@achim Lemmy is also in Rust! And there are two Rust libraries:

- https://docs.rs/activitypub_federation/latest/activitypub_federation/ (from Lemmy devs)
- https://docs.rs/apx_sdk/latest/apx_sdk/ (this one is developed by me)

@achim I don't know about Mastodon, but here are some general tips:

- Your actor is served with content-type application/json, but it should be application/ld+json; profile="https://www.w3.org/ns/activitystreams"
- It's better to embed the key in your actor document and identify it with a fragment ID. This is more widely supported than standalone keys.

@vftdan

Tor: here is a list https://fedilist.com/instance?q=&ip=&software=&registrations=&onion=only
I2P: http://mastodon.i2p is currently online
Yggdrasil: there was a few, but I can't find them now

@helge @DePemig For hashtags we need a way to say "give me all Notes where tag contains an object with type equal to Hashtag and name equal to tagname"

There is a FEP by @mariusor that describes collection filters: https://codeberg.org/fediverse/fep/src/branch/main/fep/6606/fep-6606.md. I guess we can re-use those conventions for lists

Another FEP is https://codeberg.org/fediverse/fep/src/branch/main/fep/5bf0/fep-5bf0.md, but I think it doesn't have implementations

@DePemig

Another example from the sender side: I am a music group and I would like to invite people to: "Follow #concert_announcement for @mycrazycoolband"

If filters are static, they could be implemented as groups / circles.

@DePemig The filtering could be done on the client side. But if I were to implement this in server-to-server context, I would probably add a new property to Follow activity, e.g. filter.