diff --git a/BUILD b/BUILD
index 2b32baae..bb4f5931 100644
--- a/BUILD
+++ b/BUILD
@@ -189,6 +189,7 @@ proto_library(
         "//envoy/extensions/filters/http/set_metadata/v3:pkg",
         "//envoy/extensions/filters/http/stateful_session/v3:pkg",
         "//envoy/extensions/filters/http/tap/v3:pkg",
+        "//envoy/extensions/filters/http/upstream_codec/v3:pkg",
         "//envoy/extensions/filters/http/wasm/v3:pkg",
         "//envoy/extensions/filters/listener/http_inspector/v3:pkg",
         "//envoy/extensions/filters/listener/original_dst/v3:pkg",
diff --git a/envoy/extensions/filters/http/upstream_codec/v3/BUILD b/envoy/extensions/filters/http/upstream_codec/v3/BUILD
new file mode 100644
index 00000000..ee92fb65
--- /dev/null
+++ b/envoy/extensions/filters/http/upstream_codec/v3/BUILD
@@ -0,0 +1,9 @@
+# DO NOT EDIT. This file is generated by tools/proto_format/proto_sync.py.
+
+load("@envoy_api//bazel:api_build_system.bzl", "api_proto_package")
+
+licenses(["notice"])  # Apache 2
+
+api_proto_package(
+    deps = ["@com_github_cncf_udpa//udpa/annotations:pkg"],
+)
diff --git a/envoy/extensions/filters/http/upstream_codec/v3/upstream_codec.proto b/envoy/extensions/filters/http/upstream_codec/v3/upstream_codec.proto
new file mode 100644
index 00000000..ea394483
--- /dev/null
+++ b/envoy/extensions/filters/http/upstream_codec/v3/upstream_codec.proto
@@ -0,0 +1,18 @@
+syntax = "proto3";
+
+package envoy.extensions.filters.http.upstream_codec.v3;
+
+import "udpa/annotations/status.proto";
+
+option java_package = "io.envoyproxy.envoy.extensions.filters.http.upstream_codec.v3";
+option java_outer_classname = "UpstreamCodecProto";
+option java_multiple_files = true;
+option go_package = "github.com/envoyproxy/go-control-plane/envoy/extensions/filters/http/upstream_codec/v3;upstream_codecv3";
+option (udpa.annotations.file_status).package_version_status = ACTIVE;
+
+// [#protodoc-title: UpstreamCodec]
+// Codec :ref:`configuration overview <config_http_filters_upstream_codec>`.
+// [#extension: envoy.filters.http.upstream_codec]
+
+message UpstreamCodec {
+}
diff --git a/envoy/extensions/upstreams/http/v3/http_protocol_options.proto b/envoy/extensions/upstreams/http/v3/http_protocol_options.proto
index 34f604ee..37debb7e 100644
--- a/envoy/extensions/upstreams/http/v3/http_protocol_options.proto
+++ b/envoy/extensions/upstreams/http/v3/http_protocol_options.proto
@@ -150,7 +150,18 @@ message HttpProtocolOptions {
     AutoHttpConfig auto_config = 5;
   }
 
-  // [#not-implemented-hide:]
+  // .. warning::
+  //   Upstream HTTP filters are not supported by default.
+  //   This warning will be removed as support moves beyond alpha.
+  //
   // Optional HTTP filters for the upstream filter chain.
+  //
+  // These filters will be applied for all HTTP streams which flow through this
+  // cluster. Unlike downstream filters, they will *not* be applied to terminated CONNECT requests.
+  //
+  // If using upstream filters, please be aware that local errors sent by
+  // upstream filters will not trigger retries, and local errors sent by
+  // upstream filters will count as a final response if hedging is configured.
+  // [#extension-category: envoy.filters.http.upstream]
   repeated filters.network.http_connection_manager.v3.HttpFilter http_filters = 6;
 }
diff --git a/versioning/BUILD b/versioning/BUILD
index ca5ad9b7..14e95db7 100644
--- a/versioning/BUILD
+++ b/versioning/BUILD
@@ -127,6 +127,7 @@ proto_library(
         "//envoy/extensions/filters/http/set_metadata/v3:pkg",
         "//envoy/extensions/filters/http/stateful_session/v3:pkg",
         "//envoy/extensions/filters/http/tap/v3:pkg",
+        "//envoy/extensions/filters/http/upstream_codec/v3:pkg",
         "//envoy/extensions/filters/http/wasm/v3:pkg",
         "//envoy/extensions/filters/listener/http_inspector/v3:pkg",
         "//envoy/extensions/filters/listener/original_dst/v3:pkg",