Imported Numbers and Hosting Orders Callbacks

You can set up callback URLs to receive event notifications when your numbers are updated.

When delivering events the order is not guaranteed (for example, a failed event scheduled for retry will not block other events that were queued).

The client's callback handler must implement the state machine that can decide what to do with unexpected events, for example, "old" events or invalid state transitions. In these cases the handler could use the API to GET the latest state for the resource.

The callback handler is expected to "ingest" the event and respond with 200 OK. The domain-specific business logic and processes should be executed outside of the callback request, as internal asynchronous jobs.

You can also add an HMAC encrypted secret which is used for hashing the payload and sending the hashed String via the X-Sinch-Signature header - that you can use to validate that an incoming request is secure.

To use callbacks, add the following IP addresses to your allowlist:

- 54.76.19.159
- 54.78.194.39
- 54.155.83.128