Make Voice AI Call API
Learn how to initiate outbound phone calls using Bolna Voice AI agents. Start making phone calls using the agent ID and recipient’s phone number.
execution_id you use to track and retrieve the call result.
Minimal example
Only two fields are required —agent_id and recipient_phone_number. Omit from_phone_number to use your account’s default number.
Realistic example with personalization
Passuser_data to inject variables into your agent’s prompt and welcome message (e.g. {customer_name} in the prompt becomes “Asha”):
Tracking the call
Use the returnedexecution_id to poll GET /executions/{execution_id} for status. The call goes through these stages:
Common 400 errors
| Message | Fix |
|---|---|
agent_id is required | Include a valid UUID agent_id |
recipient_phone_number is required | Phone number must be E.164 format, e.g. +919876543210 |
Invalid from_phone_number | Must be a number purchased in your Bolna account |
Authorizations
Bearer authentication header of the form Bearer <token>, where <token> is your auth token.
Body
Make a phone call from agent
Agent id which will initiate the outbound call
The scheduled date and time in ISO 8601 format with time zone
"2024-06-05T16:35:00.000+05:30"
Additional user dynamic variables as defined in the agent prompt
Agent configuration to override the default configuration. Currently, only voice_id for the same provider is supported.
Configuration for auto-retry of failed calls. See auto-retry documentation for details.
Skip time validation checks and make call immediately regardless of agent's calling_guardrails configuration
Response
agent status response
Response message for the call initiated
"done"
Status of the call.
queued "queued"
Unique execution_id or call_id identifier of the call.
^[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{12}"123e4567-e89b-12d3-a456-426614174000"

