Dry Run executes your workflow graph in simulation mode. Routing, conditions, and transforms run normally, but side-effect nodes (HTTP, MQTT, Modbus, notifications, file writes) return synthetic success without touching external systems.
When to use
- Test branching logic before activating a workflow.
- Verify placeholder resolution (
{{$var.key}}) without sending real commands. - Demo a workflow to stakeholders safely.
What runs vs. what is skipped
| Runs | Simulated (no external I/O) |
|---|---|
| Condition, Transform, Read Variable | HTTP Request, MQTT Publish, Modbus TCP |
| Control flow (Delay, Retry) | Write Variable (returns preview), Notification |
| Read File (empty content marker) | Device commands, email, webhooks out |
How to start a Dry Run
- Open the workflow in Studio.
- Click Run → Dry Run or use the run dropdown in the toolbar.
- Inspect step output in the run panel — simulated steps include
__dryRun: true.