cron

The cron worker schedules registered functions to run on recurring cron expressions. It exposes no callable cron::* functions; its entire surface is the cron trigger type, bound through a worker SDK trigger registration such as iii.registerTrigger({ type: 'cron', function_id, config }).

Install it with iii worker add cron. The engine builtin iii-cron must not run on the same engine because it also owns the cron trigger type. Remove iii-cron from the engine config before starting this worker; the standalone worker refuses to boot when the builtin is active.

On every firing, the worker optionally evaluates a condition function, acquires a lock through the configured backend, and invokes the target function with an event payload containing trigger, job_id, scheduled_time, and actual_time. scheduled_time and actual_time let handlers observe drift without querying the scheduler.