Building a Self-Healing API Monitor in 100 Lines of Node.js

Building a Self-Healing API Monitor in 100 Lines of Node.js Target: Honeybadger ($200) / Draft.dev ($300-500) | ~2,500 words What "Self-Healing" Actually Means Production systems fail. APIs go down, timeouts spike, third-party services flake. The question isn't whether your API will break — it's how long it stays broken before you notice and fix it. Most monitoring solutions alert you when something breaks. A self-healing monitor takes it further: it detects the failure, diagnoses the likely cause, attempts a predefined recovery action, and only pages you if recovery fails. This guide builds a self-healing API monitor in under 100 lines of Node.js that: Polls a list of endpoints on configurable intervals Detects failures (timeouts, 5xx errors, response validation failures) Executes recovery actions (restart a service, clear a cache, trigger a webhook) Applies exponential backoff before alerting Sends alerts to Slack when human intervention is required No dependencies beyond Node.js 18'