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# Fallback exhausted

POST 

Final notification of an SMS fallback chain: the backup SMS also failed, or it could not even be generated (for example, the `to` of the original send was a BSUID with no real phone number behind it). After this event the chain is over — no automatic retry follows.

When the backup SMS failed, `message_id` is the identifier of the backup SMS (the `fallback_id`) and `origin_identifier` points back to the original WhatsApp `message_id`. When the SMS could not be generated, `message_id` is the original WhatsApp send identifier.

Note: while the backup SMS is alive, its regular status events (`SENT` and the SMS error statuses) arrive as **SMS** webhooks (see the SMS API documentation) carrying `origin_identifier` to correlate them with the WhatsApp send.

Reference: https://docs.chatbridge.mx/whats-app/webhooks/fallback-exhausted-webhook

## Request

### Payload

- `message_id` (string, optional) — Identifier of the message that exhausted the chain: the backup SMS (`fallback_id`) when it failed, or the original WhatsApp send when the SMS could not be generated.
- `status` ("FALLBACK_EXHAUSTED", optional)
- `origin_identifier` (string, optional) — `message_id` of the WhatsApp send that originated the fallback. Present when the event refers to the backup SMS.