@steve @kidehen yeah, I haven't looked closely enough at the Mastodon API to say for sure.
But you can do some reverse engineering.
If you have a stream of objects, each of those has a Create activity.
Edited items can get an Edit activity.
A collection of likers can be interpreted into Like activities.
IDs will be incorrect or missing. Dates will be wrong or missing.
It's imperfect but façades always are.