rime

Minimal MCP server for Nix tooling, written in Rust. It uses the rust-mcp-sdk and exposes a set of helpful Nix/NixOS tools through the Model Context Protocol (MCP).

The binary can run as either:

• MCP over stdio
• MCP over HTTP (with SSE or JSON-only responses)

Tools

• nix_evaluate: Evaluate a Nix expression.
• nix_log: Get build log for an installable.
• nix_packages_search: Search packages in an installable.
• nix_packages_why_depends: Show why a package depends on another.
• nix_flakes_show: Show a flake's outputs.
• nix_flakes_metadata: Show flake metadata.
• nix_config_check: Run nix config check.
• nix_config_show: Run nix config show.
• nix_manual_list: List Markdown files in the Nix manual source.
• nix_manual_read: Read a Markdown file from the Nix manual.
• nixos_wiki_search: Search the NixOS wiki.
• nixos_wiki_read_page: Read a page from the NixOS wiki.
• nixos_channels: List available NixOS channels with their status.
• manix_search: Search docs with manix.
• nixhub_package_versions: Get the version history (releases, commit hashes) for a specific package using nixhub.

Note: Most tools shell out to nix; ensure nix is installed and available on PATH.

Build

With Cargo:

• Debug: cargo build
• Release: cargo build --release

With Nix (flake):

• Build: nix build .#rime (binary at ./result/bin/rime)

Run

Help:

• Cargo: cargo run -- --help
• Nix: nix run .#rime -- --help

Stdio transport:

• Cargo: cargo run -- stdio
• Nix: nix run .#rime -- stdio

HTTP transport:

• Cargo: cargo run -- http --host 127.0.0.1 --port 8080
• Nix: nix run .#rime -- http --host 127.0.0.1 --port 8080

Usage

OpenAI Codex

Add the following snippet into your ~/.codex/config.toml:

[mcp_servers.rime]
command = "/path/to/rime"
args = ["stdio"]

See codex docs.

opencode

Add a new MCP server into your opencode config, e.g. globally at ~/.config/opencode/opencode.json:

{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "rime": {
      "type": "local",
      "command": ["/path/to/rime", "stdio"],
      "enabled": true
    }
  }
}

See opencode docs.

Claude Code

Run the following command:

claude mcp add rime -- /path/to/rime stdio

See Claude Code docs.

Gemini Code

Add the following rime to mcpServers in your Gemini config, e.g. globally at ~/.gemini/settings.json.

{
  "mcpServers": {
    "rime": {
      "command": "/path/to/rime",
      "args": ["stdio"]
    }
  }
}

See Gemini Code docs.

VSCode

Add rime to .vscode/mcp.json:

{
  "servers": {
    "rime": {
      "type": "stdio",
      "command": "/path/to/rime",
      "args": ["stdio"]
    }
  }
}

See VSCode Copilot docs.

Credits

• manix
• nixhub
• mcp-nixos