Monitoring Vercel Cron: know whether the job ran

Setup

Set up in three steps

1. Create a heartbeat

   In your account, create a new one under “Heartbeats”, with the rhythm from your vercel.json. On the Hobby plan give it generous leeway, at least two hours, because Vercel starts the job some time within the hour. You receive a ping address of its own, such as https://runcheck.de/a8k3m2x9q1.

2. The check-in at the end of the route

   Open the route listed under crons in vercel.json and put the check-in after the actual work, before the response. The CRON_SECRET check comes from the Vercel documentation and stays as it is.

   // app/api/cron/route.ts
   import type { NextRequest } from 'next/server';
   
   export async function GET(request: NextRequest) {
     const authHeader = request.headers.get('authorization');
     if (!process.env.CRON_SECRET || authHeader !== `Bearer ${process.env.CRON_SECRET}`) {
       return new Response('Unauthorized', { status: 401 });
     }
   
     // ... your work ...
   
     await fetch('https://runcheck.de/a8k3m2x9q1', { signal: AbortSignal.timeout(10000) }).catch(() => {});
     return Response.json({ success: true });
   }

3. Deploy and trigger once

   After the next deployment you can run the job by hand in the Vercel dashboard. In your Cronjob.de account, “Waiting for the first check-in …” turns green.

The ready-made lines for Linux, PHP, Python, Node.js, n8n, Make, Supabase and Vercel are on the page Cron job monitoring. Your own ping address appears in your account once you create the heartbeat, with the same lines ready to copy.

When something fails

What happens when a run fails

If the invocation does not arrive, the work throws an exception or the function runs into its time limit, the last line is never reached – the check-in is missing. After the leeway we alert you; the next successful run brings the all-clear.

FAQ

Common questions about Vercel Cron

What does the vercel.json entry look like?

Like this, with your route's path and the schedule in UTC: { "crons": [ { "path": "/api/cron", "schedule": "0 5 * * *" } ] }

Why await – would the check-in not go out anyway?

A Vercel Function can be stopped as soon as the response is out. With await it waits for the check-in, ten seconds at most, and errors while checking in are ignored.

Pages Router or another framework?

The check-in is an ordinary fetch call and works in any Vercel Function on Node.js 18 or later. What matters is the place: after the work, before the response.