API reference

Base URL, authentication and conventions.

Base URL

https://api.telleo.ai/v1

Authentication

Send your AI calling API key in the X-API-Key header (or Authorization: Bearer <key>). See Authentication.

Conventions

• Request and response bodies are JSON, with snake_case field names.
• Timestamps are ISO-8601 in UTC, e.g. 2026-10-13T09:30:02Z.
• Phone numbers are E.164, e.g. [phone].
• Ids carry a prefix: call_…, batch_…, evt_…. Agent ids are UUIDs.
• Every response has an X-Request-Id header.
• Errors share one shape. See Errors.

Endpoints

POST /calls	Start a call
GET /calls	List calls
GET /calls/{id}	Get a call
POST /calls/{id}/cancel	Cancel a queued call
POST /batches	Start up to 1,000 calls
GET /batches/{id}	Batch progress
GET /agents	Your agents and the variables they use
GET PUT DELETE /webhook	Your webhook endpoint
POST /webhook/rotate-secret	New signing secret
POST /webhook/test	Send a test event