GPT MCP Proxy

What is GPT MCP Proxy?

GPT MCP Proxy is a REST API server that provides HTTP access to Multiple Command Protocol (MCP) tools. It acts as a bridge between HTTP clients and MCP‑compliant tool servers, allowing tools to be discovered and executed via REST endpoints. It is designed for integrating MCP tools with custom GPT actions.

How to use GPT MCP Proxy?

Set the environment variables NGROK_AUTH_TOKEN, NGROK_DOMAIN, and optionally MCP_CONFIG_FILE (defaults to mcp_settings.json). Create an mcp_settings.json file with your MCP server configurations. Run the server with go run main.go.

Key features of GPT MCP Proxy

• List available MCP servers and their tools.
• Get detailed information about specific tools.
• Execute tools with custom parameters.
• OpenAPI 3.1.0 specification.
• Automatic public HTTPS exposure via ngrok.

Use cases of GPT MCP Proxy

• Integrate MCP tools with custom GPT actions.
• Expose MCP‑compliant tool servers through a REST API.
• Enable HTTP clients to discover and invoke MCP tools.
• Provide a public, secure endpoint for MCP tools via ngrok.

FAQ from GPT MCP Proxy

What are the prerequisites for running GPT MCP Proxy?

Go 1.20 or later, an ngrok account with an authtoken, and MCP‑compliant tools.

What environment variables are required?

NGROK_AUTH_TOKEN and NGROK_DOMAIN are required. MCP_CONFIG_FILE is optional and defaults to mcp_settings.json.

How do I configure the MCP servers?

Create an mcp_settings.json file with an mcpServers object. Each server entry includes a command and args array.

How is the server exposed publicly?

The server automatically uses ngrok to provide public HTTPS access.

What API endpoints are available?

GET /openapi.json, GET /mcp/servers, GET /mcp/{serverName}, GET /mcp/{serverName}/tools/{toolName}, and POST /mcp/{serverName}/tools/{toolName}/execute.