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PolyAI supports outbound calling for proactive customer engagement, appointment reminders, follow-ups, and automated notifications. This guide covers the different methods available to initiate outbound calls.

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Prerequisites

Before setting up outbound calling, ensure you have:
  • An active PolyAI project
  • Outbound calling enabled on your account (contact your PolyAI representative)
  • A phone number configured for outbound calls
Outbound calling requires additional configuration by PolyAI. Contact your account manager or support@poly.ai to enable this feature.

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Outbound calling methods

PolyAI offers multiple ways to initiate outbound calls depending on your use case:

Outbound Calling API

Programmatically trigger calls via REST API

SIP integration

Route outbound calls through your SIP infrastructure

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Using the Outbound Calling API

The Outbound Calling API allows you to programmatically trigger calls and monitor their status. This is ideal for:
  • Appointment reminders - Automatically call customers before scheduled appointments
  • Follow-up calls - Re-engage customers after specific events
  • Notifications - Deliver time-sensitive information via voice
  • Campaigns - Run proactive outreach at scale

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Quick start

  1. Obtain your connector authentication token from your PolyAI representative
  2. Use the regional API endpoint matching your deployment:
    • US: https://api.us-1.platform.polyai.app
    • UK: https://api.uk-1.platform.polyai.app
    • EUW: https://api.euw-1.platform.polyai.app
  3. Trigger a call: 
curl -X POST https://api.us-1.platform.polyai.app/outbound/trigger \
  -H "X-PolyAi-Auth-Token: YOUR_CONNECTOR_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "phone_number": "+14155551234",
    "metadata": {
      "customer_name": "John",
      "appointment_time": "2:00 PM"
    }
  }'
  1. Monitor call status using the returned call_sid:
curl -X GET https://api.us-1.platform.polyai.app/outbound/status/{call_sid} \
  -H "X-PolyAi-Auth-Token: YOUR_CONNECTOR_TOKEN"
For complete API documentation, see the Outbound Calling API reference.

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SIP-based outbound calling

If you’re using a SIP integration, you can configure outbound calls through your existing telephony infrastructure. This method allows:
  • Custom SIP header injection for the outbound leg
  • Integration with your contact center platform
  • Routing through your preferred carrier
When using custom SIP handoffs, you can specify the outbound endpoint in your function: 
return {
    "handoff": True,
    "outbound_caller_id": conv.caller_number,
    "outbound_endpoint": "YOUR_OUTBOUND_ENDPOINT_NAME"
}
For detailed SIP configuration, see the Custom SIP integration guide.

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Twilio-based outbound calling

If you’re integrated with Twilio, outbound calls can be routed through your Twilio account. This leverages your existing Twilio infrastructure and phone numbers. Contact your PolyAI representative to configure Twilio-based outbound calling for your project.

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Best practices

  • Validate phone numbers - Ensure numbers are in E.164 format (e.g., +14155551234)
  • Respect time zones - Schedule calls during appropriate hours for the recipient’s location
  • Handle failures gracefully - Implement retry logic with exponential backoff for failed calls
  • Pass context via metadata - Include relevant customer information to personalize conversations
  • Monitor call outcomes - Track delivery status (answered, busy, no-answer) for optimization

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Call status tracking

When using the API, you can track call progress through these statuses:
StatusDescription
queuedCall queued for processing
ringingCall is ringing
in-progressCall is active
completedCall ended successfully
failedCall failed to connect
no-answerCall was not answered
busyDestination was busy

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Next steps

API reference

Complete API documentation

Trigger a call

API endpoint to initiate calls

Check call status

Monitor call progress

SIP integration

Configure SIP-based calling