Configure max receive size.
-    auto max_recv_message_length = filter_->max_recv_size_;
-    const MessageSizeParsedConfig* limits =
-        MessageSizeParsedConfig::GetFromCallContext(
-            GetContext<grpc_call_context_element>(),
-            filter_->message_size_service_config_parser_index_);
-    if (limits != nullptr && limits->max_recv_size().has_value() &&
-        (!max_recv_message_length.has_value() ||
-         *limits->max_recv_size() < *max_recv_message_length)) {
-      max_recv_message_length = *limits->max_recv_size();
-    }
-    // Interject decompression into the message loop.
-    return mapper_.TakeAndRun([algorithm, max_recv_message_length,
-                               filter = filter_](MessageHandle message) {
-      return filter->DecompressMessage(std::move(message), algorithm,
-                                       max_recv_message_length);
-    });
+grpc_compression_algorithm CompressionFilter::HandleOutgoingMetadata(
+    grpc_metadata_batch& outgoing_metadata) {
+  const auto algorithm = outgoing_metadata.Take(GrpcInternalEncodingRequest())
+                             .value_or(default_compression_algorithm());
+  // Convey supported compression algorithms.
+  outgoing_metadata.Set(GrpcAcceptEncodingMetadata(),
+                        enabled_compression_algorithms());
+  if (algorithm != GRPC_COMPRESS_NONE) {
+    outgoing_metadata.Set(GrpcEncodingMetadata(), algorithm);
   }
+  return algorithm;
+}
 
- private:
-  CompressionFilter* filter_;
-  PipeMapper<MessageHandle> mapper_;
-};
-
-class CompressionFilter::CompressLoop {
- public:
-  explicit CompressLoop(CompressionFilter* filter, CallArgs& call_args)
-      : filter_(filter),
-        mapper_(PipeMapper<MessageHandle>::Intercept(
-            *call_args.outgoing_messages)) {}
-
-  // Once we're ready to send initial metadata we can construct the compression
-  // loop.
-  // Returns a promise that resolves to MessageHandle.
-  auto TakeAndRun(grpc_metadata_batch& outgoing_metadata) {
-    const auto algorithm =
-        outgoing_metadata.Take(GrpcInternalEncodingRequest())
-            .value_or(filter_->default_compression_algorithm());
-    // Convey supported compression algorithms.
-    outgoing_metadata.Set(GrpcAcceptEncodingMetadata(),
-                          filter_->enabled_compression_algorithms());
-    if (algorithm != GRPC_COMPRESS_NONE) {
-      outgoing_metadata.Set(GrpcEncodingMetadata(), algorithm);
-    }
-    // Interject compression into the message loop.
-    return mapper_.TakeAndRun([filter = filter_, algorithm](MessageHandle m) {
-      return filter->CompressMessage(std::move(m), algorithm);
-    });
+CompressionFilter::DecompressArgs CompressionFilter::HandleIncomingMetadata(
+    const grpc_metadata_batch& incoming_metadata) {
+  // Configure max receive size.
+  auto max_recv_message_length = max_recv_size_;
+  const MessageSizeParsedConfig* limits =
+      MessageSizeParsedConfig::GetFromCallContext(
+          GetContext<grpc_call_context_element>(),
+          message_size_service_config_parser_index_);
+  if (limits != nullptr && limits->max_recv_size().has_value() &&
+      (!max_recv_message_length.has_value() ||
+       *limits->max_recv_size() < *max_recv_message_length)) {
+    max_recv_message_length = *limits->max_recv_size();
   }
-
- private:
-  CompressionFilter* filter_;
-  PipeMapper<MessageHandle> mapper_;
-};
+  return DecompressArgs{incoming_metadata.get(GrpcEncodingMetadata())
+                            .value_or(GRPC_COMPRESS_NONE),
+                        max_recv_message_length};
+}
 
 ArenaPromise<ServerMetadataHandle> ClientCompressionFilter::MakeCallPromise(
     CallArgs call_args, NextPromiseFactory next_promise_factory) {
-  auto compress_loop = CompressLoop(this, call_args)
-                           .TakeAndRun(*call_args.client_initial_metadata);
-  DecompressLoop decompress_loop(this, call_args);
-  auto* server_initial_metadata = call_args.server_initial_metadata;
-  // Concurrently:
-  // - call the next filter
-  // - wait for initial metadata from the server and then commence decompression
-  // - compress outgoing messages
-  return TryConcurrently(next_promise_factory(std::move(call_args)))
-      .NecessaryPull(Seq(server_initial_metadata->Wait(),
-                         [decompress_loop = std::move(decompress_loop)](
-                             ServerMetadata** server_initial_metadata) mutable
-                         -> ArenaPromise<absl::Status> {
-                           if (*server_initial_metadata == nullptr) {
-                             return ImmediateOkStatus();
-                           }
-                           return decompress_loop.TakeAndRun(
-                               (*server_initial_metadata)
-                                   ->get(GrpcEncodingMetadata())
-                                   .value_or(GRPC_COMPRESS_NONE));
-                         }))
-      .Push(std::move(compress_loop));
+  auto compression_algorithm =
+      HandleOutgoingMetadata(*call_args.client_initial_metadata);
+  call_args.client_to_server_messages->InterceptAndMap(
+      [compression_algorithm,
+       this](MessageHandle message) -> absl::optional<MessageHandle> {
+        return CompressMessage(std::move(message), compression_algorithm);
+      });
+  auto* decompress_args = GetContext<Arena>()->New<DecompressArgs>(
+      DecompressArgs{GRPC_COMPRESS_NONE, absl::nullopt});
+  auto* decompress_err =
+      GetContext<Arena>()->New<Latch<ServerMetadataHandle>>();
+  call_args.server_initial_metadata->InterceptAndMap(
+      [decompress_args, this](ServerMetadataHandle server_initial_metadata)
+          -> absl::optional<ServerMetadataHandle> {
+        if (server_initial_metadata == nullptr) return absl::nullopt;
+        *decompress_args = HandleIncomingMetadata(*server_initial_metadata);
+        return std::move(server_initial_metadata);
+      });
+  call_args.server_to_client_messages->InterceptAndMap(
+      [decompress_err, decompress_args,
+       this](MessageHandle message) -> absl::optional<MessageHandle> {
+        auto r = DecompressMessage(std::move(message), *decompress_args);
+        if (!r.ok()) {
+          decompress_err->Set(ServerMetadataFromStatus(r.status()));
+          return absl::nullopt;
+        }
+        return std::move(*r);
+      });
+  // Run the next filter, and race it with getting an error from decompression.
+  return Race(next_promise_factory(std::move(call_args)),
+              decompress_err->Wait());
 }
 
 ArenaPromise<ServerMetadataHandle> ServerCompressionFilter::MakeCallPromise(
     CallArgs call_args, NextPromiseFactory next_promise_factory) {
-  CompressLoop compress_loop(this, call_args);
-  auto decompress_loop = DecompressLoop(this, call_args)
-                             .TakeAndRun(call_args.client_initial_metadata
-                                             ->get(GrpcEncodingMetadata())
-                                             .value_or(GRPC_COMPRESS_NONE));
-  auto* read_latch = GetContext<Arena>()->New<Latch<ServerMetadata*>>();
-  auto* write_latch =
-      std::exchange(call_args.server_initial_metadata, read_latch);
+  auto decompress_args =
+      HandleIncomingMetadata(*call_args.client_initial_metadata);
+  auto* decompress_err =
+      GetContext<Arena>()->New<Latch<ServerMetadataHandle>>();
+  call_args.client_to_server_messages->InterceptAndMap(
+      [decompress_err, decompress_args,
+       this](MessageHandle message) -> absl::optional<MessageHandle> {
+        auto r = DecompressMessage(std::move(message), decompress_args);
+        gpr_log(GPR_DEBUG, "DecompressMessage returned %s",
+                r.status().ToString().c_str());
+        if (!r.ok()) {
+          decompress_err->Set(ServerMetadataFromStatus(r.status()));
+          return absl::nullopt;
+        }
+        return std::move(*r);
+      });
+  auto* compression_algorithm =
+      GetContext<Arena>()->New<grpc_compression_algorithm>();
+  call_args.server_initial_metadata->InterceptAndMap(
+      [this, compression_algorithm](ServerMetadataHandle md) {
+        if (grpc_call_trace.enabled()) {
+          gpr_log(GPR_INFO, "%s[compression] Write metadata",
+                  Activity::current()->DebugTag().c_str());
+        }
+        // Find the compression algorithm.
+        *compression_algorithm = HandleOutgoingMetadata(*md);
+        return md;
+      });
+  call_args.server_to_client_messages->InterceptAndMap(
+      [compression_algorithm,
+       this](MessageHandle message) -> absl::optional<MessageHandle> {
+        return CompressMessage(std::move(message), *compression_algorithm);
+      });
   // Concurrently:
   // - call the next filter
   // - decompress incoming messages
   // - wait for initial metadata to be sent, and then commence compression of
   //   outgoing messages
-  return TryConcurrently(next_promise_factory(std::move(call_args)))
-      .Pull(std::move(decompress_loop))
-      .Push(Seq(read_latch->Wait(),
-                [write_latch, compress_loop = std::move(compress_loop)](
-                    ServerMetadata** md) mutable {
-                  // Find the compression algorithm.
-                  auto loop = compress_loop.TakeAndRun(**md);
-                  write_latch->Set(*md);
-                  return loop;
-                }));
+  return Race(next_promise_factory(std::move(call_args)),
+              decompress_err->Wait());
 }
 
 }  // namespace grpc_core
diff --git a/src/core/ext/filters/http/message_compress/compression_filter.h b/src/core/ext/filters/http/message_compress/compression_filter.h
index 8a17bebe0dc..caf49c03336 100644
--- a/src/core/ext/filters/http/message_compress/compression_filter.h
+++ b/src/core/ext/filters/http/message_compress/compression_filter.h
@@ -34,6 +34,7 @@
 #include "src/core/lib/channel/promise_based_filter.h"
 #include "src/core/lib/compression/compression_internal.h"
 #include "src/core/lib/promise/arena_promise.h"
+#include "src/core/lib/transport/metadata_batch.h"
 #include "src/core/lib/transport/transport.h"
 
 namespace grpc_core {
@@ -62,10 +63,12 @@ namespace grpc_core {
 
 class CompressionFilter : public ChannelFilter {
  protected:
-  explicit CompressionFilter(const ChannelArgs& args);
+  struct DecompressArgs {
+    grpc_compression_algorithm algorithm;
+    absl::optional<uint32_t> max_recv_message_length;
+  };
 
-  class CompressLoop;
-  class DecompressLoop;
+  explicit CompressionFilter(const ChannelArgs& args);
 
   grpc_compression_algorithm default_compression_algorithm() const {
     return default_compression_algorithm_;
@@ -75,15 +78,19 @@ class CompressionFilter : public ChannelFilter {
     return enabled_compression_algorithms_;
   }
 
- private:
+  grpc_compression_algorithm HandleOutgoingMetadata(
+      grpc_metadata_batch& outgoing_metadata);
+  DecompressArgs HandleIncomingMetadata(
+      const grpc_metadata_batch& incoming_metadata);
+
   // Compress one message synchronously.
   MessageHandle CompressMessage(MessageHandle message,
                                 grpc_compression_algorithm algorithm) const;
   // Decompress one message synchronously.
-  absl::StatusOr<MessageHandle> DecompressMessage(
-      MessageHandle message, grpc_compression_algorithm algorithm,
-      absl::optional<uint32_t> max_recv_message_length) const;
+  absl::StatusOr<MessageHandle> DecompressMessage(MessageHandle message,
+                                                  DecompressArgs args) const;
 
+ private:
   // Max receive message length, if set.
   absl::optional<uint32_t> max_recv_size_;
   size_t message_size_service_config_parser_index_;
diff --git a/src/core/ext/filters/http/server/http_server_filter.cc b/src/core/ext/filters/http/server/http_server_filter.cc
index 23062d5c007..8ec0e54df0b 100644
--- a/src/core/ext/filters/http/server/http_server_filter.cc
+++ b/src/core/ext/filters/http/server/http_server_filter.cc
@@ -22,6 +22,7 @@
 
 #include <functional>
 #include <memory>
+#include <string>
 #include <utility>
 
 #include "absl/base/attributes.h"
@@ -30,18 +31,19 @@
 #include "absl/types/optional.h"
 
 #include <grpc/grpc.h>
+#include <grpc/support/log.h>
 
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/channel/channel_stack.h"
-#include "src/core/lib/promise/context.h"
-#include "src/core/lib/promise/detail/basic_seq.h"
-#include "src/core/lib/promise/latch.h"
+#include "src/core/lib/debug/trace.h"
+#include "src/core/lib/promise/activity.h"
+#include "src/core/lib/promise/map.h"
+#include "src/core/lib/promise/pipe.h"
+#include "src/core/lib/promise/poll.h"
 #include "src/core/lib/promise/promise.h"
-#include "src/core/lib/promise/seq.h"
-#include "src/core/lib/promise/try_concurrently.h"
-#include "src/core/lib/resource_quota/arena.h"
 #include "src/core/lib/slice/percent_encoding.h"
 #include "src/core/lib/slice/slice.h"
+#include "src/core/lib/surface/call_trace.h"
 #include "src/core/lib/transport/metadata_batch.h"
 
 namespace grpc_core {
@@ -129,24 +131,23 @@ ArenaPromise<ServerMetadataHandle> HttpServerFilter::MakeCallPromise(
     md->Remove(UserAgentMetadata());
   }
 
-  auto* read_latch = GetContext<Arena>()->New<Latch<ServerMetadata*>>();
-  auto* write_latch =
-      std::exchange(call_args.server_initial_metadata, read_latch);
-
-  return TryConcurrently(
-             Seq(next_promise_factory(std::move(call_args)),
-                 [](ServerMetadataHandle md) -> ServerMetadataHandle {
-                   FilterOutgoingMetadata(md.get());
-                   return md;
-                 }))
-      .Push(Seq(read_latch->Wait(), [write_latch](ServerMetadata** md) {
-        FilterOutgoingMetadata(*md);
-        (*md)->Set(HttpStatusMetadata(), 200);
-        (*md)->Set(ContentTypeMetadata(),
-                   ContentTypeMetadata::kApplicationGrpc);
-        write_latch->Set(*md);
-        return absl::OkStatus();
-      }));
+  call_args.server_initial_metadata->InterceptAndMap(
+      [](ServerMetadataHandle md) {
+        if (grpc_call_trace.enabled()) {
+          gpr_log(GPR_INFO, "%s[http-server] Write metadata",
+                  Activity::current()->DebugTag().c_str());
+        }
+        FilterOutgoingMetadata(md.get());
+        md->Set(HttpStatusMetadata(), 200);
+        md->Set(ContentTypeMetadata(), ContentTypeMetadata::kApplicationGrpc);
+        return md;
+      });
+
+  return Map(next_promise_factory(std::move(call_args)),
+             [](ServerMetadataHandle md) -> ServerMetadataHandle {
+               FilterOutgoingMetadata(md.get());
+               return md;
+             });
 }
 
 absl::StatusOr<HttpServerFilter> HttpServerFilter::Create(
diff --git a/src/core/ext/filters/stateful_session/stateful_session_filter.cc b/src/core/ext/filters/stateful_session/stateful_session_filter.cc
index cefed052921..e64975fd9b4 100644
--- a/src/core/ext/filters/stateful_session/stateful_session_filter.cc
+++ b/src/core/ext/filters/stateful_session/stateful_session_filter.cc
@@ -27,7 +27,6 @@
 #include <utility>
 #include <vector>
 
-#include "absl/status/status.h"
 #include "absl/strings/escaping.h"
 #include "absl/strings/match.h"
 #include "absl/strings/str_cat.h"
@@ -47,10 +46,9 @@
 #include "src/core/lib/gprpp/crash.h"
 #include "src/core/lib/gprpp/time.h"
 #include "src/core/lib/promise/context.h"
-#include "src/core/lib/promise/detail/basic_seq.h"
-#include "src/core/lib/promise/latch.h"
-#include "src/core/lib/promise/seq.h"
-#include "src/core/lib/promise/try_concurrently.h"
+#include "src/core/lib/promise/map.h"
+#include "src/core/lib/promise/pipe.h"
+#include "src/core/lib/promise/poll.h"
 #include "src/core/lib/resource_quota/arena.h"
 #include "src/core/lib/service_config/service_config_call_data.h"
 #include "src/core/lib/slice/slice.h"
@@ -165,32 +163,23 @@ ArenaPromise<ServerMetadataHandle> StatefulSessionFilter::MakeCallPromise(
                                                *cookie_value);
   }
   // Intercept server initial metadata.
-  auto* read_latch = GetContext<Arena>()->New<Latch<ServerMetadata*>>();
-  auto* write_latch =
-      std::exchange(call_args.server_initial_metadata, read_latch);
-  return TryConcurrently(
-             Seq(next_promise_factory(std::move(call_args)),
-                 [cookie_config, cookie_value](ServerMetadataHandle md) {
-                   // If we got a Trailers-Only response, then add the
-                   // cookie to the trailing metadata instead of the
-                   // initial metadata.
-                   if (md->get(GrpcTrailersOnly()).value_or(false)) {
-                     MaybeUpdateServerInitialMetadata(cookie_config,
-                                                      cookie_value, md.get());
-                   }
-                   return md;
-                 }))
-      .NecessaryPull(Seq(read_latch->Wait(),
-                         [write_latch, cookie_config,
-                          cookie_value](ServerMetadata** md) -> absl::Status {
-                           if (*md != nullptr) {
-                             // Add cookie to server initial metadata if needed.
-                             MaybeUpdateServerInitialMetadata(
-                                 cookie_config, cookie_value, *md);
-                           }
-                           write_latch->Set(*md);
-                           return absl::OkStatus();
-                         }));
+  call_args.server_initial_metadata->InterceptAndMap(
+      [cookie_config, cookie_value](ServerMetadataHandle md) {
+        // Add cookie to server initial metadata if needed.
+        MaybeUpdateServerInitialMetadata(cookie_config, cookie_value, md.get());
+        return md;
+      });
+  return Map(next_promise_factory(std::move(call_args)),
+             [cookie_config, cookie_value](ServerMetadataHandle md) {
+               // If we got a Trailers-Only response, then add the
+               // cookie to the trailing metadata instead of the
+               // initial metadata.
+               if (md->get(GrpcTrailersOnly()).value_or(false)) {
+                 MaybeUpdateServerInitialMetadata(cookie_config, cookie_value,
+                                                  md.get());
+               }
+               return md;
+             });
 }
 
 absl::optional<absl::string_view>
diff --git a/src/core/ext/transport/chttp2/transport/chttp2_transport.cc b/src/core/ext/transport/chttp2/transport/chttp2_transport.cc
index ed0b6276575..2c54d917d25 100644
--- a/src/core/ext/transport/chttp2/transport/chttp2_transport.cc
+++ b/src/core/ext/transport/chttp2/transport/chttp2_transport.cc
@@ -668,6 +668,10 @@ grpc_chttp2_stream::grpc_chttp2_stream(grpc_chttp2_transport* t,
       flow_control(&t->flow_control) {
   if (server_data) {
     id = static_cast<uint32_t>(reinterpret_cast<uintptr_t>(server_data));
+    if (grpc_http_trace.enabled()) {
+      gpr_log(GPR_DEBUG, "HTTP:%p/%p creating accept stream %d [from %p]", t,
+              this, id, server_data);
+    }
     *t->accepting_stream = this;
     grpc_chttp2_stream_map_add(&t->stream_map, id, this);
     post_destructive_reclaimer(t);
@@ -1829,6 +1833,12 @@ void grpc_chttp2_maybe_complete_recv_message(grpc_chttp2_transport* t,
   // Lambda is immediately invoked as a big scoped section that can be
   // exited out of at any point by returning.
   [&]() {
+    if (grpc_http_trace.enabled()) {
+      gpr_log(GPR_DEBUG,
+              "maybe_complete_recv_message %p final_metadata_requested=%d "
+              "seen_error=%d",
+              s, s->final_metadata_requested, s->seen_error);
+    }
     if (s->final_metadata_requested && s->seen_error) {
       grpc_slice_buffer_reset_and_unref(&s->frame_storage);
       s->recv_message->reset();
@@ -1839,6 +1849,12 @@ void grpc_chttp2_maybe_complete_recv_message(grpc_chttp2_transport* t,
           int64_t min_progress_size;
           auto r = grpc_deframe_unprocessed_incoming_frames(
               s, &min_progress_size, &**s->recv_message, s->recv_message_flags);
+          if (grpc_http_trace.enabled()) {
+            gpr_log(GPR_DEBUG, "Deframe data frame: %s",
+                    grpc_core::PollToString(r, [](absl::Status r) {
+                      return r.ToString();
+                    }).c_str());
+          }
           if (absl::holds_alternative<grpc_core::Pending>(r)) {
             if (s->read_closed) {
               grpc_slice_buffer_reset_and_unref(&s->frame_storage);
@@ -1889,6 +1905,14 @@ void grpc_chttp2_maybe_complete_recv_message(grpc_chttp2_transport* t,
 void grpc_chttp2_maybe_complete_recv_trailing_metadata(grpc_chttp2_transport* t,
                                                        grpc_chttp2_stream* s) {
   grpc_chttp2_maybe_complete_recv_message(t, s);
+  if (grpc_http_trace.enabled()) {
+    gpr_log(GPR_DEBUG,
+            "maybe_complete_recv_trailing_metadata cli=%d s=%p closure=%p "
+            "read_closed=%d "
+            "write_closed=%d %" PRIdPTR,
+            t->is_client, s, s->recv_trailing_metadata_finished, s->read_closed,
+            s->write_closed, s->frame_storage.length);
+  }
   if (s->recv_trailing_metadata_finished != nullptr && s->read_closed &&
       s->write_closed) {
     if (s->seen_error || !t->is_client) {
@@ -2048,6 +2072,14 @@ void grpc_chttp2_fail_pending_writes(grpc_chttp2_transport* t,
 void grpc_chttp2_mark_stream_closed(grpc_chttp2_transport* t,
                                     grpc_chttp2_stream* s, int close_reads,
                                     int close_writes, grpc_error_handle error) {
+  if (grpc_http_trace.enabled()) {
+    gpr_log(
+        GPR_DEBUG, "MARK_STREAM_CLOSED: t=%p s=%p(id=%d) %s [%s]", t, s, s->id,
+        (close_reads && close_writes)
+            ? "read+write"
+            : (close_reads ? "read" : (close_writes ? "write" : "nothing??")),
+        error.ToString().c_str());
+  }
   if (s->read_closed && s->write_closed) {
     // already closed, but we should still fake the status if needed.
     grpc_error_handle overall_error = removal_error(error, s, "Stream removed");
diff --git a/src/core/ext/transport/chttp2/transport/internal.h b/src/core/ext/transport/chttp2/transport/internal.h
index 0724e70cfe8..58b1e02effc 100644
--- a/src/core/ext/transport/chttp2/transport/internal.h
+++ b/src/core/ext/transport/chttp2/transport/internal.h
@@ -389,12 +389,16 @@ struct grpc_chttp2_transport
   uint32_t incoming_frame_size = 0;
   uint32_t incoming_stream_id = 0;
 
-  // active parser
-  void* parser_data = nullptr;
   grpc_chttp2_stream* incoming_stream = nullptr;
-  grpc_error_handle (*parser)(void* parser_user_data, grpc_chttp2_transport* t,
-                              grpc_chttp2_stream* s, const grpc_slice& slice,
-                              int is_last);
+  // active parser
+  struct Parser {
+    const char* name;
+    grpc_error_handle (*parser)(void* parser_user_data,
+                                grpc_chttp2_transport* t, grpc_chttp2_stream* s,
+                                const grpc_slice& slice, int is_last);
+    void* user_data = nullptr;
+  };
+  Parser parser;
 
   grpc_chttp2_write_cb* write_cb_pool = nullptr;
 
diff --git a/src/core/ext/transport/chttp2/transport/parsing.cc b/src/core/ext/transport/chttp2/transport/parsing.cc
index 2913543e171..b4d719e5623 100644
--- a/src/core/ext/transport/chttp2/transport/parsing.cc
+++ b/src/core/ext/transport/chttp2/transport/parsing.cc
@@ -18,7 +18,7 @@
 
 #include <grpc/support/port_platform.h>
 
-#include <stdint.h>
+#include <inttypes.h>
 #include <string.h>
 
 #include <initializer_list>
@@ -28,6 +28,7 @@
 #include "absl/status/status.h"
 #include "absl/strings/str_cat.h"
 #include "absl/strings/str_format.h"
+#include "absl/strings/string_view.h"
 
 #include <grpc/slice.h>
 #include <grpc/support/log.h>
@@ -127,6 +128,65 @@ uint32_t grpc_chttp2_min_read_progress_size(grpc_chttp2_transport* t) {
   GPR_UNREACHABLE_CODE(return 1);
 }
 
+namespace {
+struct KnownFlag {
+  uint8_t flag;
+  absl::string_view name;
+};
+
+std::string MakeFrameTypeString(absl::string_view frame_type, uint8_t flags,
+                                std::initializer_list<KnownFlag> known_flags) {
+  std::string result(frame_type);
+  for (const KnownFlag& known_flag : known_flags) {
+    if (flags & known_flag.flag) {
+      absl::StrAppend(&result, ":", known_flag.name);
+      flags &= ~known_flag.flag;
+    }
+  }
+  if (flags != 0) {
+    absl::StrAppend(&result, ":UNKNOWN_FLAGS=0x",
+                    absl::Hex(flags, absl::kZeroPad2));
+  }
+  return result;
+}
+
+std::string FrameTypeString(uint8_t frame_type, uint8_t flags) {
+  switch (frame_type) {
+    case GRPC_CHTTP2_FRAME_DATA:
+      return MakeFrameTypeString(
+          "DATA", flags, {{GRPC_CHTTP2_DATA_FLAG_END_STREAM, "END_STREAM"}});
+    case GRPC_CHTTP2_FRAME_HEADER:
+      return MakeFrameTypeString(
+          "HEADERS", flags,
+          {{GRPC_CHTTP2_DATA_FLAG_END_STREAM, "END_STREAM"},
+           {GRPC_CHTTP2_DATA_FLAG_END_HEADERS, "END_HEADERS"},
+           {GRPC_CHTTP2_FLAG_HAS_PRIORITY, "PRIORITY"}});
+    case GRPC_CHTTP2_FRAME_CONTINUATION:
+      return MakeFrameTypeString(
+          "HEADERS", flags,
+          {{GRPC_CHTTP2_DATA_FLAG_END_STREAM, "END_STREAM"},
+           {GRPC_CHTTP2_DATA_FLAG_END_HEADERS, "END_HEADERS"},
+           {GRPC_CHTTP2_FLAG_HAS_PRIORITY, "PRIORITY"}});
+    case GRPC_CHTTP2_FRAME_RST_STREAM:
+      return MakeFrameTypeString("RST_STREAM", flags, {});
+    case GRPC_CHTTP2_FRAME_SETTINGS:
+      return MakeFrameTypeString("SETTINGS", flags,
+                                 {{GRPC_CHTTP2_FLAG_ACK, "ACK"}});
+    case GRPC_CHTTP2_FRAME_PING:
+      return MakeFrameTypeString("PING", flags,
+                                 {{GRPC_CHTTP2_FLAG_ACK, "ACK"}});
+    case GRPC_CHTTP2_FRAME_GOAWAY:
+      return MakeFrameTypeString("GOAWAY", flags, {});
+    case GRPC_CHTTP2_FRAME_WINDOW_UPDATE:
+      return MakeFrameTypeString("WINDOW_UPDATE", flags, {});
+    default:
+      return MakeFrameTypeString(
+          absl::StrCat("UNKNOWN_FRAME_TYPE_", static_cast<int>(frame_type)),
+          flags, {});
+  }
+}
+}  // namespace
+
 grpc_error_handle grpc_chttp2_perform_read(grpc_chttp2_transport* t,
                                            const grpc_slice& slice) {
   const uint8_t* beg = GRPC_SLICE_START_PTR(slice);
@@ -250,6 +310,12 @@ grpc_error_handle grpc_chttp2_perform_read(grpc_chttp2_transport* t,
     case GRPC_DTS_FH_8:
       GPR_DEBUG_ASSERT(cur < end);
       t->incoming_stream_id |= (static_cast<uint32_t>(*cur));
+      if (grpc_http_trace.enabled()) {
+        gpr_log(GPR_INFO, "INCOMING[%p]: %s len:%d id:0x%08x", t,
+                FrameTypeString(t->incoming_frame_type, t->incoming_frame_flags)
+                    .c_str(),
+                t->incoming_frame_size, t->incoming_stream_id);
+      }
       t->deframe_state = GRPC_DTS_FRAME;
       err = init_frame_parser(t);
       if (!err.ok()) {
@@ -404,8 +470,8 @@ static HPackParser::LogInfo hpack_parser_log_info(
 static grpc_error_handle init_header_skip_frame_parser(
     grpc_chttp2_transport* t, HPackParser::Priority priority_type) {
   bool is_eoh = t->expect_continuation_stream_id != 0;
-  t->parser = grpc_chttp2_header_parser_parse;
-  t->parser_data = &t->hpack_parser;
+  t->parser = grpc_chttp2_transport::Parser{
+      "header", grpc_chttp2_header_parser_parse, &t->hpack_parser};
   t->hpack_parser.BeginFrame(
       nullptr,
       t->settings[GRPC_ACKED_SETTINGS]
@@ -417,15 +483,17 @@ static grpc_error_handle init_header_skip_frame_parser(
 
 static grpc_error_handle init_non_header_skip_frame_parser(
     grpc_chttp2_transport* t) {
-  t->parser = skip_parser;
+  t->parser =
+      grpc_chttp2_transport::Parser{"skip_parser", skip_parser, nullptr};
   return absl::OkStatus();
 }
 
 void grpc_chttp2_parsing_become_skip_parser(grpc_chttp2_transport* t) {
-  if (t->parser == grpc_chttp2_header_parser_parse) {
+  if (t->parser.parser == grpc_chttp2_header_parser_parse) {
     t->hpack_parser.StopBufferingFrame();
   } else {
-    t->parser = skip_parser;
+    t->parser =
+        grpc_chttp2_transport::Parser{"skip_parser", skip_parser, nullptr};
   }
 }
 
@@ -472,9 +540,8 @@ static grpc_error_handle init_data_frame_parser(grpc_chttp2_transport* t) {
 error_handler:
   if (status.ok()) {
     t->incoming_stream = s;
-    // t->parser = grpc_chttp2_data_parser_parse;
-    t->parser = grpc_chttp2_data_parser_parse;
-    t->parser_data = nullptr;
+    t->parser = grpc_chttp2_transport::Parser{
+        "data", grpc_chttp2_data_parser_parse, nullptr};
     t->ping_state.last_ping_sent_time = grpc_core::Timestamp::InfPast();
     return absl::OkStatus();
   } else if (s != nullptr) {
@@ -584,8 +651,8 @@ static grpc_error_handle init_header_frame_parser(grpc_chttp2_transport* t,
     t->incoming_stream = nullptr;
     return init_header_skip_frame_parser(t, priority_type);
   }
-  t->parser = grpc_chttp2_header_parser_parse;
-  t->parser_data = &t->hpack_parser;
+  t->parser = grpc_chttp2_transport::Parser{
+      "header", grpc_chttp2_header_parser_parse, &t->hpack_parser};
   if (t->header_eof) {
     s->eos_received = true;
   }
@@ -640,12 +707,17 @@ static grpc_error_handle init_window_update_frame_parser(
     grpc_chttp2_stream* s = t->incoming_stream =
         grpc_chttp2_parsing_lookup_stream(t, t->incoming_stream_id);
     if (s == nullptr) {
+      if (grpc_http_trace.enabled()) {
+        gpr_log(GPR_ERROR, "Stream %d not found, ignoring WINDOW_UPDATE",
+                t->incoming_stream_id);
+      }
       return init_non_header_skip_frame_parser(t);
     }
     s->stats.incoming.framing_bytes += 9;
   }
-  t->parser = grpc_chttp2_window_update_parser_parse;
-  t->parser_data = &t->simple.window_update;
+  t->parser = grpc_chttp2_transport::Parser{
+      "window_update", grpc_chttp2_window_update_parser_parse,
+      &t->simple.window_update};
   return absl::OkStatus();
 }
 
@@ -653,8 +725,8 @@ static grpc_error_handle init_ping_parser(grpc_chttp2_transport* t) {
   grpc_error_handle err = grpc_chttp2_ping_parser_begin_frame(
       &t->simple.ping, t->incoming_frame_size, t->incoming_frame_flags);
   if (!err.ok()) return err;
-  t->parser = grpc_chttp2_ping_parser_parse;
-  t->parser_data = &t->simple.ping;
+  t->parser = grpc_chttp2_transport::Parser{
+      "ping", grpc_chttp2_ping_parser_parse, &t->simple.ping};
   return absl::OkStatus();
 }
 
@@ -668,8 +740,8 @@ static grpc_error_handle init_rst_stream_parser(grpc_chttp2_transport* t) {
     return init_non_header_skip_frame_parser(t);
   }
   s->stats.incoming.framing_bytes += 9;
-  t->parser = grpc_chttp2_rst_stream_parser_parse;
-  t->parser_data = &t->simple.rst_stream;
+  t->parser = grpc_chttp2_transport::Parser{
+      "rst_stream", grpc_chttp2_rst_stream_parser_parse, &t->simple.rst_stream};
   return absl::OkStatus();
 }
 
@@ -677,8 +749,8 @@ static grpc_error_handle init_goaway_parser(grpc_chttp2_transport* t) {
   grpc_error_handle err = grpc_chttp2_goaway_parser_begin_frame(
       &t->goaway_parser, t->incoming_frame_size, t->incoming_frame_flags);
   if (!err.ok()) return err;
-  t->parser = grpc_chttp2_goaway_parser_parse;
-  t->parser_data = &t->goaway_parser;
+  t->parser = grpc_chttp2_transport::Parser{
+      "goaway", grpc_chttp2_goaway_parser_parse, &t->goaway_parser};
   return absl::OkStatus();
 }
 
@@ -706,8 +778,8 @@ static grpc_error_handle init_settings_frame_parser(grpc_chttp2_transport* t) {
         t, nullptr);
     t->sent_local_settings = false;
   }
-  t->parser = grpc_chttp2_settings_parser_parse;
-  t->parser_data = &t->simple.settings;
+  t->parser = grpc_chttp2_transport::Parser{
+      "settings", grpc_chttp2_settings_parser_parse, &t->simple.settings};
   return absl::OkStatus();
 }
 
@@ -715,15 +787,24 @@ static grpc_error_handle parse_frame_slice(grpc_chttp2_transport* t,
                                            const grpc_slice& slice,
                                            int is_last) {
   grpc_chttp2_stream* s = t->incoming_stream;
-  grpc_error_handle err = t->parser(t->parser_data, t, s, slice, is_last);
+  if (grpc_http_trace.enabled()) {
+    gpr_log(GPR_DEBUG,
+            "INCOMING[%p;%p]: Parse %" PRIdPTR "b %sframe fragment with %s", t,
+            s, GRPC_SLICE_LENGTH(slice), is_last ? "last " : "",
+            t->parser.name);
+  }
+  grpc_error_handle err =
+      t->parser.parser(t->parser.user_data, t, s, slice, is_last);
   intptr_t unused;
   if (GPR_LIKELY(err.ok())) {
     return err;
-  } else if (grpc_error_get_int(err, grpc_core::StatusIntProperty::kStreamId,
-                                &unused)) {
-    if (GRPC_TRACE_FLAG_ENABLED(grpc_http_trace)) {
-      gpr_log(GPR_ERROR, "%s", grpc_core::StatusToString(err).c_str());
-    }
+  }
+  if (grpc_http_trace.enabled()) {
+    gpr_log(GPR_ERROR, "INCOMING[%p;%p]: Parse failed with %s", t, s,
+            err.ToString().c_str());
+  }
+  if (grpc_error_get_int(err, grpc_core::StatusIntProperty::kStreamId,
+                         &unused)) {
     grpc_chttp2_parsing_become_skip_parser(t);
     if (s) {
       s->forced_close_error = err;
diff --git a/src/core/lib/channel/channel_stack_builder_impl.cc b/src/core/lib/channel/channel_stack_builder_impl.cc
index c57e12258c4..98cb7a0a4c8 100644
--- a/src/core/lib/channel/channel_stack_builder_impl.cc
+++ b/src/core/lib/channel/channel_stack_builder_impl.cc
@@ -37,6 +37,7 @@
 #include "src/core/lib/gpr/useful.h"
 #include "src/core/lib/iomgr/error.h"
 #include "src/core/lib/surface/call_trace.h"
+#include "src/core/lib/surface/channel_stack_type.h"
 #include "src/core/lib/transport/error_utils.h"
 #include "src/core/lib/transport/transport.h"
 
@@ -53,12 +54,24 @@ absl::StatusOr<RefCountedPtr<grpc_channel_stack>>
 ChannelStackBuilderImpl::Build() {
   std::vector<const grpc_channel_filter*> stack;
   const bool is_promising = IsPromising();
+  const bool is_client =
+      grpc_channel_stack_type_is_client(channel_stack_type());
+  const bool client_promise_tracing =
+      is_client && is_promising && grpc_call_trace.enabled();
+  const bool server_promise_tracing =
+      !is_client && is_promising && grpc_call_trace.enabled();
 
   for (const auto* filter : this->stack()) {
-    if (is_promising && grpc_call_trace.enabled()) {
+    if (client_promise_tracing) {
       stack.push_back(PromiseTracingFilterFor(filter));
     }
     stack.push_back(filter);
+    if (server_promise_tracing) {
+      stack.push_back(PromiseTracingFilterFor(filter));
+    }
+  }
+  if (server_promise_tracing) {
+    stack.pop_back();  // connected_channel must be last => can't be traced
   }
 
   // calculate the size of the channel stack
diff --git a/src/core/lib/channel/connected_channel.cc b/src/core/lib/channel/connected_channel.cc
index 9d45df4ac80..87bf124e56f 100644
--- a/src/core/lib/channel/connected_channel.cc
+++ b/src/core/lib/channel/connected_channel.cc
@@ -24,12 +24,15 @@
 #include <string.h>
 
 #include <algorithm>
+#include <functional>
+#include <initializer_list>
 #include <memory>
 #include <string>
 #include <utility>
 #include <vector>
 
 #include "absl/base/thread_annotations.h"
+#include "absl/container/inlined_vector.h"
 #include "absl/status/status.h"
 #include "absl/strings/str_cat.h"
 #include "absl/strings/str_join.h"
@@ -37,6 +40,7 @@
 #include "absl/types/variant.h"
 
 #include <grpc/grpc.h>
+#include <grpc/status.h>
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
 
@@ -59,10 +63,11 @@
 #include "src/core/lib/promise/activity.h"
 #include "src/core/lib/promise/arena_promise.h"
 #include "src/core/lib/promise/context.h"
-#include "src/core/lib/promise/latch.h"
+#include "src/core/lib/promise/detail/basic_seq.h"
 #include "src/core/lib/promise/pipe.h"
 #include "src/core/lib/promise/poll.h"
 #include "src/core/lib/resource_quota/arena.h"
+#include "src/core/lib/slice/slice.h"
 #include "src/core/lib/slice/slice_buffer.h"
 #include "src/core/lib/surface/call.h"
 #include "src/core/lib/surface/call_trace.h"
@@ -243,37 +248,37 @@ static void connected_channel_get_channel_info(
 namespace grpc_core {
 namespace {
 
-class ClientStream : public Orphanable {
+class ConnectedChannelStream : public Orphanable {
  public:
-  ClientStream(grpc_transport* transport, CallArgs call_args)
-      : transport_(transport),
-        stream_(nullptr, StreamDeleter(this)),
-        server_initial_metadata_latch_(call_args.server_initial_metadata),
-        client_to_server_messages_(call_args.outgoing_messages),
-        server_to_client_messages_(call_args.incoming_messages),
-        client_initial_metadata_(std::move(call_args.client_initial_metadata)) {
-    call_context_->IncrementRefCount("client_stream");
-    GRPC_STREAM_REF_INIT(
-        &stream_refcount_, 1,
-        [](void* p, grpc_error_handle) {
-          static_cast<ClientStream*>(p)->BeginDestroy();
-        },
-        this, "client_stream");
-    if (grpc_call_trace.enabled()) {
-      gpr_log(GPR_INFO, "%sInitImpl: intitial_metadata=%s",
-              Activity::current()->DebugTag().c_str(),
-              client_initial_metadata_->DebugString().c_str());
-    }
+  grpc_transport* transport() { return transport_; }
+  grpc_closure* stream_destroyed_closure() { return &stream_destroyed_; }
+
+  void IncrementRefCount(const char* reason) {
+#ifndef NDEBUG
+    grpc_stream_ref(&stream_refcount_, reason);
+#else
+    (void)reason;
+    grpc_stream_ref(&stream_refcount_);
+#endif
   }
 
-  void Orphan() override {
+  void Unref(const char* reason) {
+#ifndef NDEBUG
+    grpc_stream_unref(&stream_refcount_, reason);
+#else
+    (void)reason;
+    grpc_stream_unref(&stream_refcount_);
+#endif
+  }
+
+  void Orphan() final {
     bool finished;
     {
-      MutexLock lock(&mu_);
+      MutexLock lock(mu());
       if (grpc_call_trace.enabled()) {
-        gpr_log(GPR_INFO, "%sDropStream: %s",
+        gpr_log(GPR_INFO, "%s[connected] DropStream: %s finished=%s",
                 Activity::current()->DebugTag().c_str(),
-                ActiveOpsString().c_str());
+                ActiveOpsString().c_str(), finished_ ? "true" : "false");
       }
       finished = finished_;
     }
@@ -284,211 +289,139 @@ class ClientStream : public Orphanable {
       auto* cancel_op =
           GetContext<Arena>()->New<grpc_transport_stream_op_batch>();
       cancel_op->cancel_stream = true;
-      cancel_op->payload = &batch_payload_;
-      auto* stream = stream_.get();
+      cancel_op->payload = batch_payload();
+      auto* s = stream();
       cancel_op->on_complete = NewClosure(
           [this](grpc_error_handle) { Unref("shutdown client stream"); });
-      batch_payload_.cancel_stream.cancel_error = absl::CancelledError();
-      grpc_transport_perform_stream_op(transport_, stream, cancel_op);
+      batch_payload()->cancel_stream.cancel_error = absl::CancelledError();
+      grpc_transport_perform_stream_op(transport(), s, cancel_op);
     }
     Unref("orphan client stream");
   }
 
-  void IncrementRefCount(const char* reason) {
-#ifndef NDEBUG
-    grpc_stream_ref(&stream_refcount_, reason);
-#else
-    (void)reason;
-    grpc_stream_ref(&stream_refcount_);
-#endif
-  }
-
-  void Unref(const char* reason) {
-#ifndef NDEBUG
-    grpc_stream_unref(&stream_refcount_, reason);
-#else
-    (void)reason;
-    grpc_stream_unref(&stream_refcount_);
-#endif
+ protected:
+  explicit ConnectedChannelStream(grpc_transport* transport)
+      : transport_(transport), stream_(nullptr, StreamDeleter(this)) {
+    call_context_->IncrementRefCount("connected_channel_stream");
+    GRPC_STREAM_REF_INIT(
+        &stream_refcount_, 1,
+        [](void* p, grpc_error_handle) {
+          static_cast<ConnectedChannelStream*>(p)->BeginDestroy();
+        },
+        this, "client_stream");
   }
 
-  void BeginDestroy() {
-    if (stream_ != nullptr) {
-      stream_.reset();
-    } else {
-      StreamDestroyed();
-    }
+  grpc_stream* stream() { return stream_.get(); }
+  void SetStream(grpc_stream* stream) { stream_.reset(stream); }
+  grpc_stream_refcount* stream_refcount() { return &stream_refcount_; }
+  Mutex* mu() const ABSL_LOCK_RETURNED(mu_) { return &mu_; }
+  grpc_transport_stream_op_batch_payload* batch_payload() {
+    return &batch_payload_;
   }
+  bool finished() const ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu_) { return finished_; }
+  void set_finished() ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu_) { finished_ = true; }
+  virtual std::string ActiveOpsString() const
+      ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu_) = 0;
 
-  Poll<ServerMetadataHandle> PollOnce() {
-    MutexLock lock(&mu_);
-    GPR_ASSERT(!finished_);
-
+  void SchedulePush(grpc_transport_stream_op_batch* batch)
+      ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu_) {
     if (grpc_call_trace.enabled()) {
-      gpr_log(GPR_INFO, "%sPollConnectedChannel: %s",
+      gpr_log(GPR_DEBUG, "%s[connected] Push batch to transport: %s",
               Activity::current()->DebugTag().c_str(),
-              ActiveOpsString().c_str());
+              grpc_transport_stream_op_batch_string(batch).c_str());
     }
-
-    auto push_recv_message = [this]() ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu_) {
-      recv_message_state_ = PendingReceiveMessage{};
-      auto& pending_recv_message =
-          absl::get<PendingReceiveMessage>(recv_message_state_);
-      memset(&recv_message_, 0, sizeof(recv_message_));
-      recv_message_.payload = &batch_payload_;
-      recv_message_.on_complete = nullptr;
-      recv_message_.recv_message = true;
-      batch_payload_.recv_message.recv_message = &pending_recv_message.payload;
-      batch_payload_.recv_message.flags = &pending_recv_message.flags;
-      batch_payload_.recv_message.call_failed_before_recv_message = nullptr;
-      batch_payload_.recv_message.recv_message_ready =
-          &recv_message_batch_done_;
-      IncrementRefCount("recv_message");
-      recv_message_waker_ = Activity::current()->MakeOwningWaker();
-      push_recv_message_ = true;
-      SchedulePush();
-    };
-
-    if (!std::exchange(requested_metadata_, true)) {
-      if (grpc_call_trace.enabled()) {
-        gpr_log(GPR_INFO, "%sPollConnectedChannel: requesting metadata",
-                Activity::current()->DebugTag().c_str());
-      }
-      stream_.reset(static_cast<grpc_stream*>(
-          GetContext<Arena>()->Alloc(transport_->vtable->sizeof_stream)));
-      grpc_transport_init_stream(transport_, stream_.get(), &stream_refcount_,
-                                 nullptr, GetContext<Arena>());
-      grpc_transport_set_pops(transport_, stream_.get(),
-                              GetContext<CallContext>()->polling_entity());
-      memset(&metadata_, 0, sizeof(metadata_));
-      metadata_.send_initial_metadata = true;
-      metadata_.recv_initial_metadata = true;
-      metadata_.recv_trailing_metadata = true;
-      metadata_.payload = &batch_payload_;
-      metadata_.on_complete = &metadata_batch_done_;
-      batch_payload_.send_initial_metadata.send_initial_metadata =
-          client_initial_metadata_.get();
-      batch_payload_.send_initial_metadata.peer_string =
-          GetContext<CallContext>()->peer_string_atm_ptr();
-      server_initial_metadata_ =
-          GetContext<Arena>()->MakePooled<ServerMetadata>(GetContext<Arena>());
-      batch_payload_.recv_initial_metadata.recv_initial_metadata =
-          server_initial_metadata_.get();
-      batch_payload_.recv_initial_metadata.recv_initial_metadata_ready =
-          &recv_initial_metadata_ready_;
-      batch_payload_.recv_initial_metadata.trailing_metadata_available =
-          nullptr;
-      batch_payload_.recv_initial_metadata.peer_string = nullptr;
-      server_trailing_metadata_ =
-          GetContext<Arena>()->MakePooled<ServerMetadata>(GetContext<Arena>());
-      batch_payload_.recv_trailing_metadata.recv_trailing_metadata =
-          server_trailing_metadata_.get();
-      batch_payload_.recv_trailing_metadata.collect_stats =
-          &GetContext<CallContext>()->call_stats()->transport_stream_stats;
-      batch_payload_.recv_trailing_metadata.recv_trailing_metadata_ready =
-          &recv_trailing_metadata_ready_;
-      push_metadata_ = true;
-      IncrementRefCount("metadata_batch_done");
-      IncrementRefCount("initial_metadata_ready");
-      IncrementRefCount("trailing_metadata_ready");
-      initial_metadata_waker_ = Activity::current()->MakeOwningWaker();
-      trailing_metadata_waker_ = Activity::current()->MakeOwningWaker();
-      SchedulePush();
+    if (push_batches_.empty()) {
+      IncrementRefCount("push");
+      ExecCtx::Run(DEBUG_LOCATION, &push_, absl::OkStatus());
     }
+    push_batches_.push_back(batch);
+  }
+
+  void PollSendMessage(PipeReceiver<MessageHandle>* outgoing_messages,
+                       ClientMetadataHandle* client_trailing_metadata)
+      ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu_) {
     if (absl::holds_alternative<Closed>(send_message_state_)) {
       message_to_send_.reset();
     }
     if (absl::holds_alternative<Idle>(send_message_state_)) {
       message_to_send_.reset();
-      send_message_state_ = client_to_server_messages_->Next();
+      send_message_state_.emplace<PipeReceiverNextType<MessageHandle>>(
+          outgoing_messages->Next());
     }
-    if (auto* next = absl::get_if<PipeReceiver<MessageHandle>::NextType>(
+    if (auto* next = absl::get_if<PipeReceiverNextType<MessageHandle>>(
             &send_message_state_)) {
       auto r = (*next)();
       if (auto* p = absl::get_if<NextResult<MessageHandle>>(&r)) {
         memset(&send_message_, 0, sizeof(send_message_));
-        send_message_.payload = &batch_payload_;
+        send_message_.payload = batch_payload();
         send_message_.on_complete = &send_message_batch_done_;
         // No value => half close from above.
         if (p->has_value()) {
-          message_to_send_ = std::move(**p);
+          message_to_send_ = std::move(*p);
           send_message_state_ = SendMessageToTransport{};
           send_message_.send_message = true;
-          batch_payload_.send_message.send_message =
-              message_to_send_->payload();
-          batch_payload_.send_message.flags = message_to_send_->flags();
+          batch_payload()->send_message.send_message =
+              (*message_to_send_)->payload();
+          batch_payload()->send_message.flags = (*message_to_send_)->flags();
         } else {
           if (grpc_call_trace.enabled()) {
-            gpr_log(GPR_INFO, "%sPollConnectedChannel: half close",
+            gpr_log(GPR_INFO, "%s[connected] PollConnectedChannel: half close",
                     Activity::current()->DebugTag().c_str());
           }
           GPR_ASSERT(!absl::holds_alternative<Closed>(send_message_state_));
-          client_trailing_metadata_ =
-              GetContext<Arena>()->MakePooled<ClientMetadata>(
-                  GetContext<Arena>());
           send_message_state_ = Closed{};
           send_message_.send_trailing_metadata = true;
-          batch_payload_.send_trailing_metadata.send_trailing_metadata =
-              client_trailing_metadata_.get();
-          batch_payload_.send_trailing_metadata.sent = nullptr;
+          if (client_trailing_metadata != nullptr) {
+            *client_trailing_metadata =
+                GetContext<Arena>()->MakePooled<ClientMetadata>(
+                    GetContext<Arena>());
+            batch_payload()->send_trailing_metadata.send_trailing_metadata =
+                client_trailing_metadata->get();
+            batch_payload()->send_trailing_metadata.sent = nullptr;
+          } else {
+            return;  // Skip rest of function for server
+          }
         }
         IncrementRefCount("send_message");
         send_message_waker_ = Activity::current()->MakeOwningWaker();
-        push_send_message_ = true;
-        SchedulePush();
+        SchedulePush(&send_message_);
       }
     }
+  }
+
+  void PollRecvMessage(PipeSender<MessageHandle>*& incoming_messages)
+      ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu_) {
     if (auto* pending =
             absl::get_if<PendingReceiveMessage>(&recv_message_state_)) {
       if (pending->received) {
         if (pending->payload.has_value()) {
           if (grpc_call_trace.enabled()) {
             gpr_log(GPR_INFO,
-                    "%sRecvMessageBatchDone: received payload of %" PRIdPTR
-                    " bytes",
+                    "%s[connected] PollRecvMessage: received payload of "
+                    "%" PRIdPTR " bytes",
                     recv_message_waker_.ActivityDebugTag().c_str(),
                     pending->payload->Length());
           }
-          recv_message_state_ = server_to_client_messages_->Push(
-              GetContext<Arena>()->MakePooled<Message>(
+          recv_message_state_ =
+              incoming_messages->Push(GetContext<Arena>()->MakePooled<Message>(
                   std::move(*pending->payload), pending->flags));
         } else {
           if (grpc_call_trace.enabled()) {
-            gpr_log(GPR_INFO, "%sRecvMessageBatchDone: received no payload",
+            gpr_log(GPR_INFO,
+                    "%s[connected] PollRecvMessage: received no payload",
                     recv_message_waker_.ActivityDebugTag().c_str());
           }
           recv_message_state_ = Closed{};
-          std::exchange(server_to_client_messages_, nullptr)->Close();
+          std::exchange(incoming_messages, nullptr)->Close();
         }
       }
     }
-    if (server_initial_metadata_state_ ==
-        ServerInitialMetadataState::kReceivedButNotSet) {
-      server_initial_metadata_state_ = ServerInitialMetadataState::kSet;
-      server_initial_metadata_latch_->Set(server_initial_metadata_.get());
-    }
     if (absl::holds_alternative<Idle>(recv_message_state_)) {
       if (grpc_call_trace.enabled()) {
-        gpr_log(GPR_INFO, "%sPollConnectedChannel: requesting message",
+        gpr_log(GPR_INFO, "%s[connected] PollRecvMessage: requesting message",
                 Activity::current()->DebugTag().c_str());
       }
-      push_recv_message();
-    }
-    if (server_initial_metadata_state_ == ServerInitialMetadataState::kSet &&
-        !absl::holds_alternative<PipeSender<MessageHandle>::PushType>(
-            recv_message_state_) &&
-        !absl::holds_alternative<PendingReceiveMessage>(recv_message_state_) &&
-        std::exchange(queued_trailing_metadata_, false)) {
-      if (grpc_call_trace.enabled()) {
-        gpr_log(GPR_INFO,
-                "%sPollConnectedChannel: finished request, returning: {%s}; "
-                "active_ops: %s",
-                Activity::current()->DebugTag().c_str(),
-                server_trailing_metadata_->DebugString().c_str(),
-                ActiveOpsString().c_str());
-      }
-      finished_ = true;
-      return ServerMetadataHandle(std::move(server_trailing_metadata_));
+      PushRecvMessage();
     }
     if (auto* push = absl::get_if<PipeSender<MessageHandle>::PushType>(
             &recv_message_state_)) {
@@ -498,57 +431,120 @@ class ClientStream : public Orphanable {
           if (!finished_) {
             if (grpc_call_trace.enabled()) {
               gpr_log(GPR_INFO,
-                      "%sPollConnectedChannel: pushed message; requesting next",
+                      "%s[connected] PollRecvMessage: pushed message; "
+                      "requesting next",
                       Activity::current()->DebugTag().c_str());
             }
-            push_recv_message();
+            PushRecvMessage();
           } else {
             if (grpc_call_trace.enabled()) {
               gpr_log(GPR_INFO,
-                      "%sPollConnectedChannel: pushed message and finished; "
+                      "%s[connected] PollRecvMessage: pushed message "
+                      "and finished; "
                       "marking closed",
                       Activity::current()->DebugTag().c_str());
             }
             recv_message_state_ = Closed{};
+            std::exchange(incoming_messages, nullptr)->Close();
           }
         } else {
           if (grpc_call_trace.enabled()) {
             gpr_log(GPR_INFO,
-                    "%sPollConnectedChannel: failed to push message; marking "
+                    "%s[connected] PollRecvMessage: failed to push "
+                    "message; marking "
                     "closed",
                     Activity::current()->DebugTag().c_str());
           }
           recv_message_state_ = Closed{};
+          std::exchange(incoming_messages, nullptr)->Close();
         }
       }
     }
-    return Pending{};
   }
 
