Diagramming code

Produces accurate architecture and data-flow diagrams from the code that exists, not the code somebody described.

Installation

$ npx skills add trailofbits/skills

The CLI's unit is the repository, so this installs everything in trailofbits/skills, not diagramming-code alone. It writes into whichever agent directories it finds — Claude Code, Codex, Cursor, Copilot, Windsurf, Zed.

Summary

Produces accurate architecture and data-flow diagrams from the code that exists, not the code somebody described.

Reach for it when onboarding onto an unfamiliar service, or preparing a design review for a system nobody has drawn in two years.
Spans Design & architect and Operate & maintain, so it is usually worth loading for the whole piece of work rather than at one moment in it.
Stack-agnostic — nothing in it assumes a particular language or framework.
Published by Trail of Bits. Well regarded, but not the vendor of the thing it covers.
Installing pulls the whole trailofbits/skills repository: this catalogue lists 12 other entries from it, and the repo may hold more.

Where it sits in delivery

Design & architectInterfaces, module boundaries and domain language — decided before the code sets them in concrete.Everything in Design →

Operate & maintainProduction reality: debugging, performance, instrumentation, and writing down why the system is the way it is.Everything in Operate →

The skill itself

The full text lives with its publisher and changes when they change it. Read it there rather than here — a mirrored copy of somebody else's procedure goes stale silently, and this page would have no way of telling you.

github.com/trailofbits/skillsSKILL.md, source, licence, issues and history ↗