Sync a channel's membership

Channel membership sync keeps the members of a Slack channel equal to whoever is currently on call. When duty changes hands, Round Robin invites the incoming on-duty user to the channel and removes the outgoing one.

The usual reason to want this is a noisy channel: an alerting or monitoring channel that a tool posts into, where you want the current on-call in the room and nobody else being pinged out of hours. It is the membership counterpart of the on-duty group — same trigger, but instead of rewriting a @handle it rewrites who is actually in the channel.

You need: edit rights on the rotation, and Round Robin in the target channel.

Set it up

1. Sign in at app.roundrobinbot.eu and open your rotation.
2. Open the Configure menu and choose Channel Sync.
3. Pick the target channel. Any channel Round Robin is a member of will do — it does not have to be one of the rotation’s notification channels. Only channels the bot is in appear in the picker.
4. Choose a sync mode (below).
5. Click Enable Sync.

The two modes

Mode	What happens on a duty change
Strict	The channel ends up containing exactly the on-call rotation members. Rotation members who are not on call are removed, even if they were already in the channel.
Flexible	Only the people switching move: the incoming on-duty user is added, the outgoing one is removed. Everybody else stays, including idle rotation members.

Two rules apply in both modes:

• Only rotation members are ever touched. Anyone in the channel who is not part of the rotation — your manager, a bot, the alerting app — is never added or removed. Round Robin manages its own people and leaves the rest of the channel alone.
• Strict mode never empties the channel. If nobody is on call at all (an out-of-hours gap on a business-hours rotation, for instance), membership is left exactly as it is until somebody is on call again.

What Round Robin cannot manage

Some channels are refused when you save, and some removals are refused by Slack afterwards.

Public channels often block removals

By default, Slack only lets workspace admins remove people from a public channel. Round Robin can still add people, but the removals silently fail, so the channel accumulates members instead of swapping them.

Either ask a workspace owner to allow removing members from public channels in Slack’s workspace permissions, or — simpler and always reliable — use a private channel. The dashboard warns you when you pick a public channel.

Refused outright, at save time:

• #general. Slack does not allow anybody to be removed from it.
• Shared and Slack Connect channels. External people cannot be managed this way.
• Channels Round Robin is not in. Invite the bot to the channel first.

Also skipped quietly, when a sync runs: deactivated accounts and users Slack does not recognise. Unlike on-duty groups, bots and guests are valid here and are synced like anyone else, because they can be channel members.

Permissions it uses

Membership changes go through the scopes Round Robin already asks for at install: channels:manage for public channels and groups:write for private ones. Nothing extra to grant — see Permissions and scopes.

Turn it off

Use Disable on the Channel Sync page. The rotation stops changing the channel’s membership immediately, and whoever is in the channel at that moment stays — nobody is added or removed on the way out. You can re-enable it later.

The same is true if a Pro workspace goes back to the Free plan: the configuration is kept, but nothing syncs while the workspace is free, and it resumes if you upgrade again.

Next steps

• Use an on-duty group — the handle-based alternative to moving people around.
• Permissions and scopes — the scopes this uses.
• Plans and billing — what happens to the configuration on a downgrade.