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[FEATURE]: parent agent should observe background subagent's real-time progress and streaming output #27828
Description
Feature Description
Allow the parent agent to observe a background subagent's real-time progress and streaming output while it is still running.
Current Behavior
With OPENCODE_EXPERIMENTAL_BACKGROUND_SUBAGENTS=true, a parent agent can launch a background subagent via task(background=true, ...). But once launched, the subagent is a black box — the parent can only poll task_status(task_id="...") which returns the state (running, completed, cancelled) but no intermediate output or progress information.
The only way to interact with a running subagent is task(task_id="...", prompt=...), which resumes/resumes the session but interrupts the agent's current work (it stops what it was doing and responds to the new prompt).
Proposed Feature
Add a mechanism for the parent agent to stream or poll the subagent's real-time output without interrupting it. Options to consider:
- Stream endpoint: A way to subscribe to the subagent's tool call outputs and text generations as they happen (similar to tailing logs).
- Progress poll:
task_statuscould include a snapshot of the last N tool outputs or the current step description, e.g.task_status(task_id="...", include_progress=true)returning{state: "running", last_output: "Searching the web for X...", tools_called: 3}. - Shared scratchpad: An append-only buffer that the subagent writes to and the parent reads from, without mutual interruption.
Use Case
A parent agent launches multiple background subagents for parallel research tasks and wants to:
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See which ones are making progress vs. stuck
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Decide which results are ready early to start consolidating
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Provide progress feedback to the user without waiting for all subagents to finish
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I have searched existing issues and confirm this is not a duplicate.
Related
Builds on the background subagent delegation feature (PR #24174 / issue #21384).
Activity
github-actions commentedon May 16, 2026
This issue doesn't fully meet our contributing guidelines.
What needs to be fixed:
[FEATURE]:for feature requests (e.g.[FEATURE]: parent agent should observe background subagent's real-time progress and streaming output)Please edit this issue to address the above within 2 hours, or it will be automatically closed.
This issue might be a duplicate of existing issues. Please check:
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[-]Feature: parent agent should observe background subagent's real-time progress and streaming output[/-][+][FEATURE]: parent agent should observe background subagent's real-time progress and streaming output[/+]github-actions commentedon May 16, 2026
Thanks for updating the issue! It now follows the contributing guidelines and feature request template. The needs:compliance label has been removed.
github-actions commentedon May 16, 2026
Thanks for updating the issue! It now meets our contributing guidelines. We appreciate the clear description, well-explained use case, and the duplicate search. Your feature request is good to go.
github-actions commentedon May 16, 2026
Thanks for updating the issue! It now meets our contributing guidelines — the title, feature description, use case, and duplicate-search checkbox all look good. The
needs:compliancelabel has been removed.YoungJurry commentedon May 16, 2026
For tasks requiring parent-child agent collaboration — especially when the parent depends on real-time feedback from its subagents to make decisions — being able to observe the subagent's live output would be essential. Without it, the parent has no way to react to intermediate results until the subagent fully terminates.
YoungJurry commentedon May 16, 2026
Closing and re-submitting as a new issue — the triage bot did not assign labels or staff. Re-submitted to ensure proper triage.