Testers wanted: v3 preview — the pure-Python server (branch v2-test)

[mixelpixx]

Testers wanted: v3 preview — the pure-Python server (branch v2-test)

There's a new architecture on the v2-test branch and I'd like people to break
it before it goes anywhere near main.

What changed

The TypeScript layer is gone. Until now, every tool call traveled through
Node.js, zod validation, a spawned Python subprocess, and JSON over
stdin/stdout before any real work happened. On this branch the server is a
single Python process built on the official MCP Python SDK v2 — a tool call is
a function call. Same 185 tools, same behavior, one runtime.

What that means in practice:

• Install is one step. No Node 20, no npm install, no npm run build,
  no PYTHONPATH surgery. Python 3.10+ and pip install . is the whole
  procedure.
• Two transports. stdio by default (what Claude Desktop and Claude Code
  use), plus Streamable HTTP: kicad-mcp-server --transport streamable-http --port 8331.
• It runs without pcbnew. Schematic editing, kicad-cli exports/checks, and
  the IPC backend work on any stock Python. Tools that need the SWIG API
  return a structured error explaining your options instead of refusing to
  start. (Full SWIG coverage still needs a Python that can import KiCAD's
  pcbnew, same as before. SWIG is removed entirely in KiCAD 11, so reducing
  that dependency is also future-proofing.)
• Both protocol eras. The SDK serves current MCP clients and the upcoming
  2026-07-28 revision from the same server.

What "same 185 tools" means

The exact tool surface of the TypeScript layer — names, parameters, required
fields — was captured into a baseline fixture, and the test suite locks the
new server against it. The repo's ~1,400 tests pass with a failure set
identical to main. Live stdio and HTTP sessions, plus a clean-machine wheel
install (no repo checkout, no Node), were verified before pushing.

Try it

git clone -b v2-test https://github.com/mixelpixx/KiCAD-MCP-Server.git
cd KiCAD-MCP-Server
pip install .



Claude Desktop / Claude Code config:

{
  "mcpServers": {
    "kicad": {
      "command": "kicad-mcp-server"
    }
  }
}


The old TypeScript path still works unchanged on this branch, so you can run
both side by side and compare.

What I'm looking for
Install problems on any OS — especially macOS and Linux, which I can't test
as thoroughly right now
Any tool that behaves differently than it does on main
Schema oddities in whatever MCP client you use (Claude Desktop, Claude Code,
Inspector, anything else)
Streamable HTTP reports — this transport is new here
File an issue tagged v3-beta or reply in this thread. Known caveats, stated
up front: this is a beta on a beta — the MCP SDK v2 dependency is pinned to a
pre-release (mcp==2.0.0b1, stable expected late July) and will be relaxed
when it lands. Per-tool server-side timeouts from the TS layer are gone by
design; your client's timeout applies now.

If this round goes well, the TypeScript layer is removed in the release after,
and installation becomes pip install kicad-mcp-server from PyPI.