Desktop task follow-ups can interrupt active work without clear queue/interrupt semantics

Summary

When a follow-up is sent to an already-running Codex desktop task from another Codex task, the target task can pivot to the new instruction before it has completed or reported the current unit of work. The conversation history is retained, but the active execution is effectively interrupted or reprioritized without a clear user-facing warning.

This makes long, sequential implementation work unreliable: an operator may think they are adding a note for the next step, while the agent abandons an in-progress verification or partial implementation.

Reproduction

1. In the Codex desktop app, create a project task and ask it to perform a multi-step implementation that includes edits and verification.
2. Wait until the task is actively running commands or making edits.
3. From another Codex task, send a follow-up to the active task using thread/task coordination.
4. Observe that the target task receives a new injected user message (shown as coming from another Codex task) and begins responding to or implementing the new request before the current work has reached a clear checkpoint.

Actual behavior

• The follow-up appears in the target conversation immediately.
• The active task's priority changes mid-flight.
• There is no clear indication that the message will interrupt rather than queue behind the active unit of work.
• This can leave a task partially verified, with the operator needing to reconstruct what was completed.

Expected behavior

One of these should be explicit and controllable:

• Queue cross-task follow-ups until the active task reaches a tool/action checkpoint or completes its current turn.
• Require an explicit "interrupt current work" choice before injecting the follow-up.
• Clearly show in both source and target that the new message will interrupt/reprioritize the active task.

Why this matters

Codex desktop encourages multi-task project workflows. Without deterministic queue/interrupt behavior, coordinating related tasks can accidentally fragment implementation and verification work.

Environment

• Codex desktop app on Windows
• Local project task, with another Codex task forwarding follow-up instructions