basecamp-mcp

An MCP server that exposes the basecamp CLI to Claude Desktop (and any other MCP client) over HTTP. It runs as a login-time background service and is reached at a local URL.

It's a thin wrapper: each MCP tool shells out to basecamp <cmd> --json and returns the parsed result. Authentication is handled entirely by the CLI's own token store — this server never sees your password and holds no credentials.

Architecture

Claude Desktop ──HTTP(/mcp)──▶ basecamp-mcp (bun, :7331) ──spawn──▶ basecamp CLI ──▶ Basecamp API
     custom connector           launchd LaunchAgent, runs at login

• Transport: MCP Streamable HTTP (Web-standard Request/Response via Bun.serve).

• Bind address: 127.0.0.1 only, with DNS-rebinding protection — not reachable off-box.

• Lifecycle: a launchd LaunchAgent (RunAtLoad + KeepAlive) starts it at login and restarts it if it dies.

• Runtime: compiled to a single standalone executable with bun build --compile — Bun is only needed to build, not to run.

Related MCP server: Basecamp MCP Server

Quick start (macOS)

You don't need anything installed first — the setup script handles it all (Homebrew, the basecamp CLI, and Bun).

1. Open Terminal and paste this, then press Return:

   git clone https://github.com/jpaoad31/basecamp-mcp.git
   cd basecamp-mcp
   ./setup.sh

   It installs the prerequisites, builds the server, sets it to start at login, and opens a browser to log you into Basecamp. If asked for your Mac password, that's Homebrew installing — it's expected.

2. When it finishes it prints a URL. In Claude Desktop → Settings → Connectors → Add custom connector, paste that URL:

   http://127.0.0.1:7331/mcp

That's it. The server runs automatically every time you log in.

To update later: cd basecamp-mcp && git pull && ./setup.sh.

No git? (zip install)

If someone sent you a zip instead: double-click to unzip, drag the basecamp-mcp folder onto a Terminal window, press Return, then run ./setup.sh.

Prerequisites (manual install)

• The basecamp CLI installed and on your PATH.

• Bun (to build).

• You must log the CLI in once: basecamp auth login.

Install

bun install
./install.sh          # or: bun run install-service

Packaging for someone else

./package.sh          # or: bun run package

Produces basecamp-mcp.zip (source + scripts only). Send it; they run ./setup.sh. The binary is compiled on their machine, which avoids macOS Gatekeeper quarantine.

This builds dist/basecamp-mcp, writes a LaunchAgent to ~/Library/LaunchAgents/com.basecamp.mcp.plist, loads it, and health-checks it.

Then in Claude Desktop → Settings → Connectors → Add custom connector, use:

http://127.0.0.1:7331/mcp

Tools

Development

bun run dev      # watch mode, http://127.0.0.1:7331/mcp
bun run start    # run once
bun run build    # produce dist/basecamp-mcp
curl -s http://127.0.0.1:7331/health   # liveness

Override the port with PORT=… and the CLI location with BASECAMP_BIN=….

Uninstall

./uninstall.sh   # or: bun run uninstall-service

Notes & caveats

• Security: the basecamp_cli escape hatch can run any CLI command (including destructive ones and auth token). The server is bound to loopback for exactly this reason — anyone who can reach the port acts as you.

• Claude Desktop connectors: local http:// connector URLs work with recent Desktop builds. If yours refuses a non-HTTPS URL, either update Desktop or fall back to a stdio MCP config pointing at the binary.

• Logs: ~/Library/Logs/basecamp-mcp.log.