Locking

What it does

When enabled, only one execution of this step (for a given lock key) can run at a time. If a second execution tries to run the same step while a lock is held, it waits until the lock is released or the hold period elapses.

Configuring it

• Enabled — turn locking on or off for this step.
• Lock key — an expression (supporting the same {{...}} step reference syntax used elsewhere) that determines what counts as "the same resource". By default the lock is scoped to the step itself; a custom key lets you lock per-customer, per-order, or any other identifier that needs serialized access.
• Period — how long (in seconds) the lock is held before it's automatically released, in case an execution doesn't complete normally.

When to use it

Use it whenever concurrent executions could race on the same resource — e.g. two workflow runs both trying to update the same order's status at once. A lock key scoped to the order id ensures only one of them proceeds at a time.