MCP Server

devenv mcp launches a Model Context Protocol (MCP) server that exposes devenv functionality to AI assistants.

Usage

Stdio mode (default)

$ devenv mcp

The server communicates over stdin/stdout. This is the mode used when an AI tool spawns devenv as a subprocess.

HTTP mode

$ devenv mcp --http
$ devenv mcp --http 9090

Starts the MCP server as an HTTP service. The default port is 8080.

Available tools

The MCP server provides:

• search_packages — search for packages in the nixpkgs input.
• search_options — search for devenv configuration options.

Integration with Claude Code

See Claude Code integration for instructions on configuring Claude Code to use the devenv MCP server automatically.

Last updated Oct 11, 2026