@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.
federated.id is another activitypub service, only it doesn't have a nice web interface to it, it's just the API.
@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.
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.
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