PR #22759 - manaflow-ai/cmux

Leo wants to talk to the Chief from the left sidebar, next to his workspaces, and see at a glance whether it works or needs him, with its subagents beneath it. Per Leo's follow-up, the entry is optional (off by default) and placed like any other sidebar item.

Change

The Chief is a sidebar built-in (SidebarBuiltIn.chief), off by default. It is not in the default layout. Add to Sidebar… (cmux sidebar add-item chief) or the App Store adds it, and it drags, moves and is removed like any item. A click runs the new Open Chief action (home.openChief; palette, cmux home open-chief). That opens the Chief's conversation in the Home workspace's chat pane, the same path Home's own list takes, so Home is unchanged.
Truthful status. The item's indicator reads the Chief home's acpmux. The app already watched it (ChatsFeed.chiefTurnStates) but kept the lanes in a store nothing read; they are now ChatsFeed.chiefLanes. The indicator shows waiting (needs you) while any turn session optchat-<home>-<n> waits on a permission or question, working while one runs, and idle otherwise. Only the newest turn's failure shows as an error, and compactor sessions don't count. The badge counts subagents that need a person.
Subagents beneath it. Each optchat-sub-<home>-a<n> session is an indented row (SidebarItemInfo.indent) with its harness mark and its own indicator. The rows are client-only (SidebarTransientItem.anchoredOnly): they draw right under the Chief item wherever it is placed, and nowhere when it isn't in the sidebar. A click shows the tab with that subagent's chat (the workspace its spawn opened), else opens it in a new workspace on the Chief host.
Folding never hides an active subagent. Folded (the default), only idle subagents hide; working, waiting, failed and lost ones always show. Show Idle Chief Subagents (sidebar.chief.toggleIdleSubagents, checkmarked) is on the Chief item's right-click menu only, and in the palette. The fold is this Mac's view state, so it has no CLI verb.

Changelog

Added: An optional Chief item for the sidebar (Add to Sidebar or the App Store) shows whether the Chief is working or needs you, with its subagents listed under it.

Coordination / follow-ups

App Store row: asked the app-store-features lane to list "Chief in sidebar" with Get = sidebar add-item chief and Remove = remove that item. The layout is the one source of truth, with no parallel setting.
Chief pane toolbar: Leo also wants the Chief pane to get a top-right toolbar (status, subagents, actions) consistent with the pane-toolbar lane's tab-row tools. I asked that lane for its API. It goes in a follow-up PR on top of theirs, not a parallel toolbar.
The Chief's chat keeps Home's composer; unifying composers is composer-polish's work.

Observed / Not run

Observed: on Leo's Chief daemon, acpmux ls shows the naming this relies on: turns such as optchat-6b68ac4a-191 (waiting!), subagents optchat-sub-6b68ac4a-a2…a14, compactors optchat-compact-…. An earlier version of this change passed scripts/cmux-next/prepush-gate.py.
Not run: this head's pre-push gate, the compile, and ChiefSidebarItemTests (status order, newest-turn failure, compactors ignored, the item's info and default absence, folding, rows following the item and vanishing without it). Local git and builds are frozen on cosmic-gray, so the commit was made through the GitHub API (no Agent-Session: trailer) and CI is the first compile. The action exports are left to the autofix bot.
No before/after: the native sidebar has no webview gallery entry. Not dogfooded.

Agent session: cosmic-gray

🤖 Generated with Claude Code

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Summary by cubic

Adds an optional Chief item to the sidebar so you can talk to the Chief next to your workspaces and see at a glance whether it is working or needs you, with its subagents beneath it. The item is off by default: Add to Sidebar adds it, and it drags, moves, and removes like any other item.

The model now lives in CmuxNextAgentLanes (ChiefSidebar), keeping CmuxNextApp under its size cap; the App only wires it through the bridge.
The item's indicator reads the Chief home's acpmux turn states: waiting while a turn waits on a permission or question, working while one runs, idle otherwise, and only the newest turn's failure shows. A badge counts subagents that need a person. The status is kept in a dedicated watch and written only when it changes.
Subagent sessions appear as indented rows anchored right under the Chief item wherever it is placed; clicking one shows the tab with that subagent's chat, or opens it in a new workspace and reveals it, with no second open while that runs. Turn and subagent names deduped by acpmux keep their role and number. Folded (the default) hides only idle subagents, so an active one never disappears; Show Idle Chief Subagents on the right-click menu or in the palette shows them too, and is disabled until the Chief item is in the sidebar.
Clicking the item runs the new Open Chief action, which opens the Chief's conversation through the same path Home uses.
The sidebar's top-items feed (Lanes, Channels, Chief subagents) moved from SidebarWhatsNewItemFeed to SidebarModel.followTopItems; What's New now shows only as the bottom-left "cmux Updated!" card.

Status

Local builds are frozen, so the pre-push gate, compile, and tests were not run; CI is the first compile and action exports are left to the autofix bot.
ci-target-graph.json is dropped from the PR; the base autofix regenerates it.