cors-dev-proxy

A minimal CLI helper to run a local development server with CORS enabled. Perfect for frontend development when you need to proxy requests to a backend server that doesn't have CORS configured.

Installation

``bash
npm install -g cors-dev-proxy


or

pnpm add -g cors-dev-proxy

or

yarn global add cors-dev-proxy
`

Usage

`bash
cors-dev-proxy [options] [args...]
`

$3

- -i, --in - Specify the port of the backend server to proxy to
- -o, --out - Specify the port for the CORS proxy (default: 3000)

$3

Start a server and automatically detect its port:

`bash
cors-dev-proxy npm run dev
`

Specify ports explicitly:

`bash
cors-dev-proxy -i 5173 -o 3000 npm run dev
`

Run with Vite:

`bash
cors-dev-proxy vite
`

Run with any command:

`bash
cors-dev-proxy -o 8080 node server.js
`

How it works

1. Spawns your command - Runs the specified command (e.g., your dev server)
2. Detects the port - Automatically detects which port your server is listening on
3. Creates a CORS proxy - Starts a proxy server that forwards requests with proper CORS headers
4. Forwards requests - All requests to the proxy are forwarded to your backend with CORS enabled

Features

- ✨ Automatic port detection - No need to specify ports if your server outputs them
- 🔄 WebSocket support - Proxies WebSocket connections too
- 🎯 Credentials support - Handles cookies and authorization headers
- 🚀 Zero configuration - Just wrap your existing dev command
- 📦 Minimal dependencies - Lightweight and fast

CORS Headers

The proxy automatically adds:

- Access-Control-Allow-Origin - Set to the request origin or *
- Access-Control-Allow-Methods - Supports GET, POST, PUT, DELETE, OPTIONS
- Access-Control-Allow-Headers - Allows all requested headers
- Access-Control-Allow-Credentials` - Enabled when cookies/auth are present

License

MIT © Viktor Lázár