Problem solved

Developers and AI agents need a safe way to expose local servers to the internet and operate autonomously without sharing long-lived, powerful credentials. 21tunnel solves this with a master-key delegation model: an AI agent can mint scoped child keys that expire automatically, and a human can revoke everything instantly with cascade revocation. It also provides standard public tunneling features for exposing HTTP, TCP, and SSH services.

Use cases

• Expose a local web server to the internet for webhooks, demos, or integration testing
• Let an AI agent independently create and manage short-lived project-scoped tunnels
• Share a localhost application with stakeholders or collaborators via a public URL
• Add Google login and allowlist-based access control to traffic before it reaches your localhost
• Expose TCP services such as PostgreSQL for secure remote debugging
• Use SSH tunnels for remote access to development environments
• Collaborate in teams with role-based access and a queryable audit log

Audience

• Developers
• ML Engineers
• Startups
• Enterprise
• Hobbyists

Pros

• Built-in AI agent key delegation with TTL and cascade revoke
• Supports HTTP, TCP, and SSH tunnels
• Custom domains and sticky subdomains on the free tier
• Live request inspector and audit log
• Simple free tier with no card required

Cons

• Newer and smaller ecosystem than ngrok or Cloudflare Tunnel
• Edge auth and some advanced capabilities require Pro plan
• Request replay and per-tunnel allowlists are still on the roadmap
• Self-host deployment adds maintenance overhead
• Documentation may be less extensive than established competitors