How to Monitor Auth0: Login Failures, Callback Errors, and Uptime

#auth0 #monitoring #security #javascript

Auth0 Monitoring Essentials

Auth0 is your app's front door. When it's slow or unavailable, users can't log in.

Log Auth Events

app.use((err, req, res, next) => {
  if (err.status === 401) {
    console.error(JSON.stringify({
      event: 'auth_failure',
      status: err.status,
      path: req.path
    }));
  }
  next(err);
});

Health Check for External Monitoring

Add an unauthenticated health endpoint and monitor it with Vigilmon:

app.get('/health', (req, res) => {
  res.json({ status: 'ok', auth_domain: process.env.AUTH0_DOMAIN });
});

Also monitor your Auth0 tenant URL directly - if it returns an error, logins fail for everyone.

Callback URL Error Tracking

app.get('/callback', (req, res, next) => {
  if (req.query.error) {
    console.error(JSON.stringify({
      event: 'auth0_callback_error',
      error: req.query.error,
      description: req.query.error_description
    }));
  }
  next();
});