tree: 41de0c93ccb296281f5aee49bbc0d4cdf68d230c [path history] [tgz]
  1. keys/
  2. protos/
  3. src/
  4. .gitignore
  5. build_packages.bat
  7. CHANGES.txt
  9. Google.Protobuf.Tools.nuspec

This directory contains the C# Protocol Buffers runtime library.

Status: Beta - ready for external testing


The easiest way how to use C# protobufs is via the Google.Protobuf NuGet package. Just add the NuGet package to your VS project.

Besides C# runtime library, the NuGet package also contains precompiled version of protoc.exe and a copy of well known .proto files under the package's tools directory.

To generate C# files from your .proto files, invoke protoc with the --csharp_out option.

Supported platforms

The runtime library is built as a portable class library, supporting:

  • .NET 4.5
  • Windows 8
  • Windows Phone Silverlight 8
  • Windows Phone 8.1
  • .NET Core

You should be able to use Protocol Buffers in Visual Studio 2012 and all later versions. This includes all code generated by protoc, which only uses features from C# 3 and earlier.


Open the src/Google.Protobuf.sln solution in Visual Studio 2015 or later. You should be able to run the NUnit test from Test Explorer (you might need to install NUnit Visual Studio add-in).

Although users of this project are only expected to have Visual Studio 2012 or later, developers of the library are required to have Visual Studio 2015 or later, as the library uses C# 6 features in its implementation. These features have no impact when using the compiled code - they're only relevant when building the Google.Protobuf assembly.

History of C# protobufs

This subtree was originally imported from and represents the latest development version of C# protobufs, that will now be developed and maintained by Google. All the development will be done in open, under this repository (

The previous project differs from this project in a number of ways:

  • The old code only supported proto2; the new code only supports proto3 (so no unknown fields, no required/optional distinction, no extensions)
  • The old code was based on immutable message types and builders for them
  • The old code did not support maps or oneof
  • The old code had its own JSON representation, whereas the new code uses the standard protobuf JSON representation
  • The old code had no notion of the “well-known types” which have special support in the new code
  • The old project supported some older platforms (such as older versions of Silverlight) which are not currently supported in the new project