presence_change

Single-user presence change event:

{
    "type": "presence_change",
    "user": "U024BE7LH",
    "presence": "away"
}

Multiple-user batch presence change event:

{
    "type": "presence_change",
    "users": ["U024BE7LH", "U012EA2U1"],
    "presence": "away"
}

The presence_change event is sent to connections for a workspace when a user changes presence status and the app has subscribed using presence_sub. Clients can use this to update their local list of users' presence.

If a user updates their presence manually, the manual_presence_change event will also be sent to all connected clients for that user.

There are two forms of this event. When only one user's presence is being communicated, you'll receive a user field with a single user ID present within. This form is deprecated.

Pass the batch_presence_aware=1 parameter to rtm.start or rtm.connect to instruct the Slack message server to batch your presence messages and send a users attribute instead, containing an array of users changing to the same status.

Sometimes you'll get a single event for a single user but if you use batch_presence_aware=1, that single user event will be single item in the users array.

In case you missed that: if you send batch_presence_aware=1 then the shape of presence_change events changes. Instead of a string-based user field, you'll get users, an array.

If you're writing a library that supports presence_change events, you should be prepared to handle both kinds of presence events.