Some time ago I wanted to write a MCP server in Zig but found out there's no real JSON-RPC support in Zig, which MCP needs for communication. I ended up developing a JSON-RPC 2.0 library in Zig and more [1], which had its challenges.

So I finally was able to put together a MCP server in Zig. It's built from scratch implementing the protocol messages from the MCP JSON schema. It's actually quite magical to have the LLM calling my MCP server [2].

The work is not too bad. Most of the hard work has already been done in the JSON-RPC library.

[1] https://github.com/williamw520/zigjr

[2] https://github.com/williamw520/zigjr?tab=readme-ov-file#run-...