-  void RecvInitialMetadataReady(grpc_error_handle error) {
-    GPR_ASSERT(error == absl::OkStatus());
-    {
-      MutexLock lock(&mu_);
-      server_initial_metadata_state_ =
-          ServerInitialMetadataState::kReceivedButNotSet;
-      initial_metadata_waker_.Wakeup();
+  std::string SendMessageString() const ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu()) {
+    return Match(
+        send_message_state_, [](Idle) -> std::string { return "IDLE"; },
+        [](Closed) -> std::string { return "CLOSED"; },
+        [](const PipeReceiverNextType<MessageHandle>&) -> std::string {
+          return "WAITING";
+        },
+        [](SendMessageToTransport) -> std::string { return "SENDING"; });
+  }
+
+  std::string RecvMessageString() const ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu()) {
+    return Match(
+        recv_message_state_, [](Idle) -> std::string { return "IDLE"; },
+        [](Closed) -> std::string { return "CLOSED"; },
+        [](const PendingReceiveMessage&) -> std::string { return "WAITING"; },
+        [](const absl::optional<MessageHandle>& message) -> std::string {
+          return absl::StrCat(
+              "READY:", message.has_value()
+                            ? absl::StrCat((*message)->payload()->Length(), "b")
+                            : "EOS");
+        },
+        [](const PipeSender<MessageHandle>::PushType&) -> std::string {
+          return "PUSHING";
+        });
+  }
+
+  bool IsPromiseReceiving() const ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu()) {
+    return absl::holds_alternative<PipeSender<MessageHandle>::PushType>(
+               recv_message_state_) ||
+           absl::holds_alternative<PendingReceiveMessage>(recv_message_state_);
+  }
+
+ private:
+  struct SendMessageToTransport {};
+  struct Idle {};
+  struct Closed {};
+
+  class StreamDeleter {
+   public:
+    explicit StreamDeleter(ConnectedChannelStream* impl) : impl_(impl) {}
+    void operator()(grpc_stream* stream) const {
+      if (stream == nullptr) return;
+      grpc_transport_destroy_stream(impl_->transport(), stream,
+                                    impl_->stream_destroyed_closure());
     }
-    Unref("initial_metadata_ready");
+
+   private:
+    ConnectedChannelStream* impl_;
+  };
+  using StreamPtr = std::unique_ptr<grpc_stream, StreamDeleter>;
+
+  void StreamDestroyed() {
+    call_context_->RunInContext([this] {
+      auto* cc = call_context_;
+      this->~ConnectedChannelStream();
+      cc->Unref("child_stream");
+    });
   }
 
-  void RecvTrailingMetadataReady(grpc_error_handle error) {
-    GPR_ASSERT(error == absl::OkStatus());
-    {
-      MutexLock lock(&mu_);
-      queued_trailing_metadata_ = true;
-      trailing_metadata_waker_.Wakeup();
+  void BeginDestroy() {
+    if (stream_ != nullptr) {
+      stream_.reset();
+    } else {
+      StreamDestroyed();
     }
-    Unref("trailing_metadata_ready");
   }
 
-  void MetadataBatchDone(grpc_error_handle error) {
-    GPR_ASSERT(error == absl::OkStatus());
-    Unref("metadata_batch_done");
+  // Called from outside the activity to push work down to the transport.
+  void Push() {
+    PushBatches push_batches;
+    {
+      MutexLock lock(&mu_);
+      push_batches.swap(push_batches_);
+    }
+    for (auto* batch : push_batches) {
+      if (stream() != nullptr) {
+        grpc_transport_perform_stream_op(transport(), stream(), batch);
+      } else {
+        grpc_transport_stream_op_batch_finish_with_failure_from_transport(
+            batch, absl::CancelledError());
+      }
+    }
+    Unref("push");
   }
 
   void SendMessageBatchDone(grpc_error_handle error) {
@@ -571,21 +567,24 @@ class ClientStream : public Orphanable {
 
   void RecvMessageBatchDone(grpc_error_handle error) {
     {
-      MutexLock lock(&mu_);
+      MutexLock lock(mu());
       if (error != absl::OkStatus()) {
         if (grpc_call_trace.enabled()) {
-          gpr_log(GPR_INFO, "%sRecvMessageBatchDone: error=%s",
+          gpr_log(GPR_INFO, "%s[connected] RecvMessageBatchDone: error=%s",
                   recv_message_waker_.ActivityDebugTag().c_str(),
                   StatusToString(error).c_str());
         }
       } else if (absl::holds_alternative<Closed>(recv_message_state_)) {
         if (grpc_call_trace.enabled()) {
-          gpr_log(GPR_INFO, "%sRecvMessageBatchDone: already closed, ignoring",
+          gpr_log(GPR_INFO,
+                  "%s[connected] RecvMessageBatchDone: already closed, "
+                  "ignoring",
                   recv_message_waker_.ActivityDebugTag().c_str());
         }
       } else {
         if (grpc_call_trace.enabled()) {
-          gpr_log(GPR_INFO, "%sRecvMessageBatchDone: received message",
+          gpr_log(GPR_INFO,
+                  "%s[connected] RecvMessageBatchDone: received message",
                   recv_message_waker_.ActivityDebugTag().c_str());
         }
         auto pending =
@@ -599,95 +598,248 @@ class ClientStream : public Orphanable {
     Unref("recv_message");
   }
 
-  // Called from outside the activity to push work down to the transport.
-  void Push() {
-    auto do_push = [this](grpc_transport_stream_op_batch* batch) {
-      if (stream_ != nullptr) {
-        grpc_transport_perform_stream_op(transport_, stream_.get(), batch);
-      } else {
-        grpc_transport_stream_op_batch_finish_with_failure_from_transport(
-            batch, absl::CancelledError());
+  void PushRecvMessage() ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu_) {
+    recv_message_state_ = PendingReceiveMessage{};
+    auto& pending_recv_message =
+        absl::get<PendingReceiveMessage>(recv_message_state_);
+    memset(&recv_message_, 0, sizeof(recv_message_));
+    recv_message_.payload = batch_payload();
+    recv_message_.on_complete = nullptr;
+    recv_message_.recv_message = true;
+    batch_payload()->recv_message.recv_message = &pending_recv_message.payload;
+    batch_payload()->recv_message.flags = &pending_recv_message.flags;
+    batch_payload()->recv_message.call_failed_before_recv_message = nullptr;
+    batch_payload()->recv_message.recv_message_ready =
+        &recv_message_batch_done_;
+    IncrementRefCount("recv_message");
+    recv_message_waker_ = Activity::current()->MakeOwningWaker();
+    SchedulePush(&recv_message_);
+  }
+
+  mutable Mutex mu_;
+  grpc_transport* const transport_;
+  CallContext* const call_context_{GetContext<CallContext>()};
+  grpc_closure stream_destroyed_ =
+      MakeMemberClosure<ConnectedChannelStream,
+                        &ConnectedChannelStream::StreamDestroyed>(
+          this, DEBUG_LOCATION);
+  grpc_stream_refcount stream_refcount_;
+  StreamPtr stream_;
+  using PushBatches = absl::InlinedVector<grpc_transport_stream_op_batch*, 3>;
+  PushBatches push_batches_ ABSL_GUARDED_BY(mu_);
+  grpc_closure push_ =
+      MakeMemberClosure<ConnectedChannelStream, &ConnectedChannelStream::Push>(
+          this, DEBUG_LOCATION);
+
+  NextResult<MessageHandle> message_to_send_ ABSL_GUARDED_BY(mu_);
+  absl::variant<Idle, Closed, PipeReceiverNextType<MessageHandle>,
+                SendMessageToTransport>
+      send_message_state_ ABSL_GUARDED_BY(mu_);
+  grpc_transport_stream_op_batch send_message_;
+  grpc_closure send_message_batch_done_ =
+      MakeMemberClosure<ConnectedChannelStream,
+                        &ConnectedChannelStream::SendMessageBatchDone>(
+          this, DEBUG_LOCATION);
+
+  struct PendingReceiveMessage {
+    absl::optional<SliceBuffer> payload;
+    uint32_t flags;
+    bool received = false;
+  };
+  absl::variant<Idle, PendingReceiveMessage, Closed,
+                PipeSender<MessageHandle>::PushType>
+      recv_message_state_ ABSL_GUARDED_BY(mu_);
+  grpc_closure recv_message_batch_done_ =
+      MakeMemberClosure<ConnectedChannelStream,
+                        &ConnectedChannelStream::RecvMessageBatchDone>(
+          this, DEBUG_LOCATION);
+  grpc_transport_stream_op_batch recv_message_;
+
+  Waker send_message_waker_ ABSL_GUARDED_BY(mu_);
+  Waker recv_message_waker_ ABSL_GUARDED_BY(mu_);
+  bool finished_ ABSL_GUARDED_BY(mu_) = false;
+
+  grpc_transport_stream_op_batch_payload batch_payload_{
+      GetContext<grpc_call_context_element>()};
+};
+
+class ClientStream : public ConnectedChannelStream {
+ public:
+  ClientStream(grpc_transport* transport, CallArgs call_args)
+      : ConnectedChannelStream(transport),
+        server_initial_metadata_pipe_(call_args.server_initial_metadata),
+        client_to_server_messages_(call_args.client_to_server_messages),
+        server_to_client_messages_(call_args.server_to_client_messages),
+        client_initial_metadata_(std::move(call_args.client_initial_metadata)) {
+    if (grpc_call_trace.enabled()) {
+      gpr_log(GPR_INFO, "%s[connected] InitImpl: intitial_metadata=%s",
+              Activity::current()->DebugTag().c_str(),
+              client_initial_metadata_->DebugString().c_str());
+    }
+  }
+
+  Poll<ServerMetadataHandle> PollOnce() {
+    MutexLock lock(mu());
+    GPR_ASSERT(!finished());
+
+    if (grpc_call_trace.enabled()) {
+      gpr_log(GPR_INFO, "%s[connected] PollConnectedChannel: %s",
+              Activity::current()->DebugTag().c_str(),
+              ActiveOpsString().c_str());
+    }
+
+    if (!std::exchange(requested_metadata_, true)) {
+      if (grpc_call_trace.enabled()) {
+        gpr_log(GPR_INFO,
+                "%s[connected] PollConnectedChannel: requesting metadata",
+                Activity::current()->DebugTag().c_str());
       }
-    };
-    bool push_metadata;
-    bool push_send_message;
-    bool push_recv_message;
+      SetStream(static_cast<grpc_stream*>(
+          GetContext<Arena>()->Alloc(transport()->vtable->sizeof_stream)));
+      grpc_transport_init_stream(transport(), stream(), stream_refcount(),
+                                 nullptr, GetContext<Arena>());
+      grpc_transport_set_pops(transport(), stream(),
+                              GetContext<CallContext>()->polling_entity());
+      memset(&metadata_, 0, sizeof(metadata_));
+      metadata_.send_initial_metadata = true;
+      metadata_.recv_initial_metadata = true;
+      metadata_.recv_trailing_metadata = true;
+      metadata_.payload = batch_payload();
+      metadata_.on_complete = &metadata_batch_done_;
+      batch_payload()->send_initial_metadata.send_initial_metadata =
+          client_initial_metadata_.get();
+      batch_payload()->send_initial_metadata.peer_string =
+          GetContext<CallContext>()->peer_string_atm_ptr();
+      server_initial_metadata_ =
+          GetContext<Arena>()->MakePooled<ServerMetadata>(GetContext<Arena>());
+      batch_payload()->recv_initial_metadata.recv_initial_metadata =
+          server_initial_metadata_.get();
+      batch_payload()->recv_initial_metadata.recv_initial_metadata_ready =
+          &recv_initial_metadata_ready_;
+      batch_payload()->recv_initial_metadata.trailing_metadata_available =
+          nullptr;
+      batch_payload()->recv_initial_metadata.peer_string = nullptr;
+      server_trailing_metadata_ =
+          GetContext<Arena>()->MakePooled<ServerMetadata>(GetContext<Arena>());
+      batch_payload()->recv_trailing_metadata.recv_trailing_metadata =
+          server_trailing_metadata_.get();
+      batch_payload()->recv_trailing_metadata.collect_stats =
+          &GetContext<CallContext>()->call_stats()->transport_stream_stats;
+      batch_payload()->recv_trailing_metadata.recv_trailing_metadata_ready =
+          &recv_trailing_metadata_ready_;
+      IncrementRefCount("metadata_batch_done");
+      IncrementRefCount("initial_metadata_ready");
+      IncrementRefCount("trailing_metadata_ready");
+      initial_metadata_waker_ = Activity::current()->MakeOwningWaker();
+      trailing_metadata_waker_ = Activity::current()->MakeOwningWaker();
+      SchedulePush(&metadata_);
+    }
+    if (server_initial_metadata_state_ ==
+        ServerInitialMetadataState::kReceivedButNotPushed) {
+      server_initial_metadata_state_ = ServerInitialMetadataState::kPushing;
+      server_initial_metadata_push_promise_ =
+          server_initial_metadata_pipe_->Push(
+              std::move(server_initial_metadata_));
+    }
+    if (server_initial_metadata_state_ ==
+        ServerInitialMetadataState::kPushing) {
+      auto r = (*server_initial_metadata_push_promise_)();
+      if (absl::holds_alternative<bool>(r)) {
+        server_initial_metadata_state_ = ServerInitialMetadataState::kPushed;
+        server_initial_metadata_push_promise_.reset();
+      }
+    }
+    PollSendMessage(client_to_server_messages_, &client_trailing_metadata_);
+    PollRecvMessage(server_to_client_messages_);
+    if (server_initial_metadata_state_ == ServerInitialMetadataState::kPushed &&
+        !IsPromiseReceiving() &&
+        std::exchange(queued_trailing_metadata_, false)) {
+      if (grpc_call_trace.enabled()) {
+        gpr_log(GPR_INFO,
+                "%s[connected] PollConnectedChannel: finished request, "
+                "returning: {%s}; "
+                "active_ops: %s",
+                Activity::current()->DebugTag().c_str(),
+                server_trailing_metadata_->DebugString().c_str(),
+                ActiveOpsString().c_str());
+      }
+      set_finished();
+      return ServerMetadataHandle(std::move(server_trailing_metadata_));
+    }
+    return Pending{};
+  }
+
+  void RecvInitialMetadataReady(grpc_error_handle error) {
+    GPR_ASSERT(error == absl::OkStatus());
     {
-      MutexLock lock(&mu_);
-      push_metadata = std::exchange(push_metadata_, false);
-      push_send_message = std::exchange(push_send_message_, false);
-      push_recv_message = std::exchange(push_recv_message_, false);
-      scheduled_push_ = false;
-    }
-    if (push_metadata) do_push(&metadata_);
-    if (push_send_message) do_push(&send_message_);
-    if (push_recv_message) do_push(&recv_message_);
-    Unref("push");
+      MutexLock lock(mu());
+      server_initial_metadata_state_ =
+          ServerInitialMetadataState::kReceivedButNotPushed;
+      initial_metadata_waker_.Wakeup();
+    }
+    Unref("initial_metadata_ready");
   }
 
-  void StreamDestroyed() {
-    call_context_->RunInContext([this] {
-      auto* cc = call_context_;
-      this->~ClientStream();
-      cc->Unref("child_stream");
-    });
+  void RecvTrailingMetadataReady(grpc_error_handle error) {
+    GPR_ASSERT(error == absl::OkStatus());
+    {
+      MutexLock lock(mu());
+      queued_trailing_metadata_ = true;
+      if (grpc_call_trace.enabled()) {
+        gpr_log(GPR_DEBUG,
+                "%s[connected] RecvTrailingMetadataReady: "
+                "queued_trailing_metadata_ "
+                "set to true; active_ops: %s",
+                trailing_metadata_waker_.ActivityDebugTag().c_str(),
+                ActiveOpsString().c_str());
+      }
+      trailing_metadata_waker_.Wakeup();
+    }
+    Unref("trailing_metadata_ready");
   }
 
- private:
-  struct Idle {};
-  struct Closed {};
-  struct SendMessageToTransport {};
+  void MetadataBatchDone(grpc_error_handle error) {
+    GPR_ASSERT(error == absl::OkStatus());
+    Unref("metadata_batch_done");
+  }
 
+ private:
   enum class ServerInitialMetadataState : uint8_t {
     // Initial metadata has not been received from the server.
     kNotReceived,
     // Initial metadata has been received from the server via the transport, but
-    // has not yet been set on the latch to publish it up the call stack.
-    kReceivedButNotSet,
+    // has not yet been pushed onto the pipe to publish it up the call stack.
+    kReceivedButNotPushed,
     // Initial metadata has been received from the server via the transport and
-    // has been set on the latch to publish it up the call stack.
-    kSet,
-  };
-
-  class StreamDeleter {
-   public:
-    explicit StreamDeleter(ClientStream* impl) : impl_(impl) {}
-    void operator()(grpc_stream* stream) const {
-      if (stream == nullptr) return;
-      grpc_transport_destroy_stream(impl_->transport_, stream,
-                                    &impl_->stream_destroyed_);
-    }
-
-   private:
-    ClientStream* impl_;
+    // has been pushed on the pipe to publish it up the call stack.
+    // It's still in the pipe and has not been removed by the call at the top
+    // yet.
+    kPushing,
+    // Initial metadata has been received from the server via the transport and
+    // has been pushed on the pipe to publish it up the call stack AND removed
+    // by the call at the top.
+    kPushed,
   };
-  using StreamPtr = std::unique_ptr<grpc_stream, StreamDeleter>;
 
-  void SchedulePush() ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu_) {
-    if (std::exchange(scheduled_push_, true)) return;
-    IncrementRefCount("push");
-    ExecCtx::Run(DEBUG_LOCATION, &push_, absl::OkStatus());
-  }
-
-  std::string ActiveOpsString() const ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu_) {
+  std::string ActiveOpsString() const override
+      ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu()) {
     std::vector<std::string> ops;
-    if (finished_) ops.push_back("FINISHED");
-    // Pushes
-    std::vector<std::string> pushes;
-    if (push_metadata_) pushes.push_back("metadata");
-    if (push_send_message_) pushes.push_back("send_message");
-    if (push_recv_message_) pushes.push_back("recv_message");
-    if (!pushes.empty()) {
-      ops.push_back(
-          absl::StrCat(scheduled_push_ ? "push:" : "unscheduled-push:",
-                       absl::StrJoin(pushes, ",")));
-    } else if (scheduled_push_) {
-      ops.push_back("push:nothing");
+    if (finished()) ops.push_back("FINISHED");
+    // Outstanding Operations on Transport
+    std::vector<std::string> waiting;
+    if (initial_metadata_waker_ != Waker()) {
+      waiting.push_back("initial_metadata");
+    }
+    if (trailing_metadata_waker_ != Waker()) {
+      waiting.push_back("trailing_metadata");
+    }
+    if (!waiting.empty()) {
+      ops.push_back(absl::StrCat("waiting:", absl::StrJoin(waiting, ",")));
     }
     // Results from transport
     std::vector<std::string> queued;
     if (server_initial_metadata_state_ ==
-        ServerInitialMetadataState::kReceivedButNotSet) {
+        ServerInitialMetadataState::kReceivedButNotPushed) {
       queued.push_back("initial_metadata");
     }
     if (queued_trailing_metadata_) queued.push_back("trailing_metadata");
@@ -707,94 +859,31 @@ class ClientStream : public Orphanable {
     return absl::StrJoin(ops, " ");
   }
 
-  std::string SendMessageString() const ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu_) {
-    return Match(
-        send_message_state_, [](Idle) -> std::string { return "IDLE"; },
-        [](Closed) -> std::string { return "CLOSED"; },
-        [](const PipeReceiver<MessageHandle>::NextType&) -> std::string {
-          return "WAITING";
-        },
-        [](SendMessageToTransport) -> std::string { return "SENDING"; });
-  }
-
-  std::string RecvMessageString() const ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu_) {
-    return Match(
-        recv_message_state_, [](Idle) -> std::string { return "IDLE"; },
-        [](Closed) -> std::string { return "CLOSED"; },
-        [](const PendingReceiveMessage&) -> std::string { return "WAITING"; },
-        [](const absl::optional<MessageHandle>& message) -> std::string {
-          return absl::StrCat(
-              "READY:", message.has_value()
-                            ? absl::StrCat((*message)->payload()->Length(), "b")
-                            : "EOS");
-        },
-        [](const PipeSender<MessageHandle>::PushType&) -> std::string {
-          return "PUSHING";
-        });
-  }
-
-  Mutex mu_;
   bool requested_metadata_ = false;
-  bool push_metadata_ ABSL_GUARDED_BY(mu_) = false;
-  bool push_send_message_ ABSL_GUARDED_BY(mu_) = false;
-  bool push_recv_message_ ABSL_GUARDED_BY(mu_) = false;
-  bool scheduled_push_ ABSL_GUARDED_BY(mu_) = false;
   ServerInitialMetadataState server_initial_metadata_state_
-      ABSL_GUARDED_BY(mu_) = ServerInitialMetadataState::kNotReceived;
-  bool queued_trailing_metadata_ ABSL_GUARDED_BY(mu_) = false;
-  bool finished_ ABSL_GUARDED_BY(mu_) = false;
-  CallContext* const call_context_{GetContext<CallContext>()};
-  Waker initial_metadata_waker_ ABSL_GUARDED_BY(mu_);
-  Waker trailing_metadata_waker_ ABSL_GUARDED_BY(mu_);
-  Waker send_message_waker_ ABSL_GUARDED_BY(mu_);
-  Waker recv_message_waker_ ABSL_GUARDED_BY(mu_);
-  grpc_transport* const transport_;
-  grpc_stream_refcount stream_refcount_;
-  StreamPtr stream_;
-  Latch<ServerMetadata*>* server_initial_metadata_latch_;
+      ABSL_GUARDED_BY(mu()) = ServerInitialMetadataState::kNotReceived;
+  bool queued_trailing_metadata_ ABSL_GUARDED_BY(mu()) = false;
+  Waker initial_metadata_waker_ ABSL_GUARDED_BY(mu());
+  Waker trailing_metadata_waker_ ABSL_GUARDED_BY(mu());
+  PipeSender<ServerMetadataHandle>* server_initial_metadata_pipe_;
   PipeReceiver<MessageHandle>* client_to_server_messages_;
   PipeSender<MessageHandle>* server_to_client_messages_;
-  MessageHandle message_to_send_ ABSL_GUARDED_BY(mu_);
-  absl::variant<Idle, Closed, PipeReceiver<MessageHandle>::NextType,
-                SendMessageToTransport>
-      send_message_state_ ABSL_GUARDED_BY(mu_);
-  struct PendingReceiveMessage {
-    absl::optional<SliceBuffer> payload;
-    uint32_t flags;
-    bool received = false;
-  };
-  absl::variant<Idle, PendingReceiveMessage, Closed,
-                PipeSender<MessageHandle>::PushType>
-      recv_message_state_ ABSL_GUARDED_BY(mu_);
   grpc_closure recv_initial_metadata_ready_ =
       MakeMemberClosure<ClientStream, &ClientStream::RecvInitialMetadataReady>(
           this, DEBUG_LOCATION);
   grpc_closure recv_trailing_metadata_ready_ =
       MakeMemberClosure<ClientStream, &ClientStream::RecvTrailingMetadataReady>(
           this, DEBUG_LOCATION);
-  grpc_closure push_ = MakeMemberClosure<ClientStream, &ClientStream::Push>(
-      this, DEBUG_LOCATION);
   ClientMetadataHandle client_initial_metadata_;
   ClientMetadataHandle client_trailing_metadata_;
   ServerMetadataHandle server_initial_metadata_;
   ServerMetadataHandle server_trailing_metadata_;
+  absl::optional<PipeSender<ServerMetadataHandle>::PushType>
+      server_initial_metadata_push_promise_;
   grpc_transport_stream_op_batch metadata_;
   grpc_closure metadata_batch_done_ =
       MakeMemberClosure<ClientStream, &ClientStream::MetadataBatchDone>(
           this, DEBUG_LOCATION);
-  grpc_transport_stream_op_batch send_message_;
-  grpc_closure send_message_batch_done_ =
-      MakeMemberClosure<ClientStream, &ClientStream::SendMessageBatchDone>(
-          this, DEBUG_LOCATION);
-  grpc_closure recv_message_batch_done_ =
-      MakeMemberClosure<ClientStream, &ClientStream::RecvMessageBatchDone>(
-          this, DEBUG_LOCATION);
-  grpc_transport_stream_op_batch recv_message_;
-  grpc_transport_stream_op_batch_payload batch_payload_{
-      GetContext<grpc_call_context_element>()};
-  grpc_closure stream_destroyed_ =
-      MakeMemberClosure<ClientStream, &ClientStream::StreamDestroyed>(
-          this, DEBUG_LOCATION);
 };
 
 class ClientConnectedCallPromise {
@@ -815,7 +904,8 @@ class ClientConnectedCallPromise {
   }
 
   static ArenaPromise<ServerMetadataHandle> Make(grpc_transport* transport,
-                                                 CallArgs call_args) {
+                                                 CallArgs call_args,
+                                                 NextPromiseFactory) {
     return ClientConnectedCallPromise(transport, std::move(call_args));
   }
 
@@ -825,8 +915,430 @@ class ClientConnectedCallPromise {
   OrphanablePtr<ClientStream> impl_;
 };
 
+class ServerStream final : public ConnectedChannelStream {
+ public:
+  ServerStream(grpc_transport* transport,
+               NextPromiseFactory next_promise_factory)
+      : ConnectedChannelStream(transport) {
+    SetStream(static_cast<grpc_stream*>(
+        GetContext<Arena>()->Alloc(transport->vtable->sizeof_stream)));
+    grpc_transport_init_stream(
+        transport, stream(), stream_refcount(),
+        GetContext<CallContext>()->server_call_context()->server_stream_data(),
+        GetContext<Arena>());
+    grpc_transport_set_pops(transport, stream(),
+                            GetContext<CallContext>()->polling_entity());
+
+    // Fetch initial metadata
+    auto& gim = call_state_.emplace<GettingInitialMetadata>(this);
+    gim.recv_initial_metadata_ready_waker =
+        Activity::current()->MakeOwningWaker();
+    memset(&gim.recv_initial_metadata, 0, sizeof(gim.recv_initial_metadata));
+    gim.recv_initial_metadata.payload = batch_payload();
+    gim.recv_initial_metadata.on_complete = nullptr;
+    gim.recv_initial_metadata.recv_initial_metadata = true;
+    gim.next_promise_factory = std::move(next_promise_factory);
+    batch_payload()->recv_initial_metadata.recv_initial_metadata =
+        gim.client_initial_metadata.get();
+    batch_payload()->recv_initial_metadata.recv_initial_metadata_ready =
+        &gim.recv_initial_metadata_ready;
+    SchedulePush(&gim.recv_initial_metadata);
+
+    // Fetch trailing metadata (to catch cancellations)
+    auto& gtm =
+        client_trailing_metadata_state_.emplace<WaitingForTrailingMetadata>();
+    gtm.recv_trailing_metadata_ready =
+        MakeMemberClosure<ServerStream,
+                          &ServerStream::RecvTrailingMetadataReady>(this);
+    memset(&gtm.recv_trailing_metadata, 0, sizeof(gtm.recv_trailing_metadata));
+    gtm.recv_trailing_metadata.payload = batch_payload();
+    gtm.recv_trailing_metadata.recv_trailing_metadata = true;
+    batch_payload()->recv_trailing_metadata.recv_trailing_metadata =
+        gtm.result.get();
+    batch_payload()->recv_trailing_metadata.collect_stats =
+        &GetContext<CallContext>()->call_stats()->transport_stream_stats;
+    batch_payload()->recv_trailing_metadata.recv_trailing_metadata_ready =
+        &gtm.recv_trailing_metadata_ready;
+    SchedulePush(&gtm.recv_trailing_metadata);
+    gtm.waker = Activity::current()->MakeOwningWaker();
+  }
+
+  Poll<ServerMetadataHandle> PollOnce() {
+    MutexLock lock(mu());
+
+    auto poll_send_initial_metadata = [this]() ABSL_EXCLUSIVE_LOCKS_REQUIRED(
+                                          mu()) {
+      if (auto* promise =
+              absl::get_if<PipeReceiverNextType<ServerMetadataHandle>>(
+                  &server_initial_metadata_)) {
+        auto r = (*promise)();
+        if (auto* md = absl::get_if<NextResult<ServerMetadataHandle>>(&r)) {
+          if (grpc_call_trace.enabled()) {
+            gpr_log(
+                GPR_INFO, "%s[connected] got initial metadata %s",
+                Activity::current()->DebugTag().c_str(),
+                (md->has_value() ? (**md)->DebugString() : "<trailers-only>")
+                    .c_str());
+          }
+          memset(&send_initial_metadata_, 0, sizeof(send_initial_metadata_));
+          send_initial_metadata_.send_initial_metadata = true;
+          send_initial_metadata_.payload = batch_payload();
+          send_initial_metadata_.on_complete = &send_initial_metadata_done_;
+          batch_payload()->send_initial_metadata.send_initial_metadata =
+              server_initial_metadata_
+                  .emplace<ServerMetadataHandle>(std::move(**md))
+                  .get();
+          batch_payload()->send_initial_metadata.peer_string = nullptr;
+          SchedulePush(&send_initial_metadata_);
+          return true;
+        } else {
+          return false;
+        }
+      } else {
+        return true;
+      }
+    };
+
+    if (grpc_call_trace.enabled()) {
+      gpr_log(GPR_INFO, "%s[connected] PollConnectedChannel: %s",
+              Activity::current()->DebugTag().c_str(),
+              ActiveOpsString().c_str());
+    }
+
+    poll_send_initial_metadata();
+
+    if (auto* p = absl::get_if<GotClientHalfClose>(
+            &client_trailing_metadata_state_)) {
+      pipes_.client_to_server.sender.Close();
+      if (!p->result.ok()) {
+        // client cancelled, we should cancel too
+        if (absl::holds_alternative<absl::monostate>(call_state_) ||
+            absl::holds_alternative<GotInitialMetadata>(call_state_) ||
+            absl::holds_alternative<MessageLoop>(call_state_)) {
+          if (!absl::holds_alternative<ServerMetadataHandle>(
+                  server_initial_metadata_)) {
+            // pretend we've sent initial metadata to stop that op from
+            // progressing if it's stuck somewhere above us in the stack
+            server_initial_metadata_.emplace<ServerMetadataHandle>();
+          }
+          // cancel the call - this status will be returned to the server bottom
+          // promise
+          call_state_.emplace<Complete>(
+              Complete{ServerMetadataFromStatus(p->result)});
+        }
+      }
+    }
+
+    if (auto* p = absl::get_if<GotInitialMetadata>(&call_state_)) {
+      incoming_messages_ = &pipes_.client_to_server.sender;
+      auto promise = p->next_promise_factory(CallArgs{
+          std::move(p->client_initial_metadata),
+          &pipes_.server_initial_metadata.sender,
+          &pipes_.client_to_server.receiver, &pipes_.server_to_client.sender});
+      call_state_.emplace<MessageLoop>(
+          MessageLoop{&pipes_.server_to_client.receiver, std::move(promise)});
+      server_initial_metadata_
+          .emplace<PipeReceiverNextType<ServerMetadataHandle>>(
+              pipes_.server_initial_metadata.receiver.Next());
+    }
+    if (incoming_messages_ != nullptr) {
+      PollRecvMessage(incoming_messages_);
+    }
+    if (auto* p = absl::get_if<MessageLoop>(&call_state_)) {
+      if (absl::holds_alternative<ServerMetadataHandle>(
+              server_initial_metadata_)) {
+        PollSendMessage(p->outgoing_messages, nullptr);
+      }
+      auto poll = p->promise();
+      if (auto* r = absl::get_if<ServerMetadataHandle>(&poll)) {
+        if (grpc_call_trace.enabled()) {
+          gpr_log(GPR_INFO, "%s[connected] got trailing metadata %s; %s",
+                  Activity::current()->DebugTag().c_str(),
+                  (*r)->DebugString().c_str(), ActiveOpsString().c_str());
+        }
+        auto& completing = call_state_.emplace<Completing>();
+        completing.server_trailing_metadata = std::move(*r);
+        completing.on_complete =
+            MakeMemberClosure<ServerStream,
+                              &ServerStream::SendTrailingMetadataDone>(this);
+        completing.waker = Activity::current()->MakeOwningWaker();
+        auto& op = completing.send_trailing_metadata;
+        memset(&op, 0, sizeof(op));
+        op.payload = batch_payload();
+        op.on_complete = &completing.on_complete;
+        // If we've gotten initial server metadata, we can send trailing
+        // metadata.
+        // Otherwise we need to cancel the call.
+        // There could be an unlucky ordering, so we poll here to make sure.
+        if (poll_send_initial_metadata()) {
+          op.send_trailing_metadata = true;
+          batch_payload()->send_trailing_metadata.send_trailing_metadata =
+              completing.server_trailing_metadata.get();
+          batch_payload()->send_trailing_metadata.sent = &completing.sent;
+        } else {
+          op.cancel_stream = true;
+          const auto status_code =
+              completing.server_trailing_metadata->get(GrpcStatusMetadata())
+                  .value_or(GRPC_STATUS_UNKNOWN);
+          batch_payload()->cancel_stream.cancel_error = grpc_error_set_int(
+              absl::Status(static_cast<absl::StatusCode>(status_code),
+                           completing.server_trailing_metadata
+                               ->GetOrCreatePointer(GrpcMessageMetadata())
+                               ->as_string_view()),
+              StatusIntProperty::kRpcStatus, status_code);
+        }
+        SchedulePush(&op);
+      }
+    }
+    if (auto* p = absl::get_if<Complete>(&call_state_)) {
+      set_finished();
+      return std::move(p->result);
+    }
+    return Pending{};
+  }
+
+ private:
+  // Call state: we've asked the transport for initial metadata and are
+  // waiting for it before proceeding.
+  struct GettingInitialMetadata {
+    explicit GettingInitialMetadata(ServerStream* stream)
+        : recv_initial_metadata_ready(
+              MakeMemberClosure<ServerStream,
+                                &ServerStream::RecvInitialMetadataReady>(
+                  stream)) {}
+    // The batch we're using to get initial metadata.
+    grpc_transport_stream_op_batch recv_initial_metadata;
+    // Waker to re-enter the activity once the transport returns.
+    Waker recv_initial_metadata_ready_waker;
+    // Initial metadata storage for the transport.
+    ClientMetadataHandle client_initial_metadata =
+        GetContext<Arena>()->MakePooled<ClientMetadata>(GetContext<Arena>());
+    // Closure for the transport to call when it's ready.
+    grpc_closure recv_initial_metadata_ready;
+    // Next promise factory to use once we have initial metadata.
+    NextPromiseFactory next_promise_factory;
+  };
+
+  // Call state: transport has returned initial metadata, we're waiting to
+  // re-enter the activity to process it.
+  struct GotInitialMetadata {
+    ClientMetadataHandle client_initial_metadata;
+    NextPromiseFactory next_promise_factory;
+  };
+
+  // Call state: we're sending/receiving messages and processing the filter
+  // stack.
+  struct MessageLoop {
+    PipeReceiver<MessageHandle>* outgoing_messages;
+    ArenaPromise<ServerMetadataHandle> promise;
+  };
+
+  // Call state: promise stack has returned trailing metadata, we're sending it
+  // to the transport to communicate.
+  struct Completing {
+    ServerMetadataHandle server_trailing_metadata;
+    grpc_transport_stream_op_batch send_trailing_metadata;
+    grpc_closure on_complete;
+    bool sent = false;
+    Waker waker;
+  };
+
+  // Call state: server metadata has been communicated to the transport and sent
+  // to the client.
+  // The metadata will be returned down to the server call to tick the
+  // cancellation bit or not on the originating batch.
+  struct Complete {
+    ServerMetadataHandle result;
+  };
+
+  // Trailing metadata state: we've asked the transport for trailing metadata
+  // and are waiting for it before proceeding.
+  struct WaitingForTrailingMetadata {
+    ClientMetadataHandle result =
+        GetContext<Arena>()->MakePooled<ClientMetadata>(GetContext<Arena>());
+    grpc_transport_stream_op_batch recv_trailing_metadata;
+    grpc_closure recv_trailing_metadata_ready;
+    Waker waker;
+  };
+
+  // We've received trailing metadata from the transport - which indicates reads
+  // are closed.
+  // We convert to an absl::Status here and use that to drive a decision to
+  // cancel the call (on error) or not.
+  struct GotClientHalfClose {
+    absl::Status result;
+  };
+
+  void RecvInitialMetadataReady(absl::Status status) {
+    MutexLock lock(mu());
+    auto& getting = absl::get<GettingInitialMetadata>(call_state_);
+    auto waker = std::move(getting.recv_initial_metadata_ready_waker);
+    if (grpc_call_trace.enabled()) {
+      gpr_log(GPR_DEBUG, "%sGOT INITIAL METADATA: err=%s %s",
+              waker.ActivityDebugTag().c_str(), status.ToString().c_str(),
+              getting.client_initial_metadata->DebugString().c_str());
+    }
+    GotInitialMetadata got{std::move(getting.client_initial_metadata),
+                           std::move(getting.next_promise_factory)};
+    call_state_.emplace<GotInitialMetadata>(std::move(got));
+    waker.Wakeup();
+  }
+
+  void SendTrailingMetadataDone(absl::Status result) {
+    MutexLock lock(mu());
+    auto& completing = absl::get<Completing>(call_state_);
+    auto md = std::move(completing.server_trailing_metadata);
+    auto waker = std::move(completing.waker);
+    if (grpc_call_trace.enabled()) {
+      gpr_log(GPR_DEBUG, "%sSEND TRAILING METADATA DONE: err=%s sent=%s %s",
+              waker.ActivityDebugTag().c_str(), result.ToString().c_str(),
+              completing.sent ? "true" : "false", md->DebugString().c_str());
+    }
+    md->Set(GrpcStatusFromWire(), completing.sent);
+    if (!result.ok()) {
+      md->Clear();
+      md->Set(GrpcStatusMetadata(),
+              static_cast<grpc_status_code>(result.code()));
+      md->Set(GrpcMessageMetadata(), Slice::FromCopiedString(result.message()));
+      md->Set(GrpcStatusFromWire(), false);
+    }
+    call_state_.emplace<Complete>(Complete{std::move(md)});
+    waker.Wakeup();
+  }
+
+  std::string ActiveOpsString() const override
+      ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu()) {
+    std::vector<std::string> ops;
+    ops.push_back(absl::StrCat(
+        "call_state:",
+        Match(
+            call_state_,
+            [](const absl::monostate&) { return "absl::monostate"; },
+            [](const GettingInitialMetadata&) { return "GETTING"; },
+            [](const GotInitialMetadata&) { return "GOT"; },
+            [](const MessageLoop&) { return "RUNNING"; },
+            [](const Completing&) { return "COMPLETING"; },
+            [](const Complete&) { return "COMPLETE"; })));
+    ops.push_back(
+        absl::StrCat("client_trailing_metadata_state:",
+                     Match(
+                         client_trailing_metadata_state_,
+                         [](const absl::monostate&) -> std::string {
+                           return "absl::monostate";
+                         },
+                         [](const WaitingForTrailingMetadata&) -> std::string {
+                           return "WAITING";
+                         },
+                         [](const GotClientHalfClose& got) -> std::string {
+                           return absl::StrCat("GOT:", got.result.ToString());
+                         })));
+    // Send initial metadata
+    ops.push_back(absl::StrCat(
+        "server_initial_metadata_state:",
+        Match(
+            server_initial_metadata_,
+            [](const absl::monostate&) { return "absl::monostate"; },
+            [](const PipeReceiverNextType<ServerMetadataHandle>&) {
+              return "WAITING";
+            },
+            [](const ServerMetadataHandle&) { return "GOT"; })));
+    // Send message
+    std::string send_message_state = SendMessageString();
+    if (send_message_state != "WAITING") {
+      ops.push_back(absl::StrCat("send_message:", send_message_state));
+    }
+    // Receive message
+    std::string recv_message_state = RecvMessageString();
+    if (recv_message_state != "IDLE") {
+      ops.push_back(absl::StrCat("recv_message:", recv_message_state));
+    }
+    return absl::StrJoin(ops, " ");
+  }
+
+  void SendInitialMetadataDone() {}
+
+  void RecvTrailingMetadataReady(absl::Status error) {
+    MutexLock lock(mu());
+    auto& state =
+        absl::get<WaitingForTrailingMetadata>(client_trailing_metadata_state_);
+    if (grpc_call_trace.enabled()) {
+      gpr_log(GPR_INFO,
+              "%sRecvTrailingMetadataReady: error:%s metadata:%s state:%s",
+              state.waker.ActivityDebugTag().c_str(), error.ToString().c_str(),
+              state.result->DebugString().c_str(), ActiveOpsString().c_str());
+    }
+    auto waker = std::move(state.waker);
+    ServerMetadataHandle result = std::move(state.result);
+    if (error.ok()) {
+      auto* message = result->get_pointer(GrpcMessageMetadata());
+      error = absl::Status(
+          static_cast<absl::StatusCode>(
+              result->get(GrpcStatusMetadata()).value_or(GRPC_STATUS_UNKNOWN)),
+          message == nullptr ? "" : message->as_string_view());
+    }
+    client_trailing_metadata_state_.emplace<GotClientHalfClose>(
+        GotClientHalfClose{error});
+    waker.Wakeup();
+  }
+
+  struct Pipes {
+    Pipe<MessageHandle> server_to_client;
+    Pipe<MessageHandle> client_to_server;
+    Pipe<ServerMetadataHandle> server_initial_metadata;
+  };
+
+  using CallState =
+      absl::variant<absl::monostate, GettingInitialMetadata, GotInitialMetadata,
+                    MessageLoop, Completing, Complete>;
+  CallState call_state_ ABSL_GUARDED_BY(mu()) = absl::monostate{};
+  using ClientTrailingMetadataState =
+      absl::variant<absl::monostate, WaitingForTrailingMetadata,
+                    GotClientHalfClose>;
+  ClientTrailingMetadataState client_trailing_metadata_state_
+      ABSL_GUARDED_BY(mu()) = absl::monostate{};
+  absl::variant<absl::monostate, PipeReceiverNextType<ServerMetadataHandle>,
+                ServerMetadataHandle>
+      ABSL_GUARDED_BY(mu()) server_initial_metadata_ = absl::monostate{};
+  PipeSender<MessageHandle>* incoming_messages_ = nullptr;
+  grpc_transport_stream_op_batch send_initial_metadata_;
+  grpc_closure send_initial_metadata_done_ =
+      MakeMemberClosure<ServerStream, &ServerStream::SendInitialMetadataDone>(
+          this);
+  Pipes pipes_ ABSL_GUARDED_BY(mu());
+};
+
+class ServerConnectedCallPromise {
+ public:
+  ServerConnectedCallPromise(grpc_transport* transport,
+                             NextPromiseFactory next_promise_factory)
+      : impl_(GetContext<Arena>()->New<ServerStream>(
+            transport, std::move(next_promise_factory))) {}
+
+  ServerConnectedCallPromise(const ServerConnectedCallPromise&) = delete;
+  ServerConnectedCallPromise& operator=(const ServerConnectedCallPromise&) =
+      delete;
+  ServerConnectedCallPromise(ServerConnectedCallPromise&& other) noexcept
+      : impl_(std::exchange(other.impl_, nullptr)) {}
+  ServerConnectedCallPromise& operator=(
+      ServerConnectedCallPromise&& other) noexcept {
+    impl_ = std::move(other.impl_);
+    return *this;
+  }
+
+  static ArenaPromise<ServerMetadataHandle> Make(grpc_transport* transport,
+                                                 CallArgs,
+                                                 NextPromiseFactory next) {
+    return ServerConnectedCallPromise(transport, std::move(next));
+  }
+
+  Poll<ServerMetadataHandle> operator()() { return impl_->PollOnce(); }
+
+ private:
+  OrphanablePtr<ServerStream> impl_;
+};
+
 template <ArenaPromise<ServerMetadataHandle> (*make_call_promise)(
-    grpc_transport*, CallArgs)>
+    grpc_transport*, CallArgs, NextPromiseFactory)>
 grpc_channel_filter MakeConnectedFilter() {
   // Create a vtable that contains both the legacy call methods (for filter
   // stack based calls) and the new promise based method for creating promise
@@ -835,15 +1347,14 @@ grpc_channel_filter MakeConnectedFilter() {
   // and only if all the filters in the stack are promise based will the call
   // be promise based.
   return {
-    connected_channel_start_transport_stream_op_batch,
-        make_call_promise == nullptr
-            ? nullptr
-            : +[](grpc_channel_element* elem, CallArgs call_args,
-                 NextPromiseFactory) {
-                grpc_transport* transport =
-                    static_cast<channel_data*>(elem->channel_data)->transport;
-                return make_call_promise(transport, std::move(call_args));
-              },
+      connected_channel_start_transport_stream_op_batch,
+      [](grpc_channel_element* elem, CallArgs call_args,
+         NextPromiseFactory next) {
+        grpc_transport* transport =
+            static_cast<channel_data*>(elem->channel_data)->transport;
+        return make_call_promise(transport, std::move(call_args),
+                                 std::move(next));
+      },
       connected_channel_start_transport_op,
       sizeof(call_data),
       connected_channel_init_call_elem,
@@ -857,7 +1368,7 @@ grpc_channel_filter MakeConnectedFilter() {
         // and I'm not sure what that is yet.
         // This is only "safe" because call stacks place no additional data
         // after the last call element, and the last call element MUST be the
-        // connected channel. 
+        // connected channel.
         channel_stack->call_stack_size += grpc_transport_stream_size(
             static_cast<channel_data*>(elem->channel_data)->transport);
       },
@@ -868,7 +1379,7 @@ grpc_channel_filter MakeConnectedFilter() {
 }
 
 ArenaPromise<ServerMetadataHandle> MakeTransportCallPromise(
-    grpc_transport* transport, CallArgs call_args) {
+    grpc_transport* transport, CallArgs call_args, NextPromiseFactory) {
   return transport->vtable->make_call_promise(transport, std::move(call_args));
 }
 
@@ -878,7 +1389,8 @@ const grpc_channel_filter kPromiseBasedTransportFilter =
 const grpc_channel_filter kClientEmulatedFilter =
     MakeConnectedFilter<ClientConnectedCallPromise::Make>();
 
-const grpc_channel_filter kNoPromiseFilter = MakeConnectedFilter<nullptr>();
+const grpc_channel_filter kServerEmulatedFilter =
+    MakeConnectedFilter<ServerConnectedCallPromise::Make>();
 
 }  // namespace
 }  // namespace grpc_core
@@ -903,8 +1415,8 @@ bool grpc_add_connected_filter(grpc_core::ChannelStackBuilder* builder) {
     builder->AppendFilter(&grpc_core::kClientEmulatedFilter);
   } else {
     // Option 3: the transport does not support promise based calls, and we're
-    // on the server so we can't construct promise based calls just yet.
-    builder->AppendFilter(&grpc_core::kNoPromiseFilter);
+    // on the server so we use the server filter.
+    builder->AppendFilter(&grpc_core::kServerEmulatedFilter);
   }
   return true;
 }
diff --git a/src/core/lib/channel/promise_based_filter.cc b/src/core/lib/channel/promise_based_filter.cc
index ef5bc1d2989..fd334201a2e 100644
--- a/src/core/lib/channel/promise_based_filter.cc
+++ b/src/core/lib/channel/promise_based_filter.cc
@@ -24,6 +24,7 @@
 
