Codebase Design
Design deep modules: small interfaces hiding a lot of behavior, with tests at the seams.
Claude Grok Codex architecturemodulesboundaries
What it is
Codebase Design is for greenfield layout and for refactors that have started to sprawl. It prefers a few deep modules over a forest of 20-line files that import each other in a circle.
When to use
Use when starting a package, splitting a god file, or reviewing a module boundary.
How to install
Install codebase-design/SKILL.md at user level for architecture sessions.
# Claude Code
.claude/skills/codebase-design/SKILL.md
# Grok Build
.grok/skills/codebase-design/SKILL.md
# Codex
.agents/skills/codebase-design/SKILL.mdExample prompt
Propose a module map for this billing folder. Name the seams and the tests each seam needs.
Source: Open Agent Skills ecosystem