HTTP Debug Proxy

Lightweight HTTP request inspector - capture, replay, and debug API calls.

Features

• Zero-config proxy - Just point it at your API
• Request/response capture - See exactly what's being sent/received
• Real-time WebSocket updates - Live streaming of requests in the browser
• Web UI - Clean HTML interface at /__debug/requests
• JSON API - Programmatic access to captured requests
• Auto-cleanup - Keeps last 100 requests

Installation

go install github.com/mizrahidaniel/http-debug-proxy@latest

Usage

# Proxy requests to an API
http-debug-proxy --target=https://api.github.com --port=8080

# Make requests through the proxy
curl http://localhost:8080/users/octocat

# View captured requests
open http://localhost:8080/__debug/requests

Debug UI

Navigate to http://localhost:PORT/__debug/requests to see:

• All captured requests & responses
• Response times & status codes
• Request/response bodies
• Color-coded status (green=2xx, orange=4xx, red=5xx)

JSON API

# Get all captured requests as JSON
curl http://localhost:8080/api/requests

# Clear captured requests (POST)
curl -X POST http://localhost:8080/api/clear

WebSocket API

Connect to ws://localhost:PORT/ws for real-time request streaming:

const ws = new WebSocket('ws://localhost:8080/ws');

ws.onmessage = (event) => {
  const request = JSON.parse(event.data);
  console.log(`${request.method} ${request.url} -> ${request.response.status}`);
};

Features:

• Broadcasts all captured requests to connected clients
• Sends full request history on connect
• Auto-reconnects on disconnect
• CORS-enabled for local development

Use Cases

• Webhook debugging - Inspect incoming webhook payloads
• API integration - Debug third-party API calls
• Mobile app testing - Capture app → backend traffic
• CI/CD debugging - Record failed API calls in tests

Example

# Start proxy
http-debug-proxy --target=https://jsonplaceholder.typicode.com

# Make some requests
curl http://localhost:8080/posts/1
curl http://localhost:8080/users

# View in browser
open http://localhost:8080/__debug/requests

Why This?

Like ngrok's inspector, but:

• Self-hosted - No external service
• Lightweight - Single binary, no dependencies
• Simple - Point and shoot

Building from Source

git clone https://github.com/mizrahidaniel/http-debug-proxy
cd http-debug-proxy
go build
./http-debug-proxy --target=https://api.example.com

License

MIT