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How to set up SIP

The AI agent can also make and receive phone calls. SIP integration allows you to connect external telephony infrastructure, such as corporate Asterisk/PBX systems, VoIP providers, or public SIP servers (including Twilio).

Through SIP, your AI agent can act as a virtual voice endpoint—initiating, answering, transferring, or managing calls using standard telephony protocols while maintaining real-time interaction with caller.

What is SIP?

SIP (Session Initiation Protocol) is a communication protocol used to establish, manage, and terminate voice calls over the internet. Within the Flametree platform, SIP integration is used to:

  • Initiate outbound calls to users
  • Receive inbound calls from clients
  • Conduct full voice conversations with AI agent participation

Requirements

To connect SIP integration, you will need:

  • Your SIP provider details:
    • SIP domain (for example, sip.example.com)
    • SIP account login and password
  • Voice models:
    • Speech-to-Text (STT) — for transcribing user speech
    • Text-to-Speech (TTS) — for generating spoken responses from the AI agent

Unlike Twilio, SIP does not provide built-in voice models, so they must be connected separately.

Step 1: Add SIP Integration in the Platform

  1. Go to Settings > Channels.
  2. Select SIP.
  3. Select Add +.
  4. Enter the following information:
FieldDescription
Name, DescriptionDisplay Name and Description for the SIP Connection
SIP DomainSIP provider domain (for example, sip.twilio.com)
SIP UserSIP account login
SIP PasswordSIP account password
SIP LoginOptional, should be set if not the same as SIP_USER
SIP PasswordOptional, caller phone number
  1. Click Save

Next Steps

Once your SIP integration is created, proceed to the next step — create your Voice Agent.