This is another pattern for running an async long-running process. In this pattern, the caller sends callbackurl to the long-running process and, when the process is complete, the sender reverts back to the caller using callbackurl.

To demonstrate a simple webhook implementation with Logic Apps, we have created two sets of Logic Apps: one for the caller and one for the sender, which is the long-running process orchestrator. The sender Logic App has an HTTP request trigger with a delay of 5 minutes and an HTTP action to send the response back to the caller workflow:

The caller Logic App has a recurrence trigger and an HTTP webhook action that will post the sample data, along with callbackurl, to the sender for processing. It will wait for a response from the sender Logic App:

Once the request is received in the sender Logic App, it will wait for 5 minutes and then send a response to the caller workflow through the callback URI:

This example has shown how easy it is to set up a webhook pattern in Logic Apps and work with long-running async services. Another great example of this pattern is with durable functions, which you can use along with Logic Apps to implement an enterprise-level stateful workflow. Toon Vanhoutee has written a great blog post that you can refer to for more guidance on Durable Functions with Logic Apps: https://toonvanhoutte.wordpress.com/2018/08/19/perform-long-running-logic-apps-tasks-with-durable-functions/