mcptunnels

mcptunnels is a command-line tool designed to expose local MCP (Model Context Protocol) servers to the public internet. It simplifies the process by requiring only one command to generate a public URL, eliminating the need for accounts, signups, or complex configurations. The service emphasizes anonymity and ephemerality, with tunnels expiring after 24 hours and being deleted server-side immediately upon process termination (Ctrl-C).

By default, mcptunnels secures public endpoints with OAuth 2.1, generating a password via the CLI. This security feature is designed to be automatically discovered by clients like ChatGPT, Claude, and Cursor. For use cases requiring open access, an `--no-auth` option is available. The tool also offers a self-hostable relay (`tunneld`) for users who prefer to manage their own infrastructure, though a hosted relay at `tunnel.mcptunnels.xyz` is provided by default.

Unlike generic tunneling solutions such as ngrok or cloudflared, mcptunnels is specifically tailored for MCP servers. It handles stdio to Streamable HTTP bridging, which is crucial for many MCP server setups, a feature not typically offered by generic tunnels. This makes it particularly useful for connecting AI clients to local servers, demonstrating servers to teammates without deployment, or testing servers during development. The project is currently in v1, with a roadmap including permanent tunnels to address user growth beyond ephemeral needs.