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HITL Approval

When a pipeline contains a HITL gate, the DAG Visualizer becomes the approval interface. The gate pauses execution and waits for a human decision before downstream jobs proceed.

The approval banner

When a gate is waiting, a banner appears at the bottom of the visualizer:

HITL approval banner with Approve and Reject buttons

The banner shows:

  • The gate message configured on the source node in the constructor
  • An Approve button (green)
  • A Reject button (red)
  • The gate job ID for reference

The banner is polled every 2 seconds — it appears automatically when a gate becomes active, without requiring a page refresh.

Making a decision

Approve

Click Approve to allow the pipeline to continue. The gate job completes successfully and all downstream jobs are released to run.

Reject

Click Reject to stop the pipeline at this gate. The gate job fails and downstream dependents are cancelled.

Reviewing output before deciding

Use the Workspace Files panel to download and review job outputs before making a decision.

A typical pre-training review workflow:

  1. preprocess completes — preprocessing_report.txt appears in the files panel
  2. The HITL banner appears: "Review data quality report before training begins"
  3. Click preprocessing_report.txt to download and review it
  4. If data quality is acceptable → Approve → training proceeds
  5. If data looks wrong → Reject → training is cancelled, investigate preprocess

Gate timeout

If no decision is made within the configured timeout period, the gate automatically fails. Downstream jobs are cancelled.

The timeout is set per-gate in the constructor's Gate Timeout field. Default is 48 hours.

Gate job in the graph

The gate node is visible in the pipeline graph like any other job:

Gate status Meaning
RUNNING (blue) Waiting for human approval
COMPLETED (green) Approved — downstream jobs released
FAILED (red) Rejected or timed out

Click the gate node to open its log stream, which shows registration confirmation and wait status.

Multiple gates in one pipeline

A pipeline can have multiple HITL gates — one per source node that has a gate configured. Each gate has its own banner entry and must be approved or rejected independently. The banner shows them one at a time as they become active.