[WhaleTech (ryo-whaletech)]

Motivation & Context

A workflow can complete successfully without caller-facing output. Its fully consumed streaming run still finalizes to an empty AgentResponse, but ContextProvider.after_run currently sees SessionContext.response is None. The provider lifecycle contract says the response is populated when this hook runs.

Description & Review Guide

• What are the major changes? Build the provider-visible response with the existing AgentResponse.from_updates finalizer even when no updates were forwarded, and add a focused zero-output regression test with a non-streaming control.
• What is the impact of these changes? On successful empty streams, after_run providers receive an empty finalized response instead of None. Non-empty streams, non-streaming runs, yielded updates, and public API signatures are unchanged. Existing history and memory providers add no output messages for the empty response.
• What do you want reviewers to focus on? Whether finalizing an empty update sequence for the provider hook correctly implements the documented lifecycle.

Related Issue

Fixes #8388

Contribution Checklist

• The code builds clean without any errors or warnings
• All unit tests pass, and I have added new tests where possible
• The PR follows the Contribution Guidelines
• This PR is linked to an issue and there is no other open PR for this issue (see Related Issue above).
• This is not a breaking change. If it is a breaking change, add the breaking change label (or add "[BREAKING]" to the title prefix, before or after any language prefix) — a workflow keeps the label and title prefix in sync automatically.

[Copilot]

🟢 Approval recommended

No unresolved review issues were identified.

Pull request overview

This PR ensures after_run providers receive an empty AgentResponse for zero-output workflow runs.

Changes:

• Finalizes empty streamed update sequences before provider callbacks.
• Adds regression coverage for streaming and non-streaming zero-output runs.

File summaries

File	Summary
python/packages/core/tests/workflow/test_workflow_agent.py	Adds zero-output lifecycle regression coverage.
python/packages/core/agent_framework/_workflows/_agent.py	Finalizes provider-visible responses for empty streams.

Review details

• Files reviewed: 2/2 changed files
• Comments generated: 0
• Review effort level: Lite (auto)

Note

Copilot is running an experiment and ran this review at Lite.

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[Eduard van Valkenburg (eavanvalkenburg)]

Thanks for the contribution. The approval-gated workflows ran, but the current head is not green: Python - Tests failed on Python 3.11/Ubuntu, the remaining Python test matrix jobs were cancelled, and Merge Gatekeeper failed. Could you please fix the failing test/checks, then re-request review? Thanks!

[Eduard van Valkenburg (eavanvalkenburg)]

Reviewed the complete diff and found no actionable issues. All reported checks for the current head are green.