I Built Karpathy's AI Knowledge Base in Claude: Try it!
A 36-minute live build of the second brain Karpathy posted — rebuilt locally in Claude with three folders, one file, and zero code.
May 23rdA 4-minute tutorial on giving Claude the ability to truly watch any video -- by replacing timer-based frame grabs with FFmpeg scene detection.
Timer-based frame sampling makes Claude effectively blind on long videos -- switching to FFmpeg scene detection fixes this by capturing one frame every time the content actually changes, regardless of duration.
The old approach of grabbing 100 frames at fixed intervals leaves Claude nearly blind on videos longer than an hour -- one frame every six minutes on a ten-hour course. The fix is FFmpeg scene detection, which captures a frame every time the actual content changes rather than on a clock, paired with yt-dlp to pull YouTube captions for free. The result is a /watch skill usable from both Claude's desktop app and Claude Code CLI, with an optional Obsidian ingestion step that connects each video to an existing knowledge graph.
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Opens on completed output with caption 'it already did everything.' States the skill's capabilities (YouTube, Zoom, Loom) and previews the video structure: how it works, what it does, how to install.

Explains the original Brad skill and its blind spot: 100 frames at fixed intervals = 1 frame/36s on a 1-hour video, 1 frame/6min on a 10-hour course. Claude was reading transcript with a few random screenshots.

Introduces the scene-detection approach: one frame every time the content actually changes. Animated timeline shows the dense, event-triggered frame capture vs the sparse timer-based grid.

yt-dlp pulls YouTube captions for free. Non-YouTube sources (Loom, Zoom) fall back to Whisper or Deepgram. Illustrated with animated audio-to-text flow diagram.

After analysis, Claude asks: save to knowledge base? Demo shows Obsidian graph view with the new video node connected to existing research. Positions the skill as a second-brain feed, not just a one-off summarizer.

GitHub releases page, download the .skill file, Settings -> Capabilities -> enable Code Execution + File Creation, import skill, type /watch <link>.

Clone the repo (or paste the GitHub URL and Claude clones itself). Demo on a Karpathy video: /watch <url>, Claude runs, extracts frames, pulls transcript, delivers analysis. Closes with Obsidian ingestion prompt and teaser for next video on second-brain setup.
Fixed-interval frame sampling fails silently on long videos -- switching to scene-change detection produces a frame set that is always proportional to content density, not duration.
“On a one-hour video, that is one frame every thirty-six seconds. On a ten-hour video, one frame every six minutes.”
“Clothe was basically just reading the transcript with a few random screenshots.”
“So instead of grabbing frames on a timer, it grabs one frame every time the scene actually changes.”
See every word as it's spoken — crank it to 2× and still catch all of it. The same dual-channel trick behind Amazon's Kindle + Audible.
The video opens in medias res on a finished Claude analysis -- frames, transcript, and key concepts already populated -- with the on-screen caption 'it already did everything.' The spoken hook follows immediately: a result-first structure that shows the payoff before a single line of explanation.
Replace fixed-interval frame grabs with FFmpeg scene-change detection so the frame set is always proportional to content density, not video length.
Show the finished, impressive output in the first five seconds. Explanation follows only after the viewer has already seen proof that it works.
“In the next video, I will show you how to set up this second brain. This took me a month in order to build it correctly.”
Soft close with a compelling hook for the follow-up. GitHub link placed in description rather than spoken.
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04:52A 36-minute live build of the second brain Karpathy posted — rebuilt locally in Claude with three folders, one file, and zero code.
May 23rdA 27-minute walkthrough of every Claude feature beginners skip — from smarter prompts to reusable skills that do your work for you.
June 15thSix short phrases a non-coder uses to stop Claude from handing work back and to keep every session on track.
June 14thA 7-minute walkthrough replacing the Claude Desktop app with VS Code as a full AI operating system for non-developers.
June 12thA 35-minute live demo of a local browser app built with Claude that replaces Notion, Sunsama, Heptabase, and every health tracking subscription — all from one markdown folder.
June 12thEight copy-paste prompts and three startup ideas for the most powerful AI model yet — no benchmarks, just tactics.
June 11th