State Machine Designer

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LIVE TESTING

Simulator Draft

Select an available event to test a transition.

Why is an event blocked?

Inspect event conditions

Test context Change variables to test guards

Simulation variables (JSON)

INSPECTOR

Properties

None

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Design with intention.

Select a state or transition to change its properties, guards and actions.

Machine context

Guards compare simple fields. No arbitrary scripts are executed.

Quality checks

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Test paths use the initial context and bounded event exploration; they cannot prove behavior under all conditions.

Export

Export format

SCXML export supports simple guards and assignments, but not hierarchical statecharts. Single-token events required. JSON preserves all visual layout.

Using State Machine Designer

Add states and event transitions, choose an initial state and configure supported guards or assignments. Simulate events, inspect blocked transitions and save project JSON alongside diagrams, tables or traces.

This tool supports flat machines rather than hierarchical statecharts, arbitrary JavaScript guards or full SCXML semantics. Bounded test-path exploration and QA reports are not formal proofs. Browser drafts can fail or be cleared, so retain editable JSON backups.

Choose an editable finite-state machine or a review output

Project JSON: retain the supported flat machine, transitions and settings.

SVG or PNG: share its visual diagram.

CSV, Mermaid or trace output: inspect supported transition information or simulation history.

SCXML: export the supported flat subset, rather than assuming full statechart compatibility.

Practice: a two-state start-stop machine

Create Idle and Running states and choose Idle as the initial state.

Add a start event from Idle to Running and a stop event back to Idle.

Simulate those events, inspect the trace and save JSON before adding guards or assignments.

This is an authored modeling exercise, not a formal proof or an executed production controller.

State machine questions

Can I use arbitrary JavaScript guards or nested statecharts?

No. Guards and assignments use supported operators and primitive values, and the model is flat rather than hierarchical. Review transition priority and conditions within that scope.

Does a successful simulation prove every possible path is correct?

No. Simulation and bounded test-path exploration inspect particular conditions and paths. Their reports are not formal verification or full SCXML conformance. Keep the editable project and review untested cases separately.