mcpgate turns OpenAPI into MCP dynamically, on-the-fly, for any number of APIs, with no code and no config

[MicaelJarniac]

https://github.com/MicaelJarniac/mcpgate

mcpgate lets you connect any AI assistant (like Claude) to any REST API — without writing a single line of code. Just point it at an OpenAPI spec and it instantly becomes an MCP server. Run it with uvx mcpgate, no install needed.

Examples

Nametag

Connect an MCP client to the Nametag API without any custom server code.

1. Start the gateway:

uvx mcpgate --port 8000

2. Configure your MCP client (e.g. Claude Desktop — claude_desktop_config.json):

{
  "mcpServers": {
    "Nametag": {
      "baseUrl": "http://localhost:8000/mcp/",
      "headers": {
        "X-OpenAPI-URL": "https://app.nametag.one/api/openapi.json",
        "X-API-URL": "https://app.nametag.one",
        "X-Cookies": "YOUR_SESSION_COOKIE"
      }
    }
  }
}

To get YOUR_SESSION_COOKIE, open the Nametag web app in your browser, open DevTools → Application → Cookies, and copy the value of the session cookie (e.g. __Secure-authjs.session-token=<value>). Pass it as X-Cookies: __Secure-authjs.session-token=<value>.

The gateway fetches the OpenAPI spec from X-OpenAPI-URL once and caches it, then proxies every MCP tool call to X-API-URL with your session cookie attached — no backend changes required.