simple-express-proxy

Overview

simple-express-proxy is a Node.js proxy written with Express. Although it is intended to be deployed on Vercel, you can run it on your machine locally for experimental purposes.

Deploying with Vercel

Why Vercel? Because it lets you easily deploy Express applications with dynamic IPs. Moreover, you can choose the region in which you want the proxy to be located.

Simply fork this repository and connect to Vercel using your Github account. In the dashboard, select Add new > Project and choose the repository in the Import Git Repository section.

When deployment is complete, check the proxy website: if it says “invalid URL”, everything worked! If not, check the deployment logs.

Check out an example at: https://simple-express-proxy.vercel.app/https://example.org.

How to change the proxy region

Vercel can manage several regions for serverless functions. Thus, the proxy can be located anywhere in the regions listed here.

Once the deployment is complete, you can add a specific region to the Vercel project settings by following this tutorial. Do not forget to redeploy afterwards so that the changes are taken into account.

How to use

Let's assume that https://my-proxy.vercel.app is your proxy's domain. To use it, send a request to the proxy specifying as a param the URL you wish to retrieve:

(async function () {
    const proxy = 'https://my-proxy.vercel.app';

    const res = await fetch(`${proxy}/https://example.org`, {
        method: 'GET'
    });

    console.log(res.headers.get('x-url')); // shows https://example.org
    console.log(await res.text());
})();

The request method, body and headers you send to the proxy will be used by the proxy to retrieve the target URL, with the exception of certain headers such as x-forwarded-for which contains informations about the client.

Similarly, the headers, status and body included in the proxy's response are those sent by the target URL website to the proxy, with the exception of certain headers such as access-control-allow-origin for obvious reasons.

The proxy sets up a response header, x-url, which contains the final URL (after all redirections) of the request it sends.

Use it locally

Install the necessary dependencies with npm install. Then build the api folder using npx tsc (the output directory will be /dist). To start the server, simply run node dist/index.