 #include "absl/base/attributes.h"
 #include "absl/functional/function_ref.h"
+#include "absl/status/status.h"
 #include "absl/strings/str_cat.h"
 #include "absl/strings/str_format.h"
 #include "absl/strings/str_join.h"
@@ -37,6 +38,7 @@
 #include "src/core/lib/gprpp/manual_constructor.h"
 #include "src/core/lib/gprpp/status_helper.h"
 #include "src/core/lib/iomgr/error.h"
+#include "src/core/lib/promise/detail/basic_seq.h"
 #include "src/core/lib/slice/slice.h"
 
 extern grpc_core::TraceFlag grpc_trace_channel;
@@ -73,24 +75,28 @@ absl::Status StatusFromMetadata(const ServerMetadata& md) {
 ///////////////////////////////////////////////////////////////////////////////
 // BaseCallData
 
-BaseCallData::BaseCallData(grpc_call_element* elem,
-                           const grpc_call_element_args* args, uint8_t flags)
+BaseCallData::BaseCallData(
+    grpc_call_element* elem, const grpc_call_element_args* args, uint8_t flags,
+    absl::FunctionRef<Interceptor*()> make_send_interceptor,
+    absl::FunctionRef<Interceptor*()> make_recv_interceptor)
     : call_stack_(args->call_stack),
       elem_(elem),
       arena_(args->arena),
       call_combiner_(args->call_combiner),
       deadline_(args->deadline),
       context_(args->context),
-      server_initial_metadata_latch_(
+      server_initial_metadata_pipe_(
           flags & kFilterExaminesServerInitialMetadata
-              ? arena_->New<Latch<ServerMetadata*>>()
+              ? arena_->New<Pipe<ServerMetadataHandle>>(arena_)
+              : nullptr),
+      send_message_(
+          flags & kFilterExaminesOutboundMessages
+              ? arena_->New<SendMessage>(this, make_send_interceptor())
+              : nullptr),
+      receive_message_(
+          flags & kFilterExaminesInboundMessages
+              ? arena_->New<ReceiveMessage>(this, make_recv_interceptor())
               : nullptr),
-      send_message_(flags & kFilterExaminesOutboundMessages
-                        ? arena_->New<SendMessage>(this)
-                        : nullptr),
-      receive_message_(flags & kFilterExaminesInboundMessages
-                           ? arena_->New<ReceiveMessage>(this)
-                           : nullptr),
       event_engine_(
           static_cast<ChannelFilter*>(elem->channel_data)
               ->hack_until_per_channel_stack_event_engines_land_get_event_engine()) {
@@ -104,8 +110,8 @@ BaseCallData::~BaseCallData() {
     if (receive_message_ != nullptr) {
       receive_message_->~ReceiveMessage();
     }
-    if (server_initial_metadata_latch_ != nullptr) {
-      server_initial_metadata_latch_->~Latch();
+    if (server_initial_metadata_pipe_ != nullptr) {
+      server_initial_metadata_pipe_->~Pipe();
     }
   });
 }
@@ -197,7 +203,14 @@ void BaseCallData::CapturedBatch::ResumeWith(Flusher* releaser) {
   auto* batch = std::exchange(batch_, nullptr);
   GPR_ASSERT(batch != nullptr);
   uintptr_t& refcnt = *RefCountField(batch);
-  if (refcnt == 0) return;  // refcnt==0 ==> cancelled
+  if (refcnt == 0) {
+    // refcnt==0 ==> cancelled
+    if (grpc_trace_channel.enabled()) {
+      gpr_log(GPR_INFO, "%sRESUME BATCH REQUEST CANCELLED",
+              Activity::current()->DebugTag().c_str());
+    }
+    return;
+  }
   if (--refcnt == 0) {
     releaser->Resume(batch);
   }
@@ -220,6 +233,10 @@ void BaseCallData::CapturedBatch::CancelWith(grpc_error_handle error,
   uintptr_t& refcnt = *RefCountField(batch);
   if (refcnt == 0) {
     // refcnt==0 ==> cancelled
+    if (grpc_trace_channel.enabled()) {
+      gpr_log(GPR_INFO, "%sCANCEL BATCH REQUEST ALREADY CANCELLED",
+              Activity::current()->DebugTag().c_str());
+    }
     return;
   }
   refcnt = 0;
@@ -330,12 +347,13 @@ void BaseCallData::SendMessage::StartOp(CapturedBatch batch) {
   intercepted_on_complete_ = std::exchange(batch_->on_complete, &on_complete_);
 }
 
-void BaseCallData::SendMessage::GotPipe(PipeReceiver<MessageHandle>* receiver) {
+template <typename T>
+void BaseCallData::SendMessage::GotPipe(T* pipe_end) {
   if (grpc_trace_channel.enabled()) {
     gpr_log(GPR_INFO, "%s SendMessage.GotPipe st=%s", base_->LogTag().c_str(),
             StateString(state_));
   }
-  GPR_ASSERT(receiver != nullptr);
+  GPR_ASSERT(pipe_end != nullptr);
   switch (state_) {
     case State::kInitial:
       state_ = State::kIdle;
@@ -355,7 +373,7 @@ void BaseCallData::SendMessage::GotPipe(PipeReceiver<MessageHandle>* receiver) {
     case State::kCancelledButNotYetPolled:
       return;
   }
-  receiver_ = receiver;
+  interceptor_->GotPipe(pipe_end);
 }
 
 bool BaseCallData::SendMessage::IsIdle() const {
@@ -399,6 +417,7 @@ void BaseCallData::SendMessage::OnComplete(absl::Status status) {
     case State::kForwardedBatch:
       completed_status_ = status;
       state_ = State::kBatchCompleted;
+      ScopedContext ctx(base_);
       base_->WakeInsideCombiner(&flusher);
       break;
   }
@@ -442,7 +461,8 @@ void BaseCallData::SendMessage::Done(const ServerMetadata& metadata,
   }
 }
 
-void BaseCallData::SendMessage::WakeInsideCombiner(Flusher* flusher) {
+void BaseCallData::SendMessage::WakeInsideCombiner(Flusher* flusher,
+                                                   bool allow_push_to_pipe) {
   if (grpc_trace_channel.enabled()) {
     gpr_log(GPR_INFO, "%s SendMessage.WakeInsideCombiner st=%s%s",
             base_->LogTag().c_str(), StateString(state_),
@@ -454,21 +474,23 @@ void BaseCallData::SendMessage::WakeInsideCombiner(Flusher* flusher) {
     case State::kInitial:
     case State::kIdle:
     case State::kGotBatchNoPipe:
-    case State::kForwardedBatch:
     case State::kCancelled:
       break;
     case State::kCancelledButNotYetPolled:
-      pipe_.sender.Close();
+      interceptor()->Push()->Close();
       state_ = State::kCancelled;
       break;
-    case State::kGotBatch: {
-      state_ = State::kPushedToPipe;
-      auto message = GetContext<Arena>()->MakePooled<Message>();
-      message->payload()->Swap(batch_->payload->send_message.send_message);
-      message->mutable_flags() = batch_->payload->send_message.flags;
-      push_ = pipe_.sender.Push(std::move(message));
-      next_ = receiver_->Next();
-    }
+    case State::kGotBatch:
+      if (allow_push_to_pipe) {
+        state_ = State::kPushedToPipe;
+        auto message = GetContext<Arena>()->MakePooled<Message>();
+        message->payload()->Swap(batch_->payload->send_message.send_message);
+        message->mutable_flags() = batch_->payload->send_message.flags;
+        push_ = interceptor()->Push()->Push(std::move(message));
+        next_.emplace(interceptor()->Pull()->Next());
+      } else {
+        break;
+      }
       ABSL_FALLTHROUGH_INTENDED;
     case State::kPushedToPipe: {
       GPR_ASSERT(push_.has_value());
@@ -499,25 +521,25 @@ void BaseCallData::SendMessage::WakeInsideCombiner(Flusher* flusher) {
         batch_->payload->send_message.flags = (**p)->flags();
         state_ = State::kForwardedBatch;
         batch_.ResumeWith(flusher);
-        next_result_ = std::move(*p);
         next_.reset();
+        if (!absl::holds_alternative<Pending>((*push_)())) push_.reset();
       }
     } break;
+    case State::kForwardedBatch:
+      if (push_.has_value() && !absl::holds_alternative<Pending>((*push_)())) {
+        push_.reset();
+      }
+      break;
     case State::kBatchCompleted:
-      next_result_.reset();
-      // We've cleared out the NextResult on the pipe from promise to us, but
-      // there's also the pipe from us to the promise (so that the promise can
-      // intercept the sent messages). The push promise here is pushing into the
-      // latter pipe, and so we need to keep polling it until it's done, which
-      // depending on what happens inside the promise may take some time.
-      if (absl::holds_alternative<Pending>((*push_)())) break;
+      if (push_.has_value() && absl::holds_alternative<Pending>((*push_)())) {
+        break;
+      }
       if (completed_status_.ok()) {
         state_ = State::kIdle;
         Activity::current()->ForceImmediateRepoll();
       } else {
         state_ = State::kCancelled;
       }
-      push_.reset();
       flusher->AddClosure(intercepted_on_complete_, completed_status_,
                           "batch_completed");
       break;
@@ -557,6 +579,8 @@ const char* BaseCallData::ReceiveMessage::StateString(State state) {
       return "COMPLETED_WHILE_PULLED_FROM_PIPE";
     case State::kCompletedWhilePushedToPipe:
       return "COMPLETED_WHILE_PUSHED_TO_PIPE";
+    case State::kCompletedWhileBatchCompleted:
+      return "COMPLETED_WHILE_BATCH_COMPLETED";
   }
   return "UNKNOWN";
 }
@@ -579,6 +603,7 @@ void BaseCallData::ReceiveMessage::StartOp(CapturedBatch& batch) {
     case State::kForwardedBatchNoPipe:
     case State::kBatchCompleted:
     case State::kBatchCompletedNoPipe:
+    case State::kCompletedWhileBatchCompleted:
     case State::kPushedToPipe:
     case State::kPulledFromPipe:
     case State::kCompletedWhilePulledFromPipe:
@@ -598,7 +623,8 @@ void BaseCallData::ReceiveMessage::StartOp(CapturedBatch& batch) {
       batch->payload->recv_message.recv_message_ready, &on_complete_);
 }
 
-void BaseCallData::ReceiveMessage::GotPipe(PipeSender<MessageHandle>* sender) {
+template <typename T>
+void BaseCallData::ReceiveMessage::GotPipe(T* pipe_end) {
   if (grpc_trace_channel.enabled()) {
     gpr_log(GPR_INFO, "%s ReceiveMessage.GotPipe st=%s",
             base_->LogTag().c_str(), StateString(state_));
@@ -621,6 +647,7 @@ void BaseCallData::ReceiveMessage::GotPipe(PipeSender<MessageHandle>* sender) {
     case State::kPulledFromPipe:
     case State::kCompletedWhilePulledFromPipe:
     case State::kCompletedWhilePushedToPipe:
+    case State::kCompletedWhileBatchCompleted:
     case State::kCancelledWhilstForwarding:
     case State::kCancelledWhilstIdle:
     case State::kBatchCompletedButCancelled:
@@ -628,7 +655,7 @@ void BaseCallData::ReceiveMessage::GotPipe(PipeSender<MessageHandle>* sender) {
     case State::kCancelled:
       return;
   }
-  sender_ = sender;
+  interceptor()->GotPipe(pipe_end);
 }
 
 void BaseCallData::ReceiveMessage::OnComplete(absl::Status status) {
@@ -643,6 +670,7 @@ void BaseCallData::ReceiveMessage::OnComplete(absl::Status status) {
     case State::kPushedToPipe:
     case State::kPulledFromPipe:
     case State::kBatchCompleted:
+    case State::kCompletedWhileBatchCompleted:
     case State::kBatchCompletedNoPipe:
     case State::kCancelled:
     case State::kBatchCompletedButCancelled:
@@ -684,6 +712,10 @@ void BaseCallData::ReceiveMessage::Done(const ServerMetadata& metadata,
     case State::kForwardedBatchNoPipe:
       state_ = State::kCancelledWhilstForwarding;
       break;
+    case State::kCompletedWhileBatchCompleted:
+    case State::kBatchCompleted:
+      state_ = State::kCompletedWhileBatchCompleted;
+      break;
     case State::kCompletedWhilePulledFromPipe:
     case State::kCompletedWhilePushedToPipe:
     case State::kPulledFromPipe:
@@ -705,7 +737,6 @@ void BaseCallData::ReceiveMessage::Done(const ServerMetadata& metadata,
         state_ = State::kCancelled;
       }
     } break;
-    case State::kBatchCompleted:
     case State::kBatchCompletedNoPipe:
     case State::kBatchCompletedButCancelled:
       Crash(absl::StrFormat("ILLEGAL STATE: %s", StateString(state_)));
@@ -716,12 +747,15 @@ void BaseCallData::ReceiveMessage::Done(const ServerMetadata& metadata,
   }
 }
 
-void BaseCallData::ReceiveMessage::WakeInsideCombiner(Flusher* flusher) {
+void BaseCallData::ReceiveMessage::WakeInsideCombiner(Flusher* flusher,
+                                                      bool allow_push_to_pipe) {
   if (grpc_trace_channel.enabled()) {
     gpr_log(GPR_INFO,
-            "%s ReceiveMessage.WakeInsideCombiner st=%s push?=%s next?=%s",
+            "%s ReceiveMessage.WakeInsideCombiner st=%s push?=%s next?=%s "
+            "allow_push_to_pipe=%s",
             base_->LogTag().c_str(), StateString(state_),
-            push_.has_value() ? "yes" : "no", next_.has_value() ? "yes" : "no");
+            push_.has_value() ? "yes" : "no", next_.has_value() ? "yes" : "no",
+            allow_push_to_pipe ? "yes" : "no");
   }
   switch (state_) {
     case State::kInitial:
@@ -733,31 +767,38 @@ void BaseCallData::ReceiveMessage::WakeInsideCombiner(Flusher* flusher) {
     case State::kBatchCompletedNoPipe:
       break;
     case State::kCancelledWhilstIdle:
-      sender_->Close();
+      interceptor_->Push()->Close();
       state_ = State::kCancelled;
       break;
     case State::kBatchCompletedButCancelled:
-      sender_->Close();
+    case State::kCompletedWhileBatchCompleted:
+      interceptor()->Push()->Close();
       state_ = State::kCancelled;
       flusher->AddClosure(std::exchange(intercepted_on_complete_, nullptr),
                           completed_status_, "recv_message");
       break;
     case State::kBatchCompleted:
       if (completed_status_.ok() && intercepted_slice_buffer_->has_value()) {
-        state_ = State::kPushedToPipe;
+        if (!allow_push_to_pipe) break;
+        if (state_ == State::kBatchCompleted) {
+          state_ = State::kPushedToPipe;
+        } else {
+          state_ = State::kCompletedWhilePushedToPipe;
+        }
         auto message = GetContext<Arena>()->MakePooled<Message>();
         message->payload()->Swap(&**intercepted_slice_buffer_);
         message->mutable_flags() = *intercepted_flags_;
-        push_ = sender_->Push(std::move(message));
-        next_ = pipe_.receiver.Next();
+        push_ = interceptor()->Push()->Push(std::move(message));
+        next_.emplace(interceptor()->Pull()->Next());
       } else {
-        sender_->Close();
+        interceptor()->Push()->Close();
         state_ = State::kCancelled;
         flusher->AddClosure(std::exchange(intercepted_on_complete_, nullptr),
                             completed_status_, "recv_message");
         break;
       }
-      GPR_ASSERT(state_ == State::kPushedToPipe);
+      GPR_ASSERT(state_ == State::kPushedToPipe ||
+                 state_ == State::kCompletedWhilePushedToPipe);
       ABSL_FALLTHROUGH_INTENDED;
     case State::kCompletedWhilePushedToPipe:
     case State::kPushedToPipe: {
@@ -777,12 +818,6 @@ void BaseCallData::ReceiveMessage::WakeInsideCombiner(Flusher* flusher) {
       GPR_ASSERT(next_.has_value());
       auto r_next = (*next_)();
       if (auto* p = absl::get_if<NextResult<MessageHandle>>(&r_next)) {
-        if (grpc_trace_channel.enabled()) {
-          gpr_log(GPR_INFO,
-                  "%s ReceiveMessage.WakeInsideCombiner next complete: %s",
-                  base_->LogTag().c_str(),
-                  p->has_value() ? "got message" : "end of stream");
-        }
         next_.reset();
         if (p->has_value()) {
           *intercepted_slice_buffer_ = std::move(*(**p)->payload());
@@ -796,6 +831,18 @@ void BaseCallData::ReceiveMessage::WakeInsideCombiner(Flusher* flusher) {
           *intercepted_slice_buffer_ = absl::nullopt;
           *intercepted_flags_ = 0;
           state_ = State::kCancelled;
+          flusher->AddClosure(
+              std::exchange(intercepted_on_complete_, nullptr),
+              p->cancelled() ? absl::CancelledError() : absl::OkStatus(),
+              "recv_message");
+        }
+        if (grpc_trace_channel.enabled()) {
+          gpr_log(GPR_INFO,
+                  "%s ReceiveMessage.WakeInsideCombiner next complete: %s "
+                  "new_state=%s",
+                  base_->LogTag().c_str(),
+                  p->has_value() ? "got message" : "end of stream",
+                  StateString(state_));
         }
       }
     }
@@ -814,7 +861,7 @@ void BaseCallData::ReceiveMessage::WakeInsideCombiner(Flusher* flusher) {
                   base_->LogTag().c_str());
         }
         if (state_ == State::kCompletedWhilePulledFromPipe) {
-          sender_->Close();
+          interceptor()->Push()->Close();
           state_ = State::kCancelled;
         } else {
           state_ = State::kIdle;
@@ -836,56 +883,76 @@ struct ClientCallData::RecvInitialMetadata final {
     // Initial state; no op seen
     kInitial,
     // No op seen, but we have a latch that would like to modify it when we do
-    kGotLatch,
+    kGotPipe,
     // Responded to trailing metadata prior to getting a recv_initial_metadata
     kRespondedToTrailingMetadataPriorToHook,
     // Hooked, no latch yet
-    kHookedWaitingForLatch,
+    kHookedWaitingForPipe,
     // Hooked, latch seen
-    kHookedAndGotLatch,
+    kHookedAndGotPipe,
     // Got the callback, haven't set latch yet
-    kCompleteWaitingForLatch,
+    kCompleteWaitingForPipe,
     // Got the callback and got the latch
-    kCompleteAndGotLatch,
+    kCompleteAndGotPipe,
     // Got the callback and set the latch
-    kCompleteAndSetLatch,
+    kCompleteAndPushedToPipe,
     // Called the original callback
     kResponded,
     // Called the original callback with an error: still need to set the latch
-    kRespondedButNeedToSetLatch,
+    kRespondedButNeedToClosePipe,
   };
 
   State state = kInitial;
   grpc_closure* original_on_ready = nullptr;
   grpc_closure on_ready;
   grpc_metadata_batch* metadata = nullptr;
-  Latch<ServerMetadata*>* server_initial_metadata_publisher = nullptr;
+  PipeSender<ServerMetadataHandle>* server_initial_metadata_publisher = nullptr;
+  absl::optional<PipeSender<ServerMetadataHandle>::PushType> metadata_push_;
+  absl::optional<PipeReceiverNextType<ServerMetadataHandle>> metadata_next_;
 
   static const char* StateString(State state) {
     switch (state) {
       case kInitial:
         return "INITIAL";
-      case kGotLatch:
-        return "GOT_LATCH";
+      case kGotPipe:
+        return "GOT_PIPE";
       case kRespondedToTrailingMetadataPriorToHook:
         return "RESPONDED_TO_TRAILING_METADATA_PRIOR_TO_HOOK";
-      case kHookedWaitingForLatch:
-        return "HOOKED_WAITING_FOR_LATCH";
-      case kHookedAndGotLatch:
-        return "HOOKED_AND_GOT_LATCH";
-      case kCompleteWaitingForLatch:
-        return "COMPLETE_WAITING_FOR_LATCH";
-      case kCompleteAndGotLatch:
-        return "COMPLETE_AND_GOT_LATCH";
-      case kCompleteAndSetLatch:
-        return "COMPLETE_AND_SET_LATCH";
+      case kHookedWaitingForPipe:
+        return "HOOKED_WAITING_FOR_PIPE";
+      case kHookedAndGotPipe:
+        return "HOOKED_AND_GOT_PIPE";
+      case kCompleteWaitingForPipe:
+        return "COMPLETE_WAITING_FOR_PIPE";
+      case kCompleteAndGotPipe:
+        return "COMPLETE_AND_GOT_PIPE";
+      case kCompleteAndPushedToPipe:
+        return "COMPLETE_AND_PUSHED_TO_PIPE";
       case kResponded:
         return "RESPONDED";
-      case kRespondedButNeedToSetLatch:
-        return "RESPONDED_BUT_NEED_TO_SET_LATCH";
+      case kRespondedButNeedToClosePipe:
+        return "RESPONDED_BUT_NEED_TO_CLOSE_PIPE";
     }
     return "UNKNOWN";
   }
+
+  bool AllowRecvMessage() const {
+    switch (state) {
+      case kInitial:
+      case kGotPipe:
+      case kHookedWaitingForPipe:
+      case kHookedAndGotPipe:
+      case kCompleteWaitingForPipe:
+      case kCompleteAndGotPipe:
+      case kCompleteAndPushedToPipe:
+      case kRespondedToTrailingMetadataPriorToHook:
+        return false;
+      case kResponded:
+      case kRespondedButNeedToClosePipe:
+        return true;
+    }
+    GPR_UNREACHABLE_CODE(return false);
+  }
 };
 
 class ClientCallData::PollContext {
@@ -903,6 +970,7 @@ class ClientCallData::PollContext {
   PollContext& operator=(const PollContext&) = delete;
 
   void Run() {
+    GPR_DEBUG_ASSERT(HasContext<Arena>());
     if (grpc_trace_channel.enabled()) {
       gpr_log(GPR_INFO, "%s ClientCallData.PollContext.Run %s",
               self_->LogTag().c_str(), self_->DebugString().c_str());
@@ -910,43 +978,69 @@ class ClientCallData::PollContext {
     GPR_ASSERT(have_scoped_activity_);
     repoll_ = false;
     if (self_->send_message() != nullptr) {
-      self_->send_message()->WakeInsideCombiner(flusher_);
+      self_->send_message()->WakeInsideCombiner(flusher_, true);
     }
     if (self_->receive_message() != nullptr) {
-      self_->receive_message()->WakeInsideCombiner(flusher_);
+      self_->receive_message()->WakeInsideCombiner(
+          flusher_, self_->recv_initial_metadata_ == nullptr
+                        ? true
+                        : self_->recv_initial_metadata_->AllowRecvMessage());
     }
-    if (self_->server_initial_metadata_latch() != nullptr) {
+    if (self_->server_initial_metadata_pipe() != nullptr) {
+      if (self_->recv_initial_metadata_->metadata_push_.has_value()) {
+        if (!absl::holds_alternative<Pending>(
+                (*self_->recv_initial_metadata_->metadata_push_)())) {
+          self_->recv_initial_metadata_->metadata_push_.reset();
+        }
+      }
       switch (self_->recv_initial_metadata_->state) {
         case RecvInitialMetadata::kInitial:
-        case RecvInitialMetadata::kGotLatch:
-        case RecvInitialMetadata::kHookedWaitingForLatch:
-        case RecvInitialMetadata::kHookedAndGotLatch:
-        case RecvInitialMetadata::kCompleteWaitingForLatch:
+        case RecvInitialMetadata::kGotPipe:
+        case RecvInitialMetadata::kHookedWaitingForPipe:
+        case RecvInitialMetadata::kHookedAndGotPipe:
+        case RecvInitialMetadata::kCompleteWaitingForPipe:
         case RecvInitialMetadata::kResponded:
         case RecvInitialMetadata::kRespondedToTrailingMetadataPriorToHook:
           break;
-        case RecvInitialMetadata::kRespondedButNeedToSetLatch:
-          self_->recv_initial_metadata_->server_initial_metadata_publisher->Set(
-              nullptr);
+        case RecvInitialMetadata::kRespondedButNeedToClosePipe:
+          self_->recv_initial_metadata_->server_initial_metadata_publisher
+              ->Close();
           self_->recv_initial_metadata_->state =
               RecvInitialMetadata::kResponded;
           break;
-        case RecvInitialMetadata::kCompleteAndGotLatch:
+        case RecvInitialMetadata::kCompleteAndGotPipe:
           self_->recv_initial_metadata_->state =
-              RecvInitialMetadata::kCompleteAndSetLatch;
-          self_->recv_initial_metadata_->server_initial_metadata_publisher->Set(
-              self_->recv_initial_metadata_->metadata);
+              RecvInitialMetadata::kCompleteAndPushedToPipe;
+          GPR_ASSERT(
+              !self_->recv_initial_metadata_->metadata_push_.has_value());
+          GPR_ASSERT(
+              !self_->recv_initial_metadata_->metadata_next_.has_value());
+          self_->recv_initial_metadata_->metadata_push_.emplace(
+              self_->recv_initial_metadata_->server_initial_metadata_publisher
+                  ->Push(ServerMetadataHandle(
+                      self_->recv_initial_metadata_->metadata,
+                      Arena::PooledDeleter(nullptr))));
+          repoll_ = true;  // ensure Push() gets polled.
+          self_->recv_initial_metadata_->metadata_next_.emplace(
+              self_->server_initial_metadata_pipe()->receiver.Next());
           ABSL_FALLTHROUGH_INTENDED;
-        case RecvInitialMetadata::kCompleteAndSetLatch: {
-          Poll<ServerMetadata**> p =
-              self_->server_initial_metadata_latch()->Wait()();
-          if (ServerMetadata*** ppp = absl::get_if<ServerMetadata**>(&p)) {
-            ServerMetadata* md = **ppp;
-            if (self_->recv_initial_metadata_->metadata != md) {
-              *self_->recv_initial_metadata_->metadata = std::move(*md);
+        case RecvInitialMetadata::kCompleteAndPushedToPipe: {
+          GPR_ASSERT(self_->recv_initial_metadata_->metadata_next_.has_value());
+          Poll<NextResult<ServerMetadataHandle>> p =
+              (*self_->recv_initial_metadata_->metadata_next_)();
+          if (NextResult<ServerMetadataHandle>* nr =
+                  absl::get_if<kPollReadyIdx>(&p)) {
+            if (nr->has_value()) {
+              ServerMetadataHandle md = std::move(nr->value());
+              if (self_->recv_initial_metadata_->metadata != md.get()) {
+                *self_->recv_initial_metadata_->metadata = std::move(*md);
+              }
+            } else {
+              self_->recv_initial_metadata_->metadata->Clear();
             }
             self_->recv_initial_metadata_->state =
                 RecvInitialMetadata::kResponded;
+            repoll_ = true;
             flusher_->AddClosure(
                 std::exchange(self_->recv_initial_metadata_->original_on_ready,
                               nullptr),
@@ -992,25 +1086,25 @@ class ClientCallData::PollContext {
             if (self_->recv_initial_metadata_ != nullptr) {
               switch (self_->recv_initial_metadata_->state) {
                 case RecvInitialMetadata::kInitial:
-                case RecvInitialMetadata::kGotLatch:
+                case RecvInitialMetadata::kGotPipe:
                   self_->recv_initial_metadata_->state = RecvInitialMetadata::
                       kRespondedToTrailingMetadataPriorToHook;
                   break;
                 case RecvInitialMetadata::
                     kRespondedToTrailingMetadataPriorToHook:
-                case RecvInitialMetadata::kRespondedButNeedToSetLatch:
+                case RecvInitialMetadata::kRespondedButNeedToClosePipe:
                   Crash(absl::StrFormat("ILLEGAL STATE: %s",
                                         RecvInitialMetadata::StateString(
                                             self_->recv_initial_metadata_
                                                 ->state)));  // not reachable
                   break;
-                case RecvInitialMetadata::kHookedWaitingForLatch:
-                case RecvInitialMetadata::kHookedAndGotLatch:
+                case RecvInitialMetadata::kHookedWaitingForPipe:
+                case RecvInitialMetadata::kHookedAndGotPipe:
                 case RecvInitialMetadata::kResponded:
-                case RecvInitialMetadata::kCompleteAndGotLatch:
-                case RecvInitialMetadata::kCompleteAndSetLatch:
+                case RecvInitialMetadata::kCompleteAndGotPipe:
+                case RecvInitialMetadata::kCompleteAndPushedToPipe:
                   break;
-                case RecvInitialMetadata::kCompleteWaitingForLatch:
+                case RecvInitialMetadata::kCompleteWaitingForPipe:
                   self_->recv_initial_metadata_->state =
                       RecvInitialMetadata::kResponded;
                   flusher_->AddClosure(
@@ -1027,25 +1121,25 @@ class ClientCallData::PollContext {
             if (self_->recv_initial_metadata_ != nullptr) {
               switch (self_->recv_initial_metadata_->state) {
                 case RecvInitialMetadata::kInitial:
-                case RecvInitialMetadata::kGotLatch:
+                case RecvInitialMetadata::kGotPipe:
                   self_->recv_initial_metadata_->state = RecvInitialMetadata::
                       kRespondedToTrailingMetadataPriorToHook;
                   break;
-                case RecvInitialMetadata::kHookedWaitingForLatch:
-                case RecvInitialMetadata::kHookedAndGotLatch:
+                case RecvInitialMetadata::kHookedWaitingForPipe:
+                case RecvInitialMetadata::kHookedAndGotPipe:
                 case RecvInitialMetadata::kResponded:
                   break;
                 case RecvInitialMetadata::
                     kRespondedToTrailingMetadataPriorToHook:
-                case RecvInitialMetadata::kRespondedButNeedToSetLatch:
+                case RecvInitialMetadata::kRespondedButNeedToClosePipe:
                   Crash(absl::StrFormat("ILLEGAL STATE: %s",
                                         RecvInitialMetadata::StateString(
                                             self_->recv_initial_metadata_
                                                 ->state)));  // not reachable
                   break;
-                case RecvInitialMetadata::kCompleteWaitingForLatch:
-                case RecvInitialMetadata::kCompleteAndGotLatch:
-                case RecvInitialMetadata::kCompleteAndSetLatch:
+                case RecvInitialMetadata::kCompleteWaitingForPipe:
+                case RecvInitialMetadata::kCompleteAndGotPipe:
+                case RecvInitialMetadata::kCompleteAndPushedToPipe:
                   self_->recv_initial_metadata_->state =
                       RecvInitialMetadata::kResponded;
                   flusher_->AddClosure(
@@ -1110,6 +1204,7 @@ class ClientCallData::PollContext {
       auto run = [](void* p, grpc_error_handle) {
         auto* next_poll = static_cast<NextPoll*>(p);
         {
+          ScopedContext ctx(next_poll->call_data);
           Flusher flusher(next_poll->call_data);
           next_poll->call_data->WakeInsideCombiner(&flusher);
         }
@@ -1144,11 +1239,16 @@ class ClientCallData::PollContext {
 ClientCallData::ClientCallData(grpc_call_element* elem,
                                const grpc_call_element_args* args,
                                uint8_t flags)
-    : BaseCallData(elem, args, flags) {
+    : BaseCallData(
+          elem, args, flags,
+          [args]() {
+            return args->arena->New<ReceiveInterceptor>(args->arena);
+          },
+          [args]() { return args->arena->New<SendInterceptor>(args->arena); }) {
   GRPC_CLOSURE_INIT(&recv_trailing_metadata_ready_,
                     RecvTrailingMetadataReadyCallback, this,
                     grpc_schedule_on_exec_ctx);
-  if (server_initial_metadata_latch() != nullptr) {
+  if (server_initial_metadata_pipe() != nullptr) {
     recv_initial_metadata_ = arena()->New<RecvInitialMetadata>();
   }
 }
@@ -1211,7 +1311,7 @@ std::string ClientCallData::DebugString() const {
       " sent_initial_state=", StateString(send_initial_state_),
       " recv_trailing_state=", StateString(recv_trailing_state_), " captured={",
       absl::StrJoin(captured, ","), "}",
-      server_initial_metadata_latch() == nullptr
+      server_initial_metadata_pipe() == nullptr
           ? ""
           : absl::StrCat(" recv_initial_metadata=",
                          RecvInitialMetadata::StateString(
@@ -1253,21 +1353,21 @@ void ClientCallData::StartBatch(grpc_transport_stream_op_batch* b) {
     switch (recv_initial_metadata_->state) {
       case RecvInitialMetadata::kInitial:
         recv_initial_metadata_->state =
-            RecvInitialMetadata::kHookedWaitingForLatch;
+            RecvInitialMetadata::kHookedWaitingForPipe;
         break;
-      case RecvInitialMetadata::kGotLatch:
-        recv_initial_metadata_->state = RecvInitialMetadata::kHookedAndGotLatch;
+      case RecvInitialMetadata::kGotPipe:
+        recv_initial_metadata_->state = RecvInitialMetadata::kHookedAndGotPipe;
         break;
       case RecvInitialMetadata::kRespondedToTrailingMetadataPriorToHook:
         hook = false;
         break;
-      case RecvInitialMetadata::kHookedWaitingForLatch:
-      case RecvInitialMetadata::kHookedAndGotLatch:
-      case RecvInitialMetadata::kCompleteWaitingForLatch:
-      case RecvInitialMetadata::kCompleteAndGotLatch:
-      case RecvInitialMetadata::kCompleteAndSetLatch:
+      case RecvInitialMetadata::kHookedWaitingForPipe:
+      case RecvInitialMetadata::kHookedAndGotPipe:
+      case RecvInitialMetadata::kCompleteWaitingForPipe:
+      case RecvInitialMetadata::kCompleteAndGotPipe:
+      case RecvInitialMetadata::kCompleteAndPushedToPipe:
       case RecvInitialMetadata::kResponded:
-      case RecvInitialMetadata::kRespondedButNeedToSetLatch:
+      case RecvInitialMetadata::kRespondedButNeedToClosePipe:
         Crash(absl::StrFormat(
             "ILLEGAL STATE: %s",
             RecvInitialMetadata::StateString(
@@ -1371,9 +1471,9 @@ void ClientCallData::Cancel(grpc_error_handle error, Flusher* flusher) {
   }
   if (recv_initial_metadata_ != nullptr) {
     switch (recv_initial_metadata_->state) {
-      case RecvInitialMetadata::kCompleteWaitingForLatch:
-      case RecvInitialMetadata::kCompleteAndGotLatch:
-      case RecvInitialMetadata::kCompleteAndSetLatch:
+      case RecvInitialMetadata::kCompleteWaitingForPipe:
+      case RecvInitialMetadata::kCompleteAndGotPipe:
+      case RecvInitialMetadata::kCompleteAndPushedToPipe:
         recv_initial_metadata_->state = RecvInitialMetadata::kResponded;
         GRPC_CALL_COMBINER_START(
             call_combiner(),
@@ -1381,13 +1481,13 @@ void ClientCallData::Cancel(grpc_error_handle error, Flusher* flusher) {
             error, "propagate cancellation");
         break;
       case RecvInitialMetadata::kInitial:
-      case RecvInitialMetadata::kGotLatch:
+      case RecvInitialMetadata::kGotPipe:
       case RecvInitialMetadata::kRespondedToTrailingMetadataPriorToHook:
-      case RecvInitialMetadata::kHookedWaitingForLatch:
-      case RecvInitialMetadata::kHookedAndGotLatch:
+      case RecvInitialMetadata::kHookedWaitingForPipe:
+      case RecvInitialMetadata::kHookedAndGotPipe:
       case RecvInitialMetadata::kResponded:
         break;
-      case RecvInitialMetadata::kRespondedButNeedToSetLatch:
+      case RecvInitialMetadata::kRespondedButNeedToClosePipe:
         Crash(absl::StrFormat(
             "ILLEGAL STATE: %s",
             RecvInitialMetadata::StateString(recv_initial_metadata_->state)));
@@ -1413,8 +1513,15 @@ void ClientCallData::StartPromise(Flusher* flusher) {
   promise_ = filter->MakeCallPromise(
       CallArgs{WrapMetadata(send_initial_metadata_batch_->payload
                                 ->send_initial_metadata.send_initial_metadata),
-               server_initial_metadata_latch(), outgoing_messages_pipe(),
-               incoming_messages_pipe()},
+               server_initial_metadata_pipe() == nullptr
+                   ? nullptr
+                   : &server_initial_metadata_pipe()->sender,
+               send_message() == nullptr
+                   ? nullptr
+                   : send_message()->interceptor()->original_receiver(),
+               receive_message() == nullptr
+                   ? nullptr
+                   : receive_message()->interceptor()->original_sender()},
       [this](CallArgs call_args) {
         return MakeNextPromise(std::move(call_args));
       });
@@ -1423,28 +1530,30 @@ void ClientCallData::StartPromise(Flusher* flusher) {
 
 void ClientCallData::RecvInitialMetadataReady(grpc_error_handle error) {
   if (grpc_trace_channel.enabled()) {
-    gpr_log(GPR_INFO, "%s ClientCallData.RecvInitialMetadataReady %s",
-            LogTag().c_str(), DebugString().c_str());
+    gpr_log(GPR_INFO,
+            "%s ClientCallData.RecvInitialMetadataReady %s error:%s md:%s",
+            LogTag().c_str(), DebugString().c_str(), error.ToString().c_str(),
+            recv_initial_metadata_->metadata->DebugString().c_str());
   }
   ScopedContext context(this);
   Flusher flusher(this);
   if (!error.ok()) {
     switch (recv_initial_metadata_->state) {
-      case RecvInitialMetadata::kHookedWaitingForLatch:
+      case RecvInitialMetadata::kHookedWaitingForPipe:
         recv_initial_metadata_->state = RecvInitialMetadata::kResponded;
         break;
-      case RecvInitialMetadata::kHookedAndGotLatch:
+      case RecvInitialMetadata::kHookedAndGotPipe:
         recv_initial_metadata_->state =
-            RecvInitialMetadata::kRespondedButNeedToSetLatch;
+            RecvInitialMetadata::kRespondedButNeedToClosePipe;
         break;
       case RecvInitialMetadata::kInitial:
-      case RecvInitialMetadata::kGotLatch:
-      case RecvInitialMetadata::kCompleteWaitingForLatch:
-      case RecvInitialMetadata::kCompleteAndGotLatch:
-      case RecvInitialMetadata::kCompleteAndSetLatch:
+      case RecvInitialMetadata::kGotPipe:
+      case RecvInitialMetadata::kCompleteWaitingForPipe:
+      case RecvInitialMetadata::kCompleteAndGotPipe:
+      case RecvInitialMetadata::kCompleteAndPushedToPipe:
       case RecvInitialMetadata::kResponded:
       case RecvInitialMetadata::kRespondedToTrailingMetadataPriorToHook:
-      case RecvInitialMetadata::kRespondedButNeedToSetLatch:
+      case RecvInitialMetadata::kRespondedButNeedToClosePipe:
         Crash(absl::StrFormat(
             "ILLEGAL STATE: %s",
             RecvInitialMetadata::StateString(
@@ -1461,22 +1570,22 @@ void ClientCallData::RecvInitialMetadataReady(grpc_error_handle error) {
         cancelled_error_, "propagate cancellation");
   } else {
     switch (recv_initial_metadata_->state) {
-      case RecvInitialMetadata::kHookedWaitingForLatch:
+      case RecvInitialMetadata::kHookedWaitingForPipe:
         recv_initial_metadata_->state =
-            RecvInitialMetadata::kCompleteWaitingForLatch;
+            RecvInitialMetadata::kCompleteWaitingForPipe;
         break;
-      case RecvInitialMetadata::kHookedAndGotLatch:
+      case RecvInitialMetadata::kHookedAndGotPipe:
         recv_initial_metadata_->state =
-            RecvInitialMetadata::kCompleteAndGotLatch;
+            RecvInitialMetadata::kCompleteAndGotPipe;
         break;
       case RecvInitialMetadata::kInitial:
-      case RecvInitialMetadata::kGotLatch:
-      case RecvInitialMetadata::kCompleteWaitingForLatch:
-      case RecvInitialMetadata::kCompleteAndGotLatch:
-      case RecvInitialMetadata::kCompleteAndSetLatch:
+      case RecvInitialMetadata::kGotPipe:
+      case RecvInitialMetadata::kCompleteWaitingForPipe:
+      case RecvInitialMetadata::kCompleteAndGotPipe:
+      case RecvInitialMetadata::kCompleteAndPushedToPipe:
       case RecvInitialMetadata::kResponded:
       case RecvInitialMetadata::kRespondedToTrailingMetadataPriorToHook:
-      case RecvInitialMetadata::kRespondedButNeedToSetLatch:
+      case RecvInitialMetadata::kRespondedButNeedToClosePipe:
         Crash(absl::StrFormat(
             "ILLEGAL STATE: %s",
             RecvInitialMetadata::StateString(
@@ -1523,24 +1632,24 @@ ArenaPromise<ServerMetadataHandle> ClientCallData::MakeNextPromise(
         call_args.server_initial_metadata;
     switch (recv_initial_metadata_->state) {
       case RecvInitialMetadata::kInitial:
-        recv_initial_metadata_->state = RecvInitialMetadata::kGotLatch;
+        recv_initial_metadata_->state = RecvInitialMetadata::kGotPipe;
         break;
-      case RecvInitialMetadata::kHookedWaitingForLatch:
-        recv_initial_metadata_->state = RecvInitialMetadata::kHookedAndGotLatch;
+      case RecvInitialMetadata::kHookedWaitingForPipe:
+        recv_initial_metadata_->state = RecvInitialMetadata::kHookedAndGotPipe;
         poll_ctx_->Repoll();
         break;
-      case RecvInitialMetadata::kCompleteWaitingForLatch:
+      case RecvInitialMetadata::kCompleteWaitingForPipe:
         recv_initial_metadata_->state =
-            RecvInitialMetadata::kCompleteAndGotLatch;
+            RecvInitialMetadata::kCompleteAndGotPipe;
         poll_ctx_->Repoll();
         break;
-      case RecvInitialMetadata::kGotLatch:
-      case RecvInitialMetadata::kHookedAndGotLatch:
-      case RecvInitialMetadata::kCompleteAndGotLatch:
-      case RecvInitialMetadata::kCompleteAndSetLatch:
+      case RecvInitialMetadata::kGotPipe:
+      case RecvInitialMetadata::kHookedAndGotPipe:
+      case RecvInitialMetadata::kCompleteAndGotPipe:
+      case RecvInitialMetadata::kCompleteAndPushedToPipe:
       case RecvInitialMetadata::kResponded:
       case RecvInitialMetadata::kRespondedToTrailingMetadataPriorToHook:
-      case RecvInitialMetadata::kRespondedButNeedToSetLatch:
+      case RecvInitialMetadata::kRespondedButNeedToClosePipe:
         Crash(absl::StrFormat(
             "ILLEGAL STATE: %s",
             RecvInitialMetadata::StateString(
@@ -1550,14 +1659,14 @@ ArenaPromise<ServerMetadataHandle> ClientCallData::MakeNextPromise(
     GPR_ASSERT(call_args.server_initial_metadata == nullptr);
   }
   if (send_message() != nullptr) {
-    send_message()->GotPipe(call_args.outgoing_messages);
+    send_message()->GotPipe(call_args.client_to_server_messages);
   } else {
-    GPR_ASSERT(call_args.outgoing_messages == nullptr);
+    GPR_ASSERT(call_args.client_to_server_messages == nullptr);
   }
   if (receive_message() != nullptr) {
-    receive_message()->GotPipe(call_args.incoming_messages);
+    receive_message()->GotPipe(call_args.server_to_client_messages);
   } else {
-    GPR_ASSERT(call_args.incoming_messages == nullptr);
+    GPR_ASSERT(call_args.server_to_client_messages == nullptr);
   }
   return ArenaPromise<ServerMetadataHandle>(
       [this]() { return PollTrailingMetadata(); });
@@ -1688,29 +1797,31 @@ void ClientCallData::OnWakeup() {
 struct ServerCallData::SendInitialMetadata {
   enum State {
     kInitial,
-    kGotLatch,
-    kQueuedWaitingForLatch,
-    kQueuedAndGotLatch,
-    kQueuedAndSetLatch,
+    kGotPipe,
+    kQueuedWaitingForPipe,
+    kQueuedAndGotPipe,
+    kQueuedAndPushedToPipe,
     kForwarded,
     kCancelled,
   };
   State state = kInitial;
   CapturedBatch batch;
-  Latch<ServerMetadata*>* server_initial_metadata_publisher = nullptr;
+  PipeSender<ServerMetadataHandle>* server_initial_metadata_publisher = nullptr;
+  absl::optional<PipeSender<ServerMetadataHandle>::PushType> metadata_push_;
+  absl::optional<PipeReceiverNextType<ServerMetadataHandle>> metadata_next_;
 
   static const char* StateString(State state) {
     switch (state) {
       case kInitial:
         return "INITIAL";
-      case kGotLatch:
-        return "GOT_LATCH";
-      case kQueuedWaitingForLatch:
-        return "QUEUED_WAITING_FOR_LATCH";
-      case kQueuedAndGotLatch:
-        return "QUEUED_AND_GOT_LATCH";
-      case kQueuedAndSetLatch:
-        return "QUEUED_AND_SET_LATCH";
+      case kGotPipe:
+        return "GOT_PIPE";
+      case kQueuedWaitingForPipe:
+        return "QUEUED_WAITING_FOR_PIPE";
+      case kQueuedAndGotPipe:
+        return "QUEUED_AND_GOT_PIPE";
+      case kQueuedAndPushedToPipe:
+        return "QUEUED_AND_PUSHED_TO_PIPE";
       case kForwarded:
         return "FORWARDED";
       case kCancelled:
@@ -1745,6 +1856,7 @@ class ServerCallData::PollContext {
         auto* next_poll = static_cast<NextPoll*>(p);
         {
           Flusher flusher(next_poll->call_data);
+          ScopedContext context(next_poll->call_data);
           next_poll->call_data->WakeInsideCombiner(&flusher);
         }
         GRPC_CALL_STACK_UNREF(next_poll->call_stack, "re-poll");
@@ -1792,6 +1904,8 @@ const char* ServerCallData::StateString(SendTrailingState state) {
       return "FORWARDED";
     case SendTrailingState::kQueuedBehindSendMessage:
       return "QUEUED_BEHIND_SEND_MESSAGE";
+    case SendTrailingState::kQueuedButHaventClosedSends:
+      return "QUEUED_BUT_HAVENT_CLOSED_SENDS";
     case SendTrailingState::kQueued:
       return "QUEUED";
     case SendTrailingState::kCancelled:
@@ -1803,8 +1917,13 @@ const char* ServerCallData::StateString(SendTrailingState state) {
 ServerCallData::ServerCallData(grpc_call_element* elem,
                                const grpc_call_element_args* args,
                                uint8_t flags)
-    : BaseCallData(elem, args, flags) {
-  if (server_initial_metadata_latch() != nullptr) {
+    : BaseCallData(
+          elem, args, flags,
+          [args]() { return args->arena->New<SendInterceptor>(args->arena); },
+          [args]() {
+            return args->arena->New<ReceiveInterceptor>(args->arena);
+          }) {
+  if (server_initial_metadata_pipe() != nullptr) {
     send_initial_metadata_ = arena()->New<SendInitialMetadata>();
   }
   GRPC_CLOSURE_INIT(&recv_initial_metadata_ready_,
@@ -1892,19 +2011,19 @@ void ServerCallData::StartBatch(grpc_transport_stream_op_batch* b) {
     switch (send_initial_metadata_->state) {
       case SendInitialMetadata::kInitial:
         send_initial_metadata_->state =
-            SendInitialMetadata::kQueuedWaitingForLatch;
+            SendInitialMetadata::kQueuedWaitingForPipe;
         break;
-      case SendInitialMetadata::kGotLatch:
-        send_initial_metadata_->state = SendInitialMetadata::kQueuedAndGotLatch;
+      case SendInitialMetadata::kGotPipe:
+        send_initial_metadata_->state = SendInitialMetadata::kQueuedAndGotPipe;
         break;
       case SendInitialMetadata::kCancelled:
         batch.CancelWith(
             cancelled_error_.ok() ? absl::CancelledError() : cancelled_error_,
             &flusher);
         break;
-      case SendInitialMetadata::kQueuedAndGotLatch:
-      case SendInitialMetadata::kQueuedWaitingForLatch:
-      case SendInitialMetadata::kQueuedAndSetLatch:
+      case SendInitialMetadata::kQueuedAndGotPipe:
+      case SendInitialMetadata::kQueuedWaitingForPipe:
+      case SendInitialMetadata::kQueuedAndPushedToPipe:
       case SendInitialMetadata::kForwarded:
         Crash(absl::StrFormat(
             "ILLEGAL STATE: %s",
@@ -1937,6 +2056,9 @@ void ServerCallData::StartBatch(grpc_transport_stream_op_batch* b) {
         }
         if (send_message() != nullptr && !send_message()->IsIdle()) {
           send_trailing_state_ = SendTrailingState::kQueuedBehindSendMessage;
+        } else if (send_message() != nullptr) {
+          send_trailing_state_ = SendTrailingState::kQueuedButHaventClosedSends;
+          wake = true;
         } else {
           send_trailing_state_ = SendTrailingState::kQueued;
           wake = true;
@@ -1944,6 +2066,7 @@ void ServerCallData::StartBatch(grpc_transport_stream_op_batch* b) {
         break;
       case SendTrailingState::kQueued:
       case SendTrailingState::kQueuedBehindSendMessage:
+      case SendTrailingState::kQueuedButHaventClosedSends:
       case SendTrailingState::kForwarded:
         Crash(
             absl::StrFormat("ILLEGAL STATE: %s",
@@ -1963,26 +2086,55 @@ void ServerCallData::StartBatch(grpc_transport_stream_op_batch* b) {
 
