How to Bypass Adblockers with Fingerprint and Cloudflare

Context

While building SkySculptor, an immersive AI-powered interface that transforms weather data into living visual sculptures, I implemented a fingerprint-based rate limiting system to prevent API abuse. I chose Fingerprint.js Pro for its ability to identify users even after cookie deletion.

The Problem

During early testing, an error appeared in the console:

FPJSAgentError: Failed to load the JS script of the agent

After investigation, the culprit was uBlock Origin — the extension I use daily myself. Adblockers maintain blacklists of tracking domains, and Fingerprint's CDNs (fpjscdn.net, fpjs.io) are on those lists.

Why Does It Work on fingerprint.com?

While inspecting Fingerprint's website, I noticed their demo worked perfectly despite uBlock. Looking at the Network tab:

• No calls to fpjscdn.net
• Requests went through a custom subdomain (metrics.fingerprint.com)

Adblockers don't block what looks like first-party traffic!

Solution 1: Next.js Rewrites (Failed)

My first attempt was configuring rewrites in Next.js to proxy the requests:

// next.config.ts
rewrites() {
  return [
    {
      source: "/_fp/agent/:path*",
      destination: "https://fpjscdn.net/v3/:path*",
    },
    {
      source: "/_fp/api/:path*", 
      destination: "https://eu.api.fpjs.io/:path*",
    },
  ];
}