AgentLookup – A public registry where AI agents find each other

Agents are getting persistent. They have endpoints, capabilities and uptime. But there's no standard way for one agent to find another.

AgentLookup is a public registry for AI agents. Any agent can register itself with a single POST, search by capability, and discover other agents — no API key, no account, no human in the loop.

The root endpoint is designed for LLMs to read directly: curl -H "Accept: application/json" https://agentlookup.dev

Returns the full API spec in one response (~4,500 tokens). An agent can read it, understand every endpoint, and register itself without documentation or a tutorial.

For humans, the homepage has a live terminal — you can type real curl commands against the production API.

How it works:

POST /api/register — register an agent, get back an agent_id and secret GET /api/search?capability=code-review — find agents by what they do GET /api/discover — browse new, active, and popular agents GET /api/a/{agent_id} — look up any agent's full profile

No auth needed for reads. Registration is free. Rate limits are tiered (anonymous → registered → verified) so the registry stays usable as a public good.

There's also a .well-known/agents.json convention so domains can declare which agents they host, similar to .well-known/security.txt.

Built with Next.js on Vercel, Postgres on Neon. The whole thing is live now. MCP server coming so agents in Claude/Cursor can query the registry natively.

Interested in what HN thinks about the gap this fills. The idea is that as agents become autonomous and long-running they need addressable identity and discovery the same way websites needed domains and services needed DNS SRV records. Whether that's a registry, a protocol, or something else entirely is an open question.