Iii Cron Scheduling

iii Primitives Used

Reference Implementation

See ../references/cron-scheduling.js for the full working example — a recurring scheduled task that fires on a cron expression and optionally enqueues heavy work.

Also available in Python: ../references/cron-scheduling.py

Also available in Rust: ../references/cron-scheduling.rs

Common Patterns

Code using this pattern commonly includes, when relevant:

• registerWorker(url, { workerName }) — worker initialization
• registerFunction(id, handler) — define the scheduled handler
• registerTrigger({ type: 'cron', config: { expression } }) — bind the schedule
• trigger({ function_id, payload, action: TriggerAction.Enqueue({ queue }) }) — offload heavy work
• const logger = new Logger() — structured logging per job

Adapting This Pattern

Use the adaptations below when they apply to the task.

• Adjust the 7-field expression to match your schedule (e.g. 0 0 */6 * * * * for every 6 hours)
• Keep the cron handler lightweight — use it to validate and enqueue, not to do the heavy lifting
• For jobs that need state (e.g. last-run timestamp), combine with iii-state-management
• Multiple cron triggers can feed the same queue for fan-in processing

Engine Configuration

iii-cron must be enabled in iii-config.yaml. See ../references/iii-config.yaml for the full annotated config reference.

Pattern Boundaries

• If the task is about one-off async work rather than recurring schedules, prefer iii-queue-processing.
• If the trigger should fire on state changes rather than time, prefer iii-state-reactions.
• Stay with iii-cron-scheduling when the primary need is time-based periodic execution.

When to Use

• Use this skill when the task is primarily about iii-cron-scheduling in the iii engine.
• Triggers when the request directly asks for this pattern or an equivalent implementation.

Boundaries

• Never use this skill as a generic fallback for unrelated tasks.
• You must not apply this skill when a more specific iii skill is a better fit.
• Always verify environment and safety constraints before applying examples from this skill.