name: encore-cron description: >- Schedule periodic / recurring work in Encore.ts using CronJob from encore.dev/cron. Covers every: "1h" interval syntax and schedule: "0 9 * * 1" cron expressions. when_to_use: >- User wants to run a job on a schedule — anything with the words schedule, scheduled, daily, hourly, weekly, periodic, recurring, every N minutes/hours, "at HH:MM UTC", midnight, batch job, aggregation job, nightly, cleanup job, or background work that runs on a timer rather than in response to a request. Trigger phrases: "every day at 02:00 UTC", "daily aggregation", "run hourly", "scheduled task", "cron", "nightly cleanup", "on a schedule".

Encore Cron Jobs

Instructions

A CronJob declaration in Encore.ts ties a schedule to an existing api(...) endpoint. The endpoint runs at the chosen cadence. Declare the CronJob at package level — not inside a function.

import { CronJob } from "encore.dev/cron";
import { api } from "encore.dev/api";

// 1. The endpoint to call (typically internal: expose: false)
export const aggregateDailyOrders = api(
  { expose: false },
  async (): Promise<void> => {
    // Aggregation logic
  }
);

// 2. Package-level cron declaration
const _ = new CronJob("aggregate-daily-orders", {
  title: "Aggregate orders for the previous day",
  schedule: "0 2 * * *",  // 02:00 UTC every day
  endpoint: aggregateDailyOrders,
});

Schedule Formats

| Field | Example | Description | |---|---|---| | every | "1h", "30m", "6h" | Simple interval. Must divide 24h evenly — "7h" is invalid. | | schedule | "0 9 * * 1" | Standard cron expression (5 fields, UTC). |

Common cron expressions

| Cron | Meaning | |---|---| | "0 * * * *" | Every hour, on the hour | | "0 2 * * *" | Daily at 02:00 UTC | | "0 0 * * 0" | Weekly on Sunday at midnight UTC | | "0 4 15 * *" | 04:00 UTC on the 15th of each month |

Important behaviour

• Cron jobs do not execute when running locally with encore run. Only deployed environments fire crons.
• The cron endpoint should be expose: false so it can't be triggered externally — only the cron scheduler should call it.
• All times in schedule are UTC. Convert from local time when designing the schedule.
• The endpoint must already exist at module load — declare it before the CronJob.

Guidelines

• Use every for "run on a regular interval" (must divide 24h).
• Use schedule for specific times of day or days of week.
• Keep endpoint logic idempotent: a cron may fire late or be retried in a redeploy window.
• For event-driven background work (not time-driven), use the encore-pubsub skill instead.