{
"id": "evt_8aZqRm4yT3vK7pNxJ2bH9c",
"type": "fax.queued",
"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.queued
Sent when a fax has been accepted and is queued for delivery.
WEBHOOK
fax.queued
{
"id": "evt_8aZqRm4yT3vK7pNxJ2bH9c",
"type": "fax.queued",
"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
Once, immediately afterPOST /v1/faxes returns 201. The credit hold has been placed, the fax record exists, and the job to dispatch to a carrier is queued.
fax.queued is the earliest confirmation your handler will receive that mintfax has taken responsibility for the fax. After this, expect one or more fax.sending events, then exactly one of fax.delivered or fax.failed.
What your handler should do
- Record the fax ID against whatever business object triggered the send (an order, a patient record, a contract).
- If you tagged the fax via the
tagsfield on submit, this payload carries those tags - good for routing back to the originating context. - Do not bill the customer or update success state yet. The fax has been accepted, not delivered.
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.queued.
Event identifier (evt_-prefixed). Stable across retry attempts.
Example:
"evt_8aZqRm4yT3vK7pNxJ2bH9c"
Event type. Always fax.queued for this delivery.
Available options:
fax.queued 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 August 12, 2026