radius-mcp-server

A local MCP (Model Context Protocol) server that gives AI assistants everything they need to know about Radius:

• Docs — full-text search and page reads over the official documentation (docs.radapp.io), sourced from a local cache of radius-project/docs.

• Source — full-text search and file reads over radius-project/radius: Go source, architecture docs, design notes, specs, and TypeSpec/Bicep type definitions.

It needs no local setup: on first use it clones shallow, read-only caches of both repos for itself (see Data sources below).

Tools

Related MCP server: directory-indexer

Quick start (once published to npm)

Most MCP clients just need to be told to run npx -y radius-mcp-server. See Connecting it to an MCP client for exact config per tool. Requires Node.js 18+ and git on PATH.

Data sources

Both are shallow (--depth 1) clones made on first use and left in place across runs; call radius_docs_sync / radius_source_sync to pull the latest.

If you already have a local radius-project/radius checkout you'd rather use instead of a managed clone — e.g. you're working in it directly — point RADIUS_REPO_PATH at it (or run this server from a directory with a sibling radius/ folder, which is auto-detected). When set, that checkout is treated as yours to manage; radius_source_sync becomes a no-op and the tools just read from it as-is.

Connecting it to an MCP client

All of these assume the package is published; swap npx -y radius-mcp-server for node /absolute/path/to/radius-mcp-server/dist/index.js to point at a local build instead (see Development).

Claude Code

claude mcp add radius -- npx -y radius-mcp-server

Or add manually to .mcp.json (project-scoped) or ~/.claude.json (user-scoped):

{
  "mcpServers": {
    "radius": {
      "command": "npx",
      "args": ["-y", "radius-mcp-server"]
    }
  }
}

Restart Claude Code (or run /mcp to check connection status) and the radius_* tools will be available.

Claude Desktop

Add the same block to your Claude Desktop config (~/Library/Application Support/Claude/claude_desktop_config.json on macOS):

{
  "mcpServers": {
    "radius": {
      "command": "npx",
      "args": ["-y", "radius-mcp-server"]
    }
  }
}

Restart Claude Desktop to pick up the new server.

VS Code (GitHub Copilot Chat)

Add to .vscode/mcp.json in your workspace (or via "MCP: Open User Configuration" for a user-wide install). Note the top-level key is servers, not mcpServers:

{
  "servers": {
    "radius": {
      "command": "npx",
      "args": ["-y", "radius-mcp-server"]
    }
  }
}

VS Code will prompt to start the server the first time it's used; check its status via the MCP Servers view.

GitHub Copilot coding agent

In the repository's Settings → Copilot → Coding agent → MCP configuration, add:

{
  "mcpServers": {
    "radius": {
      "type": "local",
      "command": "npx",
      "args": ["-y", "radius-mcp-server"],
      "tools": ["*"]
    }
  }
}

type and tools are required by Copilot coding agent's schema (unlike the other clients above). See GitHub's MCP docs if you want to allowlist specific tools instead of ["*"].

Other clients (Cursor, Windsurf, ...)

Most other MCP-capable tools follow the same mcpServers convention as Claude Desktop above — check the client's docs for the exact config file location.

Publishing to npm

To publish a new version (maintainers only):

npm login                     # once, if not already logged in
npm run build                 # or rely on the prepublishOnly hook
npm version patch             # or minor / major — bumps package.json + tags
npm publish                   # prepublishOnly runs the build automatically
git push --follow-tags

npm publish is public and effectively permanent (npm blocks re-publishing a given version, and unpublishing after 72h is restricted) — double-check package.json's version and the tarball contents (npm pack --dry-run) before running it.

Development

npm install
npm run build   # one-off build
npm run dev     # tsc --watch
npm start       # run the built server directly on stdio (Ctrl+C to stop)

Re-run npm run build (or use npm run dev in the background) after editing anything in src/, then restart the server in your MCP client to pick up changes.