What if claude-code lived inside your browser?
Source: Dev.to
Overview
I built a browser extension that lets you theme any visited website simply by prompting. The extension sends your request to OpenAI’s codex‑mini, which generates the necessary JavaScript and CSS to apply the change.
What It Can Do
- Stop autoplaying videos
- Replace newspaper links with
archive.is - Dim sidebars
- Add quality‑of‑life tweaks, such as making ChatGPT responses easier to copy/paste
Real‑World Example
Earlier today I asked the extension to add a “cost per 100 requests” column on OpenRouter’s activity page. The decimal values were hard for my ADHD brain to process, so the generated column made the data much clearer.
How It Works
While you could achieve similar results with developer tools and user styles, I’ve been impressed by Codex’s ability to turn vague prompts into functional styles using only about 10 % of the source page for context.
During development I switched between Codex and Claude (Opus). By keeping the stack lightweight—Tailwind, Alpine.js, and Basecoat (a shadcn‑style library without React)—the final code remains maintainable and performs well.
Availability
The extension isn’t published on any webstore yet, but I’ve released a BYOK (Bring Your Own Key) open‑source version. Give it a try; you’ll likely be able to replace at least three of your current extensions with it.
Source Code
Check the code here: https://github.com/alentodorov/claude-code-browser-extension