python-clean-architecture-codex

A Codex CLI skill to scaffold, review, and refactor Python/FastAPI projects with clean architecture.

Codex CLI Python FastAPI Clean Architecture Design Patterns

Install

$skill-installer install https://github.com/MKToronto/python-clean-architecture-codex

Codex will ask you to approve a few steps — say yes each time. Then restart Codex.

What It Does

Provides principles-driven design guidance, 25 Pythonic design patterns, and three-layer FastAPI architecture scaffolding directly inside Codex CLI. Inspired by Arjan Codes' methodology.

7 Design Principles

Cohesion, coupling, abstractions, composition, creation/use separation, data-first design, simplicity.

25 Pythonic Patterns

Strategy, Registry, Pub/Sub, CQRS, Repository, Builder, Adapter, Facade, and more — all implemented the Pythonic way.

22 Code Quality Rules

Naming, nesting, types, error handling, imports, structure — with a code review checklist.

Three-Layer Architecture

Routers → Operations → Database with Protocol-based dependency injection.

Workflows

Review Architecture — Full architecture review (standard or in-depth)
Check Quality — Quick check against 22 code quality rules
Suggest Patterns — Recommend Pythonic design patterns
Scaffold API — Generate a new FastAPI project with clean architecture
Add Endpoint — Scaffold a new endpoint across all three layers
Decouple — Find tight coupling and suggest DI improvements
Make Pythonic — Refactor to Pythonic patterns
Extract God Class — Find and split god classes