This article will help you understand what asynchronous passthrough is as well as how and when to use it!

A passthrough request is a direct request to an integration's API where Merge handles the authentication using the stored account credentials for the linked account. This approach is ideal for when you're looking to fetch data that Merge may not make requests for or doesn't store in our common models.

An asynchronous passthrough request is a type of passthrough request that allows you to retrieve the response at a later time. We decided to build asynchronous passthrough because third-party response times differ and can cause delays for you when calling passthrough requests. With async passthrough you won't have to wait for a response before calling other requests or endpoints!

Each category now includes a new endpoint to call async passthrough. The request to this endpoint will be the same as passthrough, however the response will contain a passthrough receipt id (instead of the data payload of a passthrough). This passthrough receipt id can be used to get the actual data payload at a later time - either through polling or webhook.

If you have experienced delays or timeouts with passthrough requests we recommend switching to use the new async passthrough functionality. Additionally our current passthrough endpoint will return a 408 status if there is a timeout in getting the response and explanation to use the new async passthrough.

In the async passthrough workflow:

For more information on how to set up webhooks, please refer to our docs page!