Getting Started with REX

Before installing anything, you may want to browse the data reference to see what REX actually collects: real annotated records from real modules. If that data looks like what your study needs, come back here.

This guide walks you through running the REX demo extension in your browser so you can generate and download your own sample data. After that, the local backend guide shows you the full server pipeline using Docker Desktop on your own machine, a good intermediate step before deciding whether to deploy your own server or use BRIC’s managed hosting.

Estimated time: 15 minutes.

What you will need

Git: for downloading the code. Install Git if you do not have it. You can check by opening a terminal and running git --version.
Node.js 18 or newer: for building the extension. Download Node.js (choose the “LTS” version). Check with node --version.
Chrome or Edge browser: REX extensions run in Chromium-based browsers. Firefox is not supported.

You do not need any programming experience to follow this guide.

Step 1: Download and build rex-demo

Open a terminal (Terminal on Mac, Command Prompt or PowerShell on Windows) and run these commands one at a time to observe each step, or click copy below to run them all at once:

git clone https://github.com/bric-digital/rex-demo.git
cd rex-demo
npm install
npm run build

git clone downloads the demo project to a new folder called rex-demo.
npm install downloads the libraries rex-demo depends on.
npm run build compiles the extension into a format Chrome can load.

When the build finishes you will see a dist/extension/ folder inside rex-demo. That folder is the extension.

Step 2: Load the extension in Chrome

Chrome does not install extensions from local folders by default: you have to enable a setting first.

Open Chrome and go to chrome://extensions in the address bar.
In the top-right corner of that page, turn on the Developer mode toggle and identify the Load unpacked button that appears in the top-left.
In the file picker, navigate to your home directory, and select the rex-demo folder you just cloned, then select the dist/extension/ subfolder inside it. Click Open (or Select Folder on Windows).

The REX Demo extension will appear in your extensions list with a toggle indicating it is active.

If you are using Edge, the steps are the same but start at edge://extensions.

Step 3: Open the extension

Extensions live in the browser toolbar. To find REX Demo:

Click the puzzle piece icon in the top-right of your Chrome toolbar. This opens the extensions panel.
Find “REX Demo” in the list and click the pin icon next to it. The REX Demo icon will now appear directly in your toolbar.
Click the REX Demo icon. The extension opens in a new tab.

Step 4: Enter a study ID

The first time you open the extension tab, REX will ask for a participant or study identifier. This is the ID that will appear in the data records; in a real study, you would give each participant a unique ID.

For now, enter test-001 and click Save (or press Enter).

REX is now active and collecting data.

Step 5: Generate some data

Browse normally for a few minutes. Visit a few different websites: news sites, a search engine, whatever you like. REX is running silently in the background, recording page visits and browsing history.

One important thing to know: REX only collects data while the extension is installed and enabled. If a participant disables the extension, uninstalls it, or uses a different browser profile, no data is collected during that time. This is by design and is important to communicate to participants.

Step 6: Download the data

Come back to the REX Demo extension tab (click the icon in the toolbar).

You will see a Download button. Click it to save a JSON file to your computer. This file contains everything REX has collected so far.

Next step

Open that JSON file and take a look at what is inside.

Exploring the Data walks you through the structure of the data and helps you decide whether REX collects what your study needs.