effectKey

Optional lambda that computes a stable effect-key from context alone.

When non-null, the engine uses the returned string to look up whether the step's side effect has already been recorded in the journal (F004). For the stateful variant, see StatefulSagaStep.effectKey.

Attach via the effectKey infix extension:

step(OrderStep.CHARGE) { ctx -> ... } effectKey { ctx -> "charge:${ctx.orderId}" }