Express.js Proxy

Route usertrax through your Express.js server using a lightweight HTTP proxy.

1. Install dependencies

   npm install express-http-proxy

2. Add proxy routes

   const express = require("express");
   const proxy = require("express-http-proxy");
   
   const app = express();
   
   app.set("trust proxy", true);
   
   // Proxy the tracking script
   app.use(
     "/cvs.js",
     proxy("usertrax.io", {
       https: true,
       proxyReqPathResolver: () => "/cvs.js",
     }),
   );
   
   // Proxy the events endpoint
   app.use(
     "/api/usertrax/events",
     proxy("api.usertrax.io", {
       https: true,
       proxyReqPathResolver: () => "/api/events",
       proxyReqOptDecorator: (proxyReqOpts, srcReq) => {
         proxyReqOpts.headers["X-Auth-Key"] = srcReq.headers["x-auth-key"] || "";
         return proxyReqOpts;
       },
     }),
   );
   
   // Your other routes...
   app.listen(3000);

3. Update your HTML

   <script>
     window.usertraxConfig = {
       endpoint: "/api/usertrax/events",
     };
   </script>
   <script src="/cvs.js" data-key="YOUR_API_KEY" defer></script>

4. Deploy

   The proxy is active once your server is running with the updated configuration.

1. Visit your website
2. Open the Network tab
3. Confirm requests go through your domain

• 401 Unauthorized: Verify proxyReqOptDecorator forwards X-Auth-Key
• Path conflicts: If /api/usertrax/events is already used, change the path in both Express and usertraxConfig.endpoint