Maestro user guide

Debugging in Flow happens on the same canvas where you build. There's no separate debug view — you run your process, inspect results in the execution panel, and make changes when you spot an issue.

The Debug button in the toolbar runs the process. The execution panel appears at the bottom of the screen and spans populate in real time as each node executes.

The Stop button ends the session explicitly. Any change to the process also exits the debug session automatically.

Refer to The Canvas for a full overview of debug controls and the execution panel layout.

The execution panel has three tabs. Each one answers a different question.

The Spans tab shows the execution trace — every node that ran, in order, with timing and a success or failure indicator. Selecting a span highlights the corresponding node on the canvas, making it easy to see exactly where execution reached.

The Incidents tab collects errors that occurred during the run. Each incident names the node that failed and includes the error message. If your process stopped unexpectedly, check here first.

The Variables tab shows runtime variable values. Select a span in the Spans tab and the Variables tab updates to show the state at that point in execution. Use this to verify that upstream nodes produced the data you expected.

After a debug run, each node on the canvas shows a success or failure indicator. The failed node's span in the Spans tab highlights it on the canvas. The Incidents tab shows the error message. The failed node's properties panel shows the full error object in the output section.

The error object includes a message field (human-readable description) and a detail field (technical cause). Start with message because it contains the user-facing failure summary.

Mock output lets you test part of a process in isolation. When you set mock output on a node, it skips actual execution and injects your test data downstream instead.

This is useful when an upstream node is slow, requires credentials not available locally, or depends on external systems. Double-clicking the node opens its expanded view, where the mock output can be set to whatever data downstream nodes expect.

Mocking multiple nodes at once lets the debug session focus on a specific section of the process.