Generic State Machine Runtime for n8n Data Tables & Sub-Workflows

Run event-sourced state machines in n8n—automatically replay cases, validate transitions, and dispatch sub-workflows

This Generic State Machine Runtime for n8n Data Tables & Sub-Workflows is an n8n workflow that replays a case’s event stream from n8n Data Tables, verifies whether a requested transition is allowed, appends new events safely (including duplicate checks), and—when a target state is configured—starts a bound n8n sub-workflow asynchronously to execute state tasks.

What this workflow does

• Receives an execution request from another workflow and validates the incoming event (or handles an inspect-only request) and its identifiers.
• Loads state-machine definitions from an n8n Data Table catalog and validates the machine/version details.
• Reconstructs current state by reading the case’s existing events from an event-stream Data Table and replaying them.
• Checks transition eligibility—either returns current status for inspect, or determines whether the requested transition is allowed.
• Appends accepted events to the case event stream with the next sequence number and resolved correlation/causation details, unless the event is a duplicate.
• Optionally dispatches a state task: if the entered target state declares a task, it looks up the machine/version/task binding and prepares a sub-workflow invocation payload.
• Starts the bound sub-workflow asynchronously when a binding exists; otherwise returns the applied transition result with an “unavailable” dispatch reason.

Use cases

• Workflow-driven business processes (e.g., order onboarding, case triage) that require strict transition rules and auditable event histories.
• Event-sourced automations where you must replay state from stored events rather than rely on mutable status fields.
• Decoupled state tasks by dispatching n8n sub-workflows when specific states are entered.

Technical details

• Uses n8n nodes including if, code, Data Table, Execute Workflow, and Execute Workflow Trigger (plus a Sticky Note for documentation).
• Requires three Data Tables: machine definitions, case event stream, and task bindings (configure and update Data Table IDs in the Data Table nodes).