YouTube transcript → Summary prompt (Firefox extension)

Available on Firefox Browser Add-ons

A lightweight Firefox extension that adds a single button on YouTube watch pages to copy:

• the video title
• the channel name
• the video URL
• a ready-to-paste ChatGPT summary prompt
• the full transcript

into your clipboard in one click.

This is intended as a fast, privacy-friendly workflow: no backend, no API key, no data sent anywhere.

Features

• Adds a “Copy prompt + transcript” button directly on YouTube video pages
• Automatically includes contextual metadata:
  • Title
  • Channel
  • URL
• Tries to:
  1. open the YouTube transcript panel automatically when needed
  2. fall back to YouTube caption tracks if the panel is not available
• Works with YouTube’s single-page navigation (SPA)

What gets copied

The clipboard content looks like this:

Title: …
Channel: …
URL: …

Please summarise this YouTube transcript.
Give me:
- a 6–10 bullet summary
- key takeaways
- any actionable items

Transcript:

<full transcript>

Installation (temporary, for development)

1. Open Firefox
2. Go to:

about:debugging#/runtime/this-firefox

3. Click Load Temporary Add-on…
4. Select the manifest.json file in this project

Open any YouTube video page and the button will appear near the action buttons (like, share, etc.).

How it works (high level)

The content script:

1. Injects a small button into the YouTube watch page UI
2. When clicked:
   • attempts to open the transcript panel via the page UI
   • reads transcript segments from the DOM if available
   • otherwise fetches captions through YouTube’s internal caption track endpoint
3. Builds a prompt that includes:
   • video metadata
   • a summary instruction
   • the transcript
4. Copies the result to the clipboard

All processing happens locally in the browser.

Limitations

• Some videos genuinely have no transcript or captions
• YouTube frequently changes its internal DOM and UI structure
• The automatic “open transcript” step relies on heuristics and localisation-dependent labels

When YouTube changes its layout, selectors may need updating.

Supported browser

• Firefox

Building

npm i -g web-ext

web-ext lint
web-ext build --overwrite-dest

Firefox submission metadata

To submit to AMO without retyping the listing text in the web form, use the checked-in amo-metadata.json file with web-ext.

For a single build/release command, run:

./scripts/release-firefox.sh patch

The script:

• increments the manifest.json version using patch, minor, or major
• builds the extension into web-ext-artifacts/
• uses amo-metadata.json for AMO listing translations
• submits/signs automatically if AMO_JWT_ISSUER and AMO_JWT_SECRET are set
• uses AMO_CHANNEL=listed by default; set AMO_CHANNEL=unlisted if needed

Example:

export AMO_JWT_ISSUER="your-amo-jwt-issuer"
export AMO_JWT_SECRET="your-amo-jwt-secret"
export AMO_CHANNEL="listed"
./scripts/release-firefox.sh minor

Folder structure

PromptTube/
├─ manifest.json
├─ icon.png
├─ content-script.js
├─ styles.css
├─ LICENCE
└─ README.md