 // Handle cancellation.
 void ServerCallData::Completed(grpc_error_handle error, Flusher* flusher) {
+  if (grpc_trace_channel.enabled()) {
+    gpr_log(
+        GPR_DEBUG,
+        "%sServerCallData::Completed: send_trailing_state=%s "
+        "send_initial_state=%s error=%s",
+        LogTag().c_str(), StateString(send_trailing_state_),
+        send_initial_metadata_ == nullptr
+            ? "null"
+            : SendInitialMetadata::StateString(send_initial_metadata_->state),
+        error.ToString().c_str());
+  }
   // Track the latest reason for cancellation.
   cancelled_error_ = error;
   // Stop running the promise.
   promise_ = ArenaPromise<ServerMetadataHandle>();
-  if (send_trailing_state_ == SendTrailingState::kQueued) {
-    send_trailing_state_ = SendTrailingState::kCancelled;
-    send_trailing_metadata_batch_.CancelWith(error, flusher);
-  } else {
-    send_trailing_state_ = SendTrailingState::kCancelled;
+  switch (send_trailing_state_) {
+    case SendTrailingState::kInitial:
+    case SendTrailingState::kForwarded:
+      send_trailing_state_ = SendTrailingState::kCancelled;
+      if (!error.ok()) {
+        auto* batch = grpc_make_transport_stream_op(
+            NewClosure([call_combiner = call_combiner()](absl::Status) {
+              GRPC_CALL_COMBINER_STOP(call_combiner, "done-cancel");
+            }));
+        batch->cancel_stream = true;
+        batch->payload->cancel_stream.cancel_error = error;
+        flusher->Resume(batch);
+      }
+      break;
+    case SendTrailingState::kQueued:
+      send_trailing_state_ = SendTrailingState::kCancelled;
+      send_trailing_metadata_batch_.CancelWith(error, flusher);
+      break;
+    case SendTrailingState::kQueuedBehindSendMessage:
+    case SendTrailingState::kQueuedButHaventClosedSends:
+    case SendTrailingState::kCancelled:
+      send_trailing_state_ = SendTrailingState::kCancelled;
+      break;
   }
   if (send_initial_metadata_ != nullptr) {
     switch (send_initial_metadata_->state) {
       case SendInitialMetadata::kInitial:
-      case SendInitialMetadata::kGotLatch:
+      case SendInitialMetadata::kGotPipe:
       case SendInitialMetadata::kForwarded:
       case SendInitialMetadata::kCancelled:
         break;
-      case SendInitialMetadata::kQueuedWaitingForLatch:
-      case SendInitialMetadata::kQueuedAndGotLatch:
-      case SendInitialMetadata::kQueuedAndSetLatch:
+      case SendInitialMetadata::kQueuedWaitingForPipe:
+      case SendInitialMetadata::kQueuedAndGotPipe:
+      case SendInitialMetadata::kQueuedAndPushedToPipe:
         send_initial_metadata_->batch.CancelWith(error, flusher);
         break;
     }
@@ -2019,19 +2171,19 @@ ArenaPromise<ServerMetadataHandle> ServerCallData::MakeNextPromise(
         call_args.server_initial_metadata;
     switch (send_initial_metadata_->state) {
       case SendInitialMetadata::kInitial:
-        send_initial_metadata_->state = SendInitialMetadata::kGotLatch;
+        send_initial_metadata_->state = SendInitialMetadata::kGotPipe;
         break;
-      case SendInitialMetadata::kGotLatch:
-      case SendInitialMetadata::kQueuedAndGotLatch:
-      case SendInitialMetadata::kQueuedAndSetLatch:
+      case SendInitialMetadata::kGotPipe:
+      case SendInitialMetadata::kQueuedAndGotPipe:
+      case SendInitialMetadata::kQueuedAndPushedToPipe:
       case SendInitialMetadata::kForwarded:
         Crash(absl::StrFormat(
             "ILLEGAL STATE: %s",
             SendInitialMetadata::StateString(
                 send_initial_metadata_->state)));  // not reachable
         break;
-      case SendInitialMetadata::kQueuedWaitingForLatch:
-        send_initial_metadata_->state = SendInitialMetadata::kQueuedAndGotLatch;
+      case SendInitialMetadata::kQueuedWaitingForPipe:
+        send_initial_metadata_->state = SendInitialMetadata::kQueuedAndGotPipe;
         break;
       case SendInitialMetadata::kCancelled:
         break;
@@ -2040,14 +2192,14 @@ ArenaPromise<ServerMetadataHandle> ServerCallData::MakeNextPromise(
     GPR_ASSERT(call_args.server_initial_metadata == nullptr);
   }
   if (send_message() != nullptr) {
-    send_message()->GotPipe(call_args.outgoing_messages);
+    send_message()->GotPipe(call_args.server_to_client_messages);
   } else {
-    GPR_ASSERT(call_args.outgoing_messages == nullptr);
+    GPR_ASSERT(call_args.server_to_client_messages == nullptr);
   }
   if (receive_message() != nullptr) {
-    receive_message()->GotPipe(call_args.incoming_messages);
+    receive_message()->GotPipe(call_args.client_to_server_messages);
   } else {
-    GPR_ASSERT(call_args.incoming_messages == nullptr);
+    GPR_ASSERT(call_args.client_to_server_messages == nullptr);
   }
   return ArenaPromise<ServerMetadataHandle>(
       [this]() { return PollTrailingMetadata(); });
@@ -2057,9 +2209,14 @@ ArenaPromise<ServerMetadataHandle> ServerCallData::MakeNextPromise(
 // All polls: await sending the trailing metadata, then foward it down the
 // stack.
 Poll<ServerMetadataHandle> ServerCallData::PollTrailingMetadata() {
+  if (grpc_trace_channel.enabled()) {
+    gpr_log(GPR_INFO, "%s PollTrailingMetadata: %s", LogTag().c_str(),
+            StateString(send_trailing_state_));
+  }
   switch (send_trailing_state_) {
     case SendTrailingState::kInitial:
     case SendTrailingState::kQueuedBehindSendMessage:
+    case SendTrailingState::kQueuedButHaventClosedSends:
       return Pending{};
     case SendTrailingState::kQueued:
       return WrapMetadata(send_trailing_metadata_batch_->payload
@@ -2125,8 +2282,15 @@ void ServerCallData::RecvInitialMetadataReady(grpc_error_handle error) {
   FakeActivity().Run([this, filter] {
     promise_ = filter->MakeCallPromise(
         CallArgs{WrapMetadata(recv_initial_metadata_),
-                 server_initial_metadata_latch(), outgoing_messages_pipe(),
-                 incoming_messages_pipe()},
+                 server_initial_metadata_pipe() == nullptr
+                     ? nullptr
+                     : &server_initial_metadata_pipe()->sender,
+                 receive_message() == nullptr
+                     ? nullptr
+                     : receive_message()->interceptor()->original_receiver(),
+                 send_message() == nullptr
+                     ? nullptr
+                     : send_message()->interceptor()->original_sender()},
         [this](CallArgs call_args) {
           return MakeNextPromise(std::move(call_args));
         });
@@ -2168,46 +2332,110 @@ void ServerCallData::WakeInsideCombiner(Flusher* flusher) {
     gpr_log(GPR_INFO, "%s: WakeInsideCombiner %s", LogTag().c_str(),
             DebugString().c_str());
   }
-  if (send_initial_metadata_ != nullptr &&
-      send_initial_metadata_->state ==
-          SendInitialMetadata::kQueuedAndGotLatch) {
-    send_initial_metadata_->state = SendInitialMetadata::kQueuedAndSetLatch;
-    send_initial_metadata_->server_initial_metadata_publisher->Set(
-        send_initial_metadata_->batch->payload->send_initial_metadata
-            .send_initial_metadata);
-  }
   poll_ctx.ClearRepoll();
+  if (send_initial_metadata_ != nullptr) {
+    if (send_initial_metadata_->state ==
+        SendInitialMetadata::kQueuedAndGotPipe) {
+      send_initial_metadata_->state =
+          SendInitialMetadata::kQueuedAndPushedToPipe;
+      GPR_ASSERT(!send_initial_metadata_->metadata_push_.has_value());
+      GPR_ASSERT(!send_initial_metadata_->metadata_next_.has_value());
+      send_initial_metadata_->metadata_push_.emplace(
+          send_initial_metadata_->server_initial_metadata_publisher->Push(
+              ServerMetadataHandle(
+                  send_initial_metadata_->batch->payload->send_initial_metadata
+                      .send_initial_metadata,
+                  Arena::PooledDeleter(nullptr))));
+      send_initial_metadata_->metadata_next_.emplace(
+          server_initial_metadata_pipe()->receiver.Next());
+    }
+    if (send_initial_metadata_->metadata_push_.has_value()) {
+      if (!absl::holds_alternative<Pending>(
+              (*send_initial_metadata_->metadata_push_)())) {
+        if (grpc_trace_channel.enabled()) {
+          gpr_log(GPR_INFO, "%s: WakeInsideCombiner: metadata_push done",
+                  LogTag().c_str());
+        }
+        send_initial_metadata_->metadata_push_.reset();
+      } else if (grpc_trace_channel.enabled()) {
+        gpr_log(GPR_INFO, "%s: WakeInsideCombiner: metadata_push pending",
+                LogTag().c_str());
+      }
+    }
+  }
   if (send_message() != nullptr) {
-    send_message()->WakeInsideCombiner(flusher);
+    if (send_trailing_state_ ==
+        SendTrailingState::kQueuedButHaventClosedSends) {
+      send_trailing_state_ = SendTrailingState::kQueued;
+      send_message()->Done(*send_trailing_metadata_batch_->payload
+                                ->send_trailing_metadata.send_trailing_metadata,
+                           flusher);
+    }
+    send_message()->WakeInsideCombiner(
+        flusher,
+        send_initial_metadata_ == nullptr ||
+            send_initial_metadata_->state == SendInitialMetadata::kForwarded);
+    if (grpc_trace_channel.enabled()) {
+      gpr_log(GPR_DEBUG,
+              "%s: After send_message WakeInsideCombiner %s is_idle=%s "
+              "is_forwarded=%s",
+              LogTag().c_str(), DebugString().c_str(),
+              send_message()->IsIdle() ? "true" : "false",
+              send_message()->IsForwarded() ? "true" : "false");
+    }
     if (send_trailing_state_ == SendTrailingState::kQueuedBehindSendMessage &&
-        send_message()->IsIdle()) {
+        (send_message()->IsIdle() ||
+         (send_trailing_metadata_batch_->send_message &&
+          send_message()->IsForwarded()))) {
       send_trailing_state_ = SendTrailingState::kQueued;
+      send_message()->Done(*send_trailing_metadata_batch_->payload
+                                ->send_trailing_metadata.send_trailing_metadata,
+                           flusher);
     }
   }
   if (receive_message() != nullptr) {
-    receive_message()->WakeInsideCombiner(flusher);
+    receive_message()->WakeInsideCombiner(flusher, true);
   }
   if (promise_.has_value()) {
     Poll<ServerMetadataHandle> poll;
     poll = promise_();
     if (grpc_trace_channel.enabled()) {
-      gpr_log(GPR_INFO, "%s: WakeInsideCombiner poll=%s", LogTag().c_str(),
-              PollToString(poll, [](const ServerMetadataHandle& h) {
-                return h->DebugString();
-              }).c_str());
+      gpr_log(
+          GPR_INFO,
+          "%s: WakeInsideCombiner poll=%s; send_initial_metadata=%s "
+          "send_trailing_metadata=%s",
+          LogTag().c_str(),
+          PollToString(
+              poll,
+              [](const ServerMetadataHandle& h) { return h->DebugString(); })
+              .c_str(),
+          send_initial_metadata_ == nullptr
+              ? "null"
+              : SendInitialMetadata::StateString(send_initial_metadata_->state),
+          StateString(send_trailing_state_));
     }
     if (send_initial_metadata_ != nullptr &&
         send_initial_metadata_->state ==
-            SendInitialMetadata::kQueuedAndSetLatch) {
-      Poll<ServerMetadata**> p = server_initial_metadata_latch()->Wait()();
-      if (ServerMetadata*** ppp = absl::get_if<ServerMetadata**>(&p)) {
-        ServerMetadata* md = **ppp;
+            SendInitialMetadata::kQueuedAndPushedToPipe) {
+      GPR_ASSERT(send_initial_metadata_->metadata_next_.has_value());
+      auto p = (*send_initial_metadata_->metadata_next_)();
+      if (grpc_trace_channel.enabled()) {
+        gpr_log(GPR_INFO,
+                "%s: WakeInsideCombiner send_initial_metadata poll=%s",
+                LogTag().c_str(),
+                PollToString(p, [](const NextResult<ServerMetadataHandle>& h) {
+                  return (*h)->DebugString();
+                }).c_str());
+      }
+      if (auto* nr = absl::get_if<NextResult<ServerMetadataHandle>>(&p)) {
+        ServerMetadataHandle md = std::move(nr->value());
         if (send_initial_metadata_->batch->payload->send_initial_metadata
-                .send_initial_metadata != md) {
+                .send_initial_metadata != md.get()) {
           *send_initial_metadata_->batch->payload->send_initial_metadata
                .send_initial_metadata = std::move(*md);
         }
         send_initial_metadata_->state = SendInitialMetadata::kForwarded;
+        poll_ctx.Repoll();
         send_initial_metadata_->batch.ResumeWith(flusher);
       }
     }
@@ -2223,6 +2451,7 @@ void ServerCallData::WakeInsideCombiner(Flusher* flusher) {
       }
       switch (send_trailing_state_) {
         case SendTrailingState::kQueuedBehindSendMessage:
+        case SendTrailingState::kQueuedButHaventClosedSends:
         case SendTrailingState::kQueued: {
           if (send_trailing_metadata_batch_->payload->send_trailing_metadata
                   .send_trailing_metadata != md) {
diff --git a/src/core/lib/channel/promise_based_filter.h b/src/core/lib/channel/promise_based_filter.h
index 57fa2608a87..0c604390b7b 100644
--- a/src/core/lib/channel/promise_based_filter.h
+++ b/src/core/lib/channel/promise_based_filter.h
@@ -19,15 +19,13 @@
 // promise-style. Most of this will be removed once the promises conversion is
 // completed.
 
-// TODO(ctiller): When removing this file, also reduce the number of *'s on the
-// server initial metadata latch.
-
 #include <grpc/support/port_platform.h>
 
 #include <stdint.h>
 #include <stdlib.h>
 
 #include <atomic>
+#include <initializer_list>
 #include <memory>
 #include <new>
 #include <string>
@@ -35,6 +33,7 @@
 #include <utility>
 
 #include "absl/container/inlined_vector.h"
+#include "absl/functional/function_ref.h"
 #include "absl/meta/type_traits.h"
 #include "absl/status/status.h"
 #include "absl/strings/string_view.h"
@@ -60,7 +59,6 @@
 #include "src/core/lib/promise/activity.h"
 #include "src/core/lib/promise/arena_promise.h"
 #include "src/core/lib/promise/context.h"
-#include "src/core/lib/promise/latch.h"
 #include "src/core/lib/promise/pipe.h"
 #include "src/core/lib/promise/poll.h"
 #include "src/core/lib/resource_quota/arena.h"
@@ -152,9 +150,27 @@ class InvalidChannelFilter : public ChannelFilter {
 
 // Call data shared between all implementations of promise-based filters.
 class BaseCallData : public Activity, private Wakeable {
- public:
+ protected:
+  // Hook to allow interception of messages on the send/receive path by
+  // PipeSender and PipeReceiver, as appropriate according to whether we're
+  // client or server.
+  class Interceptor {
+   public:
+    virtual PipeSender<MessageHandle>* Push() = 0;
+    virtual PipeReceiver<MessageHandle>* Pull() = 0;
+    virtual PipeReceiver<MessageHandle>* original_receiver() = 0;
+    virtual PipeSender<MessageHandle>* original_sender() = 0;
+    virtual void GotPipe(PipeSender<MessageHandle>*) = 0;
+    virtual void GotPipe(PipeReceiver<MessageHandle>*) = 0;
+    virtual ~Interceptor() = default;
+  };
+
   BaseCallData(grpc_call_element* elem, const grpc_call_element_args* args,
-               uint8_t flags);
+               uint8_t flags,
+               absl::FunctionRef<Interceptor*()> make_send_interceptor,
+               absl::FunctionRef<Interceptor*()> make_recv_interceptor);
+
+ public:
   ~BaseCallData() override;
 
   void set_pollent(grpc_polling_entity* pollent) {
@@ -270,6 +286,54 @@ class BaseCallData : public Activity, private Wakeable {
     return p.release();
   }
 
+  class ReceiveInterceptor final : public Interceptor {
+   public:
+    explicit ReceiveInterceptor(Arena* arena) : pipe_{arena} {}
+
+    PipeReceiver<MessageHandle>* original_receiver() override {
+      return &pipe_.receiver;
+    }
+    PipeSender<MessageHandle>* original_sender() override { abort(); }
+
+    void GotPipe(PipeReceiver<MessageHandle>* receiver) override {
+      GPR_ASSERT(receiver_ == nullptr);
+      receiver_ = receiver;
+    }
+
+    void GotPipe(PipeSender<MessageHandle>*) override { abort(); }
+
+    PipeSender<MessageHandle>* Push() override { return &pipe_.sender; }
+    PipeReceiver<MessageHandle>* Pull() override { return receiver_; }
+
+   private:
+    Pipe<MessageHandle> pipe_;
+    PipeReceiver<MessageHandle>* receiver_ = nullptr;
+  };
+
+  class SendInterceptor final : public Interceptor {
+   public:
+    explicit SendInterceptor(Arena* arena) : pipe_{arena} {}
+
+    PipeReceiver<MessageHandle>* original_receiver() override { abort(); }
+    PipeSender<MessageHandle>* original_sender() override {
+      return &pipe_.sender;
+    }
+
+    void GotPipe(PipeReceiver<MessageHandle>*) override { abort(); }
+
+    void GotPipe(PipeSender<MessageHandle>* sender) override {
+      GPR_ASSERT(sender_ == nullptr);
+      sender_ = sender;
+    }
+
+    PipeSender<MessageHandle>* Push() override { return sender_; }
+    PipeReceiver<MessageHandle>* Pull() override { return &pipe_.receiver; }
+
+   private:
+    Pipe<MessageHandle> pipe_;
+    PipeSender<MessageHandle>* sender_ = nullptr;
+  };
+
   // State machine for sending messages: handles intercepting send_message ops
   // and forwarding them through pipes to the promise, then getting the result
   // down the stack.
@@ -277,9 +341,11 @@ class BaseCallData : public Activity, private Wakeable {
   // these members for filters that don't need to intercept sent messages.
   class SendMessage {
    public:
-    explicit SendMessage(BaseCallData* base)
-        : base_(base), pipe_(base->arena()) {}
-    PipeReceiver<MessageHandle>* outgoing_pipe() { return &pipe_.receiver; }
+    SendMessage(BaseCallData* base, Interceptor* interceptor)
+        : base_(base), interceptor_(interceptor) {}
+    ~SendMessage() { interceptor_->~Interceptor(); }
+
+    Interceptor* interceptor() { return interceptor_; }
 
     // Start a send_message op.
     void StartOp(CapturedBatch batch);
@@ -287,16 +353,19 @@ class BaseCallData : public Activity, private Wakeable {
     // This happens when the promise requests to call the next filter: until
     // this occurs messages can't be sent as we don't know the pipe that the
     // promise expects to send on.
-    void GotPipe(PipeReceiver<MessageHandle>* receiver);
+    template <typename T>
+    void GotPipe(T* pipe);
     // Called from client/server polling to do the send message part of the
     // work.
-    void WakeInsideCombiner(Flusher* flusher);
+    void WakeInsideCombiner(Flusher* flusher, bool allow_push_to_pipe);
     // Call is completed, we have trailing metadata. Close things out.
     void Done(const ServerMetadata& metadata, Flusher* flusher);
     // Return true if we have a batch captured (for debug logs)
     bool HaveCapturedBatch() const { return batch_.is_captured(); }
     // Return true if we're not actively sending a message.
     bool IsIdle() const;
+    // Return true if we've released the message for forwarding down the stack.
+    bool IsForwarded() const { return state_ == State::kForwardedBatch; }
 
    private:
     enum class State : uint8_t {
@@ -331,11 +400,9 @@ class BaseCallData : public Activity, private Wakeable {
 
     BaseCallData* const base_;
     State state_ = State::kInitial;
-    Pipe<MessageHandle> pipe_;
-    PipeReceiver<MessageHandle>* receiver_ = nullptr;
+    Interceptor* const interceptor_;
     absl::optional<PipeSender<MessageHandle>::PushType> push_;
-    absl::optional<PipeReceiver<MessageHandle>::NextType> next_;
-    absl::optional<NextResult<MessageHandle>> next_result_;
+    absl::optional<PipeReceiverNextType<MessageHandle>> next_;
     CapturedBatch batch_;
     grpc_closure* intercepted_on_complete_;
     grpc_closure on_complete_ =
@@ -351,9 +418,11 @@ class BaseCallData : public Activity, private Wakeable {
   // these members for filters that don't need to intercept sent messages.
   class ReceiveMessage {
    public:
-    explicit ReceiveMessage(BaseCallData* base)
-        : base_(base), pipe_(base->arena()) {}
-    PipeSender<MessageHandle>* incoming_pipe() { return &pipe_.sender; }
+    ReceiveMessage(BaseCallData* base, Interceptor* interceptor)
+        : base_(base), interceptor_(interceptor) {}
+    ~ReceiveMessage() { interceptor_->~Interceptor(); }
+
+    Interceptor* interceptor() { return interceptor_; }
 
     // Start a recv_message op.
     void StartOp(CapturedBatch& batch);
@@ -361,10 +430,11 @@ class BaseCallData : public Activity, private Wakeable {
     // This happens when the promise requests to call the next filter: until
     // this occurs messages can't be received as we don't know the pipe that the
     // promise expects to forward them with.
-    void GotPipe(PipeSender<MessageHandle>* sender);
+    template <typename T>
+    void GotPipe(T* pipe);
     // Called from client/server polling to do the receive message part of the
     // work.
-    void WakeInsideCombiner(Flusher* flusher);
+    void WakeInsideCombiner(Flusher* flusher, bool allow_push_to_pipe);
     // Call is completed, we have trailing metadata. Close things out.
     void Done(const ServerMetadata& metadata, Flusher* flusher);
 
@@ -408,23 +478,28 @@ class BaseCallData : public Activity, private Wakeable {
       // On the next poll we'll close things out and forward on completions,
       // then transition to cancelled.
       kBatchCompletedButCancelled,
-      // Completed successfully while we're processing a recv message.
+      // Completed successfully while we're processing a recv message - see
+      // kPushedToPipe.
       kCompletedWhilePushedToPipe,
+      // Completed successfully while we're processing a recv message - see
+      // kPulledFromPipe.
       kCompletedWhilePulledFromPipe,
+      // Completed successfully while we were waiting to process
+      // kBatchCompleted.
+      kCompletedWhileBatchCompleted,
     };
     static const char* StateString(State);
 
     void OnComplete(absl::Status status);
 
     BaseCallData* const base_;
-    Pipe<MessageHandle> pipe_;
-    PipeSender<MessageHandle>* sender_;
+    Interceptor* const interceptor_;
     State state_ = State::kInitial;
     uint32_t scratch_flags_;
     absl::optional<SliceBuffer>* intercepted_slice_buffer_;
     uint32_t* intercepted_flags_;
     absl::optional<PipeSender<MessageHandle>::PushType> push_;
-    absl::optional<PipeReceiver<MessageHandle>::NextType> next_;
+    absl::optional<PipeReceiverNextType<MessageHandle>> next_;
     absl::Status completed_status_;
     grpc_closure* intercepted_on_complete_;
     grpc_closure on_complete_ =
@@ -436,15 +511,8 @@ class BaseCallData : public Activity, private Wakeable {
   CallCombiner* call_combiner() const { return call_combiner_; }
   Timestamp deadline() const { return deadline_; }
   grpc_call_stack* call_stack() const { return call_stack_; }
-  Latch<ServerMetadata*>* server_initial_metadata_latch() const {
-    return server_initial_metadata_latch_;
-  }
-  PipeReceiver<MessageHandle>* outgoing_messages_pipe() const {
-    return send_message_ == nullptr ? nullptr : send_message_->outgoing_pipe();
-  }
-  PipeSender<MessageHandle>* incoming_messages_pipe() const {
-    return receive_message_ == nullptr ? nullptr
-                                       : receive_message_->incoming_pipe();
+  Pipe<ServerMetadataHandle>* server_initial_metadata_pipe() const {
+    return server_initial_metadata_pipe_;
   }
   SendMessage* send_message() const { return send_message_; }
   ReceiveMessage* receive_message() const { return receive_message_; }
@@ -474,7 +542,7 @@ class BaseCallData : public Activity, private Wakeable {
   CallFinalization finalization_;
   grpc_call_context_element* const context_;
   std::atomic<grpc_polling_entity*> pollent_{nullptr};
-  Latch<ServerMetadata*>* const server_initial_metadata_latch_;
+  Pipe<ServerMetadataHandle>* const server_initial_metadata_pipe_;
   SendMessage* const send_message_;
   ReceiveMessage* const receive_message_;
   grpc_event_engine::experimental::EventEngine* event_engine_;
@@ -626,6 +694,9 @@ class ServerCallData : public BaseCallData {
     // metadata.
     kQueuedBehindSendMessage,
     // We saw the op, and are waiting for the promise to complete
+    // to forward it. First however we need to close sends.
+    kQueuedButHaventClosedSends,
+    // We saw the op, and are waiting for the promise to complete
     // to forward it.
     kQueued,
     // We've forwarded the op to the next filter.
diff --git a/src/core/lib/event_engine/slice.cc b/src/core/lib/event_engine/slice.cc
index bcb09c50345..b9266714bb2 100644
--- a/src/core/lib/event_engine/slice.cc
+++ b/src/core/lib/event_engine/slice.cc
@@ -93,7 +93,7 @@ Slice Slice::FromRefcountAndBytes(grpc_slice_refcount* r, const uint8_t* begin,
                                   const uint8_t* end) {
   grpc_slice out;
   out.refcount = r;
-  if (r != grpc_slice_refcount::NoopRefcount()) r->Ref();
+  if (r != grpc_slice_refcount::NoopRefcount()) r->Ref({});
   out.data.refcounted.bytes = const_cast<uint8_t*>(begin);
   out.data.refcounted.length = end - begin;
   return Slice(out);
diff --git a/src/core/lib/experiments/experiments.cc b/src/core/lib/experiments/experiments.cc
index b860e1f1c7e..093312e8878 100644
--- a/src/core/lib/experiments/experiments.cc
+++ b/src/core/lib/experiments/experiments.cc
@@ -48,6 +48,9 @@ const char* const description_promise_based_client_call =
     "(ie when all filters in a stack are promise based)";
 const char* const description_free_large_allocator =
     "If set, return all free bytes from a \042big\042 allocator";
+const char* const description_promise_based_server_call =
+    "If set, use the new gRPC promise based call code when it's appropriate "
+    "(ie when all filters in a stack are promise based)";
 const char* const description_transport_supplies_client_latency =
     "If set, use the transport represented value for client latency in "
     "opencensus";
@@ -71,6 +74,7 @@ const ExperimentMetadata g_experiment_metadata[] = {
     {"monitoring_experiment", description_monitoring_experiment, true},
     {"promise_based_client_call", description_promise_based_client_call, false},
     {"free_large_allocator", description_free_large_allocator, false},
+    {"promise_based_server_call", description_promise_based_server_call, false},
     {"transport_supplies_client_latency",
      description_transport_supplies_client_latency, false},
     {"event_engine_listener", description_event_engine_listener, false},
diff --git a/src/core/lib/experiments/experiments.h b/src/core/lib/experiments/experiments.h
index 5e8adedf3fa..b3a56f6fab8 100644
--- a/src/core/lib/experiments/experiments.h
+++ b/src/core/lib/experiments/experiments.h
@@ -40,10 +40,13 @@ inline bool IsEventEngineClientEnabled() { return IsExperimentEnabled(7); }
 inline bool IsMonitoringExperimentEnabled() { return IsExperimentEnabled(8); }
 inline bool IsPromiseBasedClientCallEnabled() { return IsExperimentEnabled(9); }
 inline bool IsFreeLargeAllocatorEnabled() { return IsExperimentEnabled(10); }
-inline bool IsTransportSuppliesClientLatencyEnabled() {
+inline bool IsPromiseBasedServerCallEnabled() {
   return IsExperimentEnabled(11);
 }
-inline bool IsEventEngineListenerEnabled() { return IsExperimentEnabled(12); }
+inline bool IsTransportSuppliesClientLatencyEnabled() {
+  return IsExperimentEnabled(12);
+}
+inline bool IsEventEngineListenerEnabled() { return IsExperimentEnabled(13); }
 
 struct ExperimentMetadata {
   const char* name;
@@ -51,7 +54,7 @@ struct ExperimentMetadata {
   bool default_value;
 };
 
-constexpr const size_t kNumExperiments = 13;
+constexpr const size_t kNumExperiments = 14;
 extern const ExperimentMetadata g_experiment_metadata[kNumExperiments];
 
 }  // namespace grpc_core
diff --git a/src/core/lib/experiments/experiments.yaml b/src/core/lib/experiments/experiments.yaml
index 8f917b5439e..3bd0827f7dc 100644
--- a/src/core/lib/experiments/experiments.yaml
+++ b/src/core/lib/experiments/experiments.yaml
@@ -119,6 +119,14 @@
   expiry: 2023/04/01
   owner: alishananda@google.com
   test_tags: [resource_quota_test]
+- name: promise_based_server_call
+  description:
+    If set, use the new gRPC promise based call code when it's appropriate
+    (ie when all filters in a stack are promise based)
+  default: false
+  expiry: 2023/06/01
+  owner: ctiller@google.com
+  test_tags: ["core_end2end_test"]
 - name: transport_supplies_client_latency
   description:
     If set, use the transport represented value for client latency in opencensus
diff --git a/src/core/lib/gprpp/debug_location.h b/src/core/lib/gprpp/debug_location.h
index 1b75086f4ec..1a29f495383 100644
--- a/src/core/lib/gprpp/debug_location.h
+++ b/src/core/lib/gprpp/debug_location.h
@@ -56,9 +56,6 @@ class SourceLocation {
 // No-op for non-debug builds.
 // Callers can use the DEBUG_LOCATION macro in either case.
 #ifndef NDEBUG
-// TODO(roth): See if there's a way to automatically populate this,
-// similarly to how absl::SourceLocation::current() works, so that
-// callers don't need to explicitly pass DEBUG_LOCATION anywhere.
 class DebugLocation {
  public:
   DebugLocation(const char* file = GRPC_DEFAULT_FILE,
diff --git a/src/core/lib/iomgr/call_combiner.cc b/src/core/lib/iomgr/call_combiner.cc
index 2b2996c2c4f..c48766f781a 100644
--- a/src/core/lib/iomgr/call_combiner.cc
+++ b/src/core/lib/iomgr/call_combiner.cc
@@ -116,9 +116,9 @@ void CallCombiner::Start(grpc_closure* closure, grpc_error_handle error,
                          DEBUG_ARGS const char* reason) {
   if (GRPC_TRACE_FLAG_ENABLED(grpc_call_combiner_trace)) {
     gpr_log(GPR_INFO,
-            "==> CallCombiner::Start() [%p] closure=%p [" DEBUG_FMT_STR
+            "==> CallCombiner::Start() [%p] closure=%s [" DEBUG_FMT_STR
             "%s] error=%s",
-            this, closure DEBUG_FMT_ARGS, reason,
+            this, closure->DebugString().c_str() DEBUG_FMT_ARGS, reason,
             StatusToString(error).c_str());
   }
   size_t prev_size =
@@ -176,8 +176,8 @@ void CallCombiner::Stop(DEBUG_ARGS const char* reason) {
           internal::StatusMoveFromHeapPtr(closure->error_data.error);
       closure->error_data.error = 0;
       if (GRPC_TRACE_FLAG_ENABLED(grpc_call_combiner_trace)) {
-        gpr_log(GPR_INFO, "  EXECUTING FROM QUEUE: closure=%p error=%s",
-                closure, StatusToString(error).c_str());
+        gpr_log(GPR_INFO, "  EXECUTING FROM QUEUE: closure=%s error=%s",
+                closure->DebugString().c_str(), StatusToString(error).c_str());
       }
       ScheduleClosure(closure, error);
       break;
diff --git a/src/core/lib/iomgr/closure.cc b/src/core/lib/iomgr/closure.cc
new file mode 100644
index 00000000000..cf1a184032c
--- /dev/null
+++ b/src/core/lib/iomgr/closure.cc
@@ -0,0 +1,27 @@
+// Copyright 2022 gRPC authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include <grpc/support/port_platform.h>
+
+#include "src/core/lib/iomgr/closure.h"
+
+#include "absl/strings/str_format.h"
+
+std::string grpc_closure::DebugString() const {
+#ifdef NDEBUG
+  return absl::StrFormat("%p", this);
+#else
+  return absl::StrFormat("%p|created=%s:%d", this, file_created, line_created);
+#endif
+}
diff --git a/src/core/lib/iomgr/closure.h b/src/core/lib/iomgr/closure.h
index 9996f163bcd..adf8ebf2b74 100644
--- a/src/core/lib/iomgr/closure.h
+++ b/src/core/lib/iomgr/closure.h
@@ -86,6 +86,8 @@ struct grpc_closure {
   const char* file_initiated;
   int line_initiated;
 #endif
+
+  std::string DebugString() const;
 };
 
 #ifndef NDEBUG
diff --git a/src/core/lib/promise/activity.h b/src/core/lib/promise/activity.h
index 771dcd39c23..73e9bfd3574 100644
--- a/src/core/lib/promise/activity.h
+++ b/src/core/lib/promise/activity.h
@@ -102,6 +102,10 @@ class Waker {
     return wakeable_ == other.wakeable_;
   }
 
+  bool operator!=(const Waker& other) const noexcept {
+    return wakeable_ != other.wakeable_;
+  }
+
   std::string ActivityDebugTag() {
     return wakeable_ == nullptr ? "<unknown>" : wakeable_->ActivityDebugTag();
   }
diff --git a/src/core/lib/promise/for_each.h b/src/core/lib/promise/for_each.h
index 8b3f2ff82b2..cee3a730b30 100644
--- a/src/core/lib/promise/for_each.h
+++ b/src/core/lib/promise/for_each.h
@@ -17,17 +17,24 @@
 
 #include <grpc/support/port_platform.h>
 
+#include <stdint.h>
+
+#include <string>
 #include <type_traits>
 #include <utility>
 
 #include "absl/status/status.h"
+#include "absl/strings/str_cat.h"
 #include "absl/types/variant.h"
 
 #include <grpc/support/log.h>
 
+#include "src/core/lib/debug/trace.h"
 #include "src/core/lib/gprpp/construct_destruct.h"
+#include "src/core/lib/promise/activity.h"
 #include "src/core/lib/promise/detail/promise_factory.h"
 #include "src/core/lib/promise/poll.h"
+#include "src/core/lib/promise/trace.h"
 
 namespace grpc_core {
 
@@ -101,9 +108,21 @@ class ForEach {
     ReaderResult result;
   };
 
+  std::string DebugTag() {
+    return absl::StrCat(Activity::current()->DebugTag(), " FOR_EACH[0x",
+                        reinterpret_cast<uintptr_t>(this), "]: ");
+  }
+
   Poll<Result> PollReaderNext() {
+    if (grpc_trace_promise_primitives.enabled()) {
+      gpr_log(GPR_DEBUG, "%s PollReaderNext", DebugTag().c_str());
+    }
     auto r = reader_next_();
     if (auto* p = absl::get_if<kPollReadyIdx>(&r)) {
+      if (grpc_trace_promise_primitives.enabled()) {
+        gpr_log(GPR_DEBUG, "%s PollReaderNext: got has_value=%s",
+                DebugTag().c_str(), p->has_value() ? "true" : "false");
+      }
       if (p->has_value()) {
         Destruct(&reader_next_);
         auto action = action_factory_.Make(std::move(**p));
@@ -118,6 +137,9 @@ class ForEach {
   }
 
   Poll<Result> PollAction() {
+    if (grpc_trace_promise_primitives.enabled()) {
+      gpr_log(GPR_DEBUG, "%s PollAction", DebugTag().c_str());
+    }
     auto r = in_action_.promise();
     if (auto* p = absl::get_if<kPollReadyIdx>(&r)) {
       if (p->ok()) {
diff --git a/src/core/lib/promise/if.h b/src/core/lib/promise/if.h
index 09a62a8aea0..20b83685315 100644
--- a/src/core/lib/promise/if.h
+++ b/src/core/lib/promise/if.h
@@ -22,6 +22,7 @@
 #include "absl/status/statusor.h"
 #include "absl/types/variant.h"
 
+#include "src/core/lib/gprpp/construct_destruct.h"
 #include "src/core/lib/promise/detail/promise_factory.h"
 #include "src/core/lib/promise/detail/promise_like.h"
 #include "src/core/lib/promise/poll.h"
@@ -116,6 +117,66 @@ class If {
   };
 };
 
+template <typename T, typename F>
+class If<bool, T, F> {
+ private:
+  using TrueFactory = promise_detail::OncePromiseFactory<void, T>;
+  using FalseFactory = promise_detail::OncePromiseFactory<void, F>;
+  using TruePromise = typename TrueFactory::Promise;
+  using FalsePromise = typename FalseFactory::Promise;
+  using Result =
+      typename PollTraits<decltype(std::declval<TruePromise>()())>::Type;
+
+ public:
+  If(bool condition, T if_true, F if_false) : condition_(condition) {
+    TrueFactory true_factory(std::move(if_true));
+    FalseFactory false_factory(std::move(if_false));
+    if (condition_) {
+      Construct(&if_true_, true_factory.Make());
+    } else {
+      Construct(&if_false_, false_factory.Make());
+    }
+  }
+  ~If() {
+    if (condition_) {
+      Destruct(&if_true_);
+    } else {
+      Destruct(&if_false_);
+    }
+  }
+
+  If(const If&) = delete;
+  If& operator=(const If&) = delete;
+  If(If&& other) noexcept : condition_(other.condition_) {
+    if (condition_) {
+      Construct(&if_true_, std::move(other.if_true_));
+    } else {
+      Construct(&if_false_, std::move(other.if_false_));
+    }
+  }
+  If& operator=(If&& other) noexcept {
+    if (&other == this) return *this;
+    Destruct(this);
+    Construct(this, std::move(other));
+    return *this;
+  }
+
+  Poll<Result> operator()() {
+    if (condition_) {
+      return if_true_();
+    } else {
+      return if_false_();
+    }
+  }
+
+ private:
+  bool condition_;
+  union {
+    TruePromise if_true_;
+    FalsePromise if_false_;
+  };
+};
+
 }  // namespace promise_detail
 
 // If promise combinator.
diff --git a/src/core/lib/promise/interceptor_list.h b/src/core/lib/promise/interceptor_list.h
new file mode 100644
index 00000000000..2e09f574ae5
--- /dev/null
+++ b/src/core/lib/promise/interceptor_list.h
@@ -0,0 +1,309 @@
+// Copyright 2022 gRPC authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef GRPC_SRC_CORE_LIB_PROMISE_INTERCEPTOR_LIST_H
+#define GRPC_SRC_CORE_LIB_PROMISE_INTERCEPTOR_LIST_H
+
+#include <grpc/support/port_platform.h>
+
+#include <stddef.h>
+
+#include <algorithm>
+#include <new>
+#include <string>
+#include <utility>
+
+#include "absl/strings/str_cat.h"
+#include "absl/strings/str_format.h"
+#include "absl/types/optional.h"
+#include "absl/types/variant.h"
+
+#include <grpc/support/log.h>
+
+#include "src/core/lib/debug/trace.h"
+#include "src/core/lib/gprpp/construct_destruct.h"
+#include "src/core/lib/gprpp/debug_location.h"
+#include "src/core/lib/promise/context.h"
+#include "src/core/lib/promise/detail/promise_factory.h"
+#include "src/core/lib/promise/poll.h"
+#include "src/core/lib/promise/trace.h"
+#include "src/core/lib/resource_quota/arena.h"
+
+namespace grpc_core {
+
+// Tracks a list of maps of T -> optional<T> via promises.
+// When Run, runs each transformation in order, and resolves to the ulimate
+// result.
+// If a map resolves to nullopt, the chain is terminated and the result is
+// nullopt.
+// Maps can also have synchronous cleanup functions, which are guaranteed to be
+// called at the termination of each run through the chain.
+template <typename T>
+class InterceptorList {
+ private:
+  // A map of T -> T via promises.
+  class Map {
+   public:
+    explicit Map(DebugLocation from) : from_(from) {}
+    // Construct a promise to transform x into some other value at memory.
+    virtual void MakePromise(T x, void* memory) = 0;
+    // Destroy a promise constructed at memory.
+    virtual void Destroy(void* memory) = 0;
+    // Poll a promise constructed at memory.
+    // Resolves to an optional<T> -- if nullopt it means terminate the chain and
+    // resolve.
+    virtual Poll<absl::optional<T>> PollOnce(void* memory) = 0;
+    virtual ~Map() = default;
+
+    // Update the next pointer stored with this map.
+    // This is only valid to call once, and only before the map is used.
+    void SetNext(Map* next) {
+      GPR_DEBUG_ASSERT(next_ == nullptr);
+      next_ = next;
+    }
+
+    // Access the creation location for this map (for debug tracing).
+    DebugLocation from() const { return from_; }
+
+    // Access the next map in the chain (or nullptr if this is the last map).
+    Map* next() const { return next_; }
+
+   private:
+    GPR_NO_UNIQUE_ADDRESS const DebugLocation from_;
+    Map* next_ = nullptr;
+  };
+
+ public:
+  // The result of Run: a promise that will execute the entire chain.
+  class RunPromise {
+   public:
+    RunPromise(size_t memory_required, Map* factory, absl::optional<T> value) {
+      if (!value.has_value() || factory == nullptr) {
+        is_immediately_resolved_ = true;
+        Construct(&result_, std::move(value));
+      } else {
+        is_immediately_resolved_ = false;
+        Construct(&async_resolution_, memory_required);
+        factory->MakePromise(std::move(*value), async_resolution_.space.get());
+        async_resolution_.current_factory = factory;
+      }
+    }
+
+    ~RunPromise() {
+      if (is_immediately_resolved_) {
+        Destruct(&result_);
+      } else {
+        if (async_resolution_.current_factory != nullptr) {
+          async_resolution_.current_factory->Destroy(
+              async_resolution_.space.get());
+        }
+        Destruct(&async_resolution_);
+      }
+    }
+
+    RunPromise(const RunPromise&) = delete;
+    RunPromise& operator=(const RunPromise&) = delete;
+
+    RunPromise(RunPromise&& other) noexcept
+        : is_immediately_resolved_(other.is_immediately_resolved_) {
+      if (is_immediately_resolved_) {
+        Construct(&result_, std::move(other.result_));
+      } else {
+        Construct(&async_resolution_, std::move(other.async_resolution_));
+      }
+    }
+
+    RunPromise& operator=(RunPromise&& other) noexcept = delete;
+
+    Poll<absl::optional<T>> operator()() {
+      if (grpc_trace_promise_primitives.enabled()) {
+        gpr_log(GPR_DEBUG, "InterceptorList::RunPromise: %s",
+                DebugString().c_str());
+      }
+      if (is_immediately_resolved_) return std::move(result_);
+      while (true) {
+        auto r = async_resolution_.current_factory->PollOnce(
+            async_resolution_.space.get());
+        if (auto* p = absl::get_if<kPollReadyIdx>(&r)) {
+          async_resolution_.current_factory->Destroy(
+              async_resolution_.space.get());
+          async_resolution_.current_factory =
+              async_resolution_.current_factory->next();
+          if (async_resolution_.current_factory == nullptr || !p->has_value()) {
+            return std::move(*p);
+          }
+          async_resolution_.current_factory->MakePromise(
+              std::move(**p), async_resolution_.space.get());
+          continue;
+        }
+        return Pending{};
+      }
+    }
+
+   private:
+    std::string DebugString() const {
+      if (is_immediately_resolved_) {
+        return absl::StrFormat("Result:has_value:%d", result_.has_value());
+      } else {
+        return absl::StrCat(
+            "Running:",
+            async_resolution_.current_factory == nullptr
+                ? "END"
+                : ([p = async_resolution_.current_factory->from()]() {
+                    return absl::StrCat(p.file(), ":", p.line());
+                  })()
+                      .c_str());
+      }
+    }
+    struct AsyncResolution {
+      explicit AsyncResolution(size_t max_size)
+          : space(GetContext<Arena>()->MakePooledArray<char>(max_size)) {}
+      AsyncResolution(const AsyncResolution&) = delete;
+      AsyncResolution& operator=(const AsyncResolution&) = delete;
+      AsyncResolution(AsyncResolution&& other) noexcept
+          : current_factory(std::exchange(other.current_factory, nullptr)),
+            space(std::move(other.space)) {}
+      Map* current_factory;
+      Arena::PoolPtr<char[]> space;
+    };
+    union {
+      AsyncResolution async_resolution_;
+      absl::optional<T> result_;
+    };
+    // If true, the result_ union is valid, otherwise async_resolution_ is.
+    // Indicates whether the promise resolved immediately at construction or if
+    // additional steps were needed.
+    bool is_immediately_resolved_;
+  };
+
+  InterceptorList() = default;
+  InterceptorList(const InterceptorList&) = delete;
+  InterceptorList& operator=(const InterceptorList&) = delete;
+  ~InterceptorList() { DeleteFactories(); }
+
+  RunPromise Run(absl::optional<T> initial_value) {
+    return RunPromise(promise_memory_required_, first_map_,
+                      std::move(initial_value));
+  }
+
+  // Append a new map to the end of the chain.
+  template <typename Fn>
+  void AppendMap(Fn fn, DebugLocation from) {
+    Append(MakeMapToAdd(
+        std::move(fn), [] {}, from));
+  }
+
+  // Prepend a new map to the beginning of the chain.
+  template <typename Fn>
+  void PrependMap(Fn fn, DebugLocation from) {
+    Prepend(MakeMapToAdd(
+        std::move(fn), [] {}, from));
+  }
+
+  // Append a new map to the end of the chain, with a cleanup function to be
+  // called at the end of run promise execution.
+  template <typename Fn, typename CleanupFn>
+  void AppendMapWithCleanup(Fn fn, CleanupFn cleanup_fn, DebugLocation from) {
+    Append(MakeMapToAdd(std::move(fn), std::move(cleanup_fn), from));
+  }
+
+  // Prepend a new map to the beginning of the chain, with a cleanup function to
+  // be called at the end of run promise execution.
+  template <typename Fn, typename CleanupFn>
+  void PrependMapWithCleanup(Fn fn, CleanupFn cleanup_fn, DebugLocation from) {
+    Prepend(MakeMapToAdd(std::move(fn), std::move(cleanup_fn), from));
+  }
+
+ protected:
+  // Clear the interceptor list
+  void ResetInterceptorList() {
+    DeleteFactories();
+    first_map_ = nullptr;
+    last_map_ = nullptr;
+    promise_memory_required_ = 0;
+  }
+
+ private:
+  template <typename Fn, typename CleanupFn>
+  class MapImpl final : public Map {
+   public:
+    using PromiseFactory = promise_detail::RepeatedPromiseFactory<T, Fn>;
+    using Promise = typename PromiseFactory::Promise;
+
+    explicit MapImpl(Fn fn, CleanupFn cleanup_fn, DebugLocation from)
+        : Map(from), fn_(std::move(fn)), cleanup_fn_(std::move(cleanup_fn)) {}
+    ~MapImpl() override { cleanup_fn_(); }
+    void MakePromise(T x, void* memory) override {
+      new (memory) Promise(fn_.Make(std::move(x)));
+    }
+    void Destroy(void* memory) override {
+      static_cast<Promise*>(memory)->~Promise();
+    }
+    Poll<absl::optional<T>> PollOnce(void* memory) override {
+      return poll_cast<absl::optional<T>>((*static_cast<Promise*>(memory))());
+    }
+
+   private:
+    GPR_NO_UNIQUE_ADDRESS PromiseFactory fn_;
+    GPR_NO_UNIQUE_ADDRESS CleanupFn cleanup_fn_;
+  };
+
+  template <typename Fn, typename CleanupFn>
+  Map* MakeMapToAdd(Fn fn, CleanupFn cleanup_fn, DebugLocation from) {
+    using FactoryType = MapImpl<Fn, CleanupFn>;
+    promise_memory_required_ = std::max(promise_memory_required_,
+                                        sizeof(typename FactoryType::Promise));
+    return GetContext<Arena>()->New<FactoryType>(std::move(fn),
+                                                 std::move(cleanup_fn), from);
+  }
+
+  void Append(Map* f) {
+    if (first_map_ == nullptr) {
+      first_map_ = f;
+      last_map_ = f;
+    } else {
+      last_map_->SetNext(f);
+      last_map_ = f;
+    }
+  }
+
+  void Prepend(Map* f) {
+    if (first_map_ == nullptr) {
+      first_map_ = f;
+      last_map_ = f;
+    } else {
+      f->SetNext(first_map_);
+      first_map_ = f;
+    }
+  }
+
+  void DeleteFactories() {
+    for (auto* f = first_map_; f != nullptr;) {
+      auto* next = f->next();
+      f->~Map();
+      f = next;
+    }
+  }
+
+  // The first map in the chain.
+  Map* first_map_ = nullptr;
+  // The last map in the chain.
+  Map* last_map_ = nullptr;
+  // The amount of memory required to store the largest promise in the chain.
+  size_t promise_memory_required_ = 0;
+};
+
+}  // namespace grpc_core
+
+#endif  // GRPC_SRC_CORE_LIB_PROMISE_INTERCEPTOR_LIST_H
diff --git a/src/core/lib/promise/intra_activity_waiter.h b/src/core/lib/promise/intra_activity_waiter.h
index 73bc93f4100..736ec04ae7d 100644
--- a/src/core/lib/promise/intra_activity_waiter.h
+++ b/src/core/lib/promise/intra_activity_waiter.h
@@ -17,6 +17,8 @@
 
 #include <grpc/support/port_platform.h>
 
+#include <string>
+
 #include "src/core/lib/promise/activity.h"
 #include "src/core/lib/promise/poll.h"
 
@@ -40,6 +42,10 @@ class IntraActivityWaiter {
     }
   }
 
+  std::string DebugString() const {
+    return waiting_ ? "WAITING" : "NOT_WAITING";
+  }
+
  private:
   bool waiting_ = false;
 };
diff --git a/src/core/lib/promise/latch.h b/src/core/lib/promise/latch.h
index d66b461f46c..c1dca66efc1 100644
--- a/src/core/lib/promise/latch.h
+++ b/src/core/lib/promise/latch.h
@@ -17,12 +17,21 @@
 
 #include <grpc/support/port_platform.h>
 
+#include <stdint.h>
+
+#include <string>
 #include <type_traits>
+#include <utility>
+
+#include "absl/strings/str_cat.h"
 
 #include <grpc/support/log.h>
 
+#include "src/core/lib/debug/trace.h"
+#include "src/core/lib/promise/activity.h"
 #include "src/core/lib/promise/intra_activity_waiter.h"
 #include "src/core/lib/promise/poll.h"
+#include "src/core/lib/promise/trace.h"
 
 namespace grpc_core {
 
@@ -56,9 +65,13 @@ class Latch {
 #ifndef NDEBUG
     has_had_waiters_ = true;
 #endif
-    return [this]() -> Poll<T*> {
+    return [this]() -> Poll<T> {
+      if (grpc_trace_promise_primitives.enabled()) {
+        gpr_log(GPR_INFO, "%sPollWait %s", DebugTag().c_str(),
+                StateString().c_str());
+      }
       if (has_value_) {
-        return &value_;
+        return std::move(value_);
       } else {
         return waiter_.pending();
       }
@@ -67,6 +80,9 @@ class Latch {
 
   // Set the value of the latch. Can only be called once.
   void Set(T value) {
+    if (grpc_trace_promise_primitives.enabled()) {
+      gpr_log(GPR_INFO, "%sSet %s", DebugTag().c_str(), StateString().c_str());
+    }
     GPR_DEBUG_ASSERT(!has_value_);
     value_ = std::move(value);
     has_value_ = true;
@@ -74,6 +90,16 @@ class Latch {
   }
 
  private:
+  std::string DebugTag() {
+    return absl::StrCat(Activity::current()->DebugTag(), " LATCH[0x",
+                        reinterpret_cast<uintptr_t>(this), "]: ");
+  }
+
+  std::string StateString() {
+    return absl::StrCat("has_value:", has_value_ ? "true" : "false",
+                        " waiter:", waiter_.DebugString());
+  }
+
   // The value stored (if has_value_ is true), otherwise some random value, we
   // don't care.
   // Why not absl::optional<>? Writing things this way lets us compress
diff --git a/src/core/lib/promise/map_pipe.h b/src/core/lib/promise/map_pipe.h
index 45df76e32d4..6f7312da047 100644
--- a/src/core/lib/promise/map_pipe.h
+++ b/src/core/lib/promise/map_pipe.h
@@ -19,10 +19,15 @@
 
 #include "absl/status/status.h"
 
