DeepFork – reverse-engineer any OSS repo into a clean-room rebuild blueprint

DeepFork is an agent skill that reverse-engineers any open-source repository into

🧠 the cleanest possible explanation of how it actually works, and

📐 a behavioral blueprint you can rebuild from — with your changes, in your stack, clean-room.

🛑 Stop reading 60k lines to understand a tool. 🍴 Stop forking when what you wanted was

your own version.

you:    /deepfork https://github.com/karpathy/micrograd — but in TypeScript, with a graph visualizer

agent:  ⚖️  license gate ........ MIT ✓
        🕸️  knowledge graph ..... 55 nodes · 86 edges · god nodes: Value, Neuron, Layer, MLP
        🧠  UNDERSTANDING.md .... the repo, explained clean — load-bearing pieces, data flow, the core trick
        📐  BLUEPRINT.md ........ a spec you could build from without ever seeing the source
        🔨  rebuild/ ............ your TypeScript version, clean-room, tests first

Works with Claude Code (and any agent that reads skills):

npx skills add GerardoRdz96/deepfork

🕸️ Optional but recommended — the graph engine that makes the understanding pass exceptional (graphify, 65k★):

uv tool install graphifyy   # double-y! code analysis is local & free (tree-sitter)

Without graphify, DeepFork falls back to manual repo mapping. With it: god-node detection, auto-named subsystems, surprising-connection analysis, and token-cheap graph queries.

flowchart LR
    A["⚖️ Phase 0<br>License gate"] --> B["📥 Phase 1<br>Acquire"]
    B --> C["🕸️ Phase 2<br>Comprehend<br><i>graph · god nodes · subsystems</i>"]
    C --> D["🔎 Phase 3<br>Interrogate<br><i>verify the load-bearing claims</i>"]
    D --> E["📐 Phase 4<br>Blueprint<br><i>+ YOUR deltas</i>"]
    E -.->|"only behavior crosses<br>🧱 the clean-room wall"| F["🔨 Phase 5<br>Rebuild<br><i>original closed · tests first</i>"]

⚖️ License gate— SPDX check before anything else; unlicensed code never gets a rebuild.🕸️ Comprehend— graphify builds a knowledge graph (locally, free for code); the skill turns god nodes + communities + surprising connections intoUNDERSTANDING.md

.🔎 Interrogate— the agent answers what a rebuilder must know (the core trick, the contracts, what breaks at 10×), verifying inferred claims against real code.📐 Blueprint— asks what YOU want different, then writes the spec with your deltas designed in.🔨 Rebuild— fresh repo, original closed, blueprint only, tests first.

examples/micrograd/ — karpathy's micrograd (12k★) deepforked end-to-end:

• 🧠 — the autograd engine explained in 6 sections, from a real 55-node graph run ($0)UNDERSTANDING.md

• 📐 — "gradflow": the TypeScript + built-in-visualizer rebuild specBLUEPRINT.md

DeepFork is built to keep you on the right side of open source:

• ⚖️ Phase 0 license gate— checks the target's license first; refuses rebuilds of unlicensed code. - 🧱 The blueprint wall— onlybehavioral descriptionscross from the original to your rebuild. Never code. Your implementation is original work. - 🔓 Copyleft awareness— GPL/AGPL targets come with a warning and a recommendation that your rebuild stay open. - 🙏 Attribution by default— every rebuild credits the original design.

This is how engineers have legally reimplemented systems for decades (Compaq vs IBM BIOS, 1982). DeepFork just makes the discipline automatic.

Is this just "fork it"?

No. A shallow fork keeps their code, their architecture, their language, their debt. DeepFork gives you their

lessonsin a spec, and a version that's actually yours.

Is this legal?

Understanding public code is legal everywhere. Clean-room reimplementation from a behavioral spec is the industry-standard legal path. The license gate + blueprint wall keep the discipline honest. (Not legal advice; if you're rebuilding something commercial-sensitive, ask a lawyer.)

Does it work on huge repos?

Yes — pick one subsystem from the community list and deepfork that. The graph makes subsystem boundaries visible.

Which agents?

Claude Code first-class. The skill is plain markdown — Codex, Cursor, Gemini CLI and friends can run it too.

⭐ If DeepFork saved you a weekend of code-reading, star the repo — it helps others find it. ⭐

MIT · Built by 🐧 The Penguin Alley · Powered by graphify