I put together a brief README describing the proposed API for my ActivityPub PHP library: https://github.com/pterotype-project/activitypub-php. I’m looking for feedback to make sure I’m on the right track. If you are developing a federated PHP application or think you might want to use this library one day, I’d really appreciate it if you contributed to the discussion!
Feel free to comment here, or I also opened an issue to collect API feedback in one place. Thanks in advance!