Create Outbound Call

Initiate an outbound call.

This endpoint allows you to programmatically make phone calls from your agent to any phone number. The call will use the agent’s assigned phone number as the caller ID.

Flow:

Validates the agent belongs to your project and has a phone number
Initiates a call via Twilio from the agent’s number to the destination
When recipient answers, speaks the initial greeting (if provided)
Listens for recipient’s speech and sends to your webhook
Continues conversation using your webhook responses

Initiate an outbound call. This endpoint allows you to programmatically make phone calls from your agent to any phone number. The call will use the agent's assigned phone number as the caller ID. Flow: 1. Validates the agent belongs to your project and has a phone number 2. Initiates a call via Twilio from the agent's number to the destination 3. When recipient answers, speaks the initial greeting (if provided) 4. Listens for recipient's speech and sends to your webhook 5. Continues conversation using your webhook responses

Authentication

AuthorizationBearer

Bearer authentication of the form Bearer <token>, where token is your auth token.

Request

This endpoint expects an object.

agentIdstringRequired

Agent ID to make the call from

toNumberstringRequired

Phone number to call (E.164 format)

initialGreetingstring or nullOptional

Optional initial greeting to speak when recipient answers

voicestringOptionalDefaults to Polly.Amy

Voice to use for speaking (default: Polly.Amy)

systemPromptstring or nullOptional

When provided, uses Retell’s built-in LLM for the conversation instead of forwarding to a webhook. The prompt defines the AI’s personality and conversation topic.

Response

Successful Response

1	import { AgentPhoneClient } from "agentphone";
2
3	async function main() {
4	const client = new AgentPhoneClient({
5	token: "YOUR_TOKEN_HERE",
6	});
7	await client.calls.createOutboundCall({
8	agentId: "string",
9	toNumber: "string",
10	});
11	}
12	main();

Authentication

Request

Response

Errors