# Callback

Setting up a Callback URL

• Transfer and RequestToPay APIs are Asynchronous in MTN MoMo API Platform
• When a merchant system sends a POST of either /transfer, or /requesttopay APIs, the Gateway validates the request and then responds with “202 Accepted”
• The transaction is then queued for processing.
• Once processed, a callback with the final result of the transaction is sent to the merchant system
• In order to receive the callback for your transactions, please consider the following:

  a) On Sandbox

  • Register your callback host by specifying the domain as providerCallbackHost when creating your API Keys. On production this will be done via the Account Portal
  • Specify the callback URL in each of your /requesttopay or /tranfer POST
  • Use http and not https on sandbox
  • Allow PUT & POST on your callback listener host

  b) On Production

  • After Go-live you will be provided a link to log on to your Accounts Portal
  • You will be required to register you callback host on the portal when creating your API keys as shown below
  • Only https is allowed on production
  • Allow PUT & POST on your callback listener host



• The Wallet Platform will send the initial callback and if there is a delay on the callback response from the partner system the callback will timeout in 2 seconds. However, the wallet platform will initiate 20 retries at a frequency of 1 second.

  If the partner system does not respond to the callback retries, the partner callback URL will enter a short block state in which the retries will occur at a frequency of 2 minutes for 30 times. If the partner system does not respond to the retries again, the URL will enter a long block state in which the retries happen at a frequency of 60 minutes until it is automatically unblocked.

  The partner system can configure the GET methods to poll for transaction status when the callback is delayed.