{
"id": "evt_8aZqRm4yT3vK7pNxJ2bH9c",
"type": "fax.delivered",
"created": 123,
"data": {
"object": {
"id": "fax_8aZqRm4yT3vK7pNxJ2bH9c",
"status": "queued",
"to": "+12125551234",
"pages": 123,
"error_code": "<string>",
"error_subcode": "<string>",
"error_message": "<string>",
"max_attempts": 3,
"attempts": [
{
"attempt_number": 2,
"started_at": "2023-11-07T05:31:56Z",
"completed_at": "2023-11-07T05:31:56Z",
"duration_ms": 123,
"error_code": "<string>",
"error_subcode": "<string>",
"error_message": "<string>"
}
],
"webhook_url": "<string>",
"idempotency_key": "<string>",
"tags": {},
"csid": "<string>",
"submitted_at": "2023-11-07T05:31:56Z",
"completed_at": "2023-11-07T05:31:56Z",
"created_at": "2023-11-07T05:31:56Z",
"updated_at": "2023-11-07T05:31:56Z"
}
}
}Event types
fax.delivered
Sent when a fax has been successfully delivered.
WEBHOOK
fax.delivered
{
"id": "evt_8aZqRm4yT3vK7pNxJ2bH9c",
"type": "fax.delivered",
"created": 123,
"data": {
"object": {
"id": "fax_8aZqRm4yT3vK7pNxJ2bH9c",
"status": "queued",
"to": "+12125551234",
"pages": 123,
"error_code": "<string>",
"error_subcode": "<string>",
"error_message": "<string>",
"max_attempts": 3,
"attempts": [
{
"attempt_number": 2,
"started_at": "2023-11-07T05:31:56Z",
"completed_at": "2023-11-07T05:31:56Z",
"duration_ms": 123,
"error_code": "<string>",
"error_subcode": "<string>",
"error_message": "<string>"
}
],
"webhook_url": "<string>",
"idempotency_key": "<string>",
"tags": {},
"csid": "<string>",
"submitted_at": "2023-11-07T05:31:56Z",
"completed_at": "2023-11-07T05:31:56Z",
"created_at": "2023-11-07T05:31:56Z",
"updated_at": "2023-11-07T05:31:56Z"
}
}
}When it fires
Exactly once, when a delivery attempt has been confirmed successful by the carrier. The credit hold is captured into a posted charge at this moment. The fullattempts[] history is included, with the final successful attempt as the last entry. error_code and error_message are null on the top-level payload (a previous failed attempt may still have its own error_code inside attempts[]).
What your handler should do
- Mark the originating business object as complete.
- The
pagesfield is the count actually transmitted. Use it for itemized billing or audit, not the page count you submitted. fax.deliveredandfax.failedare mutually exclusive. Once you receive one, do not expect the other.- Deduplicate on
webhook-idif you persist completion state. mintfax may retry the delivery of this webhook itself if your endpoint returned non-2xx earlier; the event ID stays the same across retries.
Authorizations
API key as Bearer token. Use an account key (mfx_acct_...) for
/account/* endpoints, and an environment key (mfx_test_... for
sandbox, mfx_live_... for live) for /environment/*, /faxes,
/webhooks, and /events.
Body
application/json
Event delivery to your subscribed webhook endpoint.
Webhook delivery for fax.delivered.
Event identifier (evt_-prefixed). Stable across retry attempts.
Example:
"evt_8aZqRm4yT3vK7pNxJ2bH9c"
Event type. Always fax.delivered for this delivery.
Available options:
fax.delivered Unix epoch seconds when the event was generated.
Show child attributes
Show child attributes
Response
2XX
Acknowledged. mintfax treats any 2xx response as a successful delivery.
Last modified on July 14, 2026