Is there some blog which describes the ActivityPub in terms of implementation how everything should be built?
This can be done by reading existing codes for software such as #plemora or #mastodon but having detailed blog is a must have.

I've been working on my personal implementation for learning how #ActivityPub works and there are lots of questions for which I have to read lots of different codes to get the answers.

As an exmaple, I have a question regarding where to send the response to a thread? Should that be sent to the owner of the thread or to all of the possible audience of the thread?

Another question I have is if my server receives a response on a toot, should I just keep it to myself or should I be sending that to all of the users where the original post was sent. If I have to send it, I'll have to send the original message with the signed headers? because I cannot sign on someone else's behalf.

Implementation through trial and error has been really slow.
And... Slow and steady wins the race...