Persist and surface Human-in-the-Loop (HITL) responses + write to task/audit logs

[cmarteepants]

Description

Follow up to PR #53035 (initial HITL UI)

UI currently collects a user's response but does not persist it, surface it on reopen, or record it in logs. This limits audibility and user feedback.

Problem Statement

• Approving users can't see what they (or someone else) selected after the fact
• Airflow Admins and Users do not have no immutable record of who responded, when, and with which option
• Debugging HITL-related failures is harder because the chosen value is absent from task logs

Proposal / Requirements

1. Persist response:

• Store things like user_id, option_value, option_label and responded_at in the database when a HITL trigger is resolved
• API: Extend API to return the saved payload

2. Surface response in UI payloads: Endpoints should include the stored response under a key like hitl_response

3. Log for audibility:

• After successful save, write a structure line to task logs like [HITL] user=alice option="Approve" at 2025-07-23T14:02:11Z
• Emit the same data to the Airflow audit log if enabled

4. UI fallback:

• If hitl_response exists, display a read-only banner: Responded “Approve” by Alice at 14:02
• Disable further edits unless the operator explicitly allows overrides.

Acceptance Criteria

• Response data is persisted on backend and returned via API
• Re-Opening the Action Required dialog shows the stored response
• Task log contains the [HITL] entry with user, option, timestamp

Out of Scope

• UI changes beyond showing stored value
• Restrictions on who can edit an existing response

Related issues

No response

Are you willing to submit a PR?

• Yes I am willing to submit a PR!

Code of Conduct

• I agree to follow this project's Code of Conduct

[Lee-W]

Response data is persisted on backend and returned via API

It's persisted now.

airflow/airflow-core/src/airflow/models/hitl.py

Lines 49 to 56 in 1f6b067

	response_at = Column(UtcDateTime, nullable=True)
	user_id = Column(String(128), nullable=True)
	chosen_options = Column(
	sqlalchemy_jsonfield.JSONField(json=json),
	nullable=True,
	default=None,
	)
	params_input = Column(sqlalchemy_jsonfield.JSONField(json=json), nullable=False, default={})

Re-Opening the Action Required dialog shows the stored response

This is fetchable through API but I'll take a look at the UI

Task log contains the [HITL] entry with user, option, timestamp

Log is not yet there. But I'll create a PR for it.

[Lee-W]

Re-Opening the Action Required dialog shows the stored response

I think we can add a follow-up PR after #53035 is merged. @guan404ming Please let me know if you would like to work on it 🙂

[guan404ming]

Re-Opening the Action Required dialog shows the stored response

I've added the function in #53035. Please take another look, thanks! Feel free to let me know if anything needs to be adjusted.