Install build123d MCP in Claude Code

What you need first

• Claude Code, installed.
• uv, which gives the uvx command the server starts with.

Steps

1. Run this in a terminal, in the project folder. It adds the server for you in that project; put --scope user after claude mcp add to have it in every project.

claude mcp add --transport stdio build123d-mcp -- uvx build123d-mcp==0.3.91

2. Start Claude Code and type /mcp: the server is listed with its state.

Check it worked

Ask Claude Code: List the tools of build123d-mcp.

If it does not start

spawn uvx ENOENT

uv is not on the PATH that Claude Code sees. Install it, or write the full path of uvx in the config.