feat: make vercel compatible

Signed-off-by: Tony Tang <tonytang@lilith.com>

.gitignore

@@ -4,3 +4,4 @@
 
 coverage/
 node_modules/
+.vercel

README.md

@@ -152,21 +152,66 @@ export CORSANYWHERE_WHITELIST=https://example.com,http://example.com,http://exam
 node server.js
 ```
 
-This application can immediately be run on Heroku, see https://devcenter.heroku.com/articles/nodejs
-for instructions. Note that their [Acceptable Use Policy](https://www.heroku.com/policy/aup) forbids
-the use of Heroku for operating an open proxy, so make sure that you either enforce a whitelist as
-shown above, or severly rate-limit the number of requests.
 
-For example, to blacklist abuse.example.com and rate-limit everything to 50 requests per 3 minutes,
+## Vercel Deployment
-except for my.example.com and my2.example.com (which may be unlimited), use:
 
+CORS Anywhere can be deployed on Vercel using serverless functions. The project includes
+configuration files for easy deployment.
+
+### Quick Deploy
+
+1. **Install Vercel CLI** (if not already installed):
+   ```bash
+   npm install -g vercel
+   ```
+
+2. **Login to Vercel**:
+   ```bash
+   vercel login
+   ```
+
+3. **Deploy**:
+   ```bash
+   npm run deploy
+   ```
+   or
+   ```bash
+   vercel --prod
+   ```
+
+### Configuration
+
+The deployment uses:
+- `api/index.js` - Serverless function entry point
+- `vercel.json` - Vercel configuration with routing and function settings
+
+### Environment Variables
+
+You can configure CORS Anywhere using environment variables in your Vercel project:
+
+- `CORSANYWHERE_WHITELIST` - Comma-separated list of allowed origins
+- `CORSANYWHERE_BLACKLIST` - Comma-separated list of blocked origins  
+- `CORSANYWHERE_RATELIMIT` - Rate limiting configuration
+
+Example:
 ```
-export PORT=8080
+CORSANYWHERE_WHITELIST=https://myapp.com,https://myapp.vercel.app
-export CORSANYWHERE_BLACKLIST=https://abuse.example.com,http://abuse.example.com
+CORSANYWHERE_RATELIMIT=100 5 myapp.com
-export CORSANYWHERE_RATELIMIT='50 3 my.example.com my2.example.com'
-node server.js
 ```
 
+### Important Notes
+
+- Vercel serverless functions have execution time limits (30 seconds by default)
+- Large file downloads may timeout
+- Consider upgrading to Vercel Pro for longer function timeouts if needed
+- Rate limiting and origin restrictions are recommended to prevent abuse
+
+### Usage
+
+After deployment, your CORS proxy will be available at your Vercel domain:
+```
+https://your-project.vercel.app/http://example.com/api/data
+```
 
 ## License
 

api/index.js

@@ -0,0 +1,61 @@
+const cors_proxy = require('../lib/cors-anywhere');
+
+// Parse environment variables for configuration
+function parseEnvList(env) {
+  if (!env) {
+    return [];
+  }
+  return env.split(',');
+}
+
+const originBlacklist = parseEnvList(process.env.CORSANYWHERE_BLACKLIST);
+const originWhitelist = parseEnvList(process.env.CORSANYWHERE_WHITELIST);
+
+// Set up rate-limiting to avoid abuse
+const checkRateLimit = require('../lib/rate-limit')(process.env.CORSANYWHERE_RATELIMIT);
+
+// Create the CORS Anywhere server options
+const options = {
+  originBlacklist: originBlacklist,
+  originWhitelist: originWhitelist,
+  requireHeader: ['origin', 'x-requested-with'],
+  checkRateLimit: checkRateLimit,
+  removeHeaders: [
+    'cookie',
+    'cookie2',
+    // Strip Vercel-specific headers that might cause issues
+    'x-vercel-id',
+    'x-vercel-forwarded-for',
+    'x-vercel-deployment-url',
+    'x-vercel-trace',
+    // Keep other headers that might be useful
+  ],
+  redirectSameOrigin: true,
+  httpProxyOptions: {
+    // Vercel handles forwarding headers, so we can keep this
+    xfwd: true,
+  },
+};
+
+// Create the server (this will give us access to the internal handler)
+const server = cors_proxy.createServer(options);
+
+// Extract the request handler from the server
+// This is a bit of a hack, but necessary for Vercel serverless functions
+const requestHandler = server.listeners('request')[0];
+
+module.exports = (req, res) => {
+  // Vercel serverless functions expect the handler to be called directly
+  // But we need to ensure the request URL is properly formatted
+
+  // For Vercel, the path might include the API route prefix
+  // We need to adjust the URL to match what CORS Anywhere expects
+  const originalUrl = req.url;
+  if (req.url.startsWith('/api/')) {
+    // Remove the /api/ prefix for CORS Anywhere
+    req.url = req.url.substring(4);
+  }
+
+  // Call the CORS Anywhere handler
+  requestHandler(req, res);
+};

package.json

@@ -43,9 +43,11 @@
   "scripts": {
     "lint": "eslint .",
     "test": "mocha ./test/test*.js --reporter spec",
-    "test-coverage": "istanbul cover ./node_modules/.bin/_mocha -- test/test.js test/test-ratelimit.js --reporter spec"
+    "test-coverage": "istanbul cover ./node_modules/.bin/_mocha -- test/test.js test/test-ratelimit.js --reporter spec",
+    "dev": "node server.js",
+    "deploy": "vercel --prod"
   },
   "engines": {
-    "node": ">=0.10.0"
+    "node": ">=14.0.0"
   }
 }

vercel.json

@@ -0,0 +1,18 @@
+{
+  "version": 2,
+  "functions": {
+    "api/index.js": {
+      "maxDuration": 30
+    }
+  },
+  "routes": [
+    {
+      "src": "/(.*)",
+      "dest": "/api/index.js"
+    }
+  ],
+  "outputDirectory": null,
+  "env": {
+    "NODE_ENV": "production"
+  }
+}