+#include <grpc/support/log.h>
+
+#include "src/core/lib/debug/trace.h"
 #include "src/core/lib/promise/detail/promise_factory.h"
 #include "src/core/lib/promise/for_each.h"
 #include "src/core/lib/promise/map.h"
 #include "src/core/lib/promise/pipe.h"
+#include "src/core/lib/promise/poll.h"
+#include "src/core/lib/promise/trace.h"
 #include "src/core/lib/promise/try_seq.h"
 
 namespace grpc_core {
@@ -40,14 +45,25 @@ auto MapPipe(PipeReceiver<T> src, PipeSender<T> dst, Filter filter_factory) {
       [filter_factory = promise_detail::RepeatedPromiseFactory<T, Filter>(
            std::move(filter_factory)),
        dst = std::move(dst)](T t) mutable {
-        return TrySeq(filter_factory.Make(std::move(t)), [&dst](T t) {
-          return Map(dst.Push(std::move(t)), [](bool successful_push) {
-            if (successful_push) {
-              return absl::OkStatus();
-            }
-            return absl::CancelledError();
-          });
-        });
+        return TrySeq(
+            [] {
+              if (grpc_trace_promise_primitives.enabled()) {
+                gpr_log(GPR_DEBUG, "MapPipe: start map");
+              }
+              return Empty{};
+            },
+            filter_factory.Make(std::move(t)),
+            [&dst](T t) {
+              if (grpc_trace_promise_primitives.enabled()) {
+                gpr_log(GPR_DEBUG, "MapPipe: start push");
+              }
+              return Map(dst.Push(std::move(t)), [](bool successful_push) {
+                if (successful_push) {
+                  return absl::OkStatus();
+                }
+                return absl::CancelledError();
+              });
+            });
       });
 }
 
diff --git a/src/core/lib/promise/pipe.h b/src/core/lib/promise/pipe.h
index a1f4ed42b56..8033201fac8 100644
--- a/src/core/lib/promise/pipe.h
+++ b/src/core/lib/promise/pipe.h
@@ -18,10 +18,15 @@
 #include <grpc/support/port_platform.h>
 
 #include <stdint.h>
+#include <stdlib.h>
 
+#include <memory>
 #include <string>
+#include <type_traits>
 #include <utility>
 
+#include "absl/base/attributes.h"
+#include "absl/memory/memory.h"
 #include "absl/strings/str_cat.h"
 #include "absl/types/optional.h"
 #include "absl/types/variant.h"
@@ -29,14 +34,19 @@
 #include <grpc/support/log.h>
 
 #include "src/core/lib/debug/trace.h"
+#include "src/core/lib/gprpp/debug_location.h"
+#include "src/core/lib/gprpp/ref_counted_ptr.h"
 #include "src/core/lib/promise/activity.h"
 #include "src/core/lib/promise/context.h"
+#include "src/core/lib/promise/if.h"
+#include "src/core/lib/promise/interceptor_list.h"
 #include "src/core/lib/promise/intra_activity_waiter.h"
+#include "src/core/lib/promise/map.h"
 #include "src/core/lib/promise/poll.h"
+#include "src/core/lib/promise/seq.h"
+#include "src/core/lib/promise/trace.h"
 #include "src/core/lib/resource_quota/arena.h"
 
-extern grpc_core::DebugOnlyTraceFlag grpc_trace_promise_pipe;
-
 namespace grpc_core {
 
 namespace pipe_detail {
@@ -56,21 +66,24 @@ struct Pipe;
 template <typename T>
 class NextResult final {
  public:
-  explicit NextResult(pipe_detail::Center<T>* center) : center_(center) {}
+  NextResult() : center_(nullptr) {}
+  explicit NextResult(RefCountedPtr<pipe_detail::Center<T>> center)
+      : center_(std::move(center)) {
+    GPR_ASSERT(center_ != nullptr);
+  }
+  explicit NextResult(bool cancelled)
+      : center_(nullptr), cancelled_(cancelled) {}
   ~NextResult();
   NextResult(const NextResult&) = delete;
   NextResult& operator=(const NextResult&) = delete;
-  NextResult(NextResult&& other) noexcept
-      : center_(std::exchange(other.center_, nullptr)) {}
-  NextResult& operator=(NextResult&& other) noexcept {
-    center_ = std::exchange(other.center_, nullptr);
-    return *this;
-  }
+  NextResult(NextResult&& other) noexcept = default;
+  NextResult& operator=(NextResult&& other) noexcept = default;
 
   using value_type = T;
 
   void reset();
   bool has_value() const;
+  // Only valid if has_value()
   const T& value() const {
     GPR_ASSERT(has_value());
     return **this;
@@ -81,9 +94,12 @@ class NextResult final {
   }
   const T& operator*() const;
   T& operator*();
+  // Only valid if !has_value()
+  bool cancelled() { return cancelled_; }
 
  private:
-  pipe_detail::Center<T>* center_;
+  RefCountedPtr<pipe_detail::Center<T>> center_;
+  bool cancelled_;
 };
 
 namespace pipe_detail {
@@ -96,71 +112,39 @@ class Next;
 // Center sits between a sender and a receiver to provide a one-deep buffer of
 // Ts
 template <typename T>
-class Center {
+class Center : public InterceptorList<T> {
  public:
   // Initialize with one send ref (held by PipeSender) and one recv ref (held by
   // PipeReceiver)
   Center() {
-    send_refs_ = 1;
-    recv_refs_ = 1;
+    refs_ = 2;
     value_state_ = ValueState::kEmpty;
   }
 
-  // Add one ref to the send side of this object, and return this.
-  Center* RefSend() {
-    if (grpc_trace_promise_pipe.enabled()) {
-      gpr_log(GPR_INFO, "%s", DebugOpString("RefSend").c_str());
-    }
-    send_refs_++;
-    GPR_ASSERT(send_refs_ != 0);
-    return this;
-  }
-
-  // Add one ref to the recv side of this object, and return this.
-  Center* RefRecv() {
-    if (grpc_trace_promise_pipe.enabled()) {
-      gpr_log(GPR_INFO, "%s", DebugOpString("RefRecv").c_str());
+  // Add one ref to this object, and return this.
+  void IncrementRefCount() {
+    if (grpc_trace_promise_primitives.enabled()) {
+      gpr_log(GPR_DEBUG, "%s", DebugOpString("IncrementRefCount").c_str());
     }
-    recv_refs_++;
-    GPR_ASSERT(recv_refs_ != 0);
-    return this;
+    refs_++;
+    GPR_DEBUG_ASSERT(refs_ != 0);
   }
 
-  // Drop a send side ref
-  // If no send refs remain, wake due to send closure
-  // If no refs remain, destroy this object
-  void UnrefSend() {
-    if (grpc_trace_promise_pipe.enabled()) {
-      gpr_log(GPR_INFO, "%s", DebugOpString("UnrefSend").c_str());
-    }
-    GPR_DEBUG_ASSERT(send_refs_ > 0);
-    send_refs_--;
-    if (0 == send_refs_) {
-      on_full_.Wake();
-      on_empty_.Wake();
-      if (0 == recv_refs_) {
-        this->~Center();
-      }
-    }
+  RefCountedPtr<Center> Ref() {
+    IncrementRefCount();
+    return RefCountedPtr<Center>(this);
   }
 
-  // Drop a recv side ref
-  // If no recv refs remain, wake due to recv closure
+  // Drop a ref
   // If no refs remain, destroy this object
-  void UnrefRecv() {
-    if (grpc_trace_promise_pipe.enabled()) {
-      gpr_log(GPR_INFO, "%s", DebugOpString("UnrefRecv").c_str());
+  void Unref() {
+    if (grpc_trace_promise_primitives.enabled()) {
+      gpr_log(GPR_DEBUG, "%s", DebugOpString("Unref").c_str());
     }
-    GPR_DEBUG_ASSERT(recv_refs_ > 0);
-    recv_refs_--;
-    if (0 == recv_refs_) {
-      on_full_.Wake();
-      on_empty_.Wake();
-      if (0 == send_refs_) {
-        this->~Center();
-      } else if (value_state_ == ValueState::kReady) {
-        ResetValue();
-      }
+    GPR_DEBUG_ASSERT(refs_ > 0);
+    refs_--;
+    if (0 == refs_) {
+      this->~Center();
     }
   }
 
@@ -169,26 +153,45 @@ class Center {
   // Return true if the value was pushed.
   // Return false if the recv end is closed.
   Poll<bool> Push(T* value) {
-    if (grpc_trace_promise_pipe.enabled()) {
+    if (grpc_trace_promise_primitives.enabled()) {
       gpr_log(GPR_INFO, "%s", DebugOpString("Push").c_str());
     }
-    GPR_DEBUG_ASSERT(send_refs_ != 0);
-    if (recv_refs_ == 0) return false;
-    if (value_state_ != ValueState::kEmpty) return on_empty_.pending();
-    value_state_ = ValueState::kReady;
-    value_ = std::move(*value);
-    on_full_.Wake();
-    return true;
+    GPR_DEBUG_ASSERT(refs_ != 0);
+    switch (value_state_) {
+      case ValueState::kClosed:
+      case ValueState::kReadyClosed:
+      case ValueState::kCancelled:
+        return false;
+      case ValueState::kReady:
+      case ValueState::kAcked:
+        return on_empty_.pending();
+      case ValueState::kEmpty:
+        value_state_ = ValueState::kReady;
+        value_ = std::move(*value);
+        on_full_.Wake();
+        return true;
+    }
+    GPR_UNREACHABLE_CODE(return false);
   }
 
   Poll<bool> PollAck() {
-    if (grpc_trace_promise_pipe.enabled()) {
+    if (grpc_trace_promise_primitives.enabled()) {
       gpr_log(GPR_INFO, "%s", DebugOpString("PollAck").c_str());
     }
-    GPR_DEBUG_ASSERT(send_refs_ != 0);
-    if (recv_refs_ == 0) return value_state_ == ValueState::kAcked;
-    if (value_state_ != ValueState::kAcked) return on_empty_.pending();
-    value_state_ = ValueState::kEmpty;
+    GPR_DEBUG_ASSERT(refs_ != 0);
+    switch (value_state_) {
+      case ValueState::kClosed:
+      case ValueState::kReadyClosed:
+      case ValueState::kCancelled:
+        return false;
+      case ValueState::kReady:
+      case ValueState::kEmpty:
+        return on_empty_.pending();
+      case ValueState::kAcked:
+        value_state_ = ValueState::kEmpty;
+        on_empty_.Wake();
+        return true;
+    }
     return true;
   }
 
@@ -196,47 +199,107 @@ class Center {
   // Return Pending if there is no value.
   // Return the value if one was retrieved.
   // Return nullopt if the send end is closed and no value had been pushed.
-  Poll<NextResult<T>> Next() {
-    if (grpc_trace_promise_pipe.enabled()) {
+  Poll<absl::optional<T>> Next() {
+    if (grpc_trace_promise_primitives.enabled()) {
       gpr_log(GPR_INFO, "%s", DebugOpString("Next").c_str());
     }
-    GPR_DEBUG_ASSERT(recv_refs_ != 0);
-    if (value_state_ != ValueState::kReady) {
-      if (send_refs_ == 0) return NextResult<T>(nullptr);
-      return on_full_.pending();
+    GPR_DEBUG_ASSERT(refs_ != 0);
+    switch (value_state_) {
+      case ValueState::kEmpty:
+      case ValueState::kAcked:
+        return on_full_.pending();
+      case ValueState::kReadyClosed:
+        this->ResetInterceptorList();
+        value_state_ = ValueState::kClosed;
+        ABSL_FALLTHROUGH_INTENDED;
+      case ValueState::kReady:
+        return std::move(value_);
+      case ValueState::kClosed:
+      case ValueState::kCancelled:
+        return absl::nullopt;
     }
-    return NextResult<T>(RefRecv());
+    GPR_UNREACHABLE_CODE(return absl::nullopt);
   }
 
   void AckNext() {
-    if (grpc_trace_promise_pipe.enabled()) {
+    if (grpc_trace_promise_primitives.enabled()) {
       gpr_log(GPR_INFO, "%s", DebugOpString("AckNext").c_str());
     }
-    GPR_DEBUG_ASSERT(value_state_ == ValueState::kReady);
-    value_state_ = ValueState::kAcked;
-    on_empty_.Wake();
-    UnrefRecv();
+    switch (value_state_) {
+      case ValueState::kReady:
+        value_state_ = ValueState::kAcked;
+        on_empty_.Wake();
+        break;
+      case ValueState::kReadyClosed:
+        this->ResetInterceptorList();
+        value_state_ = ValueState::kClosed;
+        break;
+      case ValueState::kClosed:
+      case ValueState::kCancelled:
+        break;
+      case ValueState::kEmpty:
+      case ValueState::kAcked:
+        abort();
+    }
+  }
+
+  void MarkClosed() {
+    if (grpc_trace_promise_primitives.enabled()) {
+      gpr_log(GPR_INFO, "%s", DebugOpString("MarkClosed").c_str());
+    }
+    switch (value_state_) {
+      case ValueState::kEmpty:
+      case ValueState::kAcked:
+        this->ResetInterceptorList();
+        value_state_ = ValueState::kClosed;
+        on_full_.Wake();
+        break;
+      case ValueState::kReady:
+        value_state_ = ValueState::kReadyClosed;
+        break;
+      case ValueState::kReadyClosed:
+      case ValueState::kClosed:
+      case ValueState::kCancelled:
+        break;
+    }
   }
 
+  void MarkCancelled() {
+    if (grpc_trace_promise_primitives.enabled()) {
+      gpr_log(GPR_INFO, "%s", DebugOpString("MarkCancelled").c_str());
+    }
+    switch (value_state_) {
+      case ValueState::kEmpty:
+      case ValueState::kAcked:
+      case ValueState::kReady:
+      case ValueState::kReadyClosed:
+        this->ResetInterceptorList();
+        value_state_ = ValueState::kCancelled;
+        on_full_.Wake();
+        break;
+      case ValueState::kClosed:
+        value_state_ = ValueState::kCancelled;
+        break;
+      case ValueState::kCancelled:
+        break;
+    }
+  }
+
+  bool cancelled() { return value_state_ == ValueState::kCancelled; }
+
   T& value() { return value_; }
   const T& value() const { return value_; }
 
- private:
   std::string DebugTag() {
-    return absl::StrCat(Activity::current()->DebugTag(), "PIPE[0x",
-                        reinterpret_cast<uintptr_t>(this), "]: ");
-  }
-  std::string DebugOpString(std::string op) {
-    return absl::StrCat(DebugTag(), op, " send_refs=", send_refs_,
-                        " recv_refs=", recv_refs_,
-                        " value_state=", ValueStateName(value_state_));
-  }
-  void ResetValue() {
-    // Fancy dance to move out of value in the off chance that we reclaim some
-    // memory earlier.
-    [](T) {}(std::move(value_));
-    value_state_ = ValueState::kEmpty;
+    if (auto* activity = Activity::current()) {
+      return absl::StrCat(activity->DebugTag(), " PIPE[0x",
+                          reinterpret_cast<uintptr_t>(this), "]: ");
+    } else {
+      return absl::StrCat("PIPE[0x", reinterpret_cast<uintptr_t>(this), "]: ");
+    }
   }
+
+ private:
   // State of value_.
   enum class ValueState : uint8_t {
     // No value is set, it's possible to send.
@@ -246,31 +309,52 @@ class Center {
     // Value has been received and acked, we can unblock senders and transition
     // to empty.
     kAcked,
+    // Pipe is closed successfully, no more values can be sent
+    kClosed,
+    // Pipe is closed successfully, no more values can be sent
+    // (but one value is queued and ready to be received)
+    kReadyClosed,
+    // Pipe is closed unsuccessfully, no more values can be sent
+    kCancelled,
   };
+
+  std::string DebugOpString(std::string op) {
+    return absl::StrCat(DebugTag(), op, " refs=", refs_,
+                        " value_state=", ValueStateName(value_state_),
+                        " on_empty=", on_empty_.DebugString().c_str(),
+                        " on_full=", on_full_.DebugString().c_str());
+  }
+
   static const char* ValueStateName(ValueState state) {
     switch (state) {
       case ValueState::kEmpty:
-        return "kEmpty";
+        return "Empty";
       case ValueState::kReady:
-        return "kReady";
+        return "Ready";
       case ValueState::kAcked:
-        return "kAcked";
+        return "Acked";
+      case ValueState::kClosed:
+        return "Closed";
+      case ValueState::kReadyClosed:
+        return "ReadyClosed";
+      case ValueState::kCancelled:
+        return "Cancelled";
     }
     GPR_UNREACHABLE_CODE(return "unknown");
   }
+
   T value_;
-  // Number of sending objects.
-  // 0 => send is closed.
-  // 1 ref each for PipeSender and Push.
-  uint8_t send_refs_ : 2;
-  // Number of receiving objects.
-  // 0 => recv is closed.
-  // 1 ref each for PipeReceiver, Next, and NextResult.
-  uint8_t recv_refs_ : 2;
+  // Number of refs
+  uint8_t refs_;
   // Current state of the value.
-  ValueState value_state_ : 2;
+  ValueState value_state_;
   IntraActivityWaiter on_empty_;
   IntraActivityWaiter on_full_;
+
+  // Make failure to destruct show up in ASAN builds.
+#ifndef NDEBUG
+  std::unique_ptr<int> asan_canary_ = absl::make_unique<int>(0);
+#endif
 };
 
 }  // namespace pipe_detail
@@ -283,23 +367,18 @@ class PipeSender {
 
   PipeSender(const PipeSender&) = delete;
   PipeSender& operator=(const PipeSender&) = delete;
-
-  PipeSender(PipeSender&& other) noexcept : center_(other.center_) {
-    other.center_ = nullptr;
-  }
-  PipeSender& operator=(PipeSender&& other) noexcept {
-    if (center_ != nullptr) center_->UnrefSend();
-    center_ = other.center_;
-    other.center_ = nullptr;
-    return *this;
-  }
+  PipeSender(PipeSender&& other) noexcept = default;
+  PipeSender& operator=(PipeSender&& other) noexcept = default;
 
   ~PipeSender() {
-    if (center_ != nullptr) center_->UnrefSend();
+    if (center_ != nullptr) center_->MarkClosed();
   }
 
   void Close() {
-    if (auto* center = std::exchange(center_, nullptr)) center->UnrefSend();
+    if (center_ != nullptr) {
+      center_->MarkClosed();
+      center_.reset();
+    }
   }
 
   void Swap(PipeSender<T>* other) { std::swap(center_, other->center_); }
@@ -310,32 +389,37 @@ class PipeSender {
   // receiver is either closed or able to receive another message.
   PushType Push(T value);
 
+  template <typename Fn>
+  void InterceptAndMap(Fn f, DebugLocation from = {}) {
+    center_->PrependMap(std::move(f), from);
+  }
+
+  template <typename Fn, typename OnHalfClose>
+  void InterceptAndMap(Fn f, OnHalfClose cleanup_fn, DebugLocation from = {}) {
+    center_->PrependMapWithCleanup(std::move(f), std::move(cleanup_fn), from);
+  }
+
  private:
   friend struct Pipe<T>;
   explicit PipeSender(pipe_detail::Center<T>* center) : center_(center) {}
-  pipe_detail::Center<T>* center_;
+  RefCountedPtr<pipe_detail::Center<T>> center_;
+
+  // Make failure to destruct show up in ASAN builds.
+#ifndef NDEBUG
+  std::unique_ptr<int> asan_canary_ = absl::make_unique<int>(0);
+#endif
 };
 
 // Receive end of a Pipe.
 template <typename T>
 class PipeReceiver {
  public:
-  using NextType = pipe_detail::Next<T>;
-
   PipeReceiver(const PipeReceiver&) = delete;
   PipeReceiver& operator=(const PipeReceiver&) = delete;
-
-  PipeReceiver(PipeReceiver&& other) noexcept : center_(other.center_) {
-    other.center_ = nullptr;
-  }
-  PipeReceiver& operator=(PipeReceiver&& other) noexcept {
-    if (center_ != nullptr) center_->UnrefRecv();
-    center_ = other.center_;
-    other.center_ = nullptr;
-    return *this;
-  }
+  PipeReceiver(PipeReceiver&& other) noexcept = default;
+  PipeReceiver& operator=(PipeReceiver&& other) noexcept = default;
   ~PipeReceiver() {
-    if (center_ != nullptr) center_->UnrefRecv();
+    if (center_ != nullptr) center_->MarkClosed();
   }
 
   void Swap(PipeReceiver<T>* other) { std::swap(center_, other->center_); }
@@ -345,12 +429,28 @@ class PipeReceiver {
   // message was received, or no value if the other end of the pipe was closed.
   // Blocks the promise until the receiver is either closed or a message is
   // available.
-  NextType Next();
+  auto Next();
+
+  template <typename Fn>
+  void InterceptAndMap(Fn f, DebugLocation from = {}) {
+    center_->AppendMap(std::move(f), from);
+  }
+
+  template <typename Fn, typename OnHalfClose>
+  void InterceptAndMapWithHalfClose(Fn f, OnHalfClose cleanup_fn,
+                                    DebugLocation from = {}) {
+    center_->AppendMapWithCleanup(std::move(f), std::move(cleanup_fn), from);
+  }
 
  private:
   friend struct Pipe<T>;
   explicit PipeReceiver(pipe_detail::Center<T>* center) : center_(center) {}
-  pipe_detail::Center<T>* center_;
+  RefCountedPtr<pipe_detail::Center<T>> center_;
+
+  // Make failure to destruct show up in ASAN builds.
+#ifndef NDEBUG
+  std::unique_ptr<int> asan_canary_ = absl::make_unique<int>(0);
+#endif
 };
 
 namespace pipe_detail {
@@ -361,42 +461,33 @@ class Push {
  public:
   Push(const Push&) = delete;
   Push& operator=(const Push&) = delete;
-  Push(Push&& other) noexcept
-      : center_(other.center_), push_(std::move(other.push_)) {
-    other.center_ = nullptr;
-  }
-  Push& operator=(Push&& other) noexcept {
-    if (center_ != nullptr) center_->UnrefSend();
-    center_ = other.center_;
-    other.center_ = nullptr;
-    push_ = std::move(other.push_);
-    return *this;
-  }
-
-  ~Push() {
-    if (center_ != nullptr) center_->UnrefSend();
-  }
+  Push(Push&& other) noexcept = default;
+  Push& operator=(Push&& other) noexcept = default;
 
   Poll<bool> operator()() {
-    if (push_.has_value()) {
-      auto r = center_->Push(&*push_);
+    if (center_ == nullptr) return false;
+    if (auto* p = absl::get_if<T>(&state_)) {
+      auto r = center_->Push(p);
       if (auto* ok = absl::get_if<bool>(&r)) {
-        push_.reset();
+        state_.template emplace<AwaitingAck>();
         if (!*ok) return false;
       } else {
         return Pending{};
       }
     }
-    GPR_DEBUG_ASSERT(!push_.has_value());
+    GPR_DEBUG_ASSERT(absl::holds_alternative<AwaitingAck>(state_));
     return center_->PollAck();
   }
 
  private:
+  struct AwaitingAck {};
+
   friend class PipeSender<T>;
-  explicit Push(pipe_detail::Center<T>* center, T push)
-      : center_(center), push_(std::move(push)) {}
-  Center<T>* center_;
-  absl::optional<T> push_;
+  explicit Push(RefCountedPtr<pipe_detail::Center<T>> center, T push)
+      : center_(std::move(center)), state_(std::move(push)) {}
+
+  RefCountedPtr<Center<T>> center_;
+  absl::variant<T, AwaitingAck> state_;
 };
 
 // Implementation of PipeReceiver::Next promise.
@@ -405,46 +496,56 @@ class Next {
  public:
   Next(const Next&) = delete;
   Next& operator=(const Next&) = delete;
-  Next(Next&& other) noexcept : center_(other.center_) {
-    other.center_ = nullptr;
-  }
-  Next& operator=(Next&& other) noexcept {
-    if (center_ != nullptr) center_->UnrefRecv();
-    center_ = other.center_;
-    other.center_ = nullptr;
-    return *this;
-  }
+  Next(Next&& other) noexcept = default;
+  Next& operator=(Next&& other) noexcept = default;
 
-  ~Next() {
-    if (center_ != nullptr) center_->UnrefRecv();
-  }
-
-  Poll<NextResult<T>> operator()() {
-    auto r = center_->Next();
-    if (!absl::holds_alternative<Pending>(r)) {
-      std::exchange(center_, nullptr)->UnrefRecv();
-    }
-    return r;
-  }
+  Poll<absl::optional<T>> operator()() { return center_->Next(); }
 
  private:
   friend class PipeReceiver<T>;
-  explicit Next(pipe_detail::Center<T>* center) : center_(center) {}
-  Center<T>* center_;
+  explicit Next(RefCountedPtr<Center<T>> center) : center_(std::move(center)) {}
+
+  RefCountedPtr<Center<T>> center_;
 };
 
 }  // namespace pipe_detail
 
 template <typename T>
 pipe_detail::Push<T> PipeSender<T>::Push(T value) {
-  return pipe_detail::Push<T>(center_->RefSend(), std::move(value));
+  return pipe_detail::Push<T>(center_ == nullptr ? nullptr : center_->Ref(),
+                              std::move(value));
 }
 
 template <typename T>
-pipe_detail::Next<T> PipeReceiver<T>::Next() {
-  return pipe_detail::Next<T>(center_->RefRecv());
+auto PipeReceiver<T>::Next() {
+  return Seq(
+      pipe_detail::Next<T>(center_->Ref()),
+      [center = center_->Ref()](absl::optional<T> value) {
+        bool open = value.has_value();
+        bool cancelled = center->cancelled();
+        return If(
+            open,
+            [center = std::move(center), value = std::move(value)]() mutable {
+              auto run_interceptors = center->Run(std::move(value));
+              return Map(std::move(run_interceptors),
+                         [center = std::move(center)](
+                             absl::optional<T> value) mutable {
+                           if (value.has_value()) {
+                             center->value() = std::move(*value);
+                             return NextResult<T>(std::move(center));
+                           } else {
+                             center->MarkCancelled();
+                             return NextResult<T>(true);
+                           }
+                         });
+            },
+            [cancelled]() { return NextResult<T>(cancelled); });
+      });
 }
 
+template <typename T>
+using PipeReceiverNextType = decltype(std::declval<PipeReceiver<T>>().Next());
+
 template <typename T>
 bool NextResult<T>::has_value() const {
   return center_ != nullptr;
@@ -467,7 +568,10 @@ NextResult<T>::~NextResult() {
 
 template <typename T>
 void NextResult<T>::reset() {
-  if (auto* p = std::exchange(center_, nullptr)) p->AckNext();
+  if (center_ != nullptr) {
+    center_->AckNext();
+    center_.reset();
+  }
 }
 
 // A Pipe is an intra-Activity communications channel that transmits T's from
diff --git a/src/core/lib/promise/pipe.cc b/src/core/lib/promise/trace.cc
similarity index 82%
rename from src/core/lib/promise/pipe.cc
rename to src/core/lib/promise/trace.cc
index cbb408bea19..21b430526df 100644
--- a/src/core/lib/promise/pipe.cc
+++ b/src/core/lib/promise/trace.cc
@@ -14,6 +14,7 @@
 
 #include <grpc/support/port_platform.h>
 
-#include "src/core/lib/promise/pipe.h"
+#include "src/core/lib/promise/trace.h"
 
-grpc_core::DebugOnlyTraceFlag grpc_trace_promise_pipe(false, "promise_pipe");
+grpc_core::DebugOnlyTraceFlag grpc_trace_promise_primitives(
+    false, "promise_primitives");
diff --git a/src/core/lib/promise/trace.h b/src/core/lib/promise/trace.h
new file mode 100644
index 00000000000..de66138fec6
--- /dev/null
+++ b/src/core/lib/promise/trace.h
@@ -0,0 +1,24 @@
+// Copyright 2022 gRPC authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef GRPC_SRC_CORE_LIB_PROMISE_TRACE_H
+#define GRPC_SRC_CORE_LIB_PROMISE_TRACE_H
+
+#include <grpc/support/port_platform.h>
+
+#include "src/core/lib/debug/trace.h"
+
+extern grpc_core::DebugOnlyTraceFlag grpc_trace_promise_primitives;
+
+#endif  // GRPC_SRC_CORE_LIB_PROMISE_TRACE_H
diff --git a/src/core/lib/promise/try_concurrently.h b/src/core/lib/promise/try_concurrently.h
index b05c3089b8e..06ca3739bed 100644
--- a/src/core/lib/promise/try_concurrently.h
+++ b/src/core/lib/promise/try_concurrently.h
@@ -20,17 +20,22 @@
 #include <stddef.h>
 
 #include <cstdint>
+#include <string>
 #include <type_traits>
 #include <utility>
 
+#include "absl/strings/str_cat.h"
 #include "absl/types/variant.h"
 
 #include <grpc/support/log.h>
 
+#include "src/core/lib/debug/trace.h"
 #include "src/core/lib/gprpp/construct_destruct.h"
+#include "src/core/lib/promise/activity.h"
 #include "src/core/lib/promise/detail/promise_like.h"
 #include "src/core/lib/promise/detail/status.h"
 #include "src/core/lib/promise/poll.h"
+#include "src/core/lib/promise/trace.h"
 
 namespace grpc_core {
 
@@ -185,9 +190,18 @@ class TryConcurrently {
       typename PollTraits<decltype(std::declval<PromiseLike<Main>>()())>::Type;
 
   Poll<Result> operator()() {
+    if (grpc_trace_promise_primitives.enabled()) {
+      gpr_log(GPR_DEBUG, "%sBEGIN POLL: done_bits=%x necessary_bits=%x",
+              DebugTag().c_str(), done_bits_, NecessaryBits());
+    }
     auto r = pre_main_.template Run<Result, 1>(done_bits_);
     if (auto* status = absl::get_if<Result>(&r)) {
       GPR_DEBUG_ASSERT(!IsStatusOk(*status));
+      if (grpc_trace_promise_primitives.enabled()) {
+        gpr_log(GPR_DEBUG,
+                "%sFAIL POLL PRE-MAIN: done_bits=%x necessary_bits=%x",
+                DebugTag().c_str(), done_bits_, NecessaryBits());
+      }
       return std::move(*status);
     }
     if ((done_bits_ & 1) == 0) {
@@ -201,8 +215,17 @@ class TryConcurrently {
     r = post_main_.template Run<Result, 1 + PreMain::Size()>(done_bits_);
     if (auto* status = absl::get_if<Result>(&r)) {
       GPR_DEBUG_ASSERT(!IsStatusOk(*status));
+      if (grpc_trace_promise_primitives.enabled()) {
+        gpr_log(GPR_DEBUG,
+                "%sFAIL POLL POST-MAIN: done_bits=%x necessary_bits=%x",
+                DebugTag().c_str(), done_bits_, NecessaryBits());
+      }
       return std::move(*status);
     }
+    if (grpc_trace_promise_primitives.enabled()) {
+      gpr_log(GPR_DEBUG, "%sEND POLL: done_bits=%x necessary_bits=%x",
+              DebugTag().c_str(), done_bits_, NecessaryBits());
+    }
     if ((done_bits_ & NecessaryBits()) == NecessaryBits()) {
       return std::move(result_);
     }
@@ -234,6 +257,11 @@ class TryConcurrently {
   // that is all promises that are not the main one.
   constexpr uint8_t HelperBits() { return AllBits() ^ 1; }
 
+  std::string DebugTag() {
+    return absl::StrCat(Activity::current()->DebugTag(), " TRY_CONCURRENTLY[0x",
+                        reinterpret_cast<uintptr_t>(this), "]: ");
+  }
+
   // done_bits signifies which operations have completed.
   // Bit 0 is set if main_ has completed.
   // The next higher bits correspond one per pre-main promise.
diff --git a/src/core/lib/resource_quota/arena.h b/src/core/lib/resource_quota/arena.h
index 9b67d1ffba9..09d559664b0 100644
--- a/src/core/lib/resource_quota/arena.h
+++ b/src/core/lib/resource_quota/arena.h
@@ -30,6 +30,7 @@
 #include <stddef.h>
 
 #include <atomic>
+#include <limits>
 #include <memory>
 #include <new>
 #include <utility>
@@ -48,6 +49,11 @@ namespace grpc_core {
 
 namespace arena_detail {
 
+struct PoolAndSize {
+  size_t alloc_size;
+  size_t pool_index;
+};
+
 template <typename Void, size_t kIndex, size_t kObjectSize,
           size_t... kBucketSize>
 struct PoolIndexForSize;
@@ -81,10 +87,37 @@ constexpr size_t AllocationSizeFromObjectSize(
   return PoolIndexForSize<void, 0, kObjectSize, kBucketSizes...>::kSize;
 }
 
+template <size_t kIndex, size_t... kBucketSizes>
+struct ChoosePoolForAllocationSizeImpl;
+
+template <size_t kIndex, size_t kBucketSize, size_t... kBucketSizes>
+struct ChoosePoolForAllocationSizeImpl<kIndex, kBucketSize, kBucketSizes...> {
+  static PoolAndSize Fn(size_t n) {
+    if (n <= kBucketSize) return {kBucketSize, kIndex};
+    return ChoosePoolForAllocationSizeImpl<kIndex + 1, kBucketSizes...>::Fn(n);
+  }
+};
+
+template <size_t kIndex>
+struct ChoosePoolForAllocationSizeImpl<kIndex> {
+  static PoolAndSize Fn(size_t n) {
+    return PoolAndSize{n, std::numeric_limits<size_t>::max()};
+  }
+};
+
+template <size_t... kBucketSizes>
+PoolAndSize ChoosePoolForAllocationSize(
+    size_t n, absl::integer_sequence<size_t, kBucketSizes...>) {
+  return ChoosePoolForAllocationSizeImpl<0, kBucketSizes...>::Fn(n);
+}
+
 }  // namespace arena_detail
 
 class Arena {
   using PoolSizes = absl::integer_sequence<size_t, 256, 512, 768>;
+  struct FreePoolNode {
+    FreePoolNode* next;
+  };
 
  public:
   // Create an arena, with \a initial_size bytes in the first allocated buffer.
@@ -133,7 +166,8 @@ class Arena {
 
   class PooledDeleter {
    public:
-    explicit PooledDeleter(Arena* arena) : arena_(arena) {}
+    explicit PooledDeleter(std::atomic<FreePoolNode*>* free_list)
+        : free_list_(free_list) {}
     PooledDeleter() = default;
     template <typename T>
     void operator()(T* p) {
@@ -142,24 +176,57 @@ class Arena {
       // by setting the arena to nullptr.
       // This is a transitional hack and should be removed once promise based
       // filter is removed.
-      if (arena_ != nullptr) arena_->DeletePooled(p);
+      if (free_list_ != nullptr) {
+        p->~T();
+        FreePooled(p, free_list_);
+      }
     }
 
+    bool has_freelist() const { return free_list_ != nullptr; }
+
    private:
-    Arena* arena_;
+    std::atomic<FreePoolNode*>* free_list_;
   };
 
   template <typename T>
   using PoolPtr = std::unique_ptr<T, PooledDeleter>;
 
+  // Make a unique_ptr to T that is allocated from the arena.
+  // When the pointer is released, the memory may be reused for other
+  // MakePooled(.*) calls.
+  // CAUTION: The amount of memory allocated is rounded up to the nearest
+  //          value in Arena::PoolSizes, and so this may pessimize total
+  //          arena size.
   template <typename T, typename... Args>
   PoolPtr<T> MakePooled(Args&&... args) {
+    auto* free_list =
+        &pools_[arena_detail::PoolFromObjectSize<sizeof(T)>(PoolSizes())];
     return PoolPtr<T>(
         new (AllocPooled(
             arena_detail::AllocationSizeFromObjectSize<sizeof(T)>(PoolSizes()),
-            &pools_[arena_detail::PoolFromObjectSize<sizeof(T)>(PoolSizes())]))
-            T(std::forward<Args>(args)...),
-        PooledDeleter(this));
+            free_list)) T(std::forward<Args>(args)...),
+        PooledDeleter(free_list));
+  }
+
+  // Make a unique_ptr to an array of T that is allocated from the arena.
+  // When the pointer is released, the memory may be reused for other
+  // MakePooled(.*) calls.
+  // One can use MakePooledArray<char> to allocate a buffer of bytes.
+  // CAUTION: The amount of memory allocated is rounded up to the nearest
+  //          value in Arena::PoolSizes, and so this may pessimize total
+  //          arena size.
+  template <typename T>
+  PoolPtr<T[]> MakePooledArray(size_t n) {
+    auto where =
+        arena_detail::ChoosePoolForAllocationSize(n * sizeof(T), PoolSizes());
+    if (where.pool_index == std::numeric_limits<size_t>::max()) {
+      return PoolPtr<T[]>(new (Alloc(where.alloc_size)) T[n],
+                          PooledDeleter(nullptr));
+    } else {
+      return PoolPtr<T[]>(
+          new (AllocPooled(where.alloc_size, &pools_[where.pool_index])) T[n],
+          PooledDeleter(&pools_[where.pool_index]));
+    }
   }
 
  private:
@@ -202,17 +269,6 @@ class Arena {
 
   void* AllocZone(size_t size);
 
-  template <typename T>
-  void DeletePooled(T* p) {
-    p->~T();
-    FreePooled(
-        p, &pools_[arena_detail::PoolFromObjectSize<sizeof(T)>(PoolSizes())]);
-  }
-
-  struct FreePoolNode {
-    FreePoolNode* next;
-  };
-
   void* AllocPooled(size_t alloc_size, std::atomic<FreePoolNode*>* head);
   static void FreePooled(void* p, std::atomic<FreePoolNode*>* head);
 
diff --git a/src/core/lib/slice/slice.cc b/src/core/lib/slice/slice.cc
index 177ca456ec5..51ee3a83644 100644
--- a/src/core/lib/slice/slice.cc
+++ b/src/core/lib/slice/slice.cc
@@ -283,7 +283,7 @@ grpc_slice grpc_slice_sub(grpc_slice source, size_t begin, size_t end) {
     subset = grpc_slice_sub_no_ref(source, begin, end);
     // Bump the refcount
     if (subset.refcount != grpc_slice_refcount::NoopRefcount()) {
-      subset.refcount->Ref();
+      subset.refcount->Ref({});
     }
   }
   return subset;
@@ -332,7 +332,7 @@ grpc_slice grpc_slice_split_tail_maybe_ref(grpc_slice* source, size_t split,
           tail.refcount = source->refcount;
           // Bump the refcount
           if (tail.refcount != grpc_slice_refcount::NoopRefcount()) {
-            tail.refcount->Ref();
+            tail.refcount->Ref({});
           }
           break;
       }
@@ -378,7 +378,7 @@ grpc_slice grpc_slice_split_head(grpc_slice* source, size_t split) {
     head.refcount = source->refcount;
     // Bump the refcount
     if (head.refcount != grpc_slice_refcount::NoopRefcount()) {
-      head.refcount->Ref();
+      head.refcount->Ref({});
     }
     // Point into the source array
     head.data.refcounted.bytes = source->data.refcounted.bytes;
diff --git a/src/core/lib/slice/slice.h b/src/core/lib/slice/slice.h
index 17047008eca..2640ee80644 100644
--- a/src/core/lib/slice/slice.h
+++ b/src/core/lib/slice/slice.h
@@ -31,6 +31,7 @@
 #include <grpc/support/log.h>
 
 #include "src/core/lib/gpr/string.h"
+#include "src/core/lib/gprpp/debug_location.h"
 #include "src/core/lib/slice/slice_internal.h"
 #include "src/core/lib/slice/slice_refcount.h"
 
@@ -54,16 +55,17 @@
 
 namespace grpc_core {
 
-inline const grpc_slice& CSliceRef(const grpc_slice& slice) {
+inline const grpc_slice& CSliceRef(const grpc_slice& slice,
+                                   DebugLocation loc = {}) {
   if (reinterpret_cast<uintptr_t>(slice.refcount) > 1) {
-    slice.refcount->Ref();
+    slice.refcount->Ref(loc);
   }
   return slice;
 }
 
-inline void CSliceUnref(const grpc_slice& slice) {
+inline void CSliceUnref(const grpc_slice& slice, DebugLocation loc = {}) {
   if (reinterpret_cast<uintptr_t>(slice.refcount) > 1) {
-    slice.refcount->Unref();
+    slice.refcount->Unref(loc);
   }
 }
 
@@ -391,10 +393,11 @@ class GPR_MSVC_EMPTY_BASE_CLASS_WORKAROUND Slice
   Slice Copy() const { return Slice(grpc_slice_copy(c_slice())); }
 
   static Slice FromRefcountAndBytes(grpc_slice_refcount* r,
-                                    const uint8_t* begin, const uint8_t* end) {
+                                    const uint8_t* begin, const uint8_t* end,
+                                    DebugLocation location = {}) {
     grpc_slice out;
     out.refcount = r;
-    if (r != grpc_slice_refcount::NoopRefcount()) r->Ref();
+    if (r != grpc_slice_refcount::NoopRefcount()) r->Ref(location);
     out.data.refcounted.bytes = const_cast<uint8_t*>(begin);
     out.data.refcounted.length = end - begin;
     return Slice(out);
diff --git a/src/core/lib/slice/slice_buffer.h b/src/core/lib/slice/slice_buffer.h
index b87a91e1306..45d41031380 100644
--- a/src/core/lib/slice/slice_buffer.h
+++ b/src/core/lib/slice/slice_buffer.h
@@ -20,8 +20,11 @@
 #include <stdint.h>
 #include <string.h>
 
+#include <memory>
 #include <string>
 
+#include "absl/memory/memory.h"
+
 #include <grpc/slice.h>
 #include <grpc/slice_buffer.h>
 
@@ -151,6 +154,11 @@ class SliceBuffer {
  private:
   /// The backing raw slice buffer.
   grpc_slice_buffer slice_buffer_;
+
+// Make failure to destruct show up in ASAN builds.
+#ifndef NDEBUG
+  std::unique_ptr<int> asan_canary_ = absl::make_unique<int>(0);
+#endif
 };
 
 }  // namespace grpc_core
diff --git a/src/core/lib/slice/slice_refcount.cc b/src/core/lib/slice/slice_refcount.cc
new file mode 100644
index 00000000000..0a05f0a333a
--- /dev/null
+++ b/src/core/lib/slice/slice_refcount.cc
@@ -0,0 +1,20 @@
+// Copyright 2016 gRPC authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include <grpc/support/port_platform.h>
+
+#include "src/core/lib/slice/slice_refcount.h"
+
+grpc_core::DebugOnlyTraceFlag grpc_slice_refcount_trace(false,
+                                                        "slice_refcount");
diff --git a/src/core/lib/slice/slice_refcount.h b/src/core/lib/slice/slice_refcount.h
index 5a862542d45..50fdb6efd9a 100644
--- a/src/core/lib/slice/slice_refcount.h
+++ b/src/core/lib/slice/slice_refcount.h
@@ -17,10 +17,18 @@
 
 #include <grpc/support/port_platform.h>
 
+#include <inttypes.h>
 #include <stddef.h>
 
 #include <atomic>
 
+#include <grpc/support/log.h>
+
+#include "src/core/lib/debug/trace.h"
+#include "src/core/lib/gprpp/debug_location.h"
+
+extern grpc_core::DebugOnlyTraceFlag grpc_slice_refcount_trace;
+
 // grpc_slice_refcount : A reference count for grpc_slice.
 struct grpc_slice_refcount {
  public:
@@ -40,9 +48,21 @@ struct grpc_slice_refcount {
   explicit grpc_slice_refcount(DestroyerFn destroyer_fn)
       : destroyer_fn_(destroyer_fn) {}
 
-  void Ref() { ref_.fetch_add(1, std::memory_order_relaxed); }
-  void Unref() {
-    if (ref_.fetch_sub(1, std::memory_order_acq_rel) == 1) {
+  void Ref(grpc_core::DebugLocation location) {
+    auto prev_refs = ref_.fetch_add(1, std::memory_order_relaxed);
+    if (grpc_slice_refcount_trace.enabled()) {
+      gpr_log(location.file(), location.line(), GPR_LOG_SEVERITY_INFO,
+              "REF %p %" PRIdPTR "->%" PRIdPTR, this, prev_refs, prev_refs + 1);
+    }
+  }
+  void Unref(grpc_core::DebugLocation location) {
+    auto prev_refs = ref_.fetch_sub(1, std::memory_order_acq_rel);
+    if (grpc_slice_refcount_trace.enabled()) {
+      gpr_log(location.file(), location.line(), GPR_LOG_SEVERITY_INFO,
+              "UNREF %p %" PRIdPTR "->%" PRIdPTR, this, prev_refs,
+              prev_refs - 1);
+    }
+    if (prev_refs == 1) {
       destroyer_fn_(this);
     }
   }
diff --git a/src/core/lib/surface/call.cc b/src/core/lib/surface/call.cc
index 06437057a67..6f7b771e1c8 100644
--- a/src/core/lib/surface/call.cc
+++ b/src/core/lib/surface/call.cc
@@ -84,7 +84,7 @@
 #include "src/core/lib/promise/activity.h"
 #include "src/core/lib/promise/arena_promise.h"
 #include "src/core/lib/promise/context.h"
-#include "src/core/lib/promise/latch.h"
+#include "src/core/lib/promise/detail/basic_seq.h"
 #include "src/core/lib/promise/pipe.h"
 #include "src/core/lib/promise/poll.h"
 #include "src/core/lib/resource_quota/arena.h"
@@ -103,7 +103,7 @@
 grpc_core::TraceFlag grpc_call_error_trace(false, "call_error");
 grpc_core::TraceFlag grpc_compression_trace(false, "compression");
 grpc_core::TraceFlag grpc_call_trace(false, "call");
-grpc_core::TraceFlag grpc_call_refcount_trace(false, "call_refcount");
+grpc_core::DebugOnlyTraceFlag grpc_call_refcount_trace(false, "call_refcount");
 
 namespace grpc_core {
 
@@ -452,6 +452,31 @@ class FilterStackCall final : public Call {
   static constexpr gpr_atm kRecvNone = 0;
   static constexpr gpr_atm kRecvInitialMetadataFirst = 1;
 
+  enum class PendingOp {
+    kRecvMessage,
+    kRecvInitialMetadata,
+    kRecvTrailingMetadata,
+    kSends
+  };
+  static intptr_t PendingOpMask(PendingOp op) {
+    return static_cast<intptr_t>(1) << static_cast<intptr_t>(op);
+  }
+  static std::string PendingOpString(intptr_t pending_ops) {
+    std::vector<absl::string_view> pending_op_strings;
+    if (pending_ops & PendingOpMask(PendingOp::kRecvMessage)) {
+      pending_op_strings.push_back("kRecvMessage");
+    }
+    if (pending_ops & PendingOpMask(PendingOp::kRecvInitialMetadata)) {
+      pending_op_strings.push_back("kRecvInitialMetadata");
+    }
+    if (pending_ops & PendingOpMask(PendingOp::kRecvTrailingMetadata)) {
+      pending_op_strings.push_back("kRecvTrailingMetadata");
+    }
+    if (pending_ops & PendingOpMask(PendingOp::kSends)) {
+      pending_op_strings.push_back("kSends");
+    }
+    return absl::StrCat("{", absl::StrJoin(pending_op_strings, ","), "}");
+  }
   struct BatchControl {
     FilterStackCall* call_ = nullptr;
     grpc_transport_stream_op_batch op_;
@@ -476,17 +501,26 @@ class FilterStackCall final : public Call {
     } completion_data_;
     grpc_closure start_batch_;
     grpc_closure finish_batch_;
-    std::atomic<intptr_t> steps_to_complete_{0};
+    std::atomic<intptr_t> ops_pending_{0};
     AtomicError batch_error_;
-    void set_num_steps_to_complete(uintptr_t steps) {
-      steps_to_complete_.store(steps, std::memory_order_release);
+    void set_pending_ops(uintptr_t ops) {
+      ops_pending_.store(ops, std::memory_order_release);
     }
-    bool completed_batch_step() {
-      return steps_to_complete_.fetch_sub(1, std::memory_order_acq_rel) == 1;
+    bool completed_batch_step(PendingOp op) {
+      auto mask = PendingOpMask(op);
+      auto r = ops_pending_.fetch_sub(mask, std::memory_order_acq_rel);
+      if (grpc_call_trace.enabled()) {
+        gpr_log(GPR_DEBUG, "BATCH:%p COMPLETE:%s REMAINING:%s (tag:%p)", this,
+                PendingOpString(mask).c_str(),
+                PendingOpString(r & ~mask).c_str(),
+                completion_data_.notify_tag.tag);
+      }
+      GPR_ASSERT((r & mask) != 0);
+      return r == mask;
     }
 
     void PostCompletion();
-    void FinishStep();
+    void FinishStep(PendingOp op);
     void ProcessDataAfterMetadata();
     void ReceivingStreamReady(grpc_error_handle error);
     void ValidateFilteredMetadata();
@@ -1105,6 +1139,10 @@ FilterStackCall::BatchControl* FilterStackCall::ReuseOrAllocateBatchControl(
 void FilterStackCall::BatchControl::PostCompletion() {
   FilterStackCall* call = call_;
   grpc_error_handle error = batch_error_.get();
+  if (grpc_call_trace.enabled()) {
+    gpr_log(GPR_DEBUG, "tag:%p batch_error=%s", completion_data_.notify_tag.tag,
+            error.ToString().c_str());
+  }
 
   if (op_.send_initial_metadata) {
     call->send_initial_metadata_.Clear();
@@ -1134,14 +1172,12 @@ void FilterStackCall::BatchControl::PostCompletion() {
   batch_error_.set(absl::OkStatus());
 
   if (completion_data_.notify_tag.is_closure) {
-    // unrefs error
     call_ = nullptr;
     Closure::Run(DEBUG_LOCATION,
                  static_cast<grpc_closure*>(completion_data_.notify_tag.tag),
                  error);
     call->InternalUnref("completion");
   } else {
-    // unrefs error
     grpc_cq_end_op(
         call->cq_, completion_data_.notify_tag.tag, error,
         [](void* user_data, grpc_cq_completion* /*storage*/) {
@@ -1154,8 +1190,8 @@ void FilterStackCall::BatchControl::PostCompletion() {
   }
 }
 
-void FilterStackCall::BatchControl::FinishStep() {
-  if (GPR_UNLIKELY(completed_batch_step())) {
+void FilterStackCall::BatchControl::FinishStep(PendingOp op) {
+  if (GPR_UNLIKELY(completed_batch_step(op))) {
     PostCompletion();
   }
 }
@@ -1165,7 +1201,7 @@ void FilterStackCall::BatchControl::ProcessDataAfterMetadata() {
   if (!call->receiving_slice_buffer_.has_value()) {
     *call->receiving_buffer_ = nullptr;
     call->receiving_message_ = false;
-    FinishStep();
+    FinishStep(PendingOp::kRecvMessage);
   } else {
     call->test_only_last_message_flags_ = call->receiving_stream_flags_;
     if ((call->receiving_stream_flags_ & GRPC_WRITE_INTERNAL_COMPRESS) &&
@@ -1180,12 +1216,20 @@ void FilterStackCall::BatchControl::ProcessDataAfterMetadata() {
         &(*call->receiving_buffer_)->data.raw.slice_buffer);
     call->receiving_message_ = false;
     call->receiving_slice_buffer_.reset();
-    FinishStep();
+    FinishStep(PendingOp::kRecvMessage);
   }
 }
 
 void FilterStackCall::BatchControl::ReceivingStreamReady(
     grpc_error_handle error) {
+  if (grpc_call_trace.enabled()) {
+    gpr_log(GPR_DEBUG,
+            "tag:%p ReceivingStreamReady error=%s "
+            "receiving_slice_buffer.has_value=%d recv_state=%" PRIdPTR,
+            completion_data_.notify_tag.tag, error.ToString().c_str(),
+            call_->receiving_slice_buffer_.has_value(),
+            gpr_atm_no_barrier_load(&call_->recv_state_));
+  }
   FilterStackCall* call = call_;
   if (!error.ok()) {
     call->receiving_slice_buffer_.reset();
@@ -1303,7 +1347,7 @@ void FilterStackCall::BatchControl::ReceivingInitialMetadataReady(
     Closure::Run(DEBUG_LOCATION, saved_rsr_closure, error);
   }
 
