> ## Documentation Index
> Fetch the complete documentation index at: https://docs.ambivertai.tech/llms.txt
> Use this file to discover all available pages before exploring further.

# Twilio Integration

> Configure Twilio for voice communication in Ambivert AI AI

## Overview

Twilio is a cloud communications platform that enables voice calling, messaging, and video capabilities. Ambivert AI AI's Twilio integration provides seamless connectivity for your voice agents.

## Prerequisites

Before setting up Twilio integration, you'll need:

* A [Twilio account](https://www.twilio.com/try-twilio)
* Account SID and Auth Token from your Twilio Console
* At least one Twilio phone number
* Ambivert AI AI instance running and accessible

## Configuration

### Step 1: Get Twilio Credentials

1. Log in to your [Twilio Console](https://console.twilio.com/)
2. Find your **Account SID** and **Auth Token** on the dashboard
3. Navigate to **Phone Numbers** → **Manage** → **Active Numbers**
4. Copy your phone number(s)

### Step 2: Configure in Ambivert AI AI

1. Navigate to **/telephony-configurations** and click **Add configuration**
2. Select **Twilio** as your provider
3. Enter your credentials:
   * Account SID
   * Auth Token
4. Click **Save Configuration**
5. Open the configuration you just created and add at least one **phone number** (with country code in E.164 format, e.g. `+1234567890`). The default caller ID is used for outbound calls.

### Step 3: Test Your Configuration

1. Create a test workflow
2. Click "Call" to verify connection
3. Check call logs for successful connection

## Inbound Calling Setup

Inbound routing is driven by the phone number itself — there is a **single webhook URL** for the entire org, and Ambivert AI resolves which agent to run from the called number's assigned inbound workflow. **When you save an inbound workflow on a phone number, Ambivert AI automatically pushes the webhook URL to that number's `VoiceUrl` in your Twilio account** (provided the credentials are correct and the number belongs to that account).

### Step 1: Assign an Inbound Workflow to the Phone Number

1. Go to **/telephony-configurations** and open your Twilio configuration
2. In the **Phone numbers** section, edit the number that should receive inbound calls
3. Set its **Inbound workflow** to the agent that should answer
4. Save

### Step 2: Verify the Webhook URL in Twilio Console

1. Go to **Phone Numbers** → **Manage** → **Active Numbers** in Twilio Console
2. Click the phone number you assigned an inbound workflow to in Step 1
3. In the **Voice Configuration** section, confirm:

   * **Webhook** is set to: `https://api.ambivertai.tech/api/v1/telephony/inbound/run`
   * **HTTP Method** is `POST`

   <Note>
     Ambivert AI pushed this URL automatically when you saved the inbound workflow
     in Step 1. If the field is empty, shows a different URL, or Ambivert AI
     surfaced a sync warning, the auto-push failed — most often because the
     credentials are incorrect or the number isn't owned by this Twilio
     account. Paste the URL into the field yourself, set the method to
     `POST`, and click **Save Configuration**. On self-hosted Ambivert AI,
     replace `api.ambivertai.tech` with your backend domain.
   </Note>

   <img className="block dark:hidden" src="https://mintlify.s3.us-west-1.amazonaws.com/ambivertai/images/twilio-inbound-config.png" alt="Twilio phone number voice configuration showing webhook URL setup for inbound calls" />

   <img className="hidden dark:block" src="https://mintlify.s3.us-west-1.amazonaws.com/ambivertai/images/twilio-inbound-config.png" alt="Twilio phone number voice configuration showing webhook URL setup for inbound calls" />

### Step 3: Verify Setup

* Ensure your Ambivert AI AI instance is publicly accessible
* Verify any firewalls allow Twilio's IP ranges

### Test Inbound Calling

1. Call your configured Twilio phone number from another phone
2. Verify your Ambivert AI AI voice agent answers and responds
3. Check call logs in both Ambivert AI AI dashboard and Twilio Console

## Troubleshooting

<AccordionGroup>
  <Accordion title="Invalid phone number error">
    Ensure phone numbers include country code in E.164 format: `+1234567890`
  </Accordion>

  <Accordion title="Authentication failed">
    * Verify Account SID and Auth Token are correct - Check for extra spaces in
      credentials - Ensure credentials haven't been regenerated in Twilio Console
  </Accordion>

  <Accordion title="Webhook signature validation failing">
    * Confirm your Auth Token matches exactly - Verify the webhook URL matches
      what Twilio sends - Check if you're behind a proxy that modifies requests
  </Accordion>

  <Accordion title="No audio on calls">
    * Verify WebSocket connection is established - Check firewall rules for
      WebSocket traffic - Ensure audio pipeline is configured correctly
  </Accordion>

  <Accordion title="Inbound calls go to voicemail">
    * Verify the Twilio number's webhook is set to
      `https://api.ambivertai.tech/api/v1/telephony/inbound/run` - Ensure the webhook
      URL is publicly accessible from the internet - Confirm the called number
      exists in your Ambivert AI telephony configuration and has an **Inbound
      workflow** assigned - Verify Ambivert AI AI instance is running and responding
  </Accordion>

  <Accordion title="Voice agent doesn't respond to inbound calls">
    * Confirm the phone number has an **Inbound workflow** assigned in
      /telephony-configurations - Check webhook signature validation is working
      (Auth Token in Ambivert AI matches Twilio Console) - Verify WebSocket connection
      establishes successfully - Review call logs for error messages
  </Accordion>
</AccordionGroup>

## Best Practices

* Test your configuration with a single call before running campaigns
* Monitor Twilio Console for usage and billing