Stream privacy settings

There are three types of streams in Zulip.

  • Public: Anyone can join, and anyone can view the complete message history without joining.

  • Private, shared history: You must be added by a member of the stream. The complete message history is available as soon as you are added.

  • Private, protected history: You must be added by a member of the stream. You only have access to the messages that are sent after you are added.

Privacy model for private streams

At a high level:

  • Organization admins can see and modify most aspects of a private stream, including the membership and estimated traffic. Admins cannot see stream messages or do anything that would indirectly give them access to stream messages, like adding members or changing the stream privacy settings.

  • Non-admins cannot easily see which private streams exist, or interact with them in any way until they are added. Given a stream name, they can figure out whether a stream with that name exists, but cannot see any other details about the stream.

Detailed permissions

Public streams

Org admins Stream members Org members
Join
Add others
See subscriber list
See full history
See estimated traffic
Change the privacy
Rename
Edit the description
Remove others
Delete

Private streams

Org admins Stream members Org members
Join
Add others
See subscriber list
See full history [1]
See estimated traffic
Change the privacy [2]
Rename
Edit the description
Remove others
Delete

[1] Depends on the stream type.

[2] Yes, but only if subscribed. If you have a private stream without an admin, you'll have to add an admin in order to change the stream's privacy.