Webhooks are user-defined HTTP callbacks that allow interactions between otherwise independent web applications.
Thorn is a Python framework for building webhooks and event-driven applications. There is also an introduction post with more information on using Thorn.
PyWebhooks is a proof-of-concept library for building webhooks-based services.
What's a webhook? is a high-level explanation of this concept that also contains some basic security considerations when using them.
How to Listen for Webhooks with Python has code examples in both Flask and Django for how to receive an HTTP POST webhook request, as well as how to test it locally with Ngrok.
Webhooks for Beginners - Full Course is an entire free video course that shows both how to use and implement webhooks into applications.
Webhooks do’s and dont’s: what we learned after integrating +100 APIs
Webhooks Provide an Efficient Alternative to API Polling is a high-level overview of the advantages of webhooks over alternatives such as constant polling for updates.