-  FinishStep();
+  FinishStep(PendingOp::kRecvInitialMetadata);
 }
 
 void FilterStackCall::BatchControl::ReceivingTrailingMetadataReady(
@@ -1312,7 +1356,7 @@ void FilterStackCall::BatchControl::ReceivingTrailingMetadataReady(
                           "recv_trailing_metadata_ready");
   grpc_metadata_batch* md = &call_->recv_trailing_metadata_;
   call_->RecvTrailingFilter(md, error);
-  FinishStep();
+  FinishStep(PendingOp::kRecvTrailingMetadata);
 }
 
 void FilterStackCall::BatchControl::FinishBatch(grpc_error_handle error) {
@@ -1323,7 +1367,7 @@ void FilterStackCall::BatchControl::FinishBatch(grpc_error_handle error) {
   if (!error.ok()) {
     call_->CancelWithError(error);
   }
-  FinishStep();
+  FinishStep(PendingOp::kSends);
 }
 
 namespace {
@@ -1350,12 +1394,11 @@ grpc_call_error FilterStackCall::StartBatch(const grpc_op* ops, size_t nops,
   size_t i;
   const grpc_op* op;
   BatchControl* bctl;
-  bool has_send_ops = false;
-  int num_recv_ops = 0;
   grpc_call_error error = GRPC_CALL_OK;
   grpc_transport_stream_op_batch* stream_op;
   grpc_transport_stream_op_batch_payload* stream_op_payload;
   uint32_t seen_ops = 0;
+  intptr_t pending_ops = 0;
 
   for (i = 0; i < nops; i++) {
     if (seen_ops & (1u << ops[i].op)) {
@@ -1472,7 +1515,7 @@ grpc_call_error FilterStackCall::StartBatch(const grpc_op* ops, size_t nops,
           stream_op_payload->send_initial_metadata.peer_string =
               peer_string_atm_ptr();
         }
-        has_send_ops = true;
+        pending_ops |= PendingOpMask(PendingOp::kSends);
         break;
       }
       case GRPC_OP_SEND_MESSAGE: {
@@ -1504,7 +1547,7 @@ grpc_call_error FilterStackCall::StartBatch(const grpc_op* ops, size_t nops,
             send_slice_buffer_.c_slice_buffer());
         stream_op_payload->send_message.flags = flags;
         stream_op_payload->send_message.send_message = &send_slice_buffer_;
-        has_send_ops = true;
+        pending_ops |= PendingOpMask(PendingOp::kSends);
         break;
       }
       case GRPC_OP_SEND_CLOSE_FROM_CLIENT: {
@@ -1525,7 +1568,7 @@ grpc_call_error FilterStackCall::StartBatch(const grpc_op* ops, size_t nops,
         sent_final_op_ = true;
         stream_op_payload->send_trailing_metadata.send_trailing_metadata =
             &send_trailing_metadata_;
-        has_send_ops = true;
+        pending_ops |= PendingOpMask(PendingOp::kSends);
         break;
       }
       case GRPC_OP_SEND_STATUS_FROM_SERVER: {
@@ -1589,7 +1632,7 @@ grpc_call_error FilterStackCall::StartBatch(const grpc_op* ops, size_t nops,
             &send_trailing_metadata_;
         stream_op_payload->send_trailing_metadata.sent =
             &sent_server_trailing_metadata_;
-        has_send_ops = true;
+        pending_ops |= PendingOpMask(PendingOp::kSends);
         break;
       }
       case GRPC_OP_RECV_INITIAL_METADATA: {
@@ -1624,7 +1667,7 @@ grpc_call_error FilterStackCall::StartBatch(const grpc_op* ops, size_t nops,
           stream_op_payload->recv_initial_metadata.peer_string =
               peer_string_atm_ptr();
         }
-        ++num_recv_ops;
+        pending_ops |= PendingOpMask(PendingOp::kRecvInitialMetadata);
         break;
       }
       case GRPC_OP_RECV_MESSAGE: {
@@ -1660,7 +1703,7 @@ grpc_call_error FilterStackCall::StartBatch(const grpc_op* ops, size_t nops,
             bctl, grpc_schedule_on_exec_ctx);
         stream_op_payload->recv_message.recv_message_ready =
             &receiving_stream_ready_;
-        ++num_recv_ops;
+        pending_ops |= PendingOpMask(PendingOp::kRecvMessage);
         break;
       }
       case GRPC_OP_RECV_STATUS_ON_CLIENT: {
@@ -1699,7 +1742,7 @@ grpc_call_error FilterStackCall::StartBatch(const grpc_op* ops, size_t nops,
             bctl, grpc_schedule_on_exec_ctx);
         stream_op_payload->recv_trailing_metadata.recv_trailing_metadata_ready =
             &receiving_trailing_metadata_ready_;
-        ++num_recv_ops;
+        pending_ops |= PendingOpMask(PendingOp::kRecvTrailingMetadata);
         break;
       }
       case GRPC_OP_RECV_CLOSE_ON_SERVER: {
@@ -1732,7 +1775,7 @@ grpc_call_error FilterStackCall::StartBatch(const grpc_op* ops, size_t nops,
             bctl, grpc_schedule_on_exec_ctx);
         stream_op_payload->recv_trailing_metadata.recv_trailing_metadata_ready =
             &receiving_trailing_metadata_ready_;
-        ++num_recv_ops;
+        pending_ops |= PendingOpMask(PendingOp::kRecvTrailingMetadata);
         break;
       }
     }
@@ -1742,9 +1785,9 @@ grpc_call_error FilterStackCall::StartBatch(const grpc_op* ops, size_t nops,
   if (!is_notify_tag_closure) {
     GPR_ASSERT(grpc_cq_begin_op(cq_, notify_tag));
   }
-  bctl->set_num_steps_to_complete((has_send_ops ? 1 : 0) + num_recv_ops);
+  bctl->set_pending_ops(pending_ops);
 
-  if (has_send_ops) {
+  if (pending_ops & PendingOpMask(PendingOp::kSends)) {
     GRPC_CLOSURE_INIT(
         &bctl->finish_batch_,
         [](void* bctl, grpc_error_handle error) {
@@ -1754,6 +1797,13 @@ grpc_call_error FilterStackCall::StartBatch(const grpc_op* ops, size_t nops,
     stream_op->on_complete = &bctl->finish_batch_;
   }
 
+  if (grpc_call_trace.enabled()) {
+    gpr_log(GPR_DEBUG, "BATCH:%p START:%s BATCH:%s (tag:%p)", bctl,
+            PendingOpString(pending_ops).c_str(),
+            grpc_transport_stream_op_batch_string(stream_op).c_str(),
+            bctl->completion_data_.notify_tag.tag);
+  }
+
   ExecuteBatch(stream_op, &bctl->start_batch_);
 
 done:
@@ -1827,21 +1877,52 @@ class PromiseBasedCall : public Call,
                          public grpc_event_engine::experimental::EventEngine::
                              Closure /* for deadlines */ {
  public:
-  PromiseBasedCall(Arena* arena, const grpc_call_create_args& args);
+  PromiseBasedCall(Arena* arena, uint32_t initial_external_refs,
+                   const grpc_call_create_args& args);
 
   void ContextSet(grpc_context_index elem, void* value,
                   void (*destroy)(void* value)) override;
   void* ContextGet(grpc_context_index elem) const override;
   void SetCompletionQueue(grpc_completion_queue* cq) override;
+  void SetCompletionQueueLocked(grpc_completion_queue* cq)
+      ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu_);
+  void CancelWithError(absl::Status error) final ABSL_LOCKS_EXCLUDED(mu_) {
+    MutexLock lock(&mu_);
+    CancelWithErrorLocked(std::move(error));
+  }
+  virtual void CancelWithErrorLocked(absl::Status error)
+      ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu_) = 0;
+  bool Completed() final ABSL_LOCKS_EXCLUDED(mu_) {
+    MutexLock lock(&mu_);
+    return completed_;
+  }
+
+  void Orphan() final {
+    MutexLock lock(&mu_);
+    if (!completed_) {
+      CancelWithErrorLocked(absl::CancelledError("Call orphaned"));
+    }
+  }
 
   // Implementation of call refcounting: move this to DualRefCounted once we
   // don't need to maintain FilterStackCall compatibility
   void ExternalRef() final {
-    refs_.fetch_add(MakeRefPair(1, 0), std::memory_order_relaxed);
+    const uint64_t prev_ref_pair =
+        refs_.fetch_add(MakeRefPair(1, 0), std::memory_order_relaxed);
+    if (grpc_call_refcount_trace.enabled()) {
+      gpr_log(GPR_DEBUG, "%s EXTERNAL_REF: %d:%d->%d:%d", DebugTag().c_str(),
+              GetStrongRefs(prev_ref_pair), GetWeakRefs(prev_ref_pair),
+              GetStrongRefs(prev_ref_pair) + 1, GetWeakRefs(prev_ref_pair));
+    }
   }
   void ExternalUnref() final {
     const uint64_t prev_ref_pair =
         refs_.fetch_add(MakeRefPair(-1, 1), std::memory_order_acq_rel);
+    if (grpc_call_refcount_trace.enabled()) {
+      gpr_log(GPR_DEBUG, "%s EXTERNAL_UNREF: %d:%d->%d:%d", DebugTag().c_str(),
+              GetStrongRefs(prev_ref_pair), GetWeakRefs(prev_ref_pair),
+              GetStrongRefs(prev_ref_pair) - 1, GetWeakRefs(prev_ref_pair) + 1);
+    }
     const uint32_t strong_refs = GetStrongRefs(prev_ref_pair);
     if (GPR_UNLIKELY(strong_refs == 1)) {
       Orphan();
@@ -1849,12 +1930,22 @@ class PromiseBasedCall : public Call,
     // Now drop the weak ref.
     InternalUnref("external_ref");
   }
-  void InternalRef(const char*) final {
-    refs_.fetch_add(MakeRefPair(0, 1), std::memory_order_relaxed);
+  void InternalRef(const char* reason) final {
+    uint64_t n = refs_.fetch_add(MakeRefPair(0, 1), std::memory_order_relaxed);
+    if (grpc_call_refcount_trace.enabled()) {
+      gpr_log(GPR_DEBUG, "%s REF: %s %d:%d->%d:%d", DebugTag().c_str(), reason,
+              GetStrongRefs(n), GetWeakRefs(n), GetStrongRefs(n),
+              GetWeakRefs(n) + 1);
+    }
   }
-  void InternalUnref(const char*) final {
+  void InternalUnref(const char* reason) final {
     const uint64_t prev_ref_pair =
         refs_.fetch_sub(MakeRefPair(0, 1), std::memory_order_acq_rel);
+    if (grpc_call_refcount_trace.enabled()) {
+      gpr_log(GPR_DEBUG, "%s UNREF: %s %d:%d->%d:%d", DebugTag().c_str(),
+              reason, GetStrongRefs(prev_ref_pair), GetWeakRefs(prev_ref_pair),
+              GetStrongRefs(prev_ref_pair), GetWeakRefs(prev_ref_pair) - 1);
+    }
     if (GPR_UNLIKELY(prev_ref_pair == MakeRefPair(0, 1))) {
       DeleteThis();
     }
@@ -1954,9 +2045,12 @@ class PromiseBasedCall : public Call,
 
   void UpdateDeadline(Timestamp deadline);
   void ResetDeadline();
+
   // Implementation of EventEngine::Closure, called when deadline expires
   void Run() override;
 
+  virtual ServerCallContext* server_call_context() { return nullptr; }
+
  protected:
   class ScopedContext
       : public ScopedActivity,
@@ -1994,11 +2088,6 @@ class PromiseBasedCall : public Call,
     uint8_t TakeIndex() { return std::exchange(index_, kNullIndex); }
     bool has_value() const { return index_ != kNullIndex; }
 
-    std::string ToString() const {
-      return index_ == kNullIndex ? "null"
-                                  : std::to_string(static_cast<int>(index_));
-    }
-
    private:
     enum : uint8_t { kNullIndex = 0xff };
     uint8_t index_;
@@ -2016,22 +2105,27 @@ class PromiseBasedCall : public Call,
     // The following correspond with the batch operations from above
     kReceiveInitialMetadata,
     kReceiveStatusOnClient,
+    kReceiveCloseOnServer = kReceiveStatusOnClient,
     kSendMessage,
     kReceiveMessage,
+    kSendStatusFromServer,
+    kSendCloseFromClient = kSendStatusFromServer,
   };
 
-  static constexpr const char* PendingOpString(PendingOp reason) {
+  const char* PendingOpString(PendingOp reason) const {
     switch (reason) {
       case PendingOp::kStartingBatch:
         return "StartingBatch";
       case PendingOp::kReceiveInitialMetadata:
         return "ReceiveInitialMetadata";
       case PendingOp::kReceiveStatusOnClient:
-        return "ReceiveStatusOnClient";
+        return is_client() ? "ReceiveStatusOnClient" : "ReceiveCloseOnServer";
       case PendingOp::kSendMessage:
         return "SendMessage";
       case PendingOp::kReceiveMessage:
         return "ReceiveMessage";
+      case PendingOp::kSendStatusFromServer:
+        return is_client() ? "SendCloseFromClient" : "SendStatusFromServer";
     }
     return "Unknown";
   }
@@ -2041,7 +2135,6 @@ class PromiseBasedCall : public Call,
   }
 
   Mutex* mu() const ABSL_LOCK_RETURNED(mu_) { return &mu_; }
-
   // Begin work on a completion, recording the tag/closure to notify.
   // Use the op selected in \a ops to determine the index to allocate into.
   // Starts the "StartingBatch" PendingOp immediately.
@@ -2051,12 +2144,21 @@ class PromiseBasedCall : public Call,
   // Add one pending op to the completion, and return it.
   Completion AddOpToCompletion(const Completion& completion, PendingOp reason)
       ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu_);
+  // Stringify a completion
+  std::string CompletionString(const Completion& completion) const {
+    return completion.has_value()
+               ? absl::StrFormat(
+                     "%d:tag=%p", static_cast<int>(completion.index()),
+                     completion_info_[completion.index()].pending.tag)
+               : "no-completion";
+  }
   // Finish one op on the completion. Must have been previously been added.
   // The completion as a whole finishes when all pending ops finish.
   void FinishOpOnCompletion(Completion* completion, PendingOp reason)
       ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu_);
   // Mark the completion as failed. Does not finish it.
-  void FailCompletion(const Completion& completion);
+  void FailCompletion(const Completion& completion,
+                      SourceLocation source_location = {});
   // Run the promise polling loop until it stalls.
   void Update() ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu_);
   // Update the promise state once.
@@ -2087,6 +2189,56 @@ class PromiseBasedCall : public Call,
     finalization_.Run(&final_info);
   }
 
+  std::string PresentAndCompletionText(const char* caption, bool has,
+                                       const Completion& completion) const {
+    if (has) {
+      if (completion.has_value()) {
+        return absl::StrCat(caption, ":", CompletionString(completion), " ");
+      } else {
+        return absl::StrCat(caption,
+                            ":!!BUG:operation is present, no completion!! ");
+      }
+    } else {
+      if (!completion.has_value()) {
+        return "";
+      } else {
+        return absl::StrCat(caption, ":no-op:", CompletionString(completion),
+                            " ");
+      }
+    }
+  }
+
+  std::string PollStateDebugString() const ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu_) {
+    return absl::StrCat(PresentAndCompletionText("outstanding_send",
+                                                 outstanding_send_.has_value(),
+                                                 send_message_completion_)
+                            .c_str(),
+                        PresentAndCompletionText("outstanding_recv",
+                                                 outstanding_recv_.has_value(),
+                                                 recv_message_completion_)
+                            .c_str());
+  }
+
+  void StartRecvMessage(const grpc_op& op, const Completion& completion,
+                        PipeReceiver<MessageHandle>* receiver)
+      ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu_);
+  void PollRecvMessage(grpc_compression_algorithm compression_algorithm)
+      ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu_);
+  void CancelRecvMessage() ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu_);
+  void StartSendMessage(const grpc_op& op, const Completion& completion,
+                        PipeSender<MessageHandle>* sender)
+      ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu_);
+  bool PollSendMessage() ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu_);
+  void CancelSendMessage() ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu_);
+
+  bool completed() const ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu_) {
+    return completed_;
+  }
+  void set_completed() ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu_) { completed_ = true; }
+  bool is_sending() const ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu_) {
+    return outstanding_send_.has_value();
+  }
+
  private:
   union CompletionInfo {
     struct Pending {
@@ -2186,7 +2338,7 @@ class PromiseBasedCall : public Call,
   }
 
   mutable Mutex mu_;
-  std::atomic<uint64_t> refs_{MakeRefPair(1, 0)};
+  std::atomic<uint64_t> refs_;
   CallContext call_context_{this};
   bool keep_polling_ ABSL_GUARDED_BY(mu()) = false;
 
@@ -2200,6 +2352,14 @@ class PromiseBasedCall : public Call,
   // Current deadline.
   Timestamp deadline_ = Timestamp::InfFuture();
   grpc_event_engine::experimental::EventEngine::TaskHandle deadline_task_;
+  absl::optional<PipeSender<MessageHandle>::PushType> outstanding_send_
+      ABSL_GUARDED_BY(mu_);
+  absl::optional<PipeReceiverNextType<MessageHandle>> outstanding_recv_
+      ABSL_GUARDED_BY(mu_);
+  grpc_byte_buffer** recv_message_ ABSL_GUARDED_BY(mu_) = nullptr;
+  Completion send_message_completion_ ABSL_GUARDED_BY(mu_);
+  Completion recv_message_completion_ ABSL_GUARDED_BY(mu_);
+  bool completed_ ABSL_GUARDED_BY(mu_) = false;
 };
 
 template <typename T>
@@ -2215,10 +2375,11 @@ grpc_error_handle MakePromiseBasedCall(grpc_call_create_args* args,
   return absl::OkStatus();
 }
 
-PromiseBasedCall::PromiseBasedCall(Arena* arena,
+PromiseBasedCall::PromiseBasedCall(Arena* arena, uint32_t initial_external_refs,
                                    const grpc_call_create_args& args)
     : Call(arena, args.server_transport_data == nullptr, args.send_deadline,
            args.channel->Ref()),
+      refs_(MakeRefPair(initial_external_refs, 0)),
       cq_(args.cq) {
   if (args.cq != nullptr) {
     GPR_ASSERT(args.pollset_set_alternative == nullptr &&
@@ -2278,8 +2439,8 @@ PromiseBasedCall::Completion PromiseBasedCall::StartCompletion(
     void* tag, bool is_closure, const grpc_op* ops) {
   Completion c(BatchSlotForOp(ops[0].op));
   if (grpc_call_trace.enabled()) {
-    gpr_log(GPR_INFO, "%sStartCompletion %s tag=%p", DebugTag().c_str(),
-            c.ToString().c_str(), tag);
+    gpr_log(GPR_INFO, "%s[call] StartCompletion %s tag=%p", DebugTag().c_str(),
+            CompletionString(c).c_str(), tag);
   }
   if (!is_closure) {
     grpc_cq_begin_op(cq(), tag);
@@ -2292,9 +2453,10 @@ PromiseBasedCall::Completion PromiseBasedCall::StartCompletion(
 PromiseBasedCall::Completion PromiseBasedCall::AddOpToCompletion(
     const Completion& completion, PendingOp reason) {
   if (grpc_call_trace.enabled()) {
-    gpr_log(GPR_INFO, "%sAddOpToCompletion %s %s", DebugTag().c_str(),
-            completion.ToString().c_str(), PendingOpString(reason));
+    gpr_log(GPR_INFO, "%s[call] AddOpToCompletion %s %s", DebugTag().c_str(),
+            CompletionString(completion).c_str(), PendingOpString(reason));
   }
+  GPR_ASSERT(completion.has_value());
   auto& pending_op_bits =
       completion_info_[completion.index()].pending.pending_op_bits;
   GPR_ASSERT((pending_op_bits & PendingOpBit(reason)) == 0);
@@ -2302,10 +2464,12 @@ PromiseBasedCall::Completion PromiseBasedCall::AddOpToCompletion(
   return Completion(completion.index());
 }
 
-void PromiseBasedCall::FailCompletion(const Completion& completion) {
+void PromiseBasedCall::FailCompletion(const Completion& completion,
+                                      SourceLocation location) {
   if (grpc_call_trace.enabled()) {
-    gpr_log(GPR_INFO, "%sFailCompletion %s", DebugTag().c_str(),
-            completion.ToString().c_str());
+    gpr_log(location.file(), location.line(), GPR_LOG_SEVERITY_ERROR,
+            "%s[call] FailCompletion %s", DebugTag().c_str(),
+            CompletionString(completion).c_str());
   }
   completion_info_[completion.index()].pending.success = false;
 }
@@ -2324,8 +2488,9 @@ void PromiseBasedCall::FinishOpOnCompletion(Completion* completion,
       }
     }
     gpr_log(
-        GPR_INFO, "%sFinishOpOnCompletion %s %s %s", DebugTag().c_str(),
-        completion->ToString().c_str(), PendingOpString(reason),
+        GPR_INFO, "%s[call] FinishOpOnCompletion tag:%p %s %s %s",
+        DebugTag().c_str(), completion_info_[completion->index()].pending.tag,
+        CompletionString(*completion).c_str(), PendingOpString(reason),
         (pending.empty()
              ? (success ? std::string("done") : std::string("failed"))
              : absl::StrFormat("pending_ops={%s}", absl::StrJoin(pending, ",")))
@@ -2360,6 +2525,10 @@ void PromiseBasedCall::ForceImmediateRepoll() { keep_polling_ = true; }
 
 void PromiseBasedCall::SetCompletionQueue(grpc_completion_queue* cq) {
   MutexLock lock(&mu_);
+  SetCompletionQueueLocked(cq);
+}
+
+void PromiseBasedCall::SetCompletionQueueLocked(grpc_completion_queue* cq) {
   cq_ = cq;
   GRPC_CQ_INTERNAL_REF(cq, "bind");
   call_context_.pollent_ =
@@ -2392,6 +2561,121 @@ void PromiseBasedCall::Run() {
   InternalUnref("deadline");
 }
 
+void PromiseBasedCall::StartSendMessage(const grpc_op& op,
+                                        const Completion& completion,
+                                        PipeSender<MessageHandle>* sender) {
+  GPR_ASSERT(!outstanding_send_.has_value());
+  if (!completed_) {
+    send_message_completion_ =
+        AddOpToCompletion(completion, PendingOp::kSendMessage);
+    SliceBuffer send;
+    grpc_slice_buffer_swap(
+        &op.data.send_message.send_message->data.raw.slice_buffer,
+        send.c_slice_buffer());
+    outstanding_send_.emplace(sender->Push(
+        GetContext<Arena>()->MakePooled<Message>(std::move(send), op.flags)));
+  } else {
+    FailCompletion(completion);
+  }
+}
+
+bool PromiseBasedCall::PollSendMessage() {
+  if (!outstanding_send_.has_value()) return true;
+  Poll<bool> r = (*outstanding_send_)();
+  if (const bool* result = absl::get_if<bool>(&r)) {
+    if (grpc_call_trace.enabled()) {
+      gpr_log(GPR_DEBUG, "%sPollSendMessage completes %s", DebugTag().c_str(),
+              *result ? "successfully" : "with failure");
+    }
+    if (!*result) {
+      FailCompletion(send_message_completion_);
+      return false;
+    }
+    FinishOpOnCompletion(&send_message_completion_, PendingOp::kSendMessage);
+    outstanding_send_.reset();
+  }
+  return true;
+}
+
+void PromiseBasedCall::CancelSendMessage() {
+  if (!outstanding_send_.has_value()) return;
+  FinishOpOnCompletion(&send_message_completion_, PendingOp::kSendMessage);
+  outstanding_send_.reset();
+}
+
+void PromiseBasedCall::StartRecvMessage(const grpc_op& op,
+                                        const Completion& completion,
+                                        PipeReceiver<MessageHandle>* receiver) {
+  GPR_ASSERT(!outstanding_recv_.has_value());
+  recv_message_ = op.data.recv_message.recv_message;
+  recv_message_completion_ =
+      AddOpToCompletion(completion, PendingOp::kReceiveMessage);
+  outstanding_recv_.emplace(receiver->Next());
+}
+
+void PromiseBasedCall::PollRecvMessage(
+    grpc_compression_algorithm incoming_compression_algorithm) {
+  if (!outstanding_recv_.has_value()) return;
+  Poll<NextResult<MessageHandle>> r = (*outstanding_recv_)();
+  if (auto* result = absl::get_if<NextResult<MessageHandle>>(&r)) {
+    outstanding_recv_.reset();
+    if (result->has_value()) {
+      MessageHandle& message = **result;
+      if ((message->flags() & GRPC_WRITE_INTERNAL_COMPRESS) &&
+          (incoming_compression_algorithm != GRPC_COMPRESS_NONE)) {
+        *recv_message_ = grpc_raw_compressed_byte_buffer_create(
+            nullptr, 0, incoming_compression_algorithm);
+      } else {
+        *recv_message_ = grpc_raw_byte_buffer_create(nullptr, 0);
+      }
+      grpc_slice_buffer_move_into(message->payload()->c_slice_buffer(),
+                                  &(*recv_message_)->data.raw.slice_buffer);
+      if (grpc_call_trace.enabled()) {
+        gpr_log(GPR_INFO,
+                "%s[call] PollRecvMessage: outstanding_recv finishes: received "
+                "%" PRIdPTR " byte message",
+                DebugTag().c_str(),
+                (*recv_message_)->data.raw.slice_buffer.length);
+      }
+    } else if (result->cancelled()) {
+      if (grpc_call_trace.enabled()) {
+        gpr_log(GPR_INFO,
+                "%s[call] PollRecvMessage: outstanding_recv finishes: received "
+                "end-of-stream with error",
+                DebugTag().c_str());
+      }
+      FailCompletion(recv_message_completion_);
+      *recv_message_ = nullptr;
+    } else {
+      if (grpc_call_trace.enabled()) {
+        gpr_log(GPR_INFO,
+                "%s[call] PollRecvMessage: outstanding_recv finishes: received "
+                "end-of-stream",
+                DebugTag().c_str());
+      }
+      *recv_message_ = nullptr;
+    }
+    FinishOpOnCompletion(&recv_message_completion_, PendingOp::kReceiveMessage);
+  } else if (completed_) {
+    if (grpc_call_trace.enabled()) {
+      gpr_log(GPR_INFO,
+              "%s[call] UpdateOnce: outstanding_recv finishes: promise has "
+              "completed without queuing a message, forcing end-of-stream",
+              DebugTag().c_str());
+    }
+    outstanding_recv_.reset();
+    *recv_message_ = nullptr;
+    FinishOpOnCompletion(&recv_message_completion_, PendingOp::kReceiveMessage);
+  }
+}
+
+void PromiseBasedCall::CancelRecvMessage() {
+  if (!outstanding_recv_.has_value()) return;
+  *recv_message_ = nullptr;
+  outstanding_recv_.reset();
+  FinishOpOnCompletion(&recv_message_completion_, PendingOp::kReceiveMessage);
+}
+
 ///////////////////////////////////////////////////////////////////////////////
 // CallContext
 
@@ -2405,17 +2689,42 @@ void CallContext::IncrementRefCount(const char* reason) {
 
 void CallContext::Unref(const char* reason) { call_->InternalUnref(reason); }
 
+gpr_atm* CallContext::peer_string_atm_ptr() {
+  return call_->peer_string_atm_ptr();
+}
+
 void CallContext::UpdateDeadline(Timestamp deadline) {
   call_->UpdateDeadline(deadline);
 }
 
+ServerCallContext* CallContext::server_call_context() {
+  return call_->server_call_context();
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// PublishMetadataArray
+
+namespace {
+void PublishMetadataArray(grpc_metadata_batch* md, grpc_metadata_array* array) {
+  const auto md_count = md->count();
+  if (md_count > array->capacity) {
+    array->capacity =
+        std::max(array->capacity + md->count(), array->capacity * 3 / 2);
+    array->metadata = static_cast<grpc_metadata*>(
+        gpr_realloc(array->metadata, sizeof(grpc_metadata) * array->capacity));
+  }
+  PublishToAppEncoder encoder(array);
+  md->Encode(&encoder);
+}
+}  // namespace
+
 ///////////////////////////////////////////////////////////////////////////////
 // ClientPromiseBasedCall
 
 class ClientPromiseBasedCall final : public PromiseBasedCall {
  public:
   ClientPromiseBasedCall(Arena* arena, grpc_call_create_args* args)
-      : PromiseBasedCall(arena, *args) {
+      : PromiseBasedCall(arena, 1, *args) {
     global_stats().IncrementClientCallsCreated();
     ScopedContext context(this);
     send_initial_metadata_ =
@@ -2443,16 +2752,12 @@ class ClientPromiseBasedCall final : public PromiseBasedCall {
     // before context.
     auto c2s = std::move(client_to_server_messages_);
     auto s2c = std::move(server_to_client_messages_);
+    auto sim = std::move(server_initial_metadata_);
   }
 
   absl::string_view GetServerAuthority() const override { abort(); }
-  void CancelWithError(grpc_error_handle error) override;
-  bool Completed() override;
-  void Orphan() override {
-    MutexLock lock(mu());
-    ScopedContext ctx(this);
-    if (!completed_) Finish(ServerMetadataFromStatus(absl::CancelledError()));
-  }
+  void CancelWithErrorLocked(grpc_error_handle error) override
+      ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu());
   bool is_trailers_only() const override {
     MutexLock lock(mu());
     return is_trailers_only_;
@@ -2482,9 +2787,6 @@ class ClientPromiseBasedCall final : public PromiseBasedCall {
   // Start the underlying promise.
   void StartPromise(ClientMetadataHandle client_initial_metadata)
       ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu());
-  // Publish some metadata out to the application.
-  static void PublishMetadataArray(grpc_metadata_array* array,
-                                   ServerMetadata* md);
   // Publish status out to the application.
   void PublishStatus(
       grpc_op::grpc_op_data::grpc_op_recv_status_on_client op_args,
@@ -2495,29 +2797,23 @@ class ClientPromiseBasedCall final : public PromiseBasedCall {
       ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu());
 
   ArenaPromise<ServerMetadataHandle> promise_ ABSL_GUARDED_BY(mu());
-  Latch<ServerMetadata*> server_initial_metadata_ ABSL_GUARDED_BY(mu());
+  Pipe<ServerMetadataHandle> server_initial_metadata_ ABSL_GUARDED_BY(mu()){
+      arena()};
   Pipe<MessageHandle> client_to_server_messages_ ABSL_GUARDED_BY(mu()){arena()};
   Pipe<MessageHandle> server_to_client_messages_ ABSL_GUARDED_BY(mu()){arena()};
 
   ClientMetadataHandle send_initial_metadata_;
   grpc_metadata_array* recv_initial_metadata_ ABSL_GUARDED_BY(mu()) = nullptr;
-  grpc_byte_buffer** recv_message_ ABSL_GUARDED_BY(mu()) = nullptr;
   absl::variant<absl::monostate,
                 grpc_op::grpc_op_data::grpc_op_recv_status_on_client,
                 ServerMetadataHandle>
       recv_status_on_client_ ABSL_GUARDED_BY(mu());
-  absl::optional<PipeSender<MessageHandle>::PushType> outstanding_send_
-      ABSL_GUARDED_BY(mu());
-  absl::optional<PipeReceiver<MessageHandle>::NextType> outstanding_recv_
-      ABSL_GUARDED_BY(mu());
-  absl::optional<LatchWaitPromise<ServerMetadata*>>
+  absl::optional<PipeReceiverNextType<ServerMetadataHandle>>
       server_initial_metadata_ready_;
   absl::optional<grpc_compression_algorithm> incoming_compression_algorithm_;
   Completion recv_initial_metadata_completion_ ABSL_GUARDED_BY(mu());
   Completion recv_status_on_client_completion_ ABSL_GUARDED_BY(mu());
-  Completion send_message_completion_ ABSL_GUARDED_BY(mu());
-  Completion recv_message_completion_ ABSL_GUARDED_BY(mu());
-  bool completed_ ABSL_GUARDED_BY(mu()) = false;
+  Completion close_send_completion_ ABSL_GUARDED_BY(mu());
   bool is_trailers_only_ ABSL_GUARDED_BY(mu());
 };
 
@@ -2526,14 +2822,13 @@ void ClientPromiseBasedCall::StartPromise(
   GPR_ASSERT(!promise_.has_value());
   promise_ = channel()->channel_stack()->MakeClientCallPromise(CallArgs{
       std::move(client_initial_metadata),
-      &server_initial_metadata_,
+      &server_initial_metadata_.sender,
       &client_to_server_messages_.receiver,
       &server_to_client_messages_.sender,
   });
 }
 
-void ClientPromiseBasedCall::CancelWithError(grpc_error_handle error) {
-  MutexLock lock(mu());
+void ClientPromiseBasedCall::CancelWithErrorLocked(grpc_error_handle error) {
   ScopedContext context(this);
   Finish(ServerMetadataFromStatus(grpc_error_to_absl_status(error)));
 }
@@ -2583,7 +2878,7 @@ void ClientPromiseBasedCall::CommitBatch(const grpc_op* ops, size_t nops,
         // compression not implemented
         GPR_ASSERT(
             !op.data.send_initial_metadata.maybe_compression_level.is_set);
-        if (!completed_) {
+        if (!completed()) {
           CToMetadata(op.data.send_initial_metadata.metadata,
                       op.data.send_initial_metadata.count,
                       send_initial_metadata_.get());
@@ -2593,7 +2888,8 @@ void ClientPromiseBasedCall::CommitBatch(const grpc_op* ops, size_t nops,
       case GRPC_OP_RECV_INITIAL_METADATA: {
         recv_initial_metadata_ =
             op.data.recv_initial_metadata.recv_initial_metadata;
-        server_initial_metadata_ready_.emplace(server_initial_metadata_.Wait());
+        server_initial_metadata_ready_.emplace(
+            server_initial_metadata_.receiver.Next());
         recv_initial_metadata_completion_ =
             AddOpToCompletion(completion, PendingOp::kReceiveInitialMetadata);
       } break;
@@ -2608,32 +2904,17 @@ void ClientPromiseBasedCall::CommitBatch(const grpc_op* ops, size_t nops,
           recv_status_on_client_ = op.data.recv_status_on_client;
         }
       } break;
-      case GRPC_OP_SEND_MESSAGE: {
-        GPR_ASSERT(!outstanding_send_.has_value());
-        if (!completed_) {
-          send_message_completion_ =
-              AddOpToCompletion(completion, PendingOp::kSendMessage);
-          SliceBuffer send;
-          grpc_slice_buffer_swap(
-              &op.data.send_message.send_message->data.raw.slice_buffer,
-              send.c_slice_buffer());
-          outstanding_send_.emplace(client_to_server_messages_.sender.Push(
-              GetContext<Arena>()->MakePooled<Message>(std::move(send),
-                                                       op.flags)));
-        } else {
-          FailCompletion(completion);
-        }
-      } break;
-      case GRPC_OP_RECV_MESSAGE: {
-        GPR_ASSERT(!outstanding_recv_.has_value());
-        recv_message_ = op.data.recv_message.recv_message;
-        recv_message_completion_ =
-            AddOpToCompletion(completion, PendingOp::kReceiveMessage);
-        outstanding_recv_.emplace(server_to_client_messages_.receiver.Next());
-      } break;
-      case GRPC_OP_SEND_CLOSE_FROM_CLIENT: {
-        client_to_server_messages_.sender.Close();
-      } break;
+      case GRPC_OP_SEND_MESSAGE:
+        StartSendMessage(op, completion, &client_to_server_messages_.sender);
+        break;
+      case GRPC_OP_RECV_MESSAGE:
+        StartRecvMessage(op, completion, &server_to_client_messages_.receiver);
+        break;
+      case GRPC_OP_SEND_CLOSE_FROM_CLIENT:
+        close_send_completion_ =
+            AddOpToCompletion(completion, PendingOp::kSendCloseFromClient);
+        GPR_ASSERT(close_send_completion_.has_value());
+        break;
       case GRPC_OP_SEND_STATUS_FROM_SERVER:
       case GRPC_OP_RECV_CLOSE_ON_SERVER:
         abort();  // unreachable
@@ -2668,78 +2949,48 @@ void ClientPromiseBasedCall::PublishInitialMetadata(ServerMetadata* metadata) {
       metadata->Take(GrpcEncodingMetadata()).value_or(GRPC_COMPRESS_NONE);
   server_initial_metadata_ready_.reset();
   GPR_ASSERT(recv_initial_metadata_ != nullptr);
-  PublishMetadataArray(std::exchange(recv_initial_metadata_, nullptr),
-                       metadata);
+  PublishMetadataArray(metadata,
+                       std::exchange(recv_initial_metadata_, nullptr));
   FinishOpOnCompletion(&recv_initial_metadata_completion_,
                        PendingOp::kReceiveInitialMetadata);
 }
 
 void ClientPromiseBasedCall::UpdateOnce() {
   if (grpc_call_trace.enabled()) {
-    auto present_and_completion_text =
-        [](const char* caption, bool has,
-           const Completion& completion) -> std::string {
-      if (has) {
-        if (completion.has_value()) {
-          return absl::StrCat(caption, ":",
-                              static_cast<int>(completion.index()), " ");
-        } else {
-          return absl::StrCat(caption,
-                              ":!!BUG:operation is present, no completion!! ");
-        }
-      } else {
-        if (!completion.has_value()) {
-          return "";
-        } else {
-          return absl::StrCat(
-              caption, ":no-op:", static_cast<int>(completion.index()), " ");
-        }
-      }
-    };
-    gpr_log(
-        GPR_INFO, "%sUpdateOnce: %s%s%shas_promise=%s", DebugTag().c_str(),
-        present_and_completion_text("server_initial_metadata_ready",
-                                    server_initial_metadata_ready_.has_value(),
-                                    recv_initial_metadata_completion_)
-            .c_str(),
-        present_and_completion_text("outstanding_send",
-                                    outstanding_send_.has_value(),
-                                    send_message_completion_)
-            .c_str(),
-        present_and_completion_text("outstanding_recv",
-                                    outstanding_recv_.has_value(),
-                                    recv_message_completion_)
-            .c_str(),
-        promise_.has_value() ? "true" : "false");
-  }
-  if (send_message_completion_.has_value()) {
-    FinishOpOnCompletion(&send_message_completion_, PendingOp::kSendMessage);
+    gpr_log(GPR_INFO, "%s[call] UpdateOnce: %s%shas_promise=%s",
+            DebugTag().c_str(),
+            PresentAndCompletionText("server_initial_metadata_ready",
+                                     server_initial_metadata_ready_.has_value(),
+                                     recv_initial_metadata_completion_)
+                .c_str(),
+            PollStateDebugString().c_str(),
+            promise_.has_value() ? "true" : "false");
   }
   if (server_initial_metadata_ready_.has_value()) {
-    Poll<ServerMetadata**> r = (*server_initial_metadata_ready_)();
-    if (ServerMetadata*** server_initial_metadata =
-            absl::get_if<ServerMetadata**>(&r)) {
-      PublishInitialMetadata(**server_initial_metadata);
-    } else if (completed_) {
+    Poll<NextResult<ServerMetadataHandle>> r =
+        (*server_initial_metadata_ready_)();
+    if (auto* server_initial_metadata =
+            absl::get_if<NextResult<ServerMetadataHandle>>(&r)) {
+      PublishInitialMetadata(server_initial_metadata->value().get());
+    } else if (completed()) {
       ServerMetadata no_metadata{GetContext<Arena>()};
       PublishInitialMetadata(&no_metadata);
     }
   }
-  if (outstanding_send_.has_value()) {
-    Poll<bool> r = (*outstanding_send_)();
-    if (const bool* result = absl::get_if<bool>(&r)) {
-      outstanding_send_.reset();
-      if (!*result) {
-        FailCompletion(send_message_completion_);
-        Finish(ServerMetadataFromStatus(absl::Status(
-            absl::StatusCode::kInternal, "Failed to send message to server")));
-      }
-    }
+  if (!PollSendMessage()) {
+    Finish(ServerMetadataFromStatus(absl::Status(
+        absl::StatusCode::kInternal, "Failed to send message to server")));
+  }
+  if (!is_sending() && close_send_completion_.has_value()) {
+    client_to_server_messages_.sender.Close();
+    FinishOpOnCompletion(&close_send_completion_,
+                         PendingOp::kSendCloseFromClient);
   }
   if (promise_.has_value()) {
     Poll<ServerMetadataHandle> r = promise_();
     if (grpc_call_trace.enabled()) {
-      gpr_log(GPR_INFO, "%sUpdateOnce: promise returns %s", DebugTag().c_str(),
+      gpr_log(GPR_INFO, "%s[call] UpdateOnce: promise returns %s",
+              DebugTag().c_str(),
               PollToString(r, [](const ServerMetadataHandle& h) {
                 return h->DebugString();
               }).c_str());
@@ -2749,72 +3000,33 @@ void ClientPromiseBasedCall::UpdateOnce() {
       Finish(std::move(*result));
     }
   }
-  if (incoming_compression_algorithm_.has_value() &&
-      outstanding_recv_.has_value()) {
-    Poll<NextResult<MessageHandle>> r = (*outstanding_recv_)();
-    if (auto* result = absl::get_if<NextResult<MessageHandle>>(&r)) {
-      outstanding_recv_.reset();
-      if (result->has_value()) {
-        MessageHandle& message = **result;
-        if ((message->flags() & GRPC_WRITE_INTERNAL_COMPRESS) &&
-            (incoming_compression_algorithm_ != GRPC_COMPRESS_NONE)) {
-          *recv_message_ = grpc_raw_compressed_byte_buffer_create(
-              nullptr, 0, *incoming_compression_algorithm_);
-        } else {
-          *recv_message_ = grpc_raw_byte_buffer_create(nullptr, 0);
-        }
-        grpc_slice_buffer_move_into(message->payload()->c_slice_buffer(),
-                                    &(*recv_message_)->data.raw.slice_buffer);
-        if (grpc_call_trace.enabled()) {
-          gpr_log(GPR_INFO,
-                  "%sUpdateOnce: outstanding_recv finishes: received %" PRIdPTR
-                  " byte message",
-                  DebugTag().c_str(),
-                  (*recv_message_)->data.raw.slice_buffer.length);
-        }
-      } else {
-        if (grpc_call_trace.enabled()) {
-          gpr_log(
-              GPR_INFO,
-              "%sUpdateOnce: outstanding_recv finishes: received end-of-stream",
-              DebugTag().c_str());
-        }
-        *recv_message_ = nullptr;
-      }
-      FinishOpOnCompletion(&recv_message_completion_,
-                           PendingOp::kReceiveMessage);
-    } else if (completed_) {
-      if (grpc_call_trace.enabled()) {
-        gpr_log(GPR_INFO,
-                "%sUpdateOnce: outstanding_recv finishes: promise has "
-                "completed without queuing a message, forcing end-of-stream",
-                DebugTag().c_str());
-      }
-      outstanding_recv_.reset();
-      *recv_message_ = nullptr;
-      FinishOpOnCompletion(&recv_message_completion_,
-                           PendingOp::kReceiveMessage);
-    }
+  if (incoming_compression_algorithm_.has_value()) {
+    PollRecvMessage(*incoming_compression_algorithm_);
   }
 }
 
 void ClientPromiseBasedCall::Finish(ServerMetadataHandle trailing_metadata) {
   if (grpc_call_trace.enabled()) {
-    gpr_log(GPR_INFO, "%sFinish: %s", DebugTag().c_str(),
+    gpr_log(GPR_INFO, "%s[call] Finish: %s", DebugTag().c_str(),
             trailing_metadata->DebugString().c_str());
   }
   promise_ = ArenaPromise<ServerMetadataHandle>();
   ResetDeadline();
-  completed_ = true;
+  set_completed();
   if (recv_initial_metadata_ != nullptr) {
     ForceImmediateRepoll();
   }
   const bool pending_initial_metadata =
       server_initial_metadata_ready_.has_value();
+  if (!pending_initial_metadata) {
+    server_initial_metadata_ready_.emplace(
+        server_initial_metadata_.receiver.Next());
+  }
+  Poll<NextResult<ServerMetadataHandle>> r =
+      (*server_initial_metadata_ready_)();
   server_initial_metadata_ready_.reset();
-  Poll<ServerMetadata**> r = server_initial_metadata_.Wait()();
-  if (auto* result = absl::get_if<ServerMetadata**>(&r)) {
-    if (pending_initial_metadata) PublishInitialMetadata(**result);
+  if (auto* result = absl::get_if<NextResult<ServerMetadataHandle>>(&r)) {
+    if (pending_initial_metadata) PublishInitialMetadata(result->value().get());
     is_trailers_only_ = false;
   } else {
     if (pending_initial_metadata) {
@@ -2886,7 +3098,7 @@ void ClientPromiseBasedCall::PublishStatus(
     *op_args.error_string =
         gpr_strdup(MakeErrorString(trailing_metadata.get()).c_str());
   }
-  PublishMetadataArray(op_args.trailing_metadata, trailing_metadata.get());
+  PublishMetadataArray(trailing_metadata.get(), op_args.trailing_metadata);
   // Clear state saying we have a RECV_STATUS_ON_CLIENT outstanding
   // (so we don't call through twice)
   recv_status_on_client_ = absl::monostate();
@@ -2894,26 +3106,404 @@ void ClientPromiseBasedCall::PublishStatus(
                        PendingOp::kReceiveStatusOnClient);
 }
 
-void ClientPromiseBasedCall::PublishMetadataArray(grpc_metadata_array* array,
-                                                  ServerMetadata* md) {
-  const auto md_count = md->count();
-  if (md_count > array->capacity) {
-    array->capacity =
-        std::max(array->capacity + md->count(), array->capacity * 3 / 2);
-    array->metadata = static_cast<grpc_metadata*>(
-        gpr_realloc(array->metadata, sizeof(grpc_metadata) * array->capacity));
+///////////////////////////////////////////////////////////////////////////////
+// ServerPromiseBasedCall
+
+class ServerPromiseBasedCall final : public PromiseBasedCall {
+ public:
+  ServerPromiseBasedCall(Arena* arena, grpc_call_create_args* args);
+
+  void CancelWithErrorLocked(grpc_error_handle) override
+      ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu());
+  grpc_call_error StartBatch(const grpc_op* ops, size_t nops, void* notify_tag,
+                             bool is_notify_tag_closure) override;
+  bool failed_before_recv_message() const override { abort(); }
+  bool is_trailers_only() const override { abort(); }
+  absl::string_view GetServerAuthority() const override { return ""; }
+
+  // Polling order for the server promise stack:
+  //
+  // │ ┌───────────────────────────────────────┐
+  // │ │ ServerPromiseBasedCall::UpdateOnce    ├──► Lifetime management,
+  // │ ├───────────────────────────────────────┤    signal call end to app
+  // │ │ ConnectedChannel                      ├─┐
+  // │ ├───────────────────────────────────────┤ └► Interactions with the
+  // │ │ ... closest to transport filter       │    transport - send/recv msgs
+  // │ ├───────────────────────────────────────┤    and metadata, call phase
+  // │ │ ...                                   │    ordering
+  // │ ├───────────────────────────────────────┤
+  // │ │ ... closest to app filter             │ ┌► Request matching, initial
+  // │ ├───────────────────────────────────────┤ │  setup, publishing call to
+  // │ │ Server::ChannelData::MakeCallPromise  ├─┘  application
+  // │ ├───────────────────────────────────────┤
+  // │ │ ServerPromiseBasedCall::PollTopOfCall ├──► Application interactions,
+  // ▼ └───────────────────────────────────────┘    forwarding messages,
+  // Polling &                                      sending trailing metadata
+  // instantiation
+  // order
+
+  void UpdateOnce() ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu()) override;
+  Poll<ServerMetadataHandle> PollTopOfCall()
+      ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu());
+
+  std::string DebugTag() const override {
+    return absl::StrFormat("SERVER_CALL[%p]: ", this);
   }
-  PublishToAppEncoder encoder(array);
-  md->Encode(&encoder);
+
+  ServerCallContext* server_call_context() override { return &call_context_; }
+
+ private:
+  class RecvCloseOpCancelState {
+   public:
+    // Request that receiver be filled in per grpc_op_recv_close_on_server.
+    // Returns true if the request can be fulfilled immediately.
+    // Returns false if the request will be fulfilled later.
+    bool ReceiveCloseOnServerOpStarted(int* receiver) {
+      switch (state_) {
+        case kUnset:
+          state_ = reinterpret_cast<uintptr_t>(receiver);
+          return false;
+        case kFinishedWithFailure:
+          *receiver = 1;
+          return true;
+        case kFinishedWithSuccess:
+          *receiver = 0;
+          return true;
+        default:
+          abort();  // unreachable
+      }
+    }
+
+    // Mark the call as having completed.
+    // Returns true if this finishes a previous RequestReceiveCloseOnServer.
+    bool CompleteCall(bool success) {
+      switch (state_) {
+        case kUnset:
+          state_ = success ? kFinishedWithSuccess : kFinishedWithFailure;
+          return false;
+        case kFinishedWithFailure:
+        case kFinishedWithSuccess:
+          abort();  // unreachable
+        default:
+          *reinterpret_cast<int*>(state_) = success ? 0 : 1;
+          state_ = success ? kFinishedWithSuccess : kFinishedWithFailure;
+          return true;
+      }
+    }
+
+    std::string ToString() const {
+      switch (state_) {
+        case kUnset:
+          return "Unset";
+        case kFinishedWithFailure:
+          return "FinishedWithFailure";
+        case kFinishedWithSuccess:
+          return "FinishedWithSuccess";
+        default:
+          return absl::StrFormat("WaitingForReceiver(%p)",
+                                 reinterpret_cast<void*>(state_));
+      }
+    }
+
+   private:
+    static constexpr uintptr_t kUnset = 0;
+    static constexpr uintptr_t kFinishedWithFailure = 1;
+    static constexpr uintptr_t kFinishedWithSuccess = 2;
+    // Holds one of kUnset, kFinishedWithFailure, or kFinishedWithSuccess
+    // OR an int* that wants to receive the final status.
+    uintptr_t state_ = kUnset;
+  };
+
+  grpc_call_error ValidateBatch(const grpc_op* ops, size_t nops) const;
+  void CommitBatch(const grpc_op* ops, size_t nops,
+                   const Completion& completion)
+      ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu());
+
+  friend class ServerCallContext;
+  ServerCallContext call_context_;
+  Server* const server_;
+  ArenaPromise<ServerMetadataHandle> promise_ ABSL_GUARDED_BY(mu());
+  PipeSender<MessageHandle>* server_to_client_messages_ ABSL_GUARDED_BY(mu()) =
+      nullptr;
+  PipeReceiver<MessageHandle>* client_to_server_messages_
+      ABSL_GUARDED_BY(mu()) = nullptr;
+  using SendInitialMetadataState =
+      absl::variant<absl::monostate, PipeSender<ServerMetadataHandle>*,
+                    typename PipeSender<ServerMetadataHandle>::PushType>;
+  SendInitialMetadataState send_initial_metadata_state_ ABSL_GUARDED_BY(mu()) =
+      absl::monostate{};
+  ServerMetadataHandle send_trailing_metadata_ ABSL_GUARDED_BY(mu());
+  grpc_compression_algorithm incoming_compression_algorithm_
+      ABSL_GUARDED_BY(mu());
+  RecvCloseOpCancelState recv_close_op_cancel_state_ ABSL_GUARDED_BY(mu());
+  Completion recv_close_completion_ ABSL_GUARDED_BY(mu());
+  bool cancel_send_and_receive_ ABSL_GUARDED_BY(mu()) = false;
+  Completion send_status_from_server_completion_ ABSL_GUARDED_BY(mu());
+  ClientMetadataHandle client_initial_metadata_ ABSL_GUARDED_BY(mu());
+};
+
+ArenaPromise<ServerMetadataHandle>
+ServerCallContext::MakeTopOfServerCallPromise(
+    CallArgs call_args, grpc_completion_queue* cq,
+    grpc_metadata_array* publish_initial_metadata,
+    absl::FunctionRef<void(grpc_call* call)> publish) {
+  call_->mu()->AssertHeld();
+  call_->SetCompletionQueueLocked(cq);
+  call_->server_to_client_messages_ = call_args.server_to_client_messages;
+  call_->client_to_server_messages_ = call_args.client_to_server_messages;
+  call_->send_initial_metadata_state_ = call_args.server_initial_metadata;
+  call_->incoming_compression_algorithm_ =
+      call_args.client_initial_metadata->get(GrpcEncodingMetadata())
+          .value_or(GRPC_COMPRESS_NONE);
+  call_->client_initial_metadata_ =
+      std::move(call_args.client_initial_metadata);
+  PublishMetadataArray(call_->client_initial_metadata_.get(),
+                       publish_initial_metadata);
+  call_->ExternalRef();
+  publish(call_->c_ptr());
+  return [this]() {
+    call_->mu()->AssertHeld();
+    return call_->PollTopOfCall();
+  };
 }
 
-bool ClientPromiseBasedCall::Completed() {
+ServerPromiseBasedCall::ServerPromiseBasedCall(Arena* arena,
+                                               grpc_call_create_args* args)
+    : PromiseBasedCall(arena, 0, *args),
+      call_context_(this, args->server_transport_data),
+      server_(args->server) {
+  global_stats().IncrementServerCallsCreated();
+  channelz::ServerNode* channelz_node = server_->channelz_node();
+  if (channelz_node != nullptr) {
+    channelz_node->RecordCallStarted();
+  }
   MutexLock lock(mu());
-  return completed_;
+  ScopedContext activity_context(this);
+  promise_ = channel()->channel_stack()->MakeServerCallPromise(
+      CallArgs{nullptr, nullptr, nullptr, nullptr});
 }
 
-gpr_atm* CallContext::peer_string_atm_ptr() {
-  return call_->peer_string_atm_ptr();
+Poll<ServerMetadataHandle> ServerPromiseBasedCall::PollTopOfCall() {
+  if (grpc_call_trace.enabled()) {
+    gpr_log(GPR_INFO, "%s[call] PollTopOfCall: %s%s%s", DebugTag().c_str(),
+            cancel_send_and_receive_ ? "force-" : "",
+            send_trailing_metadata_ != nullptr
+                ? absl::StrCat("send-metadata:",
+                               send_trailing_metadata_->DebugString())
+                      .c_str()
+                : " ",
+            PollStateDebugString().c_str());
+  }
+
+  if (cancel_send_and_receive_) {
+    CancelSendMessage();
+    CancelRecvMessage();
+  }
+
+  PollSendMessage();
+  PollRecvMessage(incoming_compression_algorithm_);
+
+  if (!is_sending() && send_trailing_metadata_ != nullptr) {
+    server_to_client_messages_->Close();
+    return std::move(send_trailing_metadata_);
+  }
+
+  return Pending{};
+}
+
+void ServerPromiseBasedCall::UpdateOnce() {
+  if (grpc_call_trace.enabled()) {
+    gpr_log(
+        GPR_INFO, "%s[call] UpdateOnce: recv_close:%s%s %s%shas_promise=%s",
+        DebugTag().c_str(), recv_close_op_cancel_state_.ToString().c_str(),
+        recv_close_completion_.has_value()
+            ? absl::StrCat(":", CompletionString(recv_close_completion_))
+                  .c_str()
+            : "",
+        send_status_from_server_completion_.has_value()
+            ? absl::StrCat(
+                  "send_status:",
+                  CompletionString(send_status_from_server_completion_), " ")
+                  .c_str()
+            : "",
+        PollStateDebugString().c_str(),
+        promise_.has_value() ? "true" : "false");
+  }
+  if (auto* p =
+          absl::get_if<typename PipeSender<ServerMetadataHandle>::PushType>(
+              &send_initial_metadata_state_)) {
+    if (!absl::holds_alternative<Pending>((*p)())) {
+      send_initial_metadata_state_ = absl::monostate{};
+    }
+  }
+  if (promise_.has_value()) {
+    auto r = promise_();
+    if (grpc_call_trace.enabled()) {
+      gpr_log(GPR_INFO, "%s[call] UpdateOnce: promise returns %s",
+              DebugTag().c_str(),
+              PollToString(r, [](const ServerMetadataHandle& h) {
+                return h->DebugString();
+              }).c_str());
+    }
+    if (auto* result = absl::get_if<ServerMetadataHandle>(&r)) {
+      if (grpc_call_trace.enabled()) {
+        gpr_log(GPR_INFO, "%s[call] UpdateOnce: GotResult %s result:%s",
+                DebugTag().c_str(),
+                recv_close_op_cancel_state_.ToString().c_str(),
+                (*result)->DebugString().c_str());
+      }
+      if (recv_close_op_cancel_state_.CompleteCall(
+              (*result)->get(GrpcStatusFromWire()).value_or(false))) {
+        FinishOpOnCompletion(&recv_close_completion_,
+                             PendingOp::kReceiveCloseOnServer);
+      }
+      channelz::ServerNode* channelz_node = server_->channelz_node();
+      if (channelz_node != nullptr) {
+        if ((*result)
+                ->get(GrpcStatusMetadata())
+                .value_or(GRPC_STATUS_UNKNOWN) == GRPC_STATUS_OK) {
+          channelz_node->RecordCallSucceeded();
+        } else {
+          channelz_node->RecordCallFailed();
+        }
+      }
+      if (send_status_from_server_completion_.has_value()) {
+        FinishOpOnCompletion(&send_status_from_server_completion_,
+                             PendingOp::kSendStatusFromServer);
+      }
+      CancelSendMessage();
+      CancelRecvMessage();
+      set_completed();
+      promise_ = ArenaPromise<ServerMetadataHandle>();
+    }
+  }
+}
+
+grpc_call_error ServerPromiseBasedCall::ValidateBatch(const grpc_op* ops,
+                                                      size_t nops) const {
+  BitSet<8> got_ops;
+  for (size_t op_idx = 0; op_idx < nops; op_idx++) {
+    const grpc_op& op = ops[op_idx];
+    switch (op.op) {
+      case GRPC_OP_SEND_INITIAL_METADATA:
+        if (!AreInitialMetadataFlagsValid(op.flags)) {
+          return GRPC_CALL_ERROR_INVALID_FLAGS;
+        }
+        if (!ValidateMetadata(op.data.send_initial_metadata.count,
+                              op.data.send_initial_metadata.metadata)) {
+          return GRPC_CALL_ERROR_INVALID_METADATA;
+        }
+        break;
+      case GRPC_OP_SEND_MESSAGE:
+        if (!AreWriteFlagsValid(op.flags)) {
+          return GRPC_CALL_ERROR_INVALID_FLAGS;
+        }
+        break;
+      case GRPC_OP_RECV_MESSAGE:
+      case GRPC_OP_RECV_CLOSE_ON_SERVER:
+      case GRPC_OP_SEND_STATUS_FROM_SERVER:
+        if (op.flags != 0) return GRPC_CALL_ERROR_INVALID_FLAGS;
+        break;
+      case GRPC_OP_RECV_INITIAL_METADATA:
+      case GRPC_OP_SEND_CLOSE_FROM_CLIENT:
+      case GRPC_OP_RECV_STATUS_ON_CLIENT:
+        return GRPC_CALL_ERROR_NOT_ON_SERVER;
+    }
+    if (got_ops.is_set(op.op)) return GRPC_CALL_ERROR_TOO_MANY_OPERATIONS;
+    got_ops.set(op.op);
+  }
+  return GRPC_CALL_OK;
+}
+
+void ServerPromiseBasedCall::CommitBatch(const grpc_op* ops, size_t nops,
+                                         const Completion& completion) {
+  for (size_t op_idx = 0; op_idx < nops; op_idx++) {
+    const grpc_op& op = ops[op_idx];
+    switch (op.op) {
+      case GRPC_OP_SEND_INITIAL_METADATA: {
+        // compression not implemented
+        GPR_ASSERT(
+            !op.data.send_initial_metadata.maybe_compression_level.is_set);
+        if (!completed()) {
+          auto metadata = arena()->MakePooled<ServerMetadata>(arena());
+          CToMetadata(op.data.send_initial_metadata.metadata,
+                      op.data.send_initial_metadata.count, metadata.get());
+          if (grpc_call_trace.enabled()) {
+            gpr_log(GPR_INFO, "%s[call] Send initial metadata",
+                    DebugTag().c_str());
+          }
+          auto* pipe = absl::get<PipeSender<ServerMetadataHandle>*>(
+              send_initial_metadata_state_);
+          send_initial_metadata_state_ = pipe->Push(std::move(metadata));
+        }
+      } break;
+      case GRPC_OP_SEND_MESSAGE:
+        StartSendMessage(op, completion, server_to_client_messages_);
+        break;
+      case GRPC_OP_RECV_MESSAGE:
+        StartRecvMessage(op, completion, client_to_server_messages_);
+        break;
+      case GRPC_OP_SEND_STATUS_FROM_SERVER:
+        send_trailing_metadata_ = arena()->MakePooled<ServerMetadata>(arena());
+        CToMetadata(op.data.send_status_from_server.trailing_metadata,
+                    op.data.send_status_from_server.trailing_metadata_count,
+                    send_trailing_metadata_.get());
+        send_trailing_metadata_->Set(GrpcStatusMetadata(),
+                                     op.data.send_status_from_server.status);
+        if (auto* details = op.data.send_status_from_server.status_details) {
+          send_trailing_metadata_->Set(GrpcMessageMetadata(),
+                                       Slice(CSliceRef(*details)));
+        }
+        send_status_from_server_completion_ =
+            AddOpToCompletion(completion, PendingOp::kSendStatusFromServer);
+        break;
+      case GRPC_OP_RECV_CLOSE_ON_SERVER:
+        if (grpc_call_trace.enabled()) {
+          gpr_log(GPR_INFO, "%s[call] StartBatch: RecvClose %s",
+                  DebugTag().c_str(),
+                  recv_close_op_cancel_state_.ToString().c_str());
+        }
+        if (!recv_close_op_cancel_state_.ReceiveCloseOnServerOpStarted(
+                op.data.recv_close_on_server.cancelled)) {
+          recv_close_completion_ =
+              AddOpToCompletion(completion, PendingOp::kReceiveCloseOnServer);
+        }
+        break;
+      case GRPC_OP_RECV_STATUS_ON_CLIENT:
+      case GRPC_OP_SEND_CLOSE_FROM_CLIENT:
+      case GRPC_OP_RECV_INITIAL_METADATA:
+        abort();  // unreachable
+    }
+  }
+}
+
+grpc_call_error ServerPromiseBasedCall::StartBatch(const grpc_op* ops,
+                                                   size_t nops,
+                                                   void* notify_tag,
+                                                   bool is_notify_tag_closure) {
+  MutexLock lock(mu());
+  ScopedContext activity_context(this);
+  if (nops == 0) {
+    EndOpImmediately(cq(), notify_tag, is_notify_tag_closure);
+    return GRPC_CALL_OK;
+  }
+  const grpc_call_error validation_result = ValidateBatch(ops, nops);
+  if (validation_result != GRPC_CALL_OK) {
+    return validation_result;
+  }
+  Completion completion =
+      StartCompletion(notify_tag, is_notify_tag_closure, ops);
+  CommitBatch(ops, nops, completion);
+  Update();
+  FinishOpOnCompletion(&completion, PendingOp::kStartingBatch);
+  return GRPC_CALL_OK;
+}
+
+void ServerPromiseBasedCall::CancelWithErrorLocked(absl::Status error) {
+  if (!promise_.has_value()) return;
+  cancel_send_and_receive_ = true;
+  send_trailing_metadata_ = ServerMetadataFromStatus(error, arena());
+  ForceWakeup();
 }
 
 }  // namespace grpc_core
@@ -2933,11 +3523,14 @@ size_t grpc_call_get_initial_size_estimate() {
 grpc_error_handle grpc_call_create(grpc_call_create_args* args,
                                    grpc_call** out_call) {
   if (grpc_core::IsPromiseBasedClientCallEnabled() &&
-      args->channel->is_promising()) {
-    if (args->server_transport_data == nullptr) {
-      return grpc_core::MakePromiseBasedCall<grpc_core::ClientPromiseBasedCall>(
-          args, out_call);
-    }
+      args->server_transport_data == nullptr && args->channel->is_promising()) {
+    return grpc_core::MakePromiseBasedCall<grpc_core::ClientPromiseBasedCall>(
+        args, out_call);
+  }
+  if (grpc_core::IsPromiseBasedServerCallEnabled() &&
+      args->server_transport_data != nullptr && args->channel->is_promising()) {
+    return grpc_core::MakePromiseBasedCall<grpc_core::ServerPromiseBasedCall>(
+        args, out_call);
   }
   return grpc_core::FilterStackCall::Create(args, out_call);
 }
diff --git a/src/core/lib/surface/call.h b/src/core/lib/surface/call.h
index 92974700960..0a77709946d 100644
--- a/src/core/lib/surface/call.h
+++ b/src/core/lib/surface/call.h
@@ -25,6 +25,7 @@
 #include <stdint.h>
 
 #include "absl/functional/any_invocable.h"
+#include "absl/functional/function_ref.h"
 #include "absl/strings/string_view.h"
 #include "absl/types/optional.h"
 
@@ -43,12 +44,14 @@
 #include "src/core/lib/iomgr/error.h"
 #include "src/core/lib/iomgr/iomgr_fwd.h"
 #include "src/core/lib/iomgr/polling_entity.h"
+#include "src/core/lib/promise/arena_promise.h"
 #include "src/core/lib/promise/context.h"
 #include "src/core/lib/resource_quota/arena.h"
 #include "src/core/lib/slice/slice.h"
 #include "src/core/lib/surface/api_trace.h"
 #include "src/core/lib/surface/channel.h"
 #include "src/core/lib/surface/server.h"
+#include "src/core/lib/transport/transport.h"
 
 typedef void (*grpc_ioreq_completion_func)(grpc_call* call, int success,
                                            void* user_data);
@@ -74,6 +77,28 @@ typedef struct grpc_call_create_args {
 
 namespace grpc_core {
 class PromiseBasedCall;
+class ServerPromiseBasedCall;
+
+class ServerCallContext {
+ public:
+  ServerCallContext(ServerPromiseBasedCall* call,
+                    const void* server_stream_data)
+      : call_(call), server_stream_data_(server_stream_data) {}
+  ArenaPromise<ServerMetadataHandle> MakeTopOfServerCallPromise(
+      CallArgs call_args, grpc_completion_queue* cq,
+      grpc_metadata_array* publish_initial_metadata,
+      absl::FunctionRef<void(grpc_call* call)> publish);
+
+  // Server stream data as supplied by the transport (so we can link the
+  // transport stream up with the call again).
+  // TODO(ctiller): legacy API - once we move transports to promises we'll
+  // create the promise directly and not need to pass around this token.
+  const void* server_stream_data() { return server_stream_data_; }
+
+ private:
+  ServerPromiseBasedCall* const call_;
+  const void* const server_stream_data_;
+};
 
 // TODO(ctiller): move more call things into this type
 class CallContext {
@@ -98,6 +123,8 @@ class CallContext {
   gpr_atm* peer_string_atm_ptr();
   grpc_polling_entity* polling_entity() { return &pollent_; }
 
+  ServerCallContext* server_call_context();
+
  private:
   friend class PromiseBasedCall;
   // Call final info.
@@ -112,6 +139,7 @@ class CallContext {
 
 template <>
 struct ContextType<CallContext> {};
+
 }  // namespace grpc_core
 
 // Create a new call based on \a args.
diff --git a/src/core/lib/surface/call_trace.cc b/src/core/lib/surface/call_trace.cc
index f2798aefbc0..7f5a07e1b52 100644
--- a/src/core/lib/surface/call_trace.cc
+++ b/src/core/lib/surface/call_trace.cc
@@ -25,6 +25,7 @@
 #include "absl/container/flat_hash_map.h"
 #include "absl/meta/type_traits.h"
 #include "absl/status/status.h"
+#include "absl/strings/str_cat.h"
 #include "absl/types/variant.h"
 
 #include <grpc/support/log.h>
@@ -45,7 +46,8 @@ const grpc_channel_filter* PromiseTracingFilterFor(
   struct DerivedFilter : public grpc_channel_filter {
     explicit DerivedFilter(const grpc_channel_filter* filter)
         : grpc_channel_filter{
-              /* start_transport_stream_op_batch: */ grpc_call_next_op,
+              // start_transport_stream_op_batch:
+              grpc_call_next_op,
               // make_call_promise:
               [](grpc_channel_element* elem, CallArgs call_args,
                  NextPromiseFactory next_promise_factory)
@@ -54,22 +56,22 @@ const grpc_channel_filter* PromiseTracingFilterFor(
                     static_cast<const DerivedFilter*>(elem->filter)->filter;
                 gpr_log(
                     GPR_DEBUG,
-                    "%sCreateCallPromise[%s]: client_initial_metadata=%s",
+                    "%s[%s] CreateCallPromise: client_initial_metadata=%s",
                     Activity::current()->DebugTag().c_str(),
                     source_filter->name,
                     call_args.client_initial_metadata->DebugString().c_str());
                 return [source_filter, child = next_promise_factory(
                                            std::move(call_args))]() mutable {
-                  gpr_log(GPR_DEBUG, "%sPollCallPromise[%s]: begin",
+                  gpr_log(GPR_DEBUG, "%s[%s] PollCallPromise: begin",
                           Activity::current()->DebugTag().c_str(),
                           source_filter->name);
                   auto r = child();
                   if (auto* p = absl::get_if<ServerMetadataHandle>(&r)) {
-                    gpr_log(GPR_DEBUG, "%sPollCallPromise[%s]: done: %s",
+                    gpr_log(GPR_DEBUG, "%s[%s] PollCallPromise: done: %s",
                             Activity::current()->DebugTag().c_str(),
                             source_filter->name, (*p)->DebugString().c_str());
                   } else {
-                    gpr_log(GPR_DEBUG, "%sPollCallPromise[%s]: <<pending>",
+                    gpr_log(GPR_DEBUG, "%s[%s] PollCallPromise: <<pending>>",
                             Activity::current()->DebugTag().c_str(),
                             source_filter->name);
                   }
@@ -85,16 +87,24 @@ const grpc_channel_filter* PromiseTracingFilterFor(
               // destroy_call_elem:
               [](grpc_call_element*, const grpc_call_final_info*,
                  grpc_closure*) {},
-              /* sizeof_channel_data: */ 0,  // init_channel_elem:
+              // sizeof_channel_data:
+              0,
+              // init_channel_elem:
               [](grpc_channel_element*, grpc_channel_element_args*) {
                 return absl::OkStatus();
               },
               // post_init_channel_elem:
               [](grpc_channel_stack*, grpc_channel_element*) {},
-              /* destroy_channel_elem: */ [](grpc_channel_element*) {},
-              grpc_channel_next_get_info, filter->name},
-          filter(filter) {}
+              // destroy_channel_elem:
+              [](grpc_channel_element*) {}, grpc_channel_next_get_info,
+              // name:
+              nullptr},
+          filter(filter),
+          name_str(absl::StrCat(filter->name, ".trace")) {
+      this->name = name_str.c_str();
+    }
     const grpc_channel_filter* const filter;
+    const std::string name_str;
   };
   struct Globals {
     Mutex mu;
diff --git a/src/core/lib/surface/lame_client.cc b/src/core/lib/surface/lame_client.cc
index 181beb9b4b1..ecbc9eed098 100644
--- a/src/core/lib/surface/lame_client.cc
+++ b/src/core/lib/surface/lame_client.cc
@@ -76,7 +76,9 @@ ArenaPromise<ServerMetadataHandle> LameClientFilter::MakeCallPromise(
     CallArgs args, NextPromiseFactory) {
   // TODO(ctiller): remove if check once promise_based_filter is removed (Close
   // is still needed)
-  if (args.incoming_messages != nullptr) args.incoming_messages->Close();
+  if (args.server_to_client_messages != nullptr) {
+    args.server_to_client_messages->Close();
+  }
   return Immediate(ServerMetadataFromStatus(error_));
 }
 
diff --git a/src/core/lib/surface/server.cc b/src/core/lib/surface/server.cc
index 985342265f0..319039accaf 100644
--- a/src/core/lib/surface/server.cc
+++ b/src/core/lib/surface/server.cc
@@ -24,14 +24,19 @@
 
 #include <algorithm>
 #include <atomic>
+#include <initializer_list>
 #include <list>
 #include <new>
 #include <queue>
+#include <tuple>
+#include <type_traits>
 #include <utility>
 #include <vector>
 
+#include "absl/cleanup/cleanup.h"
 #include "absl/status/status.h"
 #include "absl/types/optional.h"
+#include "absl/types/variant.h"
 
 #include <grpc/byte_buffer.h>
 #include <grpc/impl/connectivity_state.h>
@@ -44,13 +49,26 @@
 #include "src/core/lib/channel/channel_trace.h"
 #include "src/core/lib/channel/channelz.h"
 #include "src/core/lib/config/core_configuration.h"
+#include "src/core/lib/experiments/experiments.h"
 #include "src/core/lib/gpr/useful.h"
 #include "src/core/lib/gprpp/crash.h"
 #include "src/core/lib/gprpp/debug_location.h"
+#include "src/core/lib/gprpp/match.h"
 #include "src/core/lib/gprpp/mpscq.h"
 #include "src/core/lib/gprpp/status_helper.h"
 #include "src/core/lib/iomgr/exec_ctx.h"
 #include "src/core/lib/iomgr/pollset_set.h"
+#include "src/core/lib/promise/activity.h"
+#include "src/core/lib/promise/context.h"
+#include "src/core/lib/promise/detail/basic_join.h"
+#include "src/core/lib/promise/detail/basic_seq.h"
+#include "src/core/lib/promise/map.h"
+#include "src/core/lib/promise/pipe.h"
+#include "src/core/lib/promise/poll.h"
+#include "src/core/lib/promise/promise.h"
+#include "src/core/lib/promise/try_join.h"
+#include "src/core/lib/promise/try_seq.h"
+#include "src/core/lib/slice/slice_buffer.h"
 #include "src/core/lib/slice/slice_internal.h"
 #include "src/core/lib/surface/api_trace.h"
 #include "src/core/lib/surface/call.h"
@@ -177,6 +195,20 @@ class Server::RequestMatcherInterface {
   virtual void RequestCallWithPossiblePublish(size_t request_queue_index,
                                               RequestedCall* call) = 0;
 
+  struct MatchResult {
+    size_t cq_idx;
+    RequestedCall* requested_call;
+  };
+
+  // This function is invoked on an incoming promise based RPC.
+  // The RequestMatcher will try to match it against an application-requested
+  // RPC if possible or will place it in the pending queue otherwise. To enable
+  // some measure of fairness between server CQs, the match is done starting at
+  // the start_request_queue_index parameter in a cyclic order rather than
+  // always starting at 0.
+  virtual ArenaPromise<absl::StatusOr<MatchResult>> MatchRequest(
+      size_t start_request_queue_index) = 0;
+
   // This function is invoked on an incoming RPC, represented by the calld
   // object. The RequestMatcher will try to match it against an
   // application-requested RPC if possible or will place it in the pending queue
@@ -208,9 +240,15 @@ class Server::RealRequestMatcher : public RequestMatcherInterface {
 
   void ZombifyPending() override {
     while (!pending_.empty()) {
-      CallData* calld = pending_.front();
-      calld->SetState(CallData::CallState::ZOMBIED);
-      calld->KillZombie();
+      Match(
+          pending_.front(),
+          [](CallData* calld) {
+            calld->SetState(CallData::CallState::ZOMBIED);
+            calld->KillZombie();
+          },
+          [](const std::shared_ptr<ActivityWaiter>& w) {
+            w->Finish(absl::InternalError("Server closed"));
+          });
       pending_.pop();
     }
   }
@@ -234,19 +272,19 @@ class Server::RealRequestMatcher : public RequestMatcherInterface {
     if (requests_per_cq_[request_queue_index].Push(&call->mpscq_node)) {
       // this was the first queued request: we need to lock and start
       // matching calls
-      struct PendingCall {
+      struct NextPendingCall {
         RequestedCall* rc = nullptr;
-        CallData* calld;
+        PendingCall pending;
       };
       auto pop_next_pending = [this, request_queue_index] {
-        PendingCall pending_call;
+        NextPendingCall pending_call;
         {
           MutexLock lock(&server_->mu_call_);
           if (!pending_.empty()) {
             pending_call.rc = reinterpret_cast<RequestedCall*>(
                 requests_per_cq_[request_queue_index].Pop());
             if (pending_call.rc != nullptr) {
-              pending_call.calld = pending_.front();
+              pending_call.pending = std::move(pending_.front());
               pending_.pop();
             }
           }
@@ -254,14 +292,20 @@ class Server::RealRequestMatcher : public RequestMatcherInterface {
         return pending_call;
       };
       while (true) {
-        PendingCall next_pending = pop_next_pending();
+        NextPendingCall next_pending = pop_next_pending();
         if (next_pending.rc == nullptr) break;
-        if (!next_pending.calld->MaybeActivate()) {
-          // Zombied Call
-          next_pending.calld->KillZombie();
-        } else {
-          next_pending.calld->Publish(request_queue_index, next_pending.rc);
-        }
+        auto mr = MatchResult{request_queue_index, next_pending.rc};
+        Match(
+            next_pending.pending,
+            [mr](CallData* calld) {
+              if (!calld->MaybeActivate()) {
+                // Zombied Call
+                calld->KillZombie();
+              } else {
+                calld->Publish(mr.cq_idx, mr.requested_call);
+              }
+            },
+            [mr](const std::shared_ptr<ActivityWaiter>& w) { w->Finish(mr); });
       }
     }
   }
@@ -306,11 +350,66 @@ class Server::RealRequestMatcher : public RequestMatcherInterface {
     calld->Publish(cq_idx, rc);
   }
 
+  ArenaPromise<absl::StatusOr<MatchResult>> MatchRequest(
+      size_t start_request_queue_index) override {
+    for (size_t i = 0; i < requests_per_cq_.size(); i++) {
+      size_t cq_idx = (start_request_queue_index + i) % requests_per_cq_.size();
+      RequestedCall* rc =
+          reinterpret_cast<RequestedCall*>(requests_per_cq_[cq_idx].TryPop());
+      if (rc != nullptr) {
+        return Immediate(MatchResult{cq_idx, rc});
+      }
+    }
+    // No cq to take the request found; queue it on the slow list.
+    // We need to ensure that all the queues are empty.  We do this under
+    // the server mu_call_ lock to ensure that if something is added to
+    // an empty request queue, it will block until the call is actually
+    // added to the pending list.
+    RequestedCall* rc = nullptr;
+    size_t cq_idx = 0;
+    size_t loop_count;
+    {
+      MutexLock lock(&server_->mu_call_);
+      for (loop_count = 0; loop_count < requests_per_cq_.size(); loop_count++) {
+        cq_idx =
+            (start_request_queue_index + loop_count) % requests_per_cq_.size();
+        rc = reinterpret_cast<RequestedCall*>(requests_per_cq_[cq_idx].Pop());
+        if (rc != nullptr) {
+          break;
+        }
+      }
+      if (rc == nullptr) {
+        auto w = std::make_shared<ActivityWaiter>(
+            Activity::current()->MakeNonOwningWaker());
+        pending_.push(w);
+        return [w]() -> Poll<absl::StatusOr<MatchResult>> {
+          std::unique_ptr<absl::StatusOr<MatchResult>> r(
+              w->result.exchange(nullptr, std::memory_order_acq_rel));
+          if (r == nullptr) return Pending{};
+          return std::move(*r);
+        };
+      }
+    }
+    return Immediate(MatchResult{cq_idx, rc});
+  }
+
   Server* server() const override { return server_; }
 
  private:
   Server* const server_;
-  std::queue<CallData*> pending_;
+  struct ActivityWaiter {
+    explicit ActivityWaiter(Waker waker) : waker(std::move(waker)) {}
+    ~ActivityWaiter() { delete result.load(std::memory_order_acquire); }
+    void Finish(absl::StatusOr<MatchResult> r) {
+      result.store(new absl::StatusOr<MatchResult>(std::move(r)),
+                   std::memory_order_release);
+      waker.Wakeup();
+    }
+    Waker waker;
+    std::atomic<absl::StatusOr<MatchResult>*> result{nullptr};
+  };
+  using PendingCall = absl::variant<CallData*, std::shared_ptr<ActivityWaiter>>;
+  std::queue<PendingCall> pending_;
   std::vector<LockedMultiProducerSingleConsumerQueue> requests_per_cq_;
 };
 
@@ -371,7 +470,10 @@ class Server::AllocatingRequestMatcherBatch
 
   void MatchOrQueue(size_t /*start_request_queue_index*/,
                     CallData* calld) override {
-    if (server()->ShutdownRefOnRequest()) {
+    const bool still_running = server()->ShutdownRefOnRequest();
+    auto cleanup_ref =
+        absl::MakeCleanup([this] { server()->ShutdownUnrefOnRequest(); });
+    if (still_running) {
       BatchCallAllocation call_info = allocator_();
       GPR_ASSERT(server()->ValidateServerRequest(
                      cq(), static_cast<void*>(call_info.tag), nullptr,
@@ -384,7 +486,25 @@ class Server::AllocatingRequestMatcherBatch
     } else {
       calld->FailCallCreation();
     }
-    server()->ShutdownUnrefOnRequest();
+  }
+
+  ArenaPromise<absl::StatusOr<MatchResult>> MatchRequest(
+      size_t /*start_request_queue_index*/) override {
+    const bool still_running = server()->ShutdownRefOnRequest();
+    auto cleanup_ref =
+        absl::MakeCleanup([this] { server()->ShutdownUnrefOnRequest(); });
+    if (still_running) {
+      BatchCallAllocation call_info = allocator_();
+      GPR_ASSERT(server()->ValidateServerRequest(
+                     cq(), static_cast<void*>(call_info.tag), nullptr,
+                     nullptr) == GRPC_CALL_OK);
+      RequestedCall* rc = new RequestedCall(
+          static_cast<void*>(call_info.tag), call_info.cq, call_info.call,
+          call_info.initial_metadata, call_info.details);
+      return Immediate(MatchResult{cq_idx(), rc});
+    } else {
+      return Immediate(absl::InternalError("Server shutdown"));
+    }
   }
 
  private:
@@ -404,6 +524,8 @@ class Server::AllocatingRequestMatcherRegistered
 
   void MatchOrQueue(size_t /*start_request_queue_index*/,
                     CallData* calld) override {
+    auto cleanup_ref =
+        absl::MakeCleanup([this] { server()->ShutdownUnrefOnRequest(); });
     if (server()->ShutdownRefOnRequest()) {
       RegisteredCallAllocation call_info = allocator_();
       GPR_ASSERT(server()->ValidateServerRequest(
@@ -418,7 +540,26 @@ class Server::AllocatingRequestMatcherRegistered
     } else {
       calld->FailCallCreation();
     }
-    server()->ShutdownUnrefOnRequest();
+  }
+
+  ArenaPromise<absl::StatusOr<MatchResult>> MatchRequest(
+      size_t /*start_request_queue_index*/) override {
+    const bool still_running = server()->ShutdownRefOnRequest();
+    auto cleanup_ref =
+        absl::MakeCleanup([this] { server()->ShutdownUnrefOnRequest(); });
+    if (still_running) {
+      RegisteredCallAllocation call_info = allocator_();
+      GPR_ASSERT(server()->ValidateServerRequest(
+                     cq(), call_info.tag, call_info.optional_payload,
+                     registered_method_) == GRPC_CALL_OK);
+      RequestedCall* rc =
+          new RequestedCall(call_info.tag, call_info.cq, call_info.call,
+                            call_info.initial_metadata, registered_method_,
+                            call_info.deadline, call_info.optional_payload);
+      return Immediate(MatchResult{cq_idx(), rc});
+    } else {
+      return Immediate(absl::InternalError("Server shutdown"));
+    }
   }
 
  private:
@@ -493,7 +634,7 @@ class ChannelBroadcaster {
 
 const grpc_channel_filter Server::kServerTopFilter = {
     Server::CallData::StartTransportStreamOpBatch,
-    nullptr,
+    Server::ChannelData::MakeCallPromise,
     grpc_channel_next_op,
     sizeof(Server::CallData),
     Server::CallData::InitCallElement,
@@ -1100,14 +1241,119 @@ void Server::ChannelData::AcceptStream(void* arg, grpc_transport* /*transport*/,
   args.send_deadline = Timestamp::InfFuture();
   grpc_call* call;
   grpc_error_handle error = grpc_call_create(&args, &call);
-  grpc_call_element* elem =
-      grpc_call_stack_element(grpc_call_get_call_stack(call), 0);
-  auto* calld = static_cast<Server::CallData*>(elem->call_data);
-  if (!error.ok()) {
-    calld->FailCallCreation();
+  grpc_call_stack* call_stack = grpc_call_get_call_stack(call);
+  if (call_stack == nullptr) {  // Promise based calls do not have a call stack
+    GPR_ASSERT(error.ok());
+    GPR_ASSERT(IsPromiseBasedServerCallEnabled());
     return;
-  }
-  calld->Start(elem);
+  } else {
+    grpc_call_element* elem = grpc_call_stack_element(call_stack, 0);
+    auto* calld = static_cast<Server::CallData*>(elem->call_data);
+    if (!error.ok()) {
+      calld->FailCallCreation();
+      return;
+    }
+    calld->Start(elem);
+  }
+}
+
+ArenaPromise<ServerMetadataHandle> Server::ChannelData::MakeCallPromise(
+    grpc_channel_element* elem, CallArgs call_args, NextPromiseFactory) {
+  auto* chand = static_cast<Server::ChannelData*>(elem->channel_data);
+  auto* server = chand->server_.get();
+  if (server->ShutdownCalled()) {
+    return [] {
+      return ServerMetadataFromStatus(absl::InternalError("Server shutdown"));
+    };
+  }
+  absl::optional<Slice> path =
+      call_args.client_initial_metadata->Take(HttpPathMetadata());
+  if (!path.has_value()) {
+    return [] {
+      return ServerMetadataFromStatus(
+          absl::InternalError("Missing :path header"));
+    };
+  }
+  auto host_ptr =
+      call_args.client_initial_metadata->get_pointer(HttpAuthorityMetadata());
+  if (host_ptr == nullptr) {
+    return [] {
+      return ServerMetadataFromStatus(
+          absl::InternalError("Missing :authority header"));
+    };
+  }
+  // TODO(ctiller): deadline handling
+  Timestamp deadline = Timestamp::InfFuture();
+  // Find request matcher.
+  RequestMatcherInterface* matcher;
+  ChannelRegisteredMethod* rm =
+      chand->GetRegisteredMethod(host_ptr->c_slice(), path->c_slice());
+  ArenaPromise<absl::StatusOr<NextResult<MessageHandle>>>
+      maybe_read_first_message([] { return NextResult<MessageHandle>(); });
+  if (rm != nullptr) {
+    matcher = rm->server_registered_method->matcher.get();
+    switch (rm->server_registered_method->payload_handling) {
+      case GRPC_SRM_PAYLOAD_NONE:
+        break;
+      case GRPC_SRM_PAYLOAD_READ_INITIAL_BYTE_BUFFER:
+        maybe_read_first_message =
+            Map(call_args.client_to_server_messages->Next(),
+                [](NextResult<MessageHandle> msg)
+                    -> absl::StatusOr<NextResult<MessageHandle>> {
+                  return std::move(msg);
+                });
+    }
+  } else {
+    matcher = server->unregistered_request_matcher_.get();
+  }
+  return TrySeq(
+      TryJoin(matcher->MatchRequest(chand->cq_idx()),
+              std::move(maybe_read_first_message)),
+      [path = std::move(*path), host = std::move(*host_ptr), deadline, server,
+       call_args = std::move(call_args)](
+          std::tuple<RequestMatcherInterface::MatchResult,
+                     NextResult<MessageHandle>>
+              match_result_and_payload) mutable {
+        auto& mr = std::get<0>(match_result_and_payload);
+        auto& payload = std::get<1>(match_result_and_payload);
+        auto* rc = mr.requested_call;
+        auto* cq_for_new_request = server->cqs_[mr.cq_idx];
+        switch (rc->type) {
+          case RequestedCall::Type::BATCH_CALL:
+            GPR_ASSERT(!payload.has_value());
+            rc->data.batch.details->host = CSliceRef(host.c_slice());
+            rc->data.batch.details->method = CSliceRef(path.c_slice());
+            rc->data.batch.details->deadline =
+                deadline.as_timespec(GPR_CLOCK_MONOTONIC);
+            break;
+          case RequestedCall::Type::REGISTERED_CALL:
+            *rc->data.registered.deadline =
+                deadline.as_timespec(GPR_CLOCK_MONOTONIC);
+            if (rc->data.registered.optional_payload != nullptr) {
+              if (payload.has_value()) {
+                auto* sb = payload.value()->payload()->c_slice_buffer();
+                *rc->data.registered.optional_payload =
+                    grpc_raw_byte_buffer_create(sb->slices, sb->count);
+              } else {
+                *rc->data.registered.optional_payload = nullptr;
+              }
+            }
+            break;
+          default:
+            GPR_UNREACHABLE_CODE(abort());
+        }
+        return GetContext<CallContext>()
+            ->server_call_context()
+            ->MakeTopOfServerCallPromise(
+                std::move(call_args), rc->cq_bound_to_call,
+                rc->initial_metadata,
+                [rc, cq_for_new_request](grpc_call* call) {
+                  *rc->call = call;
+                  grpc_cq_end_op(cq_for_new_request, rc->tag, absl::OkStatus(),
+                                 Server::DoneRequestEvent, rc, &rc->completion,
+                                 true);
+                });
+      });
 }
 
 void Server::ChannelData::FinishDestroy(void* arg,
@@ -1273,6 +1519,7 @@ void Server::CallData::KillZombie() {
   ExecCtx::Run(DEBUG_LOCATION, &kill_zombie_closure_, absl::OkStatus());
 }
 
+// If this changes, change MakeCallPromise too.
 void Server::CallData::StartNewRpc(grpc_call_element* elem) {
   auto* chand = static_cast<ChannelData*>(elem->channel_data);
   if (server_->ShutdownCalled()) {
diff --git a/src/core/lib/surface/server.h b/src/core/lib/surface/server.h
index 35f5cc5a27f..d635da585b7 100644
--- a/src/core/lib/surface/server.h
+++ b/src/core/lib/surface/server.h
@@ -56,6 +56,7 @@
 #include "src/core/lib/iomgr/endpoint.h"
 #include "src/core/lib/iomgr/error.h"
 #include "src/core/lib/iomgr/iomgr_fwd.h"
+#include "src/core/lib/promise/arena_promise.h"
 #include "src/core/lib/slice/slice.h"
 #include "src/core/lib/surface/channel.h"
 #include "src/core/lib/surface/completion_queue.h"
@@ -236,6 +237,8 @@ class Server : public InternallyRefCounted<Server>,
     static grpc_error_handle InitChannelElement(
         grpc_channel_element* elem, grpc_channel_element_args* args);
     static void DestroyChannelElement(grpc_channel_element* elem);
+    static ArenaPromise<ServerMetadataHandle> MakeCallPromise(
+        grpc_channel_element* elem, CallArgs call_args, NextPromiseFactory);
 
    private:
     class ConnectivityWatcher;
diff --git a/src/core/lib/transport/transport.cc b/src/core/lib/transport/transport.cc
index beff91dd21d..6e2e48ac24c 100644
--- a/src/core/lib/transport/transport.cc
+++ b/src/core/lib/transport/transport.cc
@@ -32,7 +32,6 @@
 #include "src/core/lib/event_engine/default_event_engine.h"
 #include "src/core/lib/gpr/alloc.h"
 #include "src/core/lib/iomgr/exec_ctx.h"
-#include "src/core/lib/promise/context.h"
 #include "src/core/lib/slice/slice.h"
 #include "src/core/lib/transport/transport_impl.h"
 
@@ -269,9 +268,9 @@ grpc_transport_stream_op_batch* grpc_make_transport_stream_op(
 
 namespace grpc_core {
 
-ServerMetadataHandle ServerMetadataFromStatus(const absl::Status& status) {
-  auto hdl =
-      GetContext<Arena>()->MakePooled<ServerMetadata>(GetContext<Arena>());
+ServerMetadataHandle ServerMetadataFromStatus(const absl::Status& status,
+                                              Arena* arena) {
+  auto hdl = arena->MakePooled<ServerMetadata>(arena);
   hdl->Set(GrpcStatusMetadata(), static_cast<grpc_status_code>(status.code()));
   if (!status.ok()) {
     hdl->Set(GrpcMessageMetadata(), Slice::FromCopiedString(status.message()));
diff --git a/src/core/lib/transport/transport.h b/src/core/lib/transport/transport.h
index 3be543a59ff..bcd151cc6af 100644
--- a/src/core/lib/transport/transport.h
+++ b/src/core/lib/transport/transport.h
@@ -52,8 +52,8 @@
 #include "src/core/lib/iomgr/iomgr_fwd.h"
 #include "src/core/lib/iomgr/polling_entity.h"
 #include "src/core/lib/promise/arena_promise.h"
+#include "src/core/lib/promise/context.h"
 #include "src/core/lib/promise/detail/status.h"
-#include "src/core/lib/promise/latch.h"
 #include "src/core/lib/promise/pipe.h"
 #include "src/core/lib/resource_quota/arena.h"
 #include "src/core/lib/slice/slice_buffer.h"
@@ -120,7 +120,8 @@ inline bool IsStatusOk(const ServerMetadataHandle& m) {
          GRPC_STATUS_OK;
 }
 
-ServerMetadataHandle ServerMetadataFromStatus(const absl::Status& status);
+ServerMetadataHandle ServerMetadataFromStatus(
+    const absl::Status& status, Arena* arena = GetContext<Arena>());
 
 template <>
 struct StatusCastImpl<ServerMetadataHandle, absl::Status> {
@@ -136,6 +137,13 @@ struct StatusCastImpl<ServerMetadataHandle, const absl::Status&> {
   }
 };
 
+template <>
+struct StatusCastImpl<ServerMetadataHandle, absl::Status&> {
+  static ServerMetadataHandle Cast(const absl::Status& m) {
+    return ServerMetadataFromStatus(m);
+  }
+};
+
 struct CallArgs {
   // Initial metadata from the client to the server.
   // During promise setup this can be manipulated by filters (and then
@@ -145,11 +153,11 @@ struct CallArgs {
   // Set once when it's available.
   // During promise setup filters can substitute their own latch for this
   // and consequently intercept the sent value and mutate/observe it.
-  Latch<ServerMetadata*>* server_initial_metadata;
+  PipeSender<ServerMetadataHandle>* server_initial_metadata;
   // Messages travelling from the application to the transport.
-  PipeReceiver<MessageHandle>* outgoing_messages;
+  PipeReceiver<MessageHandle>* client_to_server_messages;
   // Messages travelling from the transport to the application.
-  PipeSender<MessageHandle>* incoming_messages;
+  PipeSender<MessageHandle>* server_to_client_messages;
 };
 
 using NextPromiseFactory =
diff --git a/src/cpp/ext/filters/logging/BUILD b/src/cpp/ext/filters/logging/BUILD
index dff7ba34dbc..8d7b3440224 100644
--- a/src/cpp/ext/filters/logging/BUILD
+++ b/src/cpp/ext/filters/logging/BUILD
@@ -55,7 +55,6 @@ grpc_cc_library(
     ],
     external_deps = [
         "absl/random",
-        "absl/status",
         "absl/status:statusor",
         "absl/strings",
         "absl/types:optional",
@@ -74,22 +73,18 @@ grpc_cc_library(
         "//:grpc_base",
         "//:grpc_client_channel",
         "//:grpc_resolver",
-        "//:promise",
         "//:uri_parser",
         "//src/core:arena",
         "//src/core:arena_promise",
-        "//src/core:basic_seq",
         "//src/core:cancel_callback",
         "//src/core:channel_args",
         "//src/core:channel_fwd",
         "//src/core:channel_stack_type",
         "//src/core:context",
-        "//src/core:for_each",
-        "//src/core:latch",
-        "//src/core:promise_like",
-        "//src/core:seq",
+        "//src/core:map",
+        "//src/core:pipe",
+        "//src/core:poll",
         "//src/core:slice",
         "//src/core:slice_buffer",
-        "//src/core:try_concurrently",
     ],
 )
diff --git a/src/cpp/ext/filters/logging/logging_filter.cc b/src/cpp/ext/filters/logging/logging_filter.cc
index 2e664e92d18..9725d80d38a 100644
--- a/src/cpp/ext/filters/logging/logging_filter.cc
+++ b/src/cpp/ext/filters/logging/logging_filter.cc
@@ -34,7 +34,6 @@
 #include <vector>
 
 #include "absl/random/random.h"
-#include "absl/status/status.h"
 #include "absl/status/statusor.h"
 #include "absl/strings/numbers.h"
 #include "absl/strings/str_cat.h"
@@ -58,14 +57,9 @@
 #include "src/core/lib/promise/arena_promise.h"
 #include "src/core/lib/promise/cancel_callback.h"
 #include "src/core/lib/promise/context.h"
-#include "src/core/lib/promise/detail/basic_seq.h"
-#include "src/core/lib/promise/detail/promise_like.h"
-#include "src/core/lib/promise/for_each.h"
-#include "src/core/lib/promise/latch.h"
-#include "src/core/lib/promise/map_pipe.h"
-#include "src/core/lib/promise/promise.h"
-#include "src/core/lib/promise/seq.h"
-#include "src/core/lib/promise/try_concurrently.h"
+#include "src/core/lib/promise/map.h"
+#include "src/core/lib/promise/pipe.h"
+#include "src/core/lib/promise/poll.h"
 #include "src/core/lib/resolver/resolver_registry.h"
 #include "src/core/lib/resource_quota/arena.h"
 #include "src/core/lib/slice/slice.h"
@@ -365,52 +359,28 @@ class ClientLoggingFilter final : public grpc_core::ChannelFilter {
     }
     calld->LogClientHeader(/*is_client=*/true,
                            call_args.client_initial_metadata);
-    auto* server_initial_metadata = call_args.server_initial_metadata;
-    auto incoming_mapper =
-        grpc_core::PipeMapper<grpc_core::MessageHandle>::Intercept(
-            *call_args.incoming_messages);
-    grpc_core::PipeMapper<grpc_core::MessageHandle> outgoing_mapper =
-        grpc_core::PipeMapper<grpc_core::MessageHandle>::Intercept(
-            *call_args.outgoing_messages);
+    call_args.server_initial_metadata->InterceptAndMap(
+        [calld](grpc_core::ServerMetadataHandle metadata) {
+          calld->LogServerHeader(/*is_client=*/true, metadata.get());
+          return metadata;
+        });
+    call_args.client_to_server_messages->InterceptAndMapWithHalfClose(
+        [calld](grpc_core::MessageHandle message) {
+          calld->LogClientMessage(/*is_client=*/true, message->payload());
+          return message;
+        },
+        [calld] { calld->LogClientHalfClose(/*is_client=*/true); });
+    call_args.server_to_client_messages->InterceptAndMap(
+        [calld](grpc_core::MessageHandle message) {
+          calld->LogServerMessage(/*is_client=*/true, message->payload());
+          return message;
+        });
     return grpc_core::OnCancel(
-        grpc_core::TryConcurrently(
-            grpc_core::Seq(
-                next_promise_factory(std::move(call_args)),
-                [calld](grpc_core::ServerMetadataHandle metadata) mutable
-                -> grpc_core::ServerMetadataHandle {
-                  calld->LogServerTrailer(/*is_client=*/true, metadata.get());
-                  return metadata;
-                }))
-            .NecessaryPull(grpc_core::Seq(
-                server_initial_metadata->Wait(),
-                [calld](
-                    grpc_core::ServerMetadata** server_initial_metadata) mutable
-                -> grpc_core::ArenaPromise<absl::Status> {
-                  if (server_initial_metadata != nullptr) {
-                    calld->LogServerHeader(/*is_client=*/true,
-                                           *server_initial_metadata);
-                  }
-                  return grpc_core::ImmediateOkStatus();
-                }))
-            .NecessaryPull(incoming_mapper.TakeAndRun(
-                [calld](grpc_core::MessageHandle message)
-                    -> absl::StatusOr<grpc_core::MessageHandle> {
-                  calld->LogServerMessage(/*is_client=*/true,
-                                          message->payload());
-                  return message;
-                }))
-            .NecessaryPush(grpc_core::Seq(
-                outgoing_mapper.TakeAndRun(
-                    [calld](grpc_core::MessageHandle message)
-                        -> absl::StatusOr<grpc_core::MessageHandle> {
-                      calld->LogClientMessage(/*is_client=*/true,
-                                              message->payload());
-                      return message;
-                    }),
-                [calld]() mutable -> grpc_core::ArenaPromise<absl::Status> {
-                  calld->LogClientHalfClose(/*is_client=*/true);
-                  return grpc_core::ImmediateOkStatus();
-                })),
+        Map(next_promise_factory(std::move(call_args)),
+            [calld](grpc_core::ServerMetadataHandle md) {
+              calld->LogServerTrailer(/*is_client=*/true, md.get());
+              return md;
+            }),
         [calld]() { calld->LogCancel(/*is_client=*/true); });
   }
 
