The C based gRPC (C++, Python, Ruby, Objective-C, PHP, C#) https://grpc.io/

AJ Heller 83868b695e Assert Android API >= v21 (#27943 An error occurred ) * Assert Android API >= v21 This precedes a change that would otherwise break on older Android APIs, but in a more obvious way. * error if __ANDROID_API__ is not defined * update all Andriod minSdkVersions to 21 * csharp experimental: android-19 to 21		3 years ago
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Assets	change port number in examples to avoid conflict with forbidden port on win	5 years ago
ProjectSettings	Assert Android API >= v21 (#27943 An error occurred )	3 years ago
UIElementsSchema	add scaffolding for HelloworldUnity	6 years ago
.gitignore	add scaffolding for HelloworldUnity	6 years ago
README.md	Add HelloworldUnity readme	6 years ago

README.md

gRPC C# on Unity

EXPERIMENTAL ONLY

Support of the Unity platform is currently experimental.

PREREQUISITES

Unity 2018.3.5f1

BUILD

Follow instructions in https://github.com/grpc/grpc/tree/master/src/csharp/experimental#unity to obtain the grpc_csharp_unity.zip that contains gRPC C# for Unity. Unzip it under Assets/Plugins directory.
Open the HelloworldUnity.sln in Unity Editor.
Build using Unity Editor.