Webhook Inspector

A lightweight webhook testing utility built with NestJS, React, SQLite/Redis, TailwindCSS, and Docker.

What it does

• Creates anonymous webhook URLs with random UUID identifiers
• Accepts any HTTP method at /:webhookId
• Stores requests in SQLite (default) or Redis
• Polls every 1500ms for new requests
• Renders a split-pane inspector UI with request details

Stack

• Backend: NestJS + TypeScript
• Frontend: React + Vite + TailwindCSS
• Storage: SQLite (default) or Redis
• Realtime: polling
• Containerization: Docker + Docker Compose

Screenshot

Run with Docker

docker-compose up --build

• Frontend: http://localhost:3001
• Backend: http://localhost:3000

When you open the frontend, it generates a random webhook identifier, stores it in your browser, and routes you to the inspector view for that URL. The webhook URL you can send traffic to is the backend origin plus that identifier, for example http://localhost:3000/550e8400-e29b-41d4-a716-446655440000.

You can send a test payload to that webhook URL with curl:

curl -X POST http://localhost:3000/550e8400-e29b-41d4-a716-446655440000 \
  -H "Content-Type: application/json" \
  -d '{
    "event": "payment.succeeded",
    "id": "evt_123",
    "amount": 4200
  }'

By default the backend stores requests in a local SQLite database, so docker-compose up --build works with no other services. To use Redis instead, start the redis profile and point the backend at it:

STORAGE_DRIVER=redis docker-compose --profile redis up --build

Storage

The backend supports two storage drivers, selected with the STORAGE_DRIVER environment variable:

• sqlite (default) — stores requests in a local SQLite file. Configure the file path with SQLITE_PATH (defaults to ./data/webhook-inspector.db). No extra services required.
• redis — stores requests in Redis sorted sets. Configure the connection with REDIS_URL (defaults to redis://127.0.0.1:6379).

Self-hosted domains

Production setup:

• Frontend: https://app.example.com
• Backend: https://api.example.com
• Storage: local SQLite volume, or Redis on the private network only

DNS

Point app.example.com at the frontend server or load balancer. Point api.example.com at the backend server or load balancer.

Environment variables

Backend (SQLite, default):

PORT=3000
STORAGE_DRIVER=sqlite
SQLITE_PATH=/data/webhook-inspector.db
CORS_ORIGIN=https://app.example.com

Backend (Redis):

PORT=3000
STORAGE_DRIVER=redis
REDIS_URL=redis://<private-redis-host>:6379
CORS_ORIGIN=https://app.example.com

Frontend build:

VITE_API_BASE_URL=https://api.example.com

The shareable webhook URL becomes:

https://api.example.com/<webhookId>

Deployment notes

• If using SQLite, mount a persistent volume at the SQLITE_PATH directory so data survives restarts.
• If using Redis, keep it off the public internet.
• The frontend must be built with the backend URL baked in via VITE_API_BASE_URL.
• The backend already allows CORS from the configured frontend origin.
• If you use Docker, you can keep the same compose file and override the env vars for production.

Deploy on Cloudflare

The existing repo structure is still the primary setup for general use:

• backend/ is the standard NestJS backend
• frontend/ is the standard React app
• storage remains configurable as sqlite (default) or redis

The Cloudflare path is optional and deployment-only. It lives under deploy/cloudflare/ and does not replace or restructure the main app. It exists as a Cloudflare-specific adapter that serves the frontend on Cloudflare and stores requests in D1 for that deployment target.

Use deploy/cloudflare/README.md only when you want to deploy to Cloudflare.

API

ALL /:webhookId

Accepts any webhook request and stores it via the configured storage driver.

GET /api/requests/:webhookId?since=timestamp&limit=50

Returns requests newest-first.

• since is a timestamp in milliseconds
• limit defaults to 50 and is capped at 50

Local development

The app is organized as two standalone packages:

• backend/
• frontend/

You can install and run them separately if you want to develop without Docker.