Installation

There is no Chrome Web Store listing. The extension is loaded unpacked from a local checkout, which also means there is no build step, no bundler, and no dependencies to install for the extension itself.

Requirements

• A Chromium-based browser with Manifest V3 support (Chrome, Edge, Brave, Vivaldi)
• A CyTube channel you can add media to
• Nothing else - the extension is plain JavaScript, HTML, and CSS

Load the extension

1. Clone or download the repository:

   git clone https://github.com/rennerdo30/send-to-cytube.git

2. Open chrome://extensions in your browser.

3. Enable Developer mode using the toggle in the top-right corner.

4. Click Load unpacked.

5. Select the repository root - the folder containing manifest.json.

6. The Send to CyTube action icon appears in the toolbar, and a floating button appears the next time you open a YouTube watch page.

Tip

After editing any extension file, press the reload button on the extension’s card in chrome://extensions. Content-script changes also need a refresh of the YouTube tab.

Grant site access to your CyTube host

The manifest declares no CyTube host up front. Instead it declares optional_host_permissions for http://*/* and https://*/*, and the extension asks for exactly one origin at a time - the origin of the tab you targeted.

The first time you send to a given CyTube host, Chrome shows a site-access prompt. Accept it once per host and it is remembered.

If the prompt is refused on the YouTube page

Chrome only allows chrome.permissions.request() from a user gesture in certain contexts. If the in-page button reports Setup needed and the panel shows a site-access error, open the toolbar popup once and send from there for that CyTube host. After the grant exists, the in-page button works for that host from then on.

What the extension declares

From manifest.json:

Field	Value
manifest_version	3
permissions	storage, tabs, scripting, contextMenus
optional_host_permissions	http://*/*, https://*/*
content_scripts	youtube-page.js + youtube-page.css on YouTube origins, document_idle
background	background.js as a service worker
action	popup.html

tabs is needed to enumerate open tabs and read their titles and URLs so candidate CyTube tabs can be listed. scripting performs the one-shot injection into the target tab. storage keeps your three saved defaults in chrome.storage.sync.

Install the SponsorBlock channel script

This part is independent of the extension. It is CyTube channel JS and runs for every viewer in the channel who has channel JS enabled.

1. Open your channel on cytu.be.

2. Go to Channel Settings.

3. Open the admin/customization section that holds the channel JS field.

4. Paste the full contents of cytube-sponsorblock.js.

5. Save, then refresh the channel page.

A small status pill appears on the page once it is running. See the SponsorBlock guide for what it does and where it stops short.

Documentation site

The docs you are reading live in docs/ and are built with Astro Starlight.

From the repo root

npm run install:docs
npm run dev      # local preview
npm run build    # static output in docs/dist

From docs/

cd docs
npm install
npm run dev
npm run build