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Knowledge Tooltip is distributed as source code and loaded as an unpacked extension. This gives you full transparency into how the extension works and ensures your privacy.

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Prerequisites

You need one of the following Chromium-based browsers:
  • Chrome
  • Edge
  • Brave
  • Opera
  • Vivaldi
Knowledge Tooltip uses Manifest V3 and requires a recent browser version. Most browsers from 2022 onwards are supported.

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Installation steps

1

Get the source code

Clone or download the repository to your local machine:
git clone https://github.com/ibralassaf/knowledge-tooltip.git
Alternatively, download the ZIP file and extract it to a folder.
2

Open the extensions page

Navigate to your browser’s extensions page:
  • Chrome: chrome://extensions/
  • Edge: edge://extensions/
  • Brave: brave://extensions/
  • Opera: opera://extensions/
You can also access this page from the browser menu: More Tools → Extensions
3

Enable Developer Mode

Look for a toggle switch labeled Developer mode in the top right corner of the extensions page and turn it on.
Developer mode is required to load unpacked extensions. This doesn’t affect your browser’s security for normal browsing.
4

Load the extension

Click the Load unpacked button that appears after enabling Developer mode.In the file picker dialog, navigate to and select the folder containing the Knowledge Tooltip source code (the folder with manifest.json).
5

Verify installation

After loading, you should see the Knowledge Tooltip extension card appear in your extensions list:
  • Name: Knowledge Tooltip
  • Version: 2.0.0
  • Description: Get instant summaries, definitions, and quick facts for any highlighted text
The extension icon should also appear in your browser’s toolbar.
If you see an error message, verify that you selected the correct folder containing manifest.json and that all required files are present.

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Verify the extension is working

To confirm everything is set up correctly:
  1. Navigate to any webpage with text content (e.g., Wikipedia, news site)
  2. Highlight any word or phrase (at least 2 characters)
  3. A floating button with a brain icon should appear above your selection
  4. Click the button to open the Knowledge Tooltip
If the button doesn’t appear, check that the extension is enabled on the chrome://extensions/ page and that the toggle switch on the extension card is turned on.

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Required files

The extension requires these files to be present in the source folder: 
manifest.json      # Extension configuration (Manifest V3)
background.js      # Service worker for API calls
content.js         # Content script injected into pages
styles.css         # Extension styles and tooltip UI
popup.html         # Extension popup settings page
popup.js           # Popup logic and preferences
icons/             # Extension icons (16px, 48px, 128px)
  icon16.png
  icon48.png
  icon128.png

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Permissions explained

Knowledge Tooltip requests these permissions in manifest.json:
PermissionPurpose
activeTabAccess content on the current tab when you click the extension button
storageStore your preferences (enabled/disabled, language) and OpenAI API key
The extension also requests host permissions for specific APIs (Wikipedia, Wiktionary, Wikidata, OpenAI). These are only used to fetch data when you actively use the extension.

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Updating the extension

Since you’ve loaded the extension from source, updates won’t happen automatically:
  1. Pull the latest changes from the repository (or download the latest version)
  2. Go to chrome://extensions/
  3. Click the Reload button (circular arrow icon) on the Knowledge Tooltip card
Your settings and preferences are preserved when you reload the extension.

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Troubleshooting

  • Verify you selected the correct folder containing manifest.json
  • Check that Developer mode is enabled
  • Look for error messages on the extensions page
  • Try refreshing the extensions page
  • Refresh the webpage after installing the extension
  • Check that the extension is enabled (toggle on chrome://extensions/)
  • Open the extension popup and verify it’s set to “Active”
  • Try highlighting at least 2 characters of text
Make sure you selected the root folder of the extension, not a subfolder. The manifest.json file should be directly inside the selected folder.
Some websites with strict Content Security Policy (CSP) may prevent content scripts from running. This is a browser security feature and not an extension issue. The extension should work on most standard websites.

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Next steps

Quickstart Guide

Get your first tooltip in under 2 minutes

Configuration

Set up language preferences and OpenAI API key

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