Read/seen ranking

When track_read or track_seen is enabled on a feed group, you can use is_read and is_seen as variables in ranking expressions. On flat content feeds, enable them with activity_marks; notification feeds use their notification configuration. On content feeds, the ranking expression may only reference is_read or is_seen when the matching activity_marks.track_read or activity_marks.track_seen is enabled, otherwise creating or updating the feed group fails with ranking by read/seen status requires notification config or matching activity_marks tracking. Notification feeds can always rank by is_read and is_seen.

A mark only applies to activities created at or before the time it was set. On aggregated notification feeds, a group that is updated after it was marked counts as unread or unseen again.

For example, a custom flat feed group that sorts by popularity and subtracts 100 points from activities the user has read:

from getstream.models import ActivityMarksConfig, ActivitySelectorConfig, RankingConfig

client.feeds.create_feed_group(
    id="ranked_timeline",
    activity_marks=ActivityMarksConfig(track_seen=True, track_read=True),
    activity_selectors=[ActivitySelectorConfig(type="following")],
    ranking=RankingConfig(
        type="expression",
        score="popularity - (is_read ? 100 : 0)",
    ),
)

To rank unseen activities first instead (this does not include popularity):

from getstream.models import ActivityMarksConfig, ActivitySelectorConfig, RankingConfig

client.feeds.create_feed_group(
    id="unseen_timeline",
    activity_marks=ActivityMarksConfig(track_seen=True, track_read=True),
    activity_selectors=[ActivitySelectorConfig(type="following")],
    ranking=RankingConfig(
        type="expression",
        score="is_seen ? 0 : 100",
    ),
)

The same expressions work on notification feeds, where marks may be resolved per activity or aggregated group.

Example expressions

Aggregated feeds

On aggregated notification feeds, is_read and is_seen are resolved at the group level. All activities within an aggregated group share the same read/seen status. On flat feeds (content feeds with activity_marks, and flat notification feeds), they are resolved per activity. Content feeds with aggregation can't use activity_marks, so they can't rank by read/seen status.