How to Build a Webhook Delivery Monitor with JavaScript (Free APIs)

Webhooks are the backbone of modern integrations — Stripe sends payment events, GitHub sends push notifications, Slack sends message events. But when a webhook fails silently, you lose data and don't know why. In this tutorial, we'll build a webhook delivery monitor that: Accepts incoming webhooks from any service Logs every delivery with full headers and body Verifies the sender's IP and geolocation Sends alerts when deliveries fail or come from unexpected origins All using free APIs. No database. Under 80 lines of code. What We're Building A lightweight Node.js server that: Catches webhooks on any path (e.g., /hooks/stripe , /hooks/github ) Logs the sender's IP, geo data, headers, and payload Validates the origin against expected IP ranges Sends a Slack/Discord alert if something looks suspicious Prerequisites Node.js 18+ A free API key from Frostbyte (200 free credits) Step 1: Set Up the Server import http from ' node:http ' ; const API_KEY = process . env . FROSTBYTE_KEY || ' your-