💦 mcpee

Because too many MCP routers turned out to be quite poo.

Run multiple local MCP servers (stdio), aggregate, expose as HTTP. Done.

🚽 No request retries, backend supervision, restart policy, plugin system, policy engine, metrics endpoint, protocol models, authentication or custom JSON-RPC bullshit.

📖 Design tenets

1. Catalog projection is configuration.
2. Call routing is a lookup.
3. Everything else belongs to the SDK or outside the process.

Usage

• Connecting to ChatGPT

Behavior

Caution

mcpee provides no authentication or sandboxing.

Keep it on loopback, or put authentication in front of it if you expose it remotely.

Want sandboxing? Run your MCP binaries through codex sandbox windows, Seatbelt, bubblewrap, or whatever else fits your platform.

mcpee doesn't care. 🤗

• frontend: stateless Streamable HTTP at /mcp
• default listen address: 127.0.0.1:8080
• backends: stdio MCP servers owned for the process lifetime
• projected names: <backend>__<tool>
• startup fails if any backend cannot connect/list tools, or if projection is invalid
• descriptions, schemas, annotations, icons, results, errors, and request cancellation are passed through via the official SDK
• logs go brr to stderr

Configuration

listen: 127.0.0.1:8080

backends:
  - name: exec
    command: fs-mcp-rs

  - name: my-stdio-mcp
    command: my-mcp-binary
    args:
      - foxtrot
      - unicorn
    env:
      CHARLIE: KILO

Development

Built on top of github.com/modelcontextprotocol/go-sdk. Whatever it needs, we it need too.

Use mise run to discover all tasks (build / test / etc..)

The tests cover catalog projection/routing, metadata preservation, collisions/invalid names, argument forwarding, backend result forwarding, and configuration defaults.