Incoming Call Router

The Incoming Call Router decides what happens when someone calls your connected Twilio number.

Version one routes on a single, powerful rule:

1. If the caller's number matches an upcoming or in-progress booking, the call is handed to your Retell AI voice agent.
2. Otherwise, the call rings a number where a person can answer (your fallback number).

More routing rules — business hours, caller lists, menus — are on the way; the router is built to grow.

This is a connector plugin: it reuses the Twilio connection you've already set up, but needs a few details of its own (your Retell voice agent and a fallback number), so it stays disabled until you've configured it.

Before you start

• Connect your Twilio account in Company settings (account SID, auth token, and your number). The call router uses that same connection.
• Create a Retell voice agent. In your Retell dashboard, set up a voice agent for inbound calls and note its agent ID and your API key. A chat agent will not work for phone calls.

Setup

1. Open Plugins → Browse Plugins and click Install on Incoming Call Router.

2. In the Configuration section on the setup page, enter:

   • your Retell API key (stored encrypted, never shown again),
   • your Retell voice agent ID, and
   • a fallback number — the number rung when the caller has no booking (for example, your front desk or a staff mobile). This can be any phone number; it does not have to be a Twilio number. Then click Save call routing.

3. (Optional) Under Numbers to route, add any number — besides your company's default Twilio number — that should route through the call router. The picker lists the numbers on your connected Twilio account; if it can't load, you can type one instead. See Routing a separate number.

4. In your Twilio account, set the Voice "A call comes in" webhook (HTTP POST) for each number you route to the URL shown in Configuration:

   https://api.resytech.com/v1/plugins/call-router/voice/<your-token>

   The setup page shows the full URL — including a token unique to your account — with a copy button.

5. Click Enable on the setup page.

Routing a separate number

By default the router handles calls to your company's connected Twilio number — the same one your workflows and texts use.

If you'd rather route a separate line — for example, a dedicated bookings number kept apart from your main number — add it under Numbers to route on the setup page. The picker lists the numbers already on your connected Twilio account, so you just choose one (if the list can't be loaded, you can type a number instead). You can add more than one; each must be a number on the same Twilio account.

Remember to point the Voice webhook of each number you add at the URL on the setup page — otherwise Twilio won't hand its calls to the router.

How routing works

When a call comes in, the router looks up the caller's number among your customers and their bookings:

• Caller has a booking (upcoming or happening right now, not canceled) → the call is connected to your Retell AI voice agent.
• No matching booking → the call rings your fallback number.

The caller's number is matched to a customer regardless of how the phone number was formatted when it was saved, so (555) 123-4567 and +15551234567 are treated as the same number.

Permissions

• Setting up the call router (configuring, enabling) requires the Plugins permission. Administrators always have it.
• There's no per-user permission for handling calls — routing is automatic once the plugin is enabled.

Good to know

• The router uses your company's connected Twilio number, so it's a company-level capability like the SMS Inbox.
• Calls handled through Twilio and your Retell agent count toward your Twilio and Retell usage and billing.

Troubleshooting