How to query channels the current user is NOT a member of?

[shubhamsinghshubham777]

In my app, Stream Channels function as Forums (Public, Private, Hidden - invite-only). How do I search for non-member Public and Private Channels? (i.e. if someone else has created a channel, and I want to be a part of it, how do I query that channel and request my membership in it?)

So far, when trying to do the same, I receive this error message:
QueryChannels failed with error: "2 channels match your query but cannot be returned because you don't have access to them. Did you forget to include {members: $in: ["xxxxxxxxxx"]}?" More information available at https://getstream.io/chat/docs/api_errors_response

[andremion]

Hi,

By default the API only returns channels the user has permission to read, and for the messaging type that means the user must be a member. That is why the query fails unless you include members $in [userId].

To let users find channels they are not members of (your public/forum case), the channel type has to grant the read permission to non-members. You set that on the channel type's role permissions in the dashboard. Once non-members can read that channel type, you can query those channels without the members filter.

Joining is a separate step: once a user finds a channel, they become a member by being added to it (for example channelClient.addMembers(...)), subject to your permissions.

For the exact permission setup, see the permissions reference in the Stream docs.