# Grey Haven Tdd Python > Python Test-Driven Development expertise with pytest, strict red-green-refactor methodology, FastAPI testing patterns, and Pydantic model testing. Use when implementing Python features with TDD, writing pytest tests, testing FastAPI endpoints, developing with test-first approach, or when user mentions 'Python TDD', 'pytest', 'FastAPI testing', 'red-green-refactor', 'Python unit tests', 'test-driven Python', or 'Python test coverage'. Use when this capability is needed. - Skill: `tomevault-io/grey-haven-tdd-python` (Agent Skill, multi-file: 2 files) - Install (CLI): `npx skillmds@latest add tomevault-io/grey-haven-tdd-python` - Raw SKILL.md: https://api.skillmd.com/api/skills/tomevault-io/grey-haven-tdd-python/raw - Safety review: pending - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: AI & ML - Author: tomevault-io (https://skillmd.com/u/tomevault-io) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/tomevault-io/grey-haven-tdd-python --- # TDD Python Skill Python Test-Driven Development following strict red-green-refactor cycle with pytest and comprehensive coverage. ## Description Systematic Python implementation using TDD methodology, ensuring tests written first and driving design decisions. ## What's Included - **Examples**: Python TDD cycles, FastAPI TDD, Pydantic model TDD - **Reference**: pytest patterns, Python testing best practices - **Templates**: pytest templates, TDD workflows ## Use When - Implementing Python features with TDD - FastAPI development - Pydantic model development ## Related Agents - `tdd-python-implementer` **Skill Version**: 1.0 --- > Converted and distributed by [TomeVault](https://tomevault.io/claim/greyhaven-ai) — claim your Tome and manage your conversions.