Sentry error tracking: capturing exceptions with full context in Node.js

Errors in production are discovered through user complaints rather than automated detection. Stack traces in logs lack the context needed to reproduce the issue: what user triggered it, what they were doing, and what the application state was.

Integrate Sentry to automatically capture unhandled exceptions and provide rich context for each error.

const Sentry = require('@sentry/node');

Sentry.init({
  dsn: process.env.SENTRY_DSN,
  environment: process.env.NODE_ENV,
  release: process.env.APP_VERSION,
  tracesSampleRate: 0.1,  // 10% of transactions
  beforeSend(event) {
    // Scrub PII from events before sending
    if (event.user) delete event.user.email;
    return event;
  },
});

// Set user context for better error attribution
Sentry.setUser({ id: req.user.id });

// Add breadcrumbs for custom events leading up to an error
Sentry.addBreadcrumb({
  category: 'payment',
  message: 'Initiating payment for order ' + orderId,
  level: 'info',
});

// Manually capture with extra context
try {
  await processPayment(order);
} catch (err) {
  Sentry.captureException(err, {
    tags: { orderId: order.id },
    extra: { paymentProvider: order.provider },
  });
  throw err;
}

Sentry groups errors by stack trace fingerprint, showing occurrence count and affected users. This transforms error monitoring from log searching to a prioritized queue of distinct issues.

Adding automated error detection and reporting to a Node.js application