Codebase Design
Codebase Design is an agent skill (a SKILL.md file) from mattpocock/skills. Shared vocabulary for designing deep modules. It works with Claude Code and Codex and has 278,361 GitHub stars across a repository of 15 listed skills. Install it by copying the skill folder into your agent's skills directory.
github.com/mattpocock/skills/skills/engineering/codebase-design (opens in a new tab)
- Multi-skill repo
- Plugin marketplace
- Design & frontend
- Actively maintained
Add this skill
Claude
This repository is a Claude Code plugin marketplace. In Claude Code:
/plugin marketplace add mattpocock/skills
/plugin install mattpocock-skills@mattpocockIn the Claude apps, zip the codebase-design folder and upload it under Customize > Skills > + > Upload a skill (code execution must be on).
ChatGPT / Codex
Codex reads skills from .agents/skills/ in a repo or ~/.agents/skills/ for every project:
git clone --depth 1 https://github.com/mattpocock/skills.git
cp -r skills/skills/engineering/codebase-design .agents/skills/codebase-design # repo; ~/.agents/skills for all projectsStandalone skills also load in the ChatGPT desktop app.
Cursor
Cursor loads skills from .cursor/skills/ (or ~/.cursor/skills/) and also reads .claude/skills/:
git clone --depth 1 https://github.com/mattpocock/skills.git
cp -r skills/skills/engineering/codebase-design .cursor/skills/codebase-design # project; ~/.cursor/skills for all projectsSource (checked Oct 7, 2026): code.claude.com/docs/en/skills (opens in a new tab), code.claude.com/docs/en/plugin-marketplaces (opens in a new tab), support.claude.com/en/articles/12512180-using-skills-in-claude (opens in a new tab), learn.chatgpt.com/docs/build-skills (opens in a new tab), cursor.com/docs/context/skills (opens in a new tab)
What this skill does
Shared vocabulary for designing deep modules. Use when the user wants to design or improve a module's interface, find deepening opportunities, decide where a seam goes, make code more testable or AI-navigable, or when another skill needs the deep-module vocabulary. Design deep modules: a lot of behaviour behind a small interface, placed at a clean seam, testable through that interface. Use this language and these principles wherever code is being designed or restructured.
When it triggers
- Use when the user wants to design or improve a module's interface, find deepening opportunities, decide where a seam goes, make code more testable or AI-navigable, or when another skill needs the deep-module vocabulary.
More skills in mattpocock/skills
15 skills are listed from this repository.
Improve Codebase Architecturemattpocock/skills
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What is the Codebase Design skill?
Codebase Design is an agent skill (a SKILL.md file) from mattpocock/skills. Shared vocabulary for designing deep modules. It works with Claude Code and Codex and has 278,361 GitHub stars across a repository of 15 listed skills. Install it by copying the skill folder into your agent's skills directory. Its SKILL.md lives at github.com/mattpocock/skills/skills/engineering/codebase-design.
How do I install the Codebase Design skill?
In Claude Code, run /plugin marketplace add mattpocock/skills and then /plugin install mattpocock-skills@mattpocock. For Codex or Cursor, copy the codebase-design folder into .agents/skills/ or .cursor/skills/.
Is the Codebase Design skill free?
Yes. The repository is open source under the MIT license.
Is Codebase Design maintained?
The repository's most recent commit was on Oct 6, 2026. Its latest release is v1.3.1. appsgit only lists skills from repositories with a commit in the last six months.