Outbound call

Trigger an outbound call to a specific number

Basic

This API allows you to initiate outbound phone calls from a specified Millis AI voice agent to any given phone number.

​Prerequisites

Obtain your API key from your Millis AI Account.

​API Details

• Method: POST

• URL:

https://api-west.millis.ai/start_outbound_call

• Headers:

Content-Type: application/json
Authorization: YOUR_API_KEY

• Body:

{
  "from_phone": "one of your agent's phone number",
  "to_phone": "receiver's phone number",
  "metadata": {
    key: value
  }, // Optional: any extra data to attach to the session
  include_metadata_in_prompt: true/false // Optional: option to include the metadata in the agent's system prompt
}

Ensure the phone number includes the full international dialing format (e.g., [phone]), with no dashes or spaces. (Only US phone nubers are supported)

Retrieve your voice agent ID from the Agent Details page on the playground.

Example Request using curl

curl -X POST https://api-west.millis.ai:8080/start_outbound_call \
-H "Content-Type: application/json" \
-H "Authorization: YOUR_API_KEY" \
-d '{"from_phone": "[phone]", "to_phone": "[phone]"}'