understand-open-source

A Claude Code skill that gives you a deep, accurate understanding of any open-source repo — and a shareable HTML report — in one command.

Most people "understand" a library by skimming its README. This reads the real source code. It downloads the repo's actual implementation, builds a graph of how the code connects, uses that graph to find the parts that actually matter, then reads those real files and writes up how the whole thing works.

How it works

/understand-open-source <repo-name>

1. Download the real source with opensrc — the actual implementation files, not the docs.
2. Build a code graph with graphify — entities + how they connect.
3. Find the parts that matter — the graph surfaces the central code (god nodes) and subsystems so you don't read everything.
4. Read the real code for those parts — this is where the understanding actually happens.
5. Get an HTML breakdown — architecture, core abstractions with real code excerpts, a traced end-to-end flow, and where to start contributing.

Install

You need two tools installed first:

# 1. opensrc — fetches real source for npm / PyPI / GitHub repos
npm install -g opensrc

# 2. graphify — builds the navigable code graph
#    (see graphify install docs)

Then drop SKILL.md into your Claude Code skills directory (.claude/skills/understand-open-source/SKILL.md) and invoke it with /understand-open-source <repo-name>.

Example

/understand-open-source zod

→ downloads zod's source, graphs it, reads the core parser/type files the graph points at, and writes understanding-zod.html you can open in any browser.

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The graph finds the interesting parts. Reading the real code is what makes you understand it. This skill always does both, in that order.