MCP Gateway

A compact non-production-ready MCP gateway.

Built with LLM-powered tools to befriend LLMs and the tools.

Use cases

1. You need to expose the MCP server beyond localhost (ie for a dockerized harness)
2. You want to use the MCP server, but disable some of its tools
3. You need to expose the MCP, using one protocol, to a harness using other protocol

It routes (proxies) tool calls to configured downstream MCP servers. It currently supports downstream streamable-http and sse transports. It also has a dashboard where you can enable or disable certain tools.

Run

uv sync
cp gateway.example.json gateway.json
uv run mcp-gateway

Use the MCP Inspector or any MCP client against /http/mcp (or /sse/sse for a legacy client).

Configure upstream clients

Add http://localhost:64345/http/mcp as an endpoint to your client or harness.

Configure downstream servers

Edit gateway.json accordingly.

headers are optional and are never shown by the dashboard.

disabled_tools is optional per server. List downstream tool names (before any gateway renaming) to hide at startup. Restart the gateway after changing this list.

Exposed tools

The gateway exposes only tools discovered from downstream servers. It copies each tool's name, description, schemas, annotations, and result without a gateway wrapper.

When two or more downstream servers expose the same tool name, every conflicting tool is exposed as servername-toolname, for example github-search.

Tool discovery happens at gateway startup. Restart the gateway to pick up downstream inventory changes.

Disclaimer

This is a starter gateway, not an authorization boundary. Expect bugs. Never expose beyond localhost.