Query channel returns empty reaction arrays during pagination

[tpucci]

Problem

When the SDK calls channel.query() (during initial load or pagination), the API returns empty reaction arrays even when reactions exist on messages. Edit: this happens sometimes during the first sync call after a reaction is sent, meaning it is a backend issue.

Observed Behavior

After a reaction is added to a message (via WebSocket event or direct API call), the very next query channel operation returns messages with empty reaction fields.

Query channel request (from Channel.query() in lib/src/client/channel.dart:1827-1918):

{
  "state": true,
  "watch": true,
  "presence": false,
  "data": {}
}

API response shows empty reaction arrays:

{
  "id": "message-id",
  "latest_reactions": [],
  "own_reactions": [],
  "reaction_counts": {},
  "reaction_scores": {}
}

Expected Behavior

Query channel should return messages with their reaction data populated, including latest_reactions, own_reactions, reaction_counts, and reaction_scores.

SDK Version

stream_chat: 9.23.0

[tpucci]

Actually, it looks like a race condition on the backend side.
Because I can not 100% reproduce the issue and I see in my network inspector that subsequent calls have the requested data.

[tpucci]

I understood the issue rises only when using client.sendReaction. Using channel.sendReaction works.
Edit: it works until the next sync... which is eventually consistent

[xsahil03x]

Hey @tpucci , this is a known issue in the backend. I will update here if i get any news.

[xsahil03x]

Hey @tpucci , yes this was a breaking change in the backend. We now prefer/suggests to use the reactionGroups instead for the basic details about the message reactions. You can check how we use it in v10.