ie, if I wanted to follow/stream all public posts on a given instance, how would I do that?
https://w3c.github.io/activitypub/#server-to-server-interactions
@farhan a way of doing this would be to have a "Service" level actor that represents the server/instance, and all the accounts on said server CC/BCC all their activities to it automatically. Then as a third party you can subscribe to the service's inbox and get access to those activities.
As an example you can see here: https://federated.id/inbox
However, to my knowledge Mastodon/Pleroma don't have this instance Service available.
I do not understand what federated.id/inbox is?
federated.id is another activitypub service, only it doesn't have a nice web interface to it, it's just the API.
Pardon my questions, I'm reading the protocol and trying to put things together, but not fully clear yet.
@farhan it serves as a backend for a link aggregator at the moment https://littr.me. But on the long run I want it to be a generic service, something similar to email, but for federated social networks. To be able to use it, people will need clients that speak activitypub (something called Client to Server in the documentation). So far there are no such clients unfortunately.
@mariusor @farhan #AndStatus Android app is such #ActivityPub Client to Server client, please check here: https://github.com/andstatus/andstatus/issues/499
I wonder what is needed for it to work with your service.
@AndStatus but federated.id doesn't provide webfinger support, so user discovery needs to be done through the mechanism I showed in the parent message, ie, filtering the global inbox for the desired username.
@AndStatus so, I see the app is using mastodon application registration flow, which is not supported by federated.id. Besides manually adding clients I plan to support the IndieAuth[1] flow, which might be useful as a more generic alternative.
@mariusor The app registration flow is NOT Mastodon's, but rather used by Mastodon also.
Moreover, as you can see here and below, the app can you whoami endpoint to discover Actor's profile https://github.com/andstatus/andstatus/issues/499#issuecomment-457942709 - this is not supported by #Mastodon yet, but works in #Pleroma.
So, who can I connect to your server now? Any example code for a bootstrap? Could you register an account for me for testing purposes?
@AndStatus you can use the API in read-only mode without authenticating either as an app or a user.
Example code I don't really have except in Go: https://github.com/mariusor/go-littr/blob/master/app/fedbox.go
I'm not prepared to allow other apps write access to the API as it's not ready yet, and I want to be able to make breaking changes without inconveniencing anyone. I'll ping you on github when I'm confident that what I have is ready for general consumption. :)
@mariusor Thank you, will wait for your signals then :-)
@mariusor #AndStatus doesn't use Webfinger service also
Server run by the main developers of the project 
It is not focused on any particular niche interest - everyone is welcome as long as you follow our code of conduct!
@AndStatus @farhan if the application can access collections and iterate over them using next/previous you're good to go for accessing items.
Point one at https://federated.id/inbox for a public stream of what's on the service. It also supports some rudimentary filtering for the properties of Activities, Objects. Eg: https://federated.id/inbox?type=Create&object.type=Person
Submitting activities requires valid OAuth application credentials, so if you're interested in trying, ping me.