[BUG] Desktop app: custom sidebar groups render empty while claude.ai shows the same groups populated

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

In the Claude desktop app (Cowork tab), custom sidebar groups render empty or only partially populated, while the same account opened on claude.ai in a browser shows those same groups fully populated with the expected sessions.

The right-click "Move to group" menu in the desktop app shows the correct group ticked, so the assignment itself exists and was stored. The list underneath the group header simply does not include the session, and the group shows its empty state ("Drag or move sessions here").

In my case three of five groups render empty and two render partially, while the web app shows all five populated with the same sessions. The failure is silent: no error is surfaced anywhere.

The feature is also not covered in the release notes or in the desktop documentation, so the failure reads as user error rather than a bug.

What Should Happen?

The desktop sidebar lists a session under the group it is assigned to, matching what claude.ai shows in a browser for the same account. Assigning a session that belongs to a Project to a group should work the same way in both clients.

Error Messages/Logs

No error is surfaced. The failure is silent: the group simply renders its empty state while the assignment exists.

Steps to Reproduce

1. In the Claude desktop app, create custom sidebar groups.
2. Assign a Cowork session that belongs to a Project to one of them via right-click, "Move to group".
3. Look at the sidebar: the group header shows its empty state, "Drag or move sessions here".
4. Right-click the same session again: the group is ticked, so the assignment was stored.
5. Open claude.ai in a browser on the same account: the session is listed under that group.

Environment: Windows 11, Claude desktop app, Cowork tab. Both clients were compared side by side within minutes of each other, on the same account and organization. Restarting the desktop app does not change the result.

Claude Model

None

Is this a regression?

I don't know

Last Working Version

1.46388.3

Claude Code Version

1.46388.3

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Other

Additional Information

Root-cause evidence (read-only inspection of %APPDATA%\Claude)

• Local Storage holds the key persisted.dframe-group-scopes, containing groupsByScope keyed by organization UUID, the five groups as {id: "g-<uuid>", name: "..."}, and an assignments block.
• The keys inside assignments are server-side identifiers: p:cse_... for projects, chat:<uuid> for chats, and short base62 conversation IDs.
• Local Cowork sessions live in %APPDATA%\Claude\local-agent-mode-sessions\<org>\<account>\local_<uuid>.json and are identified as local_<uuid>.
• Three local session IDs whose sessions are visibly grouped in the web app were searched verbatim inside the file holding the group data: zero matches.
• The session JSON files contain no group or project field at all; only sessionId, title, userSelectedFolders, model, isArchived and related runtime fields.

The sidebar list appears to be built from local session identifiers while group membership is keyed by server identifiers, so the two never join. That is consistent with both observations: empty groups in the list, and a correctly ticked group in the context menu.

Additional observations

• There are two organization directories under local-agent-mode-sessions, one of which holds no sessions. Group data is scoped by organization UUID, which may be a second failure mode.
• Cloud and Dispatch sessions have no local session file at all, so the local set is not the same set the sidebar renders.
• Restarting the app does not help, which is what you would expect if the identifiers simply differ.

Impact

Users who work inside a Project and want groups purely for ordering cannot use groups in the desktop app; they have to switch to the browser to see their own structure.