@@ -449,50 +419,28 @@ class ServerLoggingFilter final : public grpc_core::ChannelFilter {
     }
     calld->LogClientHeader(/*is_client=*/false,
                            call_args.client_initial_metadata);
-    auto* server_initial_metadata = call_args.server_initial_metadata;
-    auto incoming_mapper =
-        grpc_core::PipeMapper<grpc_core::MessageHandle>::Intercept(
-            *call_args.incoming_messages);
-    grpc_core::PipeMapper<grpc_core::MessageHandle> outgoing_mapper =
-        grpc_core::PipeMapper<grpc_core::MessageHandle>::Intercept(
-            *call_args.outgoing_messages);
+    call_args.server_initial_metadata->InterceptAndMap(
+        [calld](grpc_core::ServerMetadataHandle metadata) {
+          calld->LogServerHeader(/*is_client=*/false, metadata.get());
+          return metadata;
+        });
+    call_args.client_to_server_messages->InterceptAndMapWithHalfClose(
+        [calld](grpc_core::MessageHandle message) {
+          calld->LogClientMessage(/*is_client=*/false, message->payload());
+          return message;
+        },
+        [calld] { calld->LogClientHalfClose(/*is_client=*/false); });
+    call_args.server_to_client_messages->InterceptAndMap(
+        [calld](grpc_core::MessageHandle message) {
+          calld->LogServerMessage(/*is_client=*/false, message->payload());
+          return message;
+        });
     return grpc_core::OnCancel(
-        grpc_core::TryConcurrently(
-            grpc_core::Seq(
-                next_promise_factory(std::move(call_args)),
-                [calld](grpc_core::ServerMetadataHandle metadata) mutable
-                -> grpc_core::ServerMetadataHandle {
-                  calld->LogServerTrailer(/*is_client=*/false, metadata.get());
-                  return metadata;
-                }))
-            .Push(grpc_core::Seq(
-                server_initial_metadata->Wait(),
-                [calld](
-                    grpc_core::ServerMetadata** server_initial_metadata) mutable
-                -> grpc_core::ArenaPromise<absl::Status> {
-                  calld->LogServerHeader(/*is_client=*/false,
-                                         *server_initial_metadata);
-                  return grpc_core::ImmediateOkStatus();
-                }))
-            .Push(outgoing_mapper.TakeAndRun(
-                [calld](grpc_core::MessageHandle message)
-                    -> absl::StatusOr<grpc_core::MessageHandle> {
-                  calld->LogServerMessage(/*is_client=*/false,
-                                          message->payload());
-                  return message;
-                }))
-            .NecessaryPull(grpc_core::Seq(
-                incoming_mapper.TakeAndRun(
-                    [calld](grpc_core::MessageHandle message)
-                        -> absl::StatusOr<grpc_core::MessageHandle> {
-                      calld->LogClientMessage(/*is_client=*/false,
-                                              message->payload());
-                      return message;
-                    }),
-                [calld]() mutable -> grpc_core::ArenaPromise<absl::Status> {
-                  calld->LogClientHalfClose(/*is_client=*/false);
-                  return grpc_core::ImmediateOkStatus();
-                })),
+        Map(next_promise_factory(std::move(call_args)),
+            [calld](grpc_core::ServerMetadataHandle md) {
+              calld->LogServerTrailer(/*is_client=*/false, md.get());
+              return md;
+            }),
         [calld]() { calld->LogCancel(/*is_client=*/false); });
   }
 };
diff --git a/src/python/grpcio/grpc_core_dependencies.py b/src/python/grpcio/grpc_core_dependencies.py
index 80fd72a77a0..6eb36ade19b 100644
--- a/src/python/grpcio/grpc_core_dependencies.py
+++ b/src/python/grpcio/grpc_core_dependencies.py
@@ -573,6 +573,7 @@ CORE_SOURCE_FILES = [
     'src/core/lib/iomgr/buffer_list.cc',
     'src/core/lib/iomgr/call_combiner.cc',
     'src/core/lib/iomgr/cfstream_handle.cc',
+    'src/core/lib/iomgr/closure.cc',
     'src/core/lib/iomgr/combiner.cc',
     'src/core/lib/iomgr/dualstack_socket_posix.cc',
     'src/core/lib/iomgr/endpoint.cc',
@@ -654,8 +655,8 @@ CORE_SOURCE_FILES = [
     'src/core/lib/load_balancing/lb_policy_registry.cc',
     'src/core/lib/matchers/matchers.cc',
     'src/core/lib/promise/activity.cc',
-    'src/core/lib/promise/pipe.cc',
     'src/core/lib/promise/sleep.cc',
+    'src/core/lib/promise/trace.cc',
     'src/core/lib/resolver/resolver.cc',
     'src/core/lib/resolver/resolver_registry.cc',
     'src/core/lib/resolver/server_address.cc',
@@ -733,6 +734,7 @@ CORE_SOURCE_FILES = [
     'src/core/lib/slice/percent_encoding.cc',
     'src/core/lib/slice/slice.cc',
     'src/core/lib/slice/slice_buffer.cc',
+    'src/core/lib/slice/slice_refcount.cc',
     'src/core/lib/slice/slice_string_helpers.cc',
     'src/core/lib/surface/api_trace.cc',
     'src/core/lib/surface/builtins.cc',
diff --git a/test/core/end2end/fixtures/h2_sockpair_with_minstack.cc b/test/core/end2end/fixtures/h2_sockpair_with_minstack.cc
index 84c93922c5b..5eb130e7474 100644
--- a/test/core/end2end/fixtures/h2_sockpair_with_minstack.cc
+++ b/test/core/end2end/fixtures/h2_sockpair_with_minstack.cc
@@ -130,15 +130,16 @@ static void chttp2_init_server_socketpair(
   auto* fixture_data = static_cast<custom_fixture_data*>(f->fixture_data);
   grpc_transport* transport;
   GPR_ASSERT(!f->server);
-  f->server = grpc_server_create(server_args, nullptr);
+  f->server = grpc_server_create(grpc_core::ChannelArgs::FromC(server_args)
+                                     .Set(GRPC_ARG_MINIMAL_STACK, true)
+                                     .ToC()
+                                     .get(),
+                                 nullptr);
   grpc_server_register_completion_queue(f->server, f->cq, nullptr);
   grpc_server_start(f->server);
-  auto final_server_args = grpc_core::CoreConfiguration::Get()
-                               .channel_args_preconditioning()
-                               .PreconditionChannelArgs(server_args)
-                               .Set(GRPC_ARG_MINIMAL_STACK, true);
-  transport = grpc_create_chttp2_transport(final_server_args,
-                                           fixture_data->ep.server, false);
+  transport = grpc_create_chttp2_transport(
+      grpc_core::Server::FromC(f->server)->channel_args(),
+      fixture_data->ep.server, false);
   server_setup_transport(f, transport);
 }
 
diff --git a/test/core/end2end/generate_tests.bzl b/test/core/end2end/generate_tests.bzl
index a901ae39fdf..f833fbc33bf 100755
--- a/test/core/end2end/generate_tests.bzl
+++ b/test/core/end2end/generate_tests.bzl
@@ -261,7 +261,7 @@ END2END_TESTS = {
         exclude_inproc = True,
         exclude_minstack = True,
     ),
-    "max_connection_age": _test_options(exclude_inproc = True),
+    "max_connection_age": _test_options(exclude_minstack = True, exclude_inproc = True),
     "max_connection_idle": _test_options(needs_fullstack = True, proxyable = False),
     "max_message_length": _test_options(exclude_minstack = True),
     "negative_deadline": _test_options(exclude_minstack = True),
diff --git a/test/core/end2end/tests/cancel_after_accept.cc b/test/core/end2end/tests/cancel_after_accept.cc
index f70b599e3a8..c440c154d0e 100644
--- a/test/core/end2end/tests/cancel_after_accept.cc
+++ b/test/core/end2end/tests/cancel_after_accept.cc
@@ -19,6 +19,8 @@
 #include <stdint.h>
 #include <string.h>
 
+#include <string>
+
 #include <grpc/byte_buffer.h>
 #include <grpc/grpc.h>
 #include <grpc/impl/propagation_bits.h>
@@ -44,6 +46,7 @@ static grpc_end2end_test_fixture begin_test(grpc_end2end_test_config config,
                                             grpc_channel_args* client_args,
                                             grpc_channel_args* server_args) {
   grpc_end2end_test_fixture f;
+  gpr_log(GPR_INFO, "%s", std::string(80, '*').c_str());
   gpr_log(GPR_INFO, "Running test: %s/%s/%s/%s", test_name, config.name,
           mode.name, use_service_config ? "service_config" : "client_api");
   f = config.create_fixture(client_args, server_args);
diff --git a/test/core/end2end/tests/grpc_authz.cc b/test/core/end2end/tests/grpc_authz.cc
index 4536faa2332..90479dec716 100644
--- a/test/core/end2end/tests/grpc_authz.cc
+++ b/test/core/end2end/tests/grpc_authz.cc
@@ -48,6 +48,7 @@ static grpc_end2end_test_fixture begin_test(grpc_end2end_test_config config,
                                             grpc_channel_args* client_args,
                                             grpc_channel_args* server_args) {
   grpc_end2end_test_fixture f;
+  gpr_log(GPR_INFO, "%s", std::string(80, '*').c_str());
   gpr_log(GPR_INFO, "Running test: %s/%s", test_name, config.name);
   f = config.create_fixture(client_args, server_args);
   config.init_server(&f, server_args);
diff --git a/test/core/end2end/tests/max_message_length.cc b/test/core/end2end/tests/max_message_length.cc
index d8f039d0bee..b778ae42b47 100644
--- a/test/core/end2end/tests/max_message_length.cc
+++ b/test/core/end2end/tests/max_message_length.cc
@@ -596,6 +596,9 @@ static void test_max_receive_message_length_on_compressed_request(
                                 nullptr);
   GPR_ASSERT(GRPC_CALL_OK == error);
 
+  // WARNING!!
+  // It's believed the following line (and the associated batch) is the only
+  // test we have for failing a receive operation in a batch.
   cqv.Expect(tag(102), false);
   cqv.Expect(tag(103), true);
   cqv.Expect(tag(1), true);
diff --git a/test/core/end2end/tests/no_logging.cc b/test/core/end2end/tests/no_logging.cc
index 771e04d748f..cce5786cc86 100644
--- a/test/core/end2end/tests/no_logging.cc
+++ b/test/core/end2end/tests/no_logging.cc
@@ -33,6 +33,7 @@
 #include <grpc/support/log.h>
 #include <grpc/support/time.h>
 
+#include "src/core/lib/gprpp/env.h"
 #include "test/core/end2end/cq_verifier.h"
 #include "test/core/end2end/end2end_tests.h"
 #include "test/core/util/test_config.h"
@@ -284,6 +285,7 @@ static void test_no_logging_in_one_request(grpc_end2end_test_config config) {
 }
 
 void no_logging(grpc_end2end_test_config config) {
+  grpc_core::SetEnv("GRPC_TRACE", "");
   gpr_set_log_verbosity(GPR_LOG_SEVERITY_DEBUG);
   grpc_tracer_set_enabled("all", 0);
   gpr_set_log_function(log_dispatcher_func);
diff --git a/test/core/end2end/tests/server_streaming.cc b/test/core/end2end/tests/server_streaming.cc
index f5b4e942918..91f899749ff 100644
--- a/test/core/end2end/tests/server_streaming.cc
+++ b/test/core/end2end/tests/server_streaming.cc
@@ -20,6 +20,7 @@
 #include <string.h>
 
 #include <memory>
+#include <string>
 
 #include <grpc/byte_buffer.h>
 #include <grpc/grpc.h>
@@ -38,9 +39,11 @@ static void* tag(intptr_t t) { return reinterpret_cast<void*>(t); }
 static grpc_end2end_test_fixture begin_test(grpc_end2end_test_config config,
                                             const char* test_name,
                                             grpc_channel_args* client_args,
-                                            grpc_channel_args* server_args) {
+                                            grpc_channel_args* server_args,
+                                            int num_messages) {
   grpc_end2end_test_fixture f;
-  gpr_log(GPR_INFO, "Running test: %s/%s", test_name, config.name);
+  gpr_log(GPR_INFO, "%s\nRunning test: %s/%s/%d", std::string(100, '*').c_str(),
+          test_name, config.name, num_messages);
   f = config.create_fixture(client_args, server_args);
   config.init_server(&f, server_args);
   config.init_client(&f, client_args);
@@ -94,8 +97,8 @@ static void end_test(grpc_end2end_test_fixture* f) {
 // writing, and expects to get the status after the messages.
 static void test_server_streaming(grpc_end2end_test_config config,
                                   int num_messages) {
-  grpc_end2end_test_fixture f =
-      begin_test(config, "test_server_streaming", nullptr, nullptr);
+  grpc_end2end_test_fixture f = begin_test(config, "test_server_streaming",
+                                           nullptr, nullptr, num_messages);
   grpc_call* c;
   grpc_call* s;
   auto cqv = std::make_unique<grpc_core::CqVerifier>(f.cq);
diff --git a/test/core/filters/filter_fuzzer.cc b/test/core/filters/filter_fuzzer.cc
index dd8b38b0337..72b2435fd83 100644
--- a/test/core/filters/filter_fuzzer.cc
+++ b/test/core/filters/filter_fuzzer.cc
@@ -66,7 +66,7 @@
 #include "src/core/lib/promise/activity.h"
 #include "src/core/lib/promise/arena_promise.h"
 #include "src/core/lib/promise/context.h"
-#include "src/core/lib/promise/latch.h"
+#include "src/core/lib/promise/pipe.h"
 #include "src/core/lib/promise/poll.h"
 #include "src/core/lib/resource_quota/arena.h"
 #include "src/core/lib/resource_quota/memory_quota.h"
@@ -436,10 +436,12 @@ class MainLoop {
           CallArgs call_args, NextPromiseFactory) override {
         Call* call = static_cast<Call*>(Activity::current());
         if (call->server_initial_metadata_) {
-          call_args.server_initial_metadata->Set(
-              call->server_initial_metadata_.get());
+          call->server_initial_metadata_push_promise_.emplace(
+              call_args.server_initial_metadata->Push(
+                  ServerMetadataHandle(call->server_initial_metadata_.get(),
+                                       Arena::PooledDeleter(nullptr))));
         } else {
-          call->unset_incoming_server_initial_metadata_latch_ =
+          call->unpushed_incoming_server_initial_metadata_pipe_ =
               call_args.server_initial_metadata;
         }
         return [call]() -> Poll<ServerMetadataHandle> {
@@ -472,10 +474,10 @@ class MainLoop {
          const filter_fuzzer::Metadata& client_initial_metadata, bool is_client)
         : main_loop_(main_loop), id_(id) {
       ScopedContext context(this);
-      auto* server_initial_metadata = arena_->New<Latch<ServerMetadata*>>();
+      auto* server_initial_metadata = arena_->New<Pipe<ServerMetadataHandle>>();
       CallArgs call_args{std::move(*LoadMetadata(client_initial_metadata,
                                                  &client_initial_metadata_)),
-                         server_initial_metadata, nullptr, nullptr};
+                         &server_initial_metadata->sender, nullptr, nullptr};
       if (is_client) {
         promise_ = main_loop_->channel_stack_->MakeClientCallPromise(
             std::move(call_args));
@@ -532,10 +534,12 @@ class MainLoop {
     void RecvInitialMetadata(const filter_fuzzer::Metadata& metadata) {
       if (server_initial_metadata_ == nullptr) {
         LoadMetadata(metadata, &server_initial_metadata_);
-        if (auto* latch = std::exchange(
-                unset_incoming_server_initial_metadata_latch_, nullptr)) {
+        if (auto* pipe = std::exchange(
+                unpushed_incoming_server_initial_metadata_pipe_, nullptr)) {
           ScopedContext context(this);
-          latch->Set(server_initial_metadata_.get());
+          server_initial_metadata_push_promise_.emplace(
+              pipe->Push(ServerMetadataHandle(server_initial_metadata_.get(),
+                                              Arena::PooledDeleter(nullptr))));
         }
       }
     }
@@ -625,8 +629,10 @@ class MainLoop {
     std::unique_ptr<filter_fuzzer::FinalInfo> final_info_;
     std::unique_ptr<ClientMetadata> client_initial_metadata_;
     std::unique_ptr<ServerMetadata> server_initial_metadata_;
-    Latch<ServerMetadata*>* unset_incoming_server_initial_metadata_latch_ =
-        nullptr;
+    PipeSender<ServerMetadataHandle>*
+        unpushed_incoming_server_initial_metadata_pipe_ = nullptr;
+    absl::optional<PipeSender<ServerMetadataHandle>::PushType>
+        server_initial_metadata_push_promise_;
     std::unique_ptr<ServerMetadata> server_trailing_metadata_;
     Waker server_trailing_metadata_waker_;
     CallFinalization finalization_;
diff --git a/test/core/promise/BUILD b/test/core/promise/BUILD
index 6546e89525c..00d5fa85c7f 100644
--- a/test/core/promise/BUILD
+++ b/test/core/promise/BUILD
@@ -45,6 +45,24 @@ grpc_cc_test(
     deps = ["//src/core:poll"],
 )
 
+grpc_cc_test(
+    name = "interceptor_list_test",
+    srcs = ["interceptor_list_test.cc"],
+    external_deps = ["gtest"],
+    language = "c++",
+    uses_event_engine = False,
+    uses_polling = False,
+    deps = [
+        "test_context",
+        "//:ref_counted_ptr",
+        "//src/core:arena",
+        "//src/core:event_engine_memory_allocator",
+        "//src/core:interceptor_list",
+        "//src/core:memory_quota",
+        "//src/core:resource_quota",
+    ],
+)
+
 grpc_cc_test(
     name = "context_test",
     srcs = ["context_test.cc"],
@@ -378,7 +396,7 @@ grpc_cc_test(
     uses_polling = False,
     deps = [
         "test_wakeup_schedulers",
-        "//:gpr",
+        "//:grpc",
         "//:ref_counted_ptr",
         "//src/core:activity",
         "//src/core:basic_join",
diff --git a/test/core/promise/activity_test.cc b/test/core/promise/activity_test.cc
index 279ebbe9de6..5ba0770caa1 100644
--- a/test/core/promise/activity_test.cc
+++ b/test/core/promise/activity_test.cc
@@ -128,12 +128,12 @@ TEST(ActivityTest, DropImmediately) {
 }
 
 template <typename B>
-class BarrierTest : public testing::Test {
+class BarrierTest : public ::testing::Test {
  public:
   using Type = B;
 };
 
-using BarrierTestTypes = testing::Types<Barrier, SingleBarrier>;
+using BarrierTestTypes = ::testing::Types<Barrier, SingleBarrier>;
 TYPED_TEST_SUITE(BarrierTest, BarrierTestTypes);
 
 TYPED_TEST(BarrierTest, Barrier) {
diff --git a/test/core/promise/for_each_test.cc b/test/core/promise/for_each_test.cc
index 73db7d537ef..71ac9b35238 100644
--- a/test/core/promise/for_each_test.cc
+++ b/test/core/promise/for_each_test.cc
@@ -16,6 +16,7 @@
 
 #include <stdint.h>
 
+#include <initializer_list>
 #include <memory>
 
 #include "gmock/gmock.h"
diff --git a/test/core/promise/if_test.cc b/test/core/promise/if_test.cc
index 5df68acdac1..0a2ccc5cbe1 100644
--- a/test/core/promise/if_test.cc
+++ b/test/core/promise/if_test.cc
@@ -52,6 +52,18 @@ TEST(IfTest, ChooseFailure) {
             Poll<absl::StatusOr<int>>(absl::StatusOr<int>()));
 }
 
+TEST(IfTest, ImmediateChooseTrue) {
+  EXPECT_EQ(If(
+                true, []() { return 1; }, []() { return 2; })(),
+            Poll<int>(1));
+}
+
+TEST(IfTest, ImmediateChooseFalse) {
+  EXPECT_EQ(If(
+                false, []() { return 1; }, []() { return 2; })(),
+            Poll<int>(2));
+}
+
 }  // namespace grpc_core
 
 int main(int argc, char** argv) {
diff --git a/test/core/promise/interceptor_list_test.cc b/test/core/promise/interceptor_list_test.cc
new file mode 100644
index 00000000000..22f0aef7803
--- /dev/null
+++ b/test/core/promise/interceptor_list_test.cc
@@ -0,0 +1,144 @@
+// Copyright 2022 gRPC authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "src/core/lib/promise/interceptor_list.h"
+
+#include <initializer_list>
+#include <memory>
+
+#include "gtest/gtest.h"
+
+#include <grpc/event_engine/memory_allocator.h>
+
+#include "src/core/lib/gprpp/ref_counted_ptr.h"
+#include "src/core/lib/resource_quota/arena.h"
+#include "src/core/lib/resource_quota/memory_quota.h"
+#include "src/core/lib/resource_quota/resource_quota.h"
+#include "test/core/promise/test_context.h"
+
+namespace grpc_core {
+namespace {
+
+class InterceptorListTest : public ::testing::Test {
+ protected:
+  MemoryAllocator memory_allocator_ = MemoryAllocator(
+      ResourceQuota::Default()->memory_quota()->CreateMemoryAllocator("test"));
+  ScopedArenaPtr arena_ = MakeScopedArena(1024, &memory_allocator_);
+  TestContext<Arena> arena_ctx_{arena_.get()};
+};
+
+TEST_F(InterceptorListTest, NoOp) { InterceptorList<std::string>(); }
+
+TEST_F(InterceptorListTest, CanRunOne) {
+  InterceptorList<std::string> list;
+  list.AppendMap([](std::string s) { return s + "a"; }, DEBUG_LOCATION);
+  EXPECT_EQ(list.Run("hello")(), Poll<absl::optional<std::string>>("helloa"));
+}
+
+TEST_F(InterceptorListTest, CanRunTwo) {
+  InterceptorList<std::string> list;
+  list.AppendMap([](std::string s) { return s + "a"; }, DEBUG_LOCATION);
+  list.AppendMap([](std::string s) { return s + "b"; }, DEBUG_LOCATION);
+  EXPECT_EQ(list.Run("hello")(), Poll<absl::optional<std::string>>("helloab"));
+}
+
+TEST_F(InterceptorListTest, CanRunTwoTwice) {
+  InterceptorList<std::string> list;
+  list.AppendMap([](std::string s) { return s + s; }, DEBUG_LOCATION);
+  list.AppendMap([](std::string s) { return s + s + s; }, DEBUG_LOCATION);
+  EXPECT_EQ(absl::get<kPollReadyIdx>(list.Run(std::string(10, 'a'))()).value(),
+            std::string(60, 'a'));
+  EXPECT_EQ(absl::get<kPollReadyIdx>(list.Run(std::string(100, 'b'))()).value(),
+            std::string(600, 'b'));
+}
+
+TEST_F(InterceptorListTest, CanRunManyWithCaptures) {
+  InterceptorList<std::string> list;
+  for (size_t i = 0; i < 26 * 1000; i++) {
+    list.AppendMap(
+        [i = std::make_shared<size_t>(i)](std::string s) {
+          return s + static_cast<char>((*i % 26) + 'a');
+        },
+        DEBUG_LOCATION);
+  }
+  std::string expected;
+  for (size_t i = 0; i < 1000; i++) {
+    expected += "abcdefghijklmnopqrstuvwxyz";
+  }
+  EXPECT_EQ(absl::get<kPollReadyIdx>(list.Run("")()).value(), expected);
+}
+
+TEST_F(InterceptorListTest, CanRunOnePrepended) {
+  InterceptorList<std::string> list;
+  list.PrependMap([](std::string s) { return s + "a"; }, DEBUG_LOCATION);
+  EXPECT_EQ(list.Run("hello")(), Poll<absl::optional<std::string>>("helloa"));
+}
+
+TEST_F(InterceptorListTest, CanRunTwoPrepended) {
+  InterceptorList<std::string> list;
+  list.PrependMap([](std::string s) { return s + "a"; }, DEBUG_LOCATION);
+  list.PrependMap([](std::string s) { return s + "b"; }, DEBUG_LOCATION);
+  EXPECT_EQ(list.Run("hello")(), Poll<absl::optional<std::string>>("helloba"));
+}
+
+TEST_F(InterceptorListTest, CanRunManyWithCapturesPrepended) {
+  InterceptorList<std::string> list;
+  for (size_t i = 0; i < 26 * 1000; i++) {
+    list.PrependMap(
+        [i = std::make_shared<size_t>(i)](std::string s) {
+          return s + static_cast<char>((*i % 26) + 'a');
+        },
+        DEBUG_LOCATION);
+  }
+  std::string expected;
+  for (size_t i = 0; i < 1000; i++) {
+    expected += "zyxwvutsrqponmlkjihgfedcba";
+  }
+  EXPECT_EQ(absl::get<kPollReadyIdx>(list.Run("")()).value(), expected);
+}
+
+TEST_F(InterceptorListTest, CanRunManyWithCapturesThatDelay) {
+  InterceptorList<std::string> list;
+  for (size_t i = 0; i < 26 * 1000; i++) {
+    list.AppendMap(
+        [i = std::make_shared<size_t>(i)](std::string s) {
+          return
+              [x = false, i, s]() mutable -> Poll<absl::optional<std::string>> {
+                if (!x) {
+                  x = true;
+                  return Pending{};
+                }
+                return s + static_cast<char>((*i % 26) + 'a');
+              };
+        },
+        DEBUG_LOCATION);
+  }
+  auto promise = list.Run("");
+  for (size_t i = 0; i < 26 * 1000; i++) {
+    EXPECT_TRUE(absl::holds_alternative<Pending>(promise())) << i;
+  }
+  std::string expected;
+  for (size_t i = 0; i < 1000; i++) {
+    expected += "abcdefghijklmnopqrstuvwxyz";
+  }
+  EXPECT_EQ(absl::get<kPollReadyIdx>(promise()).value(), expected);
+}
+
+}  // namespace
+}  // namespace grpc_core
+
+int main(int argc, char** argv) {
+  ::testing::InitGoogleTest(&argc, argv);
+  return RUN_ALL_TESTS();
+}
diff --git a/test/core/promise/latch_test.cc b/test/core/promise/latch_test.cc
index a3b4bc96a8a..d7258e71fa2 100644
--- a/test/core/promise/latch_test.cc
+++ b/test/core/promise/latch_test.cc
@@ -43,8 +43,8 @@ TEST(LatchTest, Works) {
                           latch.Set(42);
                           return true;
                         }),
-                   [](std::tuple<int*, bool> result) {
-                     EXPECT_EQ(*std::get<0>(result), 42);
+                   [](std::tuple<int, bool> result) {
+                     EXPECT_EQ(std::get<0>(result), 42);
                      return absl::OkStatus();
                    });
       },
diff --git a/test/core/promise/map_pipe_test.cc b/test/core/promise/map_pipe_test.cc
index 4ad63e66967..4fe4654b456 100644
--- a/test/core/promise/map_pipe_test.cc
+++ b/test/core/promise/map_pipe_test.cc
@@ -16,6 +16,7 @@
 
 #include <stdint.h>
 
+#include <initializer_list>
 #include <memory>
 #include <utility>
 
diff --git a/test/core/promise/pipe_test.cc b/test/core/promise/pipe_test.cc
index bcf1adbe276..e78b4acfe1f 100644
--- a/test/core/promise/pipe_test.cc
+++ b/test/core/promise/pipe_test.cc
@@ -14,9 +14,9 @@
 
 #include "src/core/lib/promise/pipe.h"
 
+#include <initializer_list>
 #include <memory>
 #include <tuple>
-#include <type_traits>
 #include <utility>
 
 #include "absl/status/status.h"
@@ -24,7 +24,7 @@
 #include "gtest/gtest.h"
 
 #include <grpc/event_engine/memory_allocator.h>
-#include <grpc/support/log.h>
+#include <grpc/grpc.h>
 
 #include "src/core/lib/gprpp/ref_counted_ptr.h"
 #include "src/core/lib/promise/activity.h"
@@ -52,11 +52,11 @@ TEST_F(PipeTest, CanSendAndReceive) {
   EXPECT_CALL(on_done, Call(absl::OkStatus()));
   MakeActivity(
       [] {
-        Pipe<int> pipe;
+        auto* pipe = GetContext<Arena>()->ManagedNew<Pipe<int>>();
         return Seq(
             // Concurrently: send 42 into the pipe, and receive from the pipe.
-            Join(pipe.sender.Push(42),
-                 Map(pipe.receiver.Next(),
+            Join(pipe->sender.Push(42),
+                 Map(pipe->receiver.Next(),
                      [](NextResult<int> r) { return r.value(); })),
             // Once complete, verify successful sending and the received value
             // is 42.
@@ -71,17 +71,103 @@ TEST_F(PipeTest, CanSendAndReceive) {
       MakeScopedArena(1024, &memory_allocator_));
 }
 
+TEST_F(PipeTest, CanInterceptAndMapAtSender) {
+  StrictMock<MockFunction<void(absl::Status)>> on_done;
+  EXPECT_CALL(on_done, Call(absl::OkStatus()));
+  MakeActivity(
+      [] {
+        auto* pipe = GetContext<Arena>()->ManagedNew<Pipe<int>>();
+        pipe->sender.InterceptAndMap([](int value) { return value / 2; });
+        return Seq(
+            // Concurrently: send 42 into the pipe, and receive from the pipe.
+            Join(pipe->sender.Push(42),
+                 Map(pipe->receiver.Next(),
+                     [](NextResult<int> r) { return r.value(); })),
+            // Once complete, verify successful sending and the received value
+            // is 21.
+            [](std::tuple<bool, int> result) {
+              EXPECT_TRUE(std::get<0>(result));
+              EXPECT_EQ(21, std::get<1>(result));
+              return absl::OkStatus();
+            });
+      },
+      NoWakeupScheduler(),
+      [&on_done](absl::Status status) { on_done.Call(std::move(status)); },
+      MakeScopedArena(1024, &memory_allocator_));
+}
+
+TEST_F(PipeTest, CanInterceptAndMapAtReceiver) {
+  StrictMock<MockFunction<void(absl::Status)>> on_done;
+  EXPECT_CALL(on_done, Call(absl::OkStatus()));
+  MakeActivity(
+      [] {
+        auto* pipe = GetContext<Arena>()->ManagedNew<Pipe<int>>();
+        pipe->receiver.InterceptAndMap([](int value) { return value / 2; });
+        return Seq(
+            // Concurrently: send 42 into the pipe, and receive from the pipe.
+            Join(pipe->sender.Push(42),
+                 Map(pipe->receiver.Next(),
+                     [](NextResult<int> r) { return r.value(); })),
+            // Once complete, verify successful sending and the received value
+            // is 21.
+            [](std::tuple<bool, int> result) {
+              EXPECT_TRUE(std::get<0>(result));
+              EXPECT_EQ(21, std::get<1>(result));
+              return absl::OkStatus();
+            });
+      },
+      NoWakeupScheduler(),
+      [&on_done](absl::Status status) { on_done.Call(std::move(status)); },
+      MakeScopedArena(1024, &memory_allocator_));
+}
+
+TEST_F(PipeTest, InterceptionOrderingIsCorrect) {
+  StrictMock<MockFunction<void(absl::Status)>> on_done;
+  EXPECT_CALL(on_done, Call(absl::OkStatus()));
+  MakeActivity(
+      [] {
+        auto* pipe = GetContext<Arena>()->ManagedNew<Pipe<std::string>>();
+        auto appender = [](char c) {
+          return [c](std::string value) {
+            value += c;
+            return value;
+          };
+        };
+        // Interception get added outwardly from the center, and run from sender
+        // to receiver, so the following should result in append "abcd".
+        pipe->receiver.InterceptAndMap(appender('c'));
+        pipe->sender.InterceptAndMap(appender('b'));
+        pipe->receiver.InterceptAndMap(appender('d'));
+        pipe->sender.InterceptAndMap(appender('a'));
+        return Seq(
+            // Concurrently: send "" into the pipe, and receive from the pipe.
+            Join(pipe->sender.Push(""),
+                 Map(pipe->receiver.Next(),
+                     [](NextResult<std::string> r) { return r.value(); })),
+            // Once complete, verify successful sending and the received value
+            // is 21.
+            [](std::tuple<bool, std::string> result) {
+              EXPECT_TRUE(std::get<0>(result));
+              EXPECT_EQ("abcd", std::get<1>(result));
+              return absl::OkStatus();
+            });
+      },
+      NoWakeupScheduler(),
+      [&on_done](absl::Status status) { on_done.Call(std::move(status)); },
+      MakeScopedArena(1024, &memory_allocator_));
+}
+
 TEST_F(PipeTest, CanReceiveAndSend) {
   StrictMock<MockFunction<void(absl::Status)>> on_done;
   EXPECT_CALL(on_done, Call(absl::OkStatus()));
   MakeActivity(
       [] {
-        Pipe<int> pipe;
+        auto* pipe = GetContext<Arena>()->ManagedNew<Pipe<int>>();
         return Seq(
             // Concurrently: receive from the pipe, and send 42 into the pipe.
-            Join(Map(pipe.receiver.Next(),
+            Join(Map(pipe->receiver.Next(),
                      [](NextResult<int> r) { return r.value(); }),
-                 pipe.sender.Push(42)),
+                 pipe->sender.Push(42)),
             // Once complete, verify the received value is 42 and successful
             // sending.
             [](std::tuple<int, bool> result) {
@@ -157,6 +243,95 @@ TEST_F(PipeTest, CanSeeClosedOnReceive) {
       MakeScopedArena(1024, &memory_allocator_));
 }
 
+TEST_F(PipeTest, CanCloseSend) {
+  StrictMock<MockFunction<void(absl::Status)>> on_done;
+  EXPECT_CALL(on_done, Call(absl::OkStatus()));
+  MakeActivity(
+      [] {
+        auto* pipe = GetContext<Arena>()->ManagedNew<Pipe<int>>();
+        return Seq(
+            // Concurrently:
+            // - wait for a received value (will stall forever since we push
+            //   nothing into the queue)
+            // - close the sender, which will signal the receiver to return an
+            //   end-of-stream.
+            Join(pipe->receiver.Next(),
+                 [pipe]() mutable {
+                   pipe->sender.Close();
+                   return absl::OkStatus();
+                 }),
+            // Verify we received end-of-stream and closed the sender.
+            [](std::tuple<NextResult<int>, absl::Status> result) {
+              EXPECT_FALSE(std::get<0>(result).has_value());
+              EXPECT_FALSE(std::get<0>(result).cancelled());
+              EXPECT_EQ(std::get<1>(result), absl::OkStatus());
+              return absl::OkStatus();
+            });
+      },
+      NoWakeupScheduler(),
+      [&on_done](absl::Status status) { on_done.Call(std::move(status)); },
+      MakeScopedArena(1024, &memory_allocator_));
+}
+
+TEST_F(PipeTest, CanCloseSendWithInterceptor) {
+  StrictMock<MockFunction<void(absl::Status)>> on_done;
+  EXPECT_CALL(on_done, Call(absl::OkStatus()));
+  MakeActivity(
+      [] {
+        auto* pipe = GetContext<Arena>()->ManagedNew<Pipe<int>>();
+        pipe->sender.InterceptAndMap([](int value) { return value + 1; });
+        return Seq(
+            // Concurrently:
+            // - wait for a received value (will stall forever since we push
+            //   nothing into the queue)
+            // - close the sender, which will signal the receiver to return an
+            //   end-of-stream.
+            Join(pipe->receiver.Next(),
+                 [pipe]() mutable {
+                   pipe->sender.Close();
+                   return absl::OkStatus();
+                 }),
+            // Verify we received end-of-stream and closed the sender.
+            [](std::tuple<NextResult<int>, absl::Status> result) {
+              EXPECT_FALSE(std::get<0>(result).has_value());
+              EXPECT_FALSE(std::get<0>(result).cancelled());
+              EXPECT_EQ(std::get<1>(result), absl::OkStatus());
+              return absl::OkStatus();
+            });
+      },
+      NoWakeupScheduler(),
+      [&on_done](absl::Status status) { on_done.Call(std::move(status)); },
+      MakeScopedArena(1024, &memory_allocator_));
+}
+
+TEST_F(PipeTest, CanCancelSendWithInterceptor) {
+  StrictMock<MockFunction<void(absl::Status)>> on_done;
+  EXPECT_CALL(on_done, Call(absl::OkStatus()));
+  MakeActivity(
+      [] {
+        auto* pipe = GetContext<Arena>()->ManagedNew<Pipe<int>>();
+        pipe->sender.InterceptAndMap([](int) { return absl::nullopt; });
+        return Seq(
+            // Concurrently:
+            // - wait for a received value (will stall forever since we push
+            //   nothing into the queue)
+            // - close the sender, which will signal the receiver to return an
+            //   end-of-stream.
+            Join(pipe->receiver.Next(), pipe->sender.Push(3)),
+            // Verify we received end-of-stream with cancellation and sent
+            // successfully.
+            [](std::tuple<NextResult<int>, bool> result) {
+              EXPECT_FALSE(std::get<0>(result).has_value());
+              EXPECT_TRUE(std::get<0>(result).cancelled());
+              EXPECT_FALSE(std::get<1>(result));
+              return absl::OkStatus();
+            });
+      },
+      NoWakeupScheduler(),
+      [&on_done](absl::Status status) { on_done.Call(std::move(status)); },
+      MakeScopedArena(1024, &memory_allocator_));
+}
+
 TEST_F(PipeTest, CanFlowControlThroughManyStages) {
   StrictMock<MockFunction<void(absl::Status)>> on_done;
   EXPECT_CALL(on_done, Call(absl::OkStatus()));
@@ -167,39 +342,38 @@ TEST_F(PipeTest, CanFlowControlThroughManyStages) {
   // completes.
   MakeActivity(
       [done] {
-        Pipe<int> pipe1;
-        Pipe<int> pipe2;
-        Pipe<int> pipe3;
-        auto sender1 = std::move(pipe1.sender);
-        auto receiver1 = std::move(pipe1.receiver);
-        auto sender2 = std::move(pipe2.sender);
-        auto receiver2 = std::move(pipe2.receiver);
-        auto sender3 = std::move(pipe3.sender);
-        auto receiver3 = std::move(pipe3.receiver);
-        return Seq(
-            Join(Seq(sender1.Push(1),
-                     [done] {
-                       *done = true;
-                       return 1;
-                     }),
-                 Seq(receiver1.Next(),
-                     [sender2 = std::move(sender2)](NextResult<int> r) mutable {
-                       return sender2.Push(r.value());
-                     }),
-                 Seq(receiver2.Next(),
-                     [sender3 = std::move(sender3)](NextResult<int> r) mutable {
-                       return sender3.Push(r.value());
-                     }),
-                 Seq(receiver3.Next(),
-                     [done](NextResult<int> r) {
-                       EXPECT_EQ(r.value(), 1);
-                       EXPECT_FALSE(*done);
-                       return 2;
-                     })),
-            [](std::tuple<int, bool, bool, int> result) {
-              EXPECT_EQ(result, std::make_tuple(1, true, true, 2));
-              return absl::OkStatus();
-            });
+        auto* pipe1 = GetContext<Arena>()->ManagedNew<Pipe<int>>();
+        auto* pipe2 = GetContext<Arena>()->ManagedNew<Pipe<int>>();
+        auto* pipe3 = GetContext<Arena>()->ManagedNew<Pipe<int>>();
+        auto* sender1 = &pipe1->sender;
+        auto* receiver1 = &pipe1->receiver;
+        auto* sender2 = &pipe2->sender;
+        auto* receiver2 = &pipe2->receiver;
+        auto* sender3 = &pipe3->sender;
+        auto* receiver3 = &pipe3->receiver;
+        return Seq(Join(Seq(sender1->Push(1),
+                            [done] {
+                              *done = true;
+                              return 1;
+                            }),
+                        Seq(receiver1->Next(),
+                            [sender2](NextResult<int> r) mutable {
+                              return sender2->Push(r.value());
+                            }),
+                        Seq(receiver2->Next(),
+                            [sender3](NextResult<int> r) mutable {
+                              return sender3->Push(r.value());
+                            }),
+                        Seq(receiver3->Next(),
+                            [done](NextResult<int> r) {
+                              EXPECT_EQ(r.value(), 1);
+                              EXPECT_FALSE(*done);
+                              return 2;
+                            })),
+                   [](std::tuple<int, bool, bool, int> result) {
+                     EXPECT_EQ(result, std::make_tuple(1, true, true, 2));
+                     return absl::OkStatus();
+                   });
       },
       NoWakeupScheduler(),
       [&on_done](absl::Status status) { on_done.Call(std::move(status)); },
@@ -210,7 +384,9 @@ TEST_F(PipeTest, CanFlowControlThroughManyStages) {
 }  // namespace grpc_core
 
 int main(int argc, char** argv) {
-  gpr_log_verbosity_init();
   ::testing::InitGoogleTest(&argc, argv);
-  return RUN_ALL_TESTS();
+  grpc_init();
+  int r = RUN_ALL_TESTS();
+  grpc_shutdown();
+  return r;
 }
diff --git a/test/core/resource_quota/arena_test.cc b/test/core/resource_quota/arena_test.cc
index be23aaad935..577deb3aad4 100644
--- a/test/core/resource_quota/arena_test.cc
+++ b/test/core/resource_quota/arena_test.cc
@@ -22,6 +22,7 @@
 #include <string.h>
 
 #include <algorithm>
+#include <memory>
 #include <ostream>
 #include <string>
 #include <vector>
@@ -174,6 +175,21 @@ TEST_F(ArenaTest, ConcurrentManagedNew) {
   args.arena->Destroy();
 }
 
+template <typename Int>
+void Scribble(Int* ints, int n, int offset) {
+  for (int i = 0; i < n; i++) {
+    ints[i] = static_cast<Int>(i + offset);
+  }
+}
+
+template <typename Int>
+bool IsScribbled(Int* ints, int n, int offset) {
+  for (int i = 0; i < n; i++) {
+    if (ints[i] != static_cast<Int>(i + offset)) return false;
+  }
+  return true;
+}
+
 TEST_F(ArenaTest, PooledObjectsArePooled) {
   struct TestObj {
     char a[100];
@@ -181,10 +197,15 @@ TEST_F(ArenaTest, PooledObjectsArePooled) {
 
   auto arena = MakeScopedArena(1024, &memory_allocator_);
   auto obj = arena->MakePooled<TestObj>();
+  Scribble(obj->a, 100, 1);
+  EXPECT_TRUE(IsScribbled(obj->a, 100, 1));
   void* p = obj.get();
   obj.reset();
   obj = arena->MakePooled<TestObj>();
+  EXPECT_FALSE(IsScribbled(obj->a, 100, 1));
   EXPECT_EQ(p, obj.get());
+  Scribble(obj->a, 100, 2);
+  EXPECT_TRUE(IsScribbled(obj->a, 100, 2));
 }
 
 TEST_F(ArenaTest, CreateManyObjects) {
@@ -196,9 +217,33 @@ TEST_F(ArenaTest, CreateManyObjects) {
   objs.reserve(1000);
   for (int i = 0; i < 1000; i++) {
     objs.emplace_back(arena->MakePooled<TestObj>());
+    Scribble(objs.back()->a, 100, i);
+  }
+  for (int i = 0; i < 1000; i++) {
+    EXPECT_TRUE(IsScribbled(objs[i]->a, 100, i));
+  }
+}
+
+TEST_F(ArenaTest, CreateManyObjectsWithDestructors) {
+  using TestObj = std::unique_ptr<int>;
+  auto arena = MakeScopedArena(1024, &memory_allocator_);
+  std::vector<Arena::PoolPtr<TestObj>> objs;
+  objs.reserve(1000);
+  for (int i = 0; i < 1000; i++) {
+    objs.emplace_back(arena->MakePooled<TestObj>(new int(i)));
   }
 }
 
+TEST_F(ArenaTest, CreatePoolArray) {
+  auto arena = MakeScopedArena(1024, &memory_allocator_);
+  auto p = arena->MakePooledArray<int>(1024);
+  EXPECT_FALSE(p.get_deleter().has_freelist());
+  p = arena->MakePooledArray<int>(5);
+  EXPECT_TRUE(p.get_deleter().has_freelist());
+  Scribble(p.get(), 5, 1);
+  EXPECT_TRUE(IsScribbled(p.get(), 5, 1));
+}
+
 }  // namespace grpc_core
 
 int main(int argc, char* argv[]) {
diff --git a/test/core/slice/slice_test.cc b/test/core/slice/slice_test.cc
index 864ac2f01e4..a292c7cd324 100644
--- a/test/core/slice/slice_test.cc
+++ b/test/core/slice/slice_test.cc
@@ -347,7 +347,7 @@ INSTANTIATE_TEST_SUITE_P(SliceSizedTest, SliceSizedTest,
                            }
                            return out;
                          }()),
-                         [](const testing::TestParamInfo<size_t>& info) {
+                         [](const ::testing::TestParamInfo<size_t>& info) {
                            return std::to_string(info.param);
                          });
 
diff --git a/test/cpp/ext/filters/logging/logging_test.cc b/test/cpp/ext/filters/logging/logging_test.cc
index 926d6cb2519..e42ed471e8a 100644
--- a/test/cpp/ext/filters/logging/logging_test.cc
+++ b/test/cpp/ext/filters/logging/logging_test.cc
@@ -147,7 +147,7 @@ class LoggingTest : public ::testing::Test {
   std::unique_ptr<EchoTestService::Stub> stub_;
 };
 
-TEST_F(LoggingTest, DISABLED_SimpleRpc) {
+TEST_F(LoggingTest, SimpleRpc) {
   g_test_logging_sink->SetConfig(
       grpc::internal::LoggingSink::Config(4096, 4096));
   EchoRequest request;
@@ -304,7 +304,7 @@ TEST_F(LoggingTest, DISABLED_SimpleRpc) {
                                      "server-trailer-value")))))));
 }
 
-TEST_F(LoggingTest, DISABLED_LoggingDisabled) {
+TEST_F(LoggingTest, LoggingDisabled) {
   g_test_logging_sink->SetConfig(grpc::internal::LoggingSink::Config());
   EchoRequest request;
   request.set_message("foo");
@@ -316,7 +316,7 @@ TEST_F(LoggingTest, DISABLED_LoggingDisabled) {
   EXPECT_TRUE(g_test_logging_sink->entries().empty());
 }
 
-TEST_F(LoggingTest, DISABLED_MetadataTruncated) {
+TEST_F(LoggingTest, MetadataTruncated) {
   g_test_logging_sink->SetConfig(grpc::internal::LoggingSink::Config(
       40 /* expect truncated metadata*/, 4096));
   EchoRequest request;
@@ -474,7 +474,7 @@ TEST_F(LoggingTest, DISABLED_MetadataTruncated) {
                                      "server-trailer-value")))))));
 }
 
-TEST_F(LoggingTest, DISABLED_PayloadTruncated) {
+TEST_F(LoggingTest, PayloadTruncated) {
   g_test_logging_sink->SetConfig(grpc::internal::LoggingSink::Config(4096, 10));
   EchoRequest request;
   // The following message should get truncated
@@ -635,7 +635,7 @@ TEST_F(LoggingTest, DISABLED_PayloadTruncated) {
                                      "server-trailer-value")))))));
 }
 
-TEST_F(LoggingTest, DISABLED_CancelledRpc) {
+TEST_F(LoggingTest, CancelledRpc) {
   g_test_logging_sink->SetConfig(
       grpc::internal::LoggingSink::Config(4096, 4096));
   EchoRequest request;
diff --git a/tools/doxygen/Doxyfile.c++.internal b/tools/doxygen/Doxyfile.c++.internal
index 9bd60293755..4bfac6921fe 100644
--- a/tools/doxygen/Doxyfile.c++.internal
+++ b/tools/doxygen/Doxyfile.c++.internal
@@ -2224,6 +2224,7 @@ src/core/lib/iomgr/call_combiner.cc \
 src/core/lib/iomgr/call_combiner.h \
 src/core/lib/iomgr/cfstream_handle.cc \
 src/core/lib/iomgr/cfstream_handle.h \
+src/core/lib/iomgr/closure.cc \
 src/core/lib/iomgr/closure.h \
 src/core/lib/iomgr/combiner.cc \
 src/core/lib/iomgr/combiner.h \
@@ -2379,19 +2380,19 @@ src/core/lib/promise/activity.cc \
 src/core/lib/promise/activity.h \
 src/core/lib/promise/arena_promise.h \
 src/core/lib/promise/context.h \
+src/core/lib/promise/detail/basic_join.h \
 src/core/lib/promise/detail/basic_seq.h \
 src/core/lib/promise/detail/promise_factory.h \
 src/core/lib/promise/detail/promise_like.h \
 src/core/lib/promise/detail/status.h \
 src/core/lib/promise/detail/switch.h \
 src/core/lib/promise/exec_ctx_wakeup_scheduler.h \
-src/core/lib/promise/for_each.h \
+src/core/lib/promise/if.h \
+src/core/lib/promise/interceptor_list.h \
 src/core/lib/promise/intra_activity_waiter.h \
 src/core/lib/promise/latch.h \
 src/core/lib/promise/loop.h \
 src/core/lib/promise/map.h \
-src/core/lib/promise/map_pipe.h \
-src/core/lib/promise/pipe.cc \
 src/core/lib/promise/pipe.h \
 src/core/lib/promise/poll.h \
 src/core/lib/promise/promise.h \
@@ -2399,7 +2400,9 @@ src/core/lib/promise/race.h \
 src/core/lib/promise/seq.h \
 src/core/lib/promise/sleep.cc \
 src/core/lib/promise/sleep.h \
-src/core/lib/promise/try_concurrently.h \
+src/core/lib/promise/trace.cc \
+src/core/lib/promise/trace.h \
+src/core/lib/promise/try_join.h \
 src/core/lib/promise/try_seq.h \
 src/core/lib/resolver/resolver.cc \
 src/core/lib/resolver/resolver.h \
@@ -2554,6 +2557,7 @@ src/core/lib/slice/slice.h \
 src/core/lib/slice/slice_buffer.cc \
 src/core/lib/slice/slice_buffer.h \
 src/core/lib/slice/slice_internal.h \
+src/core/lib/slice/slice_refcount.cc \
 src/core/lib/slice/slice_refcount.h \
 src/core/lib/slice/slice_string_helpers.cc \
 src/core/lib/slice/slice_string_helpers.h \
diff --git a/tools/doxygen/Doxyfile.core.internal b/tools/doxygen/Doxyfile.core.internal
index 6740bde46d1..4ad1acbea33 100644
--- a/tools/doxygen/Doxyfile.core.internal
+++ b/tools/doxygen/Doxyfile.core.internal
@@ -2006,6 +2006,7 @@ src/core/lib/iomgr/call_combiner.cc \
 src/core/lib/iomgr/call_combiner.h \
 src/core/lib/iomgr/cfstream_handle.cc \
 src/core/lib/iomgr/cfstream_handle.h \
+src/core/lib/iomgr/closure.cc \
 src/core/lib/iomgr/closure.h \
 src/core/lib/iomgr/combiner.cc \
 src/core/lib/iomgr/combiner.h \
@@ -2161,19 +2162,19 @@ src/core/lib/promise/activity.cc \
 src/core/lib/promise/activity.h \
 src/core/lib/promise/arena_promise.h \
 src/core/lib/promise/context.h \
+src/core/lib/promise/detail/basic_join.h \
 src/core/lib/promise/detail/basic_seq.h \
 src/core/lib/promise/detail/promise_factory.h \
 src/core/lib/promise/detail/promise_like.h \
 src/core/lib/promise/detail/status.h \
 src/core/lib/promise/detail/switch.h \
 src/core/lib/promise/exec_ctx_wakeup_scheduler.h \
-src/core/lib/promise/for_each.h \
+src/core/lib/promise/if.h \
+src/core/lib/promise/interceptor_list.h \
 src/core/lib/promise/intra_activity_waiter.h \
 src/core/lib/promise/latch.h \
 src/core/lib/promise/loop.h \
 src/core/lib/promise/map.h \
-src/core/lib/promise/map_pipe.h \
-src/core/lib/promise/pipe.cc \
 src/core/lib/promise/pipe.h \
 src/core/lib/promise/poll.h \
 src/core/lib/promise/promise.h \
@@ -2181,7 +2182,9 @@ src/core/lib/promise/race.h \
 src/core/lib/promise/seq.h \
 src/core/lib/promise/sleep.cc \
 src/core/lib/promise/sleep.h \
-src/core/lib/promise/try_concurrently.h \
+src/core/lib/promise/trace.cc \
+src/core/lib/promise/trace.h \
+src/core/lib/promise/try_join.h \
 src/core/lib/promise/try_seq.h \
 src/core/lib/resolver/resolver.cc \
 src/core/lib/resolver/resolver.h \
@@ -2336,6 +2339,7 @@ src/core/lib/slice/slice.h \
 src/core/lib/slice/slice_buffer.cc \
 src/core/lib/slice/slice_buffer.h \
 src/core/lib/slice/slice_internal.h \
+src/core/lib/slice/slice_refcount.cc \
 src/core/lib/slice/slice_refcount.h \
 src/core/lib/slice/slice_string_helpers.cc \
 src/core/lib/slice/slice_string_helpers.h \
diff --git a/tools/run_tests/generated/tests.json b/tools/run_tests/generated/tests.json
index fdba5ac14d6..3b9ff007cb8 100644
--- a/tools/run_tests/generated/tests.json
+++ b/tools/run_tests/generated/tests.json
@@ -4193,6 +4193,30 @@
     ],
     "uses_polling": true
   },
+  {
+    "args": [],
+    "benchmark": false,
+    "ci_platforms": [
+      "linux",
+      "mac",
+      "posix",
+      "windows"
+    ],
+    "cpu_cost": 1.0,
+    "exclude_configs": [],
+    "exclude_iomgrs": [],
+    "flaky": false,
+    "gtest": true,
+    "language": "c++",
+    "name": "interceptor_list_test",
+    "platforms": [
+      "linux",
+      "mac",
+      "posix",
+      "windows"
+    ],
+    "uses_polling": false
+  },
   {
     "args": [],
     "benchmark": false,