Call one agent from code with an Agent API key

In the UI: add an Agent API channel to an agent, publish it, and create a key in its Agent keys card. The secret (evr_ak_…) is shown once. An application holding it can call this one agent and nothing else; keys rotate with an overlap window and can be revoked.

In code: routes under /v1/channels/{channel_id} start sessions, send messages, follow events over SSE, answer questions, approve tools and cancel turns. A key sees only the sessions it started. Channel settings add end users through your own identity provider, browser origins, Idempotency-Key retries, a daily spend limit per caller, and access for organization members.

See Call your agent from code, Agent API and #4438, #4490, #4508, #4511, #4514, #4516.