Cron

Cron

Cron triggers run your function automatically based on a cron expression. Instead of calling main({ input }), the scheduler now invokes your exported cron(data) handler.

Use main for direct/manual execution paths (such as HTTP), and add the cron handler to respond to scheduled invocations.

Quick setup

• Expression format: minute hour day month weekday (UTC)
• Examples: * * * * * (every minute), 0 * * * * (hourly), 0 9 * * 1-5 (weekdays 09:00)
• Configure in the dashboard under Settings → Triggers → Cron

Handler signature

export async function cron(data: unknown) {
  // handle scheduled invocation
}

The handler runs on the schedule you define. Return values are logged and surfaced in execution history, just like other triggers.

Note: data currently arrives as an empty object; custom payloads are not yet available for cron triggers.

Example handler

The following function demonstrates exports for both manual invocations (main) and the new cron handler, plus an integration with @microfn/fn inside cron().

import fn from "@microfn/fn";
// Welcome to Microfn!
// This is a serverless function that runs in the cloud.
// Export a main function that takes { input: data } and returns any value.
// Strings/numbers are returned as-is, objects/arrays are JSON serialized.

export async function main({ input }) {
  return {
    message: "Hello from Microfn!",
    timestamp: new Date().toISOString(),
    receivedInput: input
  };
}

export async function cron(data) {
  // handle cron trigger
  console.log("cron triggered");

  const discordPayload = {
    channelId: "1365582079387107400",
    content: "corn 🌽",
  };

  const discordResult = await fn.executeFunction("david/send-discord-message", discordPayload);

  return "corn";
}