Number Masking - Callback service



To add this product to your account, contact a Telesign expert. This product is available for full-service accounts only.

This page explains how to retrieve transaction status results for anonymous SMS sessions created with Telesign Number Masking.

Set up a transaction callback service

To be notified when end users are interacting using your anonymous session and to view the contents of messages exchanged between them, you must set up a transaction callback service.


  • Private URI: Your service must be able to receive notifications as HTTP requests from Telesign on a private URI. Send your Telesign contact this private URI.
  • Process JSON: Process the JSON payload of these notifications, as described in the Notification Payload section below.
  • Receipt confirmation: Whenever the service successfully receives a notification from Telesign, provide us an HTTP 200 OK response to confirm.


If Telesign is unable to deliver your callback notification on the first attempt, the Telesign server tries again. If the second attempt fails, the server makes a third and final attempt.

Notification payload

When end users start transacting in an anonymous SMS session, each message exchanged between them is pushed to your transaction callback service. Notifications from the service have a JSON payload with the following properties:

Notification Schema

submit_timestampstringThe date and time that the end user's message was sent.2018-02-12T14:57:11.765723
from_phone_numberstringThe originating end user's phone number, including the country code.15551234
mo_messagestringThe content of the end user's message that this notification is for.I am standing at the corner wearing a blue shirt
mo_reference_idstringUnique, 32-digit hex value used to identify the end user's message that this notification is for.SA9WUKGP3TGRCQSRMS78QV5M5REKQ98N
session_reference_idstringUnqiue 32-digit hex value identifying the anonymous session that the message is associated with.B5862A14363C016C8832D53625270015


The following is an example of what the notification payload looks like.

Notification payload

  "submit_timestamp": "2018-02-12T14:57:11.765723",
  "from_phone_number": "15551234",
  "mo_message": "I am standing at the corner wearing a blue shirt",
  "mo_reference_id": "SA9WUKGP3TGRCQSRMS78QV5M5REKQ98N",
  "session_reference_id": "B5862A14363C016C8832D53625270015",
  "to_phone_number": "15554567"