Telephony
Connect a Twilio or Exotel phone number to Robylon so your voice agents can make and receive real calls.
Robylon works with Twilio and Exotel. Add numbers in Settings → Channels → Voice, under Phone Numbers.
Twilio or Exotel: which should I use?
Use the provider where your numbers already are. If you are starting fresh, Exotel is common for calls within India, and Twilio for calls in most other countries.
| Twilio | Exotel | |
|---|---|---|
| Setup in your provider account | None: Robylon configures the number for you | You build a call flow in Exotel that points to Robylon |
| Fields in Robylon | Label, phone number, Account SID, Auth Token, plus an API Key SID and Secret for Human numbers | Label, domain, Account SID, API key, API token, phone number, plus an App ID for AI numbers |
How do I connect a Twilio number?
Copy your Account SID and Auth Token from Twilio, then add the number in Robylon. Robylon sets up the number’s call handling in Twilio for you.
Get your Twilio credentials
In the Twilio Console, copy your Account SID and Auth Token from the account dashboard. Make sure the number you want to use is in the same Twilio account.
Add the number in Robylon
Go to Settings → Channels → Voice, click Add Phone Number, and select Twilio.
Fill in the fields
Enter a Label (a name to recognise the number in Robylon), the Twilio Phone Number with its country code, the Twilio Account SID and the Twilio Auth Token.
Choose who uses the number
In Use this number for, choose AI, Human or both. If you choose Human, also enter a Twilio API Key SID and Twilio API Key Secret from your Twilio account, so your team can call customers from the browser.
Add it
Click Add Number. Robylon checks the number with Twilio and adds it to the list.
When you add a Twilio number, Robylon points that number’s incoming call and call status webhooks in Twilio to Robylon. You do not need to set any URLs in Twilio yourself.
How do I connect an Exotel number?
Get your Exotel account ready, build a call flow in Exotel that sends calls to Robylon, then add the number in Robylon.
Complete your Exotel account setup
Your Exotel account must be fully set up before it can place AI calls:
- Company verification, which usually needs documents such as your GST certificate and PAN card.
- DND approval, which Exotel may ask you to support with a screenshot of your CRM.
- Credits in the account to pay for calls.
- Numbers for calling. Mobile numbers are recommended over landline numbers.
Build the call flow in Exotel
In Exotel, create an app (call flow) for AI calling with a Voicebot applet whose URL is https://api.robylon.ai/voice/exotel/incoming-call/streaming/. If your agent hands calls over to people, add a Connect applet with the URL https://api.robylon.ai/voice/exotel/connect-call/. Note the app’s ID.
Add the number in Robylon
Go to Settings → Channels → Voice, click Add Phone Number, and select Exotel.
Fill in the fields
Enter the details from your Exotel account:
- Label: a name to recognise the number in Robylon.
- Domain: your Exotel API domain (the default is
api.exotel.com). - Account SID, API Key and API Token: from the API settings in your Exotel dashboard.
- Exotel Phone Number: with its country code.
Choose who uses the number and add it
In Use Calling Number For, choose AI, Human or both. If you choose AI, an App ID field appears: enter the ID of the call flow you built. Then click Add Number.
How do I attach a number to a voice agent?
In the voice agent builder, click Add a Calling Number. Only numbers whose Use this number for includes AI can be attached. See Create a voice agent.
Why is my number not working?
- Calls do not go out: check the provider account has credit, the number is attached to the agent as outbound, and the call is inside the agent’s calling hours.
- Twilio number rejected when adding: check the Account SID and Auth Token belong to the account that owns the number, and that the number includes its country code.
- Exotel calls connect but the agent is silent: check the Voicebot applet URL in your Exotel call flow and the App ID in Robylon.
- Label or number already used: each label and each number can only be added once per workspace.