Twilio Voice Setup

Connect a Twilio voice number so an AI agent answers inbound calls — transcribing the caller, generating a reply, and speaking it back with barge-in support.

Twilio connects over SIP trunking. CallMissed provisions a trunk against your Twilio account and points it at a per-tenant SIP endpoint; inbound calls land in a room where a voice agent is dispatched to answer them.

Set it up

The full walkthrough lives in Bring Your Own Telephony → Twilio: which credentials to copy, what we provision on your account, and how to import your existing numbers.

You will need:

• A Twilio account (a trial account works for testing).
• A voice-capable number in the Twilio Console (Phone Numbers → Manage → Buy a number, with the Voice capability).
• A CallMissed account with the owner or admin role.

Prefer not to manage a carrier account at all? Rent a number from us instead — KYC and provisioning are handled over the API with your cm_ key.

Create the agent that answers

curl -X POST https://api.callmissed.com/api/v1/bots \
  -H "Authorization: Bearer cm_your_key" \
  -H "Content-Type: application/json" \
  -d '{
    "name": "Reception Agent",
    "type": "inbound_call",
    "system_prompt": "You are the front-desk agent for Acme Clinic. Be concise and friendly."
  }'

Pick the STT, LLM and TTS models on the agent's Voice page in the dashboard, then tune the speech knobs your chosen TTS exposes on its Speech page. The same agent works over a phone call and over WebRTC, so anything you tune once applies to both.

How the call runs

1. 1

   Caller

   Dials your Twilio number

2. 2

   Twilio

   Routes the call over your SIP trunk to CallMissed

3. 3

   STT

   Transcribes the caller's audio in real time

4. 4

   LLM

   Generates the reply from the bot's system prompt + conversation history

5. 5

   TTS

   Synthesizes speech — playback starts before generation finishes

6. 6

   Caller

   Hears the AI agent respond, and can interrupt it

The exact STT, LLM and TTS in that chain are whichever you selected on the agent — the defaults are Indian-language-first, and every option is listed under Models.

Not the TwiML webhook

Earlier versions of this page told you to set a CallMissed URL as the number's A call comes in webhook. That path is not supported and does not answer calls: a number wired that way never reaches your agent. If you configured it from the old instructions, clear the webhook and switch to the SIP setup linked above.

Tip: For browser/mobile WebRTC agents (no phone number required) use the Voice Agent and Voice Sessions API instead. Voice Calling compares the telephony paths.