Telnyx integration

A Telnyx credential row holds two fields you supply — `api_key` and `voice_application_id` — plus a `connection_id` that Rexa derives rather than asking for. On save, and again whenever you press Test connection, Rexa calls `GET /v2/call_control_applications/:id` with your key. That single read proves three things at once: the key authenticates, the application exists under that key’s account, and the application is active.

A disabled application returns `application_disabled` naming the application so you know which one to re-enable. If you did supply a `connection_id` and it does not belong to the application, you get `invalid_connection` instead of a call that silently fails later. On success Rexa stores the application id, the application name and its `webhook_event_url` so the dashboard can show what you are actually connected to.

For a Telnyx Call Control Application the application’s own id is the connection id used for outbound routing, so Rexa derives that field instead of adding another box to the form.

First, an API key that is Active — Telnyx keys begin with `KEY`, and Rexa’s `invalid_api_key` message points you back at the console if the key is truncated or disabled. Second, a Call Control Application; copy its id.

Then add a Telnyx provider in Rexa and paste both values. Validation runs immediately, so a mistyped application id fails at save time as `invalid_application` rather than at first dial. Once saved, every number routed to that application appears on `GET /v1/phone-numbers` with `provider` set to `telnyx`, and the `phone_number` value is what you pass as a campaign’s from-number.

For inbound, point the application’s webhook at Rexa’s Telnyx inbound endpoint so answered calls are handed to your agent.

Caller-ID name. `GET /v1/phone-numbers` returns a `caller_id_name` field, and it is populated for Telnyx numbers only — it is `null` for Twilio and Plivo. If displaying a CNAM value in your own tooling matters, that is a real reason to prefer Telnyx.

Telnyx is also the carrier Rexa provisions on the default path, and currently the only wired SMS provider, so a single Telnyx account can cover both the voice and the text side of a campaign.

Phone numbers are included by default: Rexa provisions and configures them, with the carrier cost inside the per-minute rate. Bringing your own Telnyx, Twilio or Plivo account is supported as an option, and on that path your carrier bills you directly for their per-leg cost.

Every tenant-and-carrier pair has its own circuit breaker. Five consecutive dispatch failures open it, and while it is open Rexa refuses to dispatch through that carrier at all. Sixty seconds later the breaker moves to half-open, which admits exactly one probe call. A successful probe closes it; a failed probe re-opens it and restarts the sixty-second clock, keeping the failure count at the threshold so the next recovery needs a good probe rather than another five failures.

The breaker is scoped per tenant, so another account’s bad afternoon never takes your carrier out of rotation. If you have a second carrier configured, the router skips the open one and tries the next by priority.