Declare recurring work with a fluent cadence, then let a single cron trigger drive it — a code-defined scheduler, edge-first. Instead of a crontab entry per job, you register tasks in code and run the scheduler once a minute; it runs whatever's due.

Scheduling tasks

A task is a Job or a plain function. Register it, then set the cadence:

import { schedule } from "@shaferllc/keel/core";

schedule(new PruneSessions()).daily();
schedule(() => syncInventory()).everyFiveMinutes();
schedule(new SendDigest()).cron("0 9 * * 1"); // 9am Mondays

Cadences

task.everyMinute();
task.everyFiveMinutes();   // and Ten / Fifteen / Thirty
task.hourly();
task.hourlyAt(15);         // :15 past every hour
task.daily();
task.dailyAt("13:30");
task.weekly(1);            // Monday (0 = Sunday) at midnight
task.monthly(15);          // the 15th at midnight
task.cron("*/10 9-17 * * 1-5"); // any 5-field cron expression

Running the scheduler

Run the scheduler once a minute from a cron trigger; runDue(now) runs every task whose expression matches now (to the minute).

Cloudflare (Cron Triggers)

Add a trigger to wrangler.jsonc ("triggers": { "crons": ["* * * * *"] }) and call the scheduler from the Worker's scheduled handler:

export default {
  async scheduled(event, env, ctx) {
    ctx.waitUntil(scheduler().runDue(new Date(event.scheduledTime)));
  },
};

Node

setInterval(() => scheduler().runDue(new Date()), 60_000);

Because the scheduler decides what's due, you only ever wire one trigger, no matter how many tasks you schedule.

Inspecting

scheduler().due(now) returns the due tasks without running them, and every task has an expression and optional name:

schedule(job).named("prune-sessions").daily();
for (const t of scheduler().due(new Date())) logger().info("due", { task: t.name });

API reference

schedule(job)

schedule(job: Job | (() => void | Promise<void>)): ScheduledTask

Registers a task on the default scheduler and returns it for cadence configuration.

scheduler() / setScheduler(next)

The default Scheduler; setScheduler replaces it (reset between tests).

ScheduledTask

Returned by schedule. Cadence setters return this (chainable): everyMinute / everyFiveMinutes / everyTenMinutes / everyFifteenMinutes / everyThirtyMinutes / hourly / hourlyAt(m) / daily / dailyAt("HH:MM") / weekly(weekday?) / monthly(day?) / cron(expr) / named(name). isDue(now) reports whether it matches a Date.

Scheduler

cronMatches(expression, date)

cronMatches(expression: string, date: Date): boolean

Whether a 5-field cron expression (min hour dom month dow) matches date to the minute. Supports *, exact values, lists (1,15), ranges (9-17), and steps (*/5, 0-30/10). Day-of-month and day-of-week follow standard cron: when both are restricted, either matching counts. Fields use the Date's own values (UTC in a Worker, local under Node).