I Reverse Engineered the Claude Chrome Extension using REA - Download free
I used the Reverse Engineer Anything (REA) repository to build my own version of the Claude side-panel agent for Chrome. It sits next to any page, reads it, clicks, types and fills forms for you. You bring your own OpenRouter key and pick the model. I built it to learn how apps like this are made, so treat it as educational.
Here is how to run it yourself.
Step 1: Download the project
The repository is linked here. Download it and unzip it. There is nothing to install or build, it is plain extension files.
Step 2: Get an OpenRouter key
Create a free account on openrouter.ai, open the Keys page and make a new key. Keep it somewhere safe, you will paste it in Step 4.
Step 3: Load it into Chrome
- Open
chrome://extensions - Turn on Developer mode (top right)
- Click Load unpacked and select the project folder
Step 4: Add your key
The settings page opens by itself after install. Paste your key, click Save API Key, then Test connection. Leave the Base URL as it is. Pick a model that supports tools. If you want it to understand screenshots, pick one that supports images too.
Step 5: Open the side panel and try it
Click the toolbar icon, or press Ctrl+E (Cmd+E on Mac). Open any page and try "Summarize this page". Leave "Ask before acting" ticked at first, so it asks before it clicks anything. Chrome will show a debugging banner while it works, that is normal.
The prompt I used to build it
Reverse-engineer Claude chrome extension and build a working alternative with similar pages, design, navigation, and functionality. I should be able to configure and use openrouter api.
/reverse-engineer-anything
If you want to build something like this yourself, the full step-by-step is in our tutorial section https://coding180.com/tutorials/reverse-engineer-any-app-rea.
You gat any issues? drop it here
