An increasing number of applications now offer webhooks as an integration, often in addition to an API. The classic example, familiar to most developers, is the GitHub webhooks which can notify your other systems such as CI tooling that a new commit has been added to a branch. If you imagine how many repositories exist on GitHub, and how many other systems react to changes on each repository… there’s a reason they are excellent with webhooks! Whether it’s your source control, updates from your IoT sensors, or an event coming from another component in your application, I have some Opinions (TM) about handling webhooks, so I thought I’d write them down and include some code as well, since I think this is an area that many applications will need to work with.
Receive and Respond
The majority of problems I’ve seen or created when working with incoming webhooks is to try to do too much in a synchronous way – so doing all the processing as the hook arrives. This leads to issues for two reasons: