---
title: "Codebase Design - Air Market"
description: "Say you're sitting down to design a piece of code, or rework an old one, and you need to decide how other code will use it. It's hard to weigh the choices when you don't have words for them. This giv…"
canonical: "https://airmarket.ai/app/codebase-design"
---

[Air Market](/) / [Developer Tools](/category/devtools) / Codebase Design

Skill by [Matt Pocock](/@mattpocock)

# Codebase Design

A shared way to talk about designing modules with clean seams

## What this does

Say you're sitting down to design a piece of code, or rework an old one, and you need to decide how other code will use it. It's hard to weigh the choices when you don't have words for them. This gives you and Claude a shared set of terms for those choices, so you can talk them through.

### Top 3 things it does for you

- Design a module's interface
- Decide where a seam between parts should go
- Make code easier to test and navigate

## Information

**Codebase Design at a glance**

|  |  |
| --- | --- |
| Kind | Skill |
| Publisher | [Matt Pocock](/@mattpocock) |
| Category | [Developer Tools](/category/devtools) |
| Works with | Agent Skills - an open standard supported by 40+ agents |
| Languages | en |
| Size | 11 KB |
| Licence | MIT |
| Repository | [mattpocock/skills](https://github.com/mattpocock/skills/tree/885e2ca4d842d139e9aef4e48d366c63cb1b8013/skills/engineering/codebase-design) |
| GitHub stars | 319,153 (as of Nov 2026) |
| Installs | 941,071, counted by skills.sh (Nov 2026) |

## Security report

**Verified.** AIR scanned this exact version of Codebase Design and flagged nothing. AIR's verdict: **safe**.

**What Codebase Design's check was run against**

|  |  |
| --- | --- |
| Commit | 885e2ca4d842d139e9aef4e48d366c63cb1b8013 |
| Content hash | 0b5af4148e31ffadcdacef5c3043fe642a48bbb5572a1a115b6e24ceb5426cd3 |
| Files read | [Browse the files at this exact commit](https://github.com/mattpocock/skills/blob/885e2ca4d842d139e9aef4e48d366c63cb1b8013/skills/engineering/codebase-design/SKILL.md) |

A scan is named by the exact content it read, not by a version number. A different version is a different artifact, and nothing here applies to a version AIR has not scanned.

[Read the full security report for Codebase Design](/security/codebase-design)

## About Codebase Design

A shared vocabulary for designing deep modules. Use it when you want to design or improve a module's interface, find places to deepen a module, or decide where a seam should go.

It also helps when you want to make code more testable and easier to navigate, and other skills can draw on the same deep-module vocabulary.

## What's inside

- SKILL.md - instructions
- agents/openai.yaml - data
- DEEPENING.md - reference
- DESIGN-IT-TWICE.md - reference

## Questions

### Is Codebase Design safe to install?

AIR scanned this exact version of Codebase Design and flagged nothing. AIR's verdict: safe. The verdict is named by the content that was read, at commit 885e2ca4d842, so it cannot drift onto a version nobody scanned. The full report is at https://airmarket.ai/security/codebase-design.

### How do I install Codebase Design?

Open https://airmarket.ai/app/codebase-design on Air Market and use the install action: Air Market hands Claude a prompt naming this exact skill, and Claude sets it up. Source, pinned to the exact commit this listing describes: https://github.com/mattpocock/skills/tree/885e2ca4d842d139e9aef4e48d366c63cb1b8013/skills/engineering/codebase-design. Install from that link, not the branch.

## Related on Air Market

- [More Developer Tools listings](/category/devtools)
- [Everything by Matt Pocock](/@mattpocock)

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Canonical URL: <https://airmarket.ai/app/codebase-design>