# Mk:development

> Use when implementing features or writing code. TDD enforcement is opt-in via --tdd / MEOWKIT_TDD=1. Provides code patterns, skill loading, and coding standards.

- Skill: `ngocsangyem/mk-development` (Agent Skill, multi-file: 4 files)
- Install (CLI): `npx skillmds@latest add ngocsangyem/mk-development`
- Raw SKILL.md: https://api.skillmd.com/api/skills/ngocsangyem/mk-development/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: ngocsangyem (https://skillmd.com/u/ngocsangyem)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/ngocsangyem/mk-development

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# Development Toolkit

Reference guides for implementation: code patterns, TDD enforcement (opt-in), and skill lazy-loading.

## When to Use

- During Phase 3 (Build) for implementation guidance
- When the `developer` agent needs coding pattern references
- For TDD enforcement rules during