ActivityPub/Primer/Streams
The streams
property of ActivityPub actors is defined as A list of supplementary Collections which may be of interest.
This property is not widely implemented. There is not a clear way to filter the list of Collections according to what a client application may need. For example, a client application that wants to show contact lists to the user would not have an easy way to find only contact lists in streams
. A client application that wants to show photo albums to the user would not have an easy way to find only photo albums in streams
.
Servers
Servers should use extension properties of the actor to provide specific collections like albums, contact lists, or filtered inbox or outbox streams.
Publishers can also include those collections in the streams
list, to allow users to review the streams even if their client software does not support the extension.
Clients
Clients should use extension properties of the actor to query specific collections like albums, contact lists, or filtered inbox or outbox streams.
Clients can also show collections in the streams
list to users, to let them manually browse the collections.
Clients may use streams
to query specific collections by heuristics -- for example, the name
property, or the type
property of items
in the collections. However, this will be inexact, and is less preferable than using well-defined extensions.