Peter Molnar petermolnar.net discusses the flow in sharing content between proprietary platforms and our websites. Its a big mix of silos and the details change based on what APIs are available from these platforms. However, when the platform provides tools for sharing the process can be seamlessly automated. However, it requires that the service support the feature.
Webmention’s API converts and adds content inline to our websites.
Micropub is an API that our software can interact with. In my case WordPress adds a micropub generated to post to my database. An example of this would be using a service like Quill.