21tunnel — the tunnel for AI agents
The tunnel for AI agents — open-source ngrok alternative
21tunnel gives AI coding agents like Claude Code, Cursor, and Devin scoped, short-lived credentials to open secure public tunnels to your localhost, with one-click cascade revoke. Also a complete open-source ngrok alternative in Rust: HTTP, TCP, SSH and gRPC tunnels, sticky subdomains, custom domains on the free tier, request inspector, teams with RBAC and audit logs. Free tier forever, self-hostable under MIT and Apache-2.0.
AI coding agents need public URLs for the work they produce on localhost. Handing them your full-access API token is the default answer, and it is a bad one.
21tunnel gives the agent its own scoped, short-lived keys instead. One master key that cannot open tunnels itself, child keys with expiry and project isolation, and one-click cascade revoke for everything the agent ever created.
Also works as a normal open-source ngrok alternative: HTTP, TCP, SSH tunnels from one Rust binary, custom domains on the free tier, request inspector, self-hostable forever.
Free tier is live. Feedback welcome, especially from anyone running agents with infrastructure access.
learn more about 21tunnel - https://21tunnel.com/blog/
