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Outbound Calls let you place phone calls programmatically: your system makes one API request, a Telzino AI agent dials the number, holds the conversation, and the result — status, duration, AI summary, and transcript reference — is delivered back to you.

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How it works

1

Trigger the call

POST /v1/agents/{agentId}/outbound-calls with the destination number. You can include per-call context for the agent, opaque metadata, and a webhook URL for the result. The API responds immediately with 202 Accepted and a call ID — the call is queued, not yet ringing.
2

The platform places the call

The dispatcher picks up your queued call (typically within a couple of seconds), assigns an agent worker, and dials the number. The agent speaks its greeting as soon as the callee answers — never while the phone is still ringing.
3

The agent has the conversation

The agent uses its full configuration: system prompt (plus your per-call call_context), voice, tools, integrations, and after-call webhooks — identical capabilities to inbound calls.
4

You receive the result

When the call reaches a terminal state, the result webhook fires (if you provided callback_url) and the call record is finalized with duration, AI summary, and a transcript reference. You can also poll the call at any time.

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Call lifecycle

Every outbound call moves through these statuses:
StatusMeaning
queuedAccepted by the API, waiting for the dispatcher
dispatching / dispatchedThe platform is assigning the call to an agent worker
dialingThe phone is ringing
in_progressThe callee answered; the conversation is live
completedThe call ended normally — summary and transcript available
no_answerRang for ~45 seconds with no answer
busyThe line was busy or the call was rejected
failedThe call could not be placed (details in the error and sip_status_code fields)
completed, no_answer, busy, and failed are terminal — the result webhook fires exactly when one of these is reached.

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The result webhook

If you pass a callback_url when triggering the call, Telzino POSTs the result to it on every terminal status: 
{
  "outbound_call_id": "0fc6daf8-7251-4553-9488-867ba0b82d8e",
  "agent_id": "aadcdc82-0c96-4171-a812-6d68ae71c44c",
  "to_number": "+18134268216",
  "status": "completed",
  "answered_at": "2026-06-11T12:50:03.843960+00:00",
  "ended_at": "2026-06-11T12:54:15.354244+00:00",
  "duration": 251,
  "summary_text": "Appointment Confirmation\n\nThe agent confirmed the customer's appointment for tomorrow at 2pm...\n\n**Sentiment:** Positive",
  "transcript_id": "de79aee6-ae41-4003-a3f4-ba9d77b59bd8",
  "metadata": { "crm_id": "123" },
  "error": null,
  "sip_status_code": null
}
  • metadata is your own payload from the trigger request, echoed back verbatim — use it to correlate the result with records in your system.
  • transcript_id links to the full transcript, retrievable via the Call Logs API.
  • For unanswered or failed calls, summary_text and transcript_id are null and sip_status_code carries the SIP failure code (e.g. 486 busy, 480 no answer).
The result webhook must be an HTTPS URL and is delivered once (10-second timeout, no retries). Treat it as a notification: if your endpoint was down, poll GET /v1/agents/{agentId}/outbound-calls/{callId} — the call record is always the source of truth.

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Good to know

If voicemail or an auto-attendant picks up, the call is treated as answered (in_progress → completed) — the agent will speak to the recording. Answering-machine detection is on the roadmap; until then, factor this into your redial logic.
The platform never retries no_answer, busy, or failed calls on its own. Your application decides whether and when to call again, using the webhook or polled status.
The agent speaks its configured greeting the moment the callee answers. An inbound-style greeting (“Thanks for calling!”) sounds wrong on an outbound call — give agents used for outbound a greeting like “Hi, this is Ava calling from Acme Corp.”
The agent’s stored configuration (prompt, voice, tools) always applies. call_context is appended to the prompt for that one call only — ideal for “you’re calling John to confirm his 2pm appointment” without creating a dedicated agent per purpose.

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Endpoints

EndpointPurpose
POST /v1/agents/{agentId}/outbound-callsTrigger an outbound call
GET /v1/agents/{agentId}/outbound-calls/{callId}Get a call’s status and result
GET /v1/agents/{agentId}/outbound-callsList an agent’s outbound calls
Authentication works exactly like the rest of the API — see Authentication.