Rooms & wings

A room is a tab inside a project. Each room has its own pane layout (the mosaic). One room is active per project at a time.

In the UI they are called rooms. The backend and persisted data still use tab internally, so a project snapshot's JSON shows tabs / TabSnapshot.

Creating, switching, closing

• Cmd+T creates a new room.
• Cmd+Shift+[ / Cmd+Shift+] switch to the previous / next room.
• Cmd+Shift+P pins the current room so it sticks to the front of the strip.
• Cmd+Shift+W closes the current room. Closing the last room in a project opens a fresh empty one in its place, so a project is never left without a room.
• Cmd+Shift+T opens the Omni menu for fuzzy-jumping to any room in any project.

atrium room list
atrium room switch <id>
atrium room rename <id> <name>
atrium room close <id>
atrium room move-to-wing <room-id> <wing>

Room names are derived automatically where atrium can do better than "Room 12": task-launched rooms take the task number and title (ATR-42 - Fix the auth middleware), and rooms running an agent pick up an adapter-derived label.

Wings

A wing is an optional grouping of rooms inside a project. Every room belongs to exactly one wing, and the horizontal tab bar shows only the active wing's rooms — so a project with dozens of rooms splits into focused sets (say feature, review, scratch) instead of one overflowing strip. Every project starts with a single default wing (main).

• Wing switcher — beside the room tabs. Expand it into an inline strip to see every wing at once; a wing with an active agent pulses so you can tell work is happening in a wing you are not looking at. The expanded state is remembered per project.
• Moving rooms — from a room's context menu, or drag any pane straight into a wing.
• Reordering — drag wings to reorder.
• Per-wing icon — give each wing its own glyph.
• Switching — pick a wing from the switcher or the command palette. Switching activates the wing's most-recent room, creating one if the wing is empty. Closing a wing's last room opens a fresh room in that wing.
• Bulk close — a wing's context menu offers Close all and Close others, scoped to that wing.

Removing a wing never closes anything — its rooms move back to the default wing.

atrium wing list
atrium wing create <name>
atrium wing rename <wing> <new-name>
atrium wing switch <wing>
atrium wing remove <wing>            # rooms fall back to the default wing

The rooms sidebar

Rooms render two ways, and the choice is per project:

• Horizontal tab bar across the top (the classic layout, and the default).
• Vertical rooms sidebar — a drawer fused to the Home sidebar, with a distinct accent-washed surface and a hairline gap to the mosaic.

Ctrl+T flips the active project's orientation. The Settings toggle sets only the app-wide default; a per-project override wins over it.

In the vertical sidebar:

• Wings are expandable folders, Arc-style — several can be open at once, with the room hierarchy indented beneath and a room count on each wing header.
• Pinned rooms get their own favorites strip at the top.
• Panes appear as sub-items under multi-pane rooms, collapsed by default.
• Footer actions — New Room (the primary call-to-action), per-wing New Room, New Wing, and the Vault.
• Collapse to an icon rail with Ctrl+B, or drag the resize handle to set a width (persisted per project; double-click the handle to snap back to the 180 px default).
• Hide settled rooms — an optional filter. A room is "settled" when it holds at least one agent pane and every one of them has been dismissed. Pinned rooms never settle, and the active room is always exempt so the sidebar keeps its current-location highlight.

Drag and drop

The rooms sidebar is a drop target as well as a list:

• Drag rooms between wings, into and out of the pinned strip, or onto the unpin zone.
• Drag a pane onto a room to merge it in, or onto empty space to spin it out into a new room.
• Drag wings to reorder them.
• All of it works in the collapsed rail too, with live drop feedback and a make-space gap showing where the item will land.

New rooms and wings scroll themselves into view, as does the focused pane's tab.

Sidebar visibility

Chord

Effect

Ctrl+B	Collapse / expand the rooms sidebar
Cmd+Shift+1	Toggle all sidebars, including the room bar
Cmd+Shift+2	Toggle just the two side sidebars (Home + Activity)
Cmd+B	Toggle the left (Home) sidebar
Cmd+Shift+A	Toggle the right sidebar

Ctrl+B and Ctrl+T shadow readline bindings (backward-char, transpose-chars) and the tmux prefix over a focused terminal, because atrium's keybinding layer handles app combos even in terminals. Rebind them in Settings → Keyboard if you need those keys to reach the shell.