supergateway

Supergateway runs MCP stdio-based servers over SSE (Server-Sent Events) or WebSockets (WS) with one command. This is useful for remote access, debugging, or connecting to clients when your MCP server only supports stdio.

Supported by Supermachine (hosted MCPs), Superinterface, and Supercorp.

Run Supergateway via npx:

npx -y supergateway --stdio "uvx mcp-server-git"

• `--stdio "command"`: Command that runs an MCP server over stdio
• `--sse "https://mcp-server-ab71a6b2-cd55-49d0-adba-562bc85956e3.supermachine.app"`: SSE URL to connect to (SSE→stdio mode)
• `--streamableHttp "https://mcp-server.example.com/mcp"`: Streamable HTTP URL to connect to (StreamableHttp→stdio mode)
• `--outputTransport stdio | sse | ws | streamableHttp`: Output MCP transport (default: sse with --stdio, stdio with --sse or --streamableHttp)
• `--port 8000`: Port to listen on (stdio→SSE or stdio→WS mode, default: 8000)
• `--baseUrl "http://localhost:8000"`: Base URL for SSE or WS clients (stdio→SSE mode; optional)
• `--ssePath "/sse"`: Path for SSE subscriptions (stdio→SSE mode, default: /sse)
• `--messagePath "/message"`: Path for messages (stdio→SSE or stdio→WS mode, default: /message)
• `--streamableHttpPath "/mcp"`: Path for Streamable HTTP (stdio→Streamable HTTP mode, default: /mcp)
• `--stateful`: Run stdio→Streamable HTTP in stateful mode
• `--sessionTimeout 60000`: Session timeout in milliseconds (stateful stdio→Streamable HTTP mode only)
• `--header "x-user-id: 123"`: Add one or more headers (stdio→SSE, SSE→stdio, or Streamable HTTP→stdio mode; can be used multiple times)
• `--oauth2Bearer "some-access-token"`: Adds an Authorization header wit