Commands and their triggers

This is a guide, not the contract. What the platform guarantees is specified under openspec/specs/. For this page: commands · shell-layout. Where this page and a specification disagree, the specification is right, and that is a defect in this page: change the behaviour there, then explain it here.

A Command is the named action that rail items, bar buttons, view actions, keybindings and the command palette all point at by id. Register the behaviour once; reference it everywhere.

ctx.registerCommand({
  id: 'notes.add',
  title: 'notes.add',
  icon: 'add',
  shortcut: 'mod+enter',        // chord: mod = ⌘ on macOS, Ctrl elsewhere
  run: () => store.add(),
});

Now any item can trigger it with command: 'notes.add' instead of its own run(). The palette (mod+k) and the shortcut reach the same behaviour.

A command can also take described arguments, answer with a result, and be opened to a caller that is not the user: another plugin, a script, an assistant driving the app. Then nobody has to build a second list of your actions beside this one. It is closed to such callers until it says otherwise. See callable commands, and, where that caller is an AG-UI agent, agent tools for the adapter that describes your commands to it and runs what it asks for, so you write no dispatch of your own.

Rail & bar items — command triggers in the chrome

The rail holds independent command triggers (the workbench labels it Activity bar in its own menus); a bar (top/status) holds components or declarative buttons.

// Rail item → triggers a command. Pin settings to the bottom.
ctx.registerRailItem({ id: 'notes.settings', rail: 'primary', icon: 'settings',
  title: 'notes.settings', anchor: 'bottom', run: () => ctx.ui.openSettings() });

// Declarative status-bar button — the host paints button + tooltip from data (no component).
// `showShortcut: true` renders the bound command's shortcut hint (OS-correct, ⌘↵ / Ctrl+Enter) —
// only when the command declares a `shortcut`.
ctx.registerBarItem({ id: 'notes.add.btn', bar: 'status-bar', slot: 'start', order: 1,
  icon: 'add', tooltip: 'notes.add', command: 'notes.add', showShortcut: true });

// Or a component-backed bar item, for full control of the cell (e.g. a live count).
ctx.registerBarItem({ id: 'notes.count', bar: 'status-bar', slot: 'start', component: NotesCount });

Bar slots are start | center | end; rail items anchor top (default) or bottom.

Where next

• Menus: a menu entry names a command by id, and a rail or bar item can carry a menu.
• Callable commands: arguments, answers and opening a command to a caller that is not the user.
• Access gating in a weaver: a command blocked at its one execute() seam until the session qualifies.