flowydStrongly-typed SOP state machines

Build, execute, and visualize workflow state machines in TypeScript — with compile-time safety on every state ID, action name, and payload shape.

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API Reference

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Compile-time type safety

Every state ID, action name, and payload field is checked by TypeScript. Typos and wrong shapes are caught before your code runs.

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Zod-validated at runtime

Each action payload is validated against its Zod schema before any transition fires. The same schema drives both the TypeScript type and the runtime check — no duplication.

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Parallel branches

ForkState fans out to concurrent steps; JoinState synchronises them with "all", "any", or a quorum threshold — resolved in a single engine tick.

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External wait states

WaitState pauses the workflow until your service layer signals completion. The engine has no I/O, no polling, no callbacks.

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Purely functional persistence

getSnapshot() produces plain JSON. restoreInstance(snapshot) reconstructs exact state. You own the database — the library owns nothing.

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Built-in visualization

Export to Mermaid stateDiagram-v2 or a JSON graph for React Flow, D3, or Cytoscape — with live status overlays.