I'm migrating Fedify from implementing FEP-c7d3 Ownership to FEP-fe34: Origin-based security model, and man, this is more complicated than I thought. It looks like it's going to require major changes to how the Activity Vocabulary API works. This isn't easy… 😂

The problem is that Fedify's Activity Vocabulary API supports property hydration. Fedify intentionally hides the following three states of properties of Activity Vocabulary objects, which seems to hinder the application of an origin-based security model:

1. When a complete object is embedded within a property of a JSON-LD object.
2. When a property of a JSON-LD object references an object by URI.
3. When it was initially #2, but the property has since been hydrated.