If you want to simplify ActivityPub integration with your project, here are libraries for the following languages:

* Go: https://github.com/go-fed/activity

* Ruby: https://github.com/rauversion/activitypub

* Rust: https://github.com/LemmyNet/activitypub-federation-rust

* JavaScript: https://github.com/immers-space/activitypub-express

* Python: https://github.com/dsblank/activitypub