compose-ui

name	compose-ui
description	Explain why a compose container failed or what the supervisor is doing by reading its log tail; use it when a person asks about container state, a worker that will not come up, or wants the Compose page open beside the chat.

compose-ui

The compose-ui worker puts the compose daemon in the Console. Its page (Compose, #/ext/compose) opens on a topology map of the engine, the namespace, and the containers laid out by start_after, and shows every container the daemon supervises with its live state, PID, and last error; starts, stops, and restarts containers or the whole project in dependency order; adds, updates, and removes declared worker packages; and tails each container's log. Every lifecycle action is the daemon's own compose::* function, so what the page does and what iii trigger compose::… does are the same operation.

The worker itself owns two things the daemon does not expose on the bus: a compose-ui::changed trigger type that fires when the daemon writes its durable project state or the compose file changes on disk, and compose-ui::logs, a read-only tail of one container's log.

When to Use

• A person asks why a container is failed or stuck in starting: compose::status gives the state and last_error; compose-ui::logs gives the last lines the process wrote before it died.
• A person wants to see the fleet, restart something, or add a worker without leaving the chat: open the Compose page with compose in the command palette or host.panels.open({ pageId: 'compose', context: { container } }) from another worker's UI.
• A worker needs to react to supervisor changes (a crash cascade, a new container, a compose file edit) without polling: bind compose-ui::changed with an empty config and re-read compose::status.

Boundaries

• Lifecycle belongs to the daemon. Call compose::up, compose::down, compose::restart, compose::add, compose::remove, and compose::update directly; this worker adds no proxies for them.
• compose-ui::project reports environment variable names only, never values.
• compose-ui::logs reads at most 500 lines and 256 KiB from the end of one file and never lists or reads anything else in the state directory.
• The worker must run in the compose project's namespace (compose supplies it; a standalone process needs III_NAMESPACE).

Functions

Function	Purpose
compose-ui::logs	{ container, lines?, file? } → last lines of <state_dir>/logs/<container>.log with size, truncated, missing.
compose-ui::project	{ file? } → the compose file as declared (namespace, engine endpoint, timeouts, each container's source, version, start_after, environment keys, run script) plus each running container's PID and listening TCP ports.

Trigger types

Type	Config	Payload
compose-ui::changed	{}	{ kind: 'state' | 'file', file, namespace, state_dir, path, captured_at }