Receiving Webhooks for Programmable Fax

When you send a Programmable Fax command and receive a successful response (i.e. 200 OK), you can expect to receive a webhook. The webhook will be delivered to the primary URL specified on the Application associated with the call. If that URL does not resolve, or your application returns a non 200 OK response, the webhook will be delivered to the failover URL, if one has been specified.

In order to minimize webhook delivery time, Telnyx:

• does not enforce the order in which webhooks are delivered
• retries webhook delivery if your application does not respond within a certain time threshold.

As a result, you may encounter:

• out-of-order webhooks
• simultaneous (or near simultaneous) webhooks
• duplicate webhooks

Duplicate webhooks may cause your application to issue duplicate commands. You can instruct Telnyx to ignore duplicate commands by sending a command_id parameter as part of your commands. Commands with duplicate command_ids within 60 seconds will be ignored.

Example: Receiving a webhook from an outbound fax

When you place an outbound fax, you will receive a number of webhooks indicating the current status of the fax. The first webhook you will receive will have A queued status indicating that Telnyx successfully received the request to send the fax.

{
  "data": {
    "event_type": "fax.queued",
    "id": "3691d047-d22a-424d-80ed-fe871981aa6d",
    "occurred_at": "2020-04-22T19:32:12.538002Z",
    "record_type": "event",
    "payload": {
      "call_duration_secs": 50,
      "connection_id": "7267xxxxxxxxxxxxxx",
      "direction": "outbound",
      "fax_id": "b679398e-8b4c-46bd-8630-6797f1ab5228",
      "from": "+35319605860",
      "original_media_url": "https://www.telnyx.com/telnyx-fax/1.pdf",
      "partial_content": true,
      "status": "queued",
      "to": "+13129457420",
      "user_id": "a5b1dfa3-fd2e-4e02-8ea4-xxxxxxxxxxxx"
    }
  },
  "meta": {
    "attempt": 1,
    "delivered_to": "http://example.com/webhooks"
  }
}

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FIELD	VALUE
record_type	Description of the record.
id	unique id for the webhook
event_type	The type of event
occurred_at	ISO-8601 datetime of when event occured
to	Destination number or SIP URI of the call
from	Number or SIP URI placing the call
fax_id	Unique ID for the Programmable Fax
client_state	Configurable state to track commands
status	Can be one of queued, media.processed, sending.started, delivered, failed

Example: Receiving a webhook on successful fax delivery

{
  "event_type": "fax.delivered",
  "id": "3320554f-6b74-4138-a74b-a1e2ec7eaf8b",
  "occurred_at": "2022-01-07T10:01:43.677850Z",
  "payload": {
    "call_duration_secs": 79,
    "connection_id": "1232154810234",
    "direction": "outbound",
    "fax_id": "c62be5bc-9b13-4b6c-abda-34dd8b541287",
    "from": "+19459457421",
    "original_media_url": "https://www.w3.org/WAI/ER/tests/xhtml/testfiles/resources/pdf/dummy.pdf",
    "page_count": 1,
    "status": "delivered",
    "to": "+13129457420",
    "user_id": "bdaa1f9f-1018-4156-867d-6c4ac9f556eb"
  }
}

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Example: Receiving a webhook on failed fax delivery

{
  "event_type": "fax.failed",
  "id": "d906ecda-db21-428e-9ca0-74dae7e7c144",
  "occurred_at": "2022-01-05T22:23:46.888808Z",
  "payload": {
    "connection_id": "1232154810234",
    "direction": "outbound",
    "failure_reason": "user_busy",
    "fax_id": "f7b303ed-674c-4962-951b-848380510893",
    "from": "+19459457421",
    "original_media_url": "https://www.w3.org/WAI/ER/tests/xhtml/testfiles/resources/pdf/dummy.pdf",
    "status": "failed",
    "to": "+13129457420",
    "user_id": "417b0cc2-39e0-4ab9-b116-e56543649aa9"
  }
}

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Possible failure reasons

Inspect the failure_reason field in webhook's payload to debug failed deliveries of your faxes. The possible failure reasons are:

• account_disabled
• connection_channel_limit_exceeded
• destination_invalid
• destination_not_in_countries_whitelist
• destination_not_in_service_plan
• destination_unreachable
• fax_signaling_error
• invalid_ecm_response_from_receiver
• no_outbound_profile
• outbound_profile_channel_limit_exceeded
• outbound_profile_daily_spend_limit_exceeded
• receiver_call_dropped
• receiver_communication_error
• receiver_decline
• receiver_incompatible_destination
• receiver_invalid_number_format
• receiver_no_answer
• receiver_no_response
• receiver_recovery_on_timer_expire
• receiver_unallocated_number
• service_unavailable
• user_busy
• user_channel_limit_exceeded