Show persistent subagent activity in the main Codex CLI TUI

What variant of Codex are you using?

Codex CLI / TUI

What feature would you like to see?

Please add a small persistent subagent activity indicator to the normal Codex TUI so it is immediately obvious when subagents are still running, without requiring /subagents to check manually.

For example, the main TUI could show something compact like:

Agents: 3 running, 1 done

or a similarly small status element near the existing status line. Activating it could open the existing /subagents view for details.

The important part is that the user should be able to tell at a glance:

• whether any subagents are currently running
• roughly how many are active / completed
• when all delegated work has finished

This does not need to show each agent's full task or detailed activity in the main view.

Why this matters

When Codex starts subagents, there is currently very little indication in the main TUI that delegated work is still happening. In practice I repeatedly have to run /subagents just to answer a basic question: "are my subagents still running?"

This makes multi-agent workflows feel hidden and harder to follow than they need to be. A persistent activity indicator would make subagents feel like a first-class part of the TUI instead of something that is only visible after opening a separate view.

This would be especially useful during longer tasks where the parent agent may be waiting on several subagents in parallel.

Related issue

Related to #36058, which requested showing each subagent's current task at a glance. That issue was closed by its author as not planned shortly after creation.

This request is intentionally narrower: it is not asking to display every subagent's current task in the main TUI. It only asks for a persistent indication that subagents are active, so users do not have to repeatedly invoke /subagents just to see whether delegated work is still running.

Start by reading the main Codex CLI/TUI status area and the existing /subagents view mentioned in the issue. Trace how running and completed subagents are represented there; done means the normal TUI persistently shows whether agents are active, approximate running/completed counts, and when all delegated work has finished.