Principle:PrefectHQ Prefect Human Approval Gate
| Metadata | |
|---|---|
| Sources | Prefect, Interactive Workflows |
| Domains | Orchestration, Human_In_The_Loop |
| Last Updated | 2026-02-09 00:00 GMT |
Overview
A pattern for pausing automated workflows to collect human approval or input via structured forms before proceeding with irreversible operations.
Description
Human Approval Gate implements the human-in-the-loop pattern for workflows that perform destructive or high-risk operations. The flow pauses execution and presents a typed form (via RunInput/BaseModel) in the Prefect UI. A human reviewer sees a preview of what will happen, can add notes, and approves or rejects. The flow resumes with the structured input. This provides:
- Safety for irreversible operations
- Audit trail of who approved what
- Configurable timeouts
- Typed input validation
Usage
Use this pattern before any destructive operation (data deletion, production deployments, financial transactions) where human oversight is required. Also useful for workflows that need manual data input at specific points.
Theoretical Basis
The Gate pattern from workflow management. A gate is a synchronization point that blocks execution until an external condition is met (human approval). Combined with typed forms (RunInput), it provides structured communication between the automated system and human operators.