Garrett — Video Keeper

"What is merely watched is soon forgotten. What is taken is kept."
— Keeper Annuary, Ch. VII

Named after Garrett, the cynical, pragmatic Master Thief trained by the secretive Keeper Order (Thief: The Dark Project), this browser extension embodies the Keeper philosophy:

Modern web platforms treat video as disposable, ephemeral streams bound to in-memory blob: URLs that disappear as soon as you scroll or close the tab. Garrett extracts, stitches, and preserves complete MP4 files directly to your machine.

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Key Capabilities

Modern streaming video players (LinkedIn, X/Twitter, Reddit, TikTok, Vimeo, and custom WebRTC/MSE players) use ephemeral blob: URLs pointing to internal MediaSource streaming engines rather than direct static file links. Garrett extracts and preserves them silently in the background:

• Multi-Tier Stream Discovery:
  1. Direct React Fiber Traversal: Reads unexposed progressive MP4 and DASH streaming locations directly from component props and React Fiber trees (fiber.return).
  2. Embedded Hydration Scans: Deeply inspects server-rendered JSON payloads (<code id^="bpr-guid-">) to discover pristine HD video sources before playback even finishes.
  3. Universal Stream & Segment Queue (garrettQueue.js): Real-time sniffer and indexer backed by chrome.storage.local that catalogs manifests (.mpd, .m3u8) and segmented chunks (.m4s, .ts) with 100% video-to-blob isolation.
  4. Performance Resource Inspection: Correlates active network requests in performance.getEntriesByType('resource') to lock onto streams in real time.
• Parallel Fragment Assembler (streamAssembler.js):
  • Downloads media initialization boxes (ftyp, moov) and segmented media fragments (moof, mdat) across concurrent background fetch workers.
  • Automatically parses and stitches MPEG-DASH and HLS playlists into pristine, playable, complete .mp4 video files with full audio.
  • Zero loss of duration: never truncates playback or relies on slow screen/canvas recording.
• 100% Invisible Background Operation:
  • No viewport seeks, scrubbing, audio disruption, or visible playback alteration.
  • Context-invalidation resilient: handles dynamic extension updates without throwing unhandled page console errors.
  • Zero external telemetry or third-party dependencies.

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Installation

Chrome & Brave (Manifest V3)

1. Clone or download this repository:

   git clone https://github.com/digitalforgeca/garrett.git

2. Navigate to your browser's extensions manager:
   • Brave: brave://extensions/
   • Chrome: chrome://extensions/
   • Edge: edge://extensions/
3. Toggle Developer mode in the top-right corner.
4. Click Load unpacked and select the root directory of this repository (garrett/).
5. Open any supported video page (e.g., LinkedIn feed, post, or media player) and refresh the page (Cmd + Shift + R or Ctrl + Shift + R).
6. Click the overlay download button to preserve the complete stream directly to disk.

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Architecture & File Map

garrett/
├── manifest.json         # Manifest V3 configuration (permissions, webRequest, content scripts)
├── pageHook.js           # MAIN-world interceptor (fetch, XHR, MSE appendBuffer, React Fiber traversal)
├── garrettQueue.js       # Universal stream & segment queue engine (indexed by blob: URL)
├── streamAssembler.js    # MPEG-DASH & HLS manifest parser and parallel segment stitcher
├── keeper.js             # Keeper Order lore, notifications, and quote generator
├── content.js            # Isolated-world controller (DOM watcher, overlay UI, download manager)
├── content.css           # Sleek overlay button and toast notification styling
├── popup.html            # Extension popup listing detected tab videos
├── popup.js              # Popup interface logic and direct download dispatcher
├── popup.css             # Extension popup dark theme styling
├── test.html             # Standalone local test lab for video stream validation
├── icons/                # Extension action and store icons (16px, 48px, 128px)
├── LICENSE               # MIT License
└── README.md             # Documentation & badge overview

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Privacy & Permissions

Garrett runs exclusively inside your local browser instance:

• No Analytics or Trackers: No user telemetry, external network pings, or data collection.
• Local Processing: Segment stitching and stream assembly occur entirely in client-side memory.
• Minimal Privileges: Permissions are limited to downloads (saving the assembled .mp4), webRequest (detecting media manifests and chunks), and storage (session-level stream indexing).

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Support & Maintainer

Garrett is maintained by Digital Forge Studios Inc. as part of our suite of high-efficiency developer and productivity tools.

• Website: digitalforgestudios.com
• GitHub: @digitalforgeca
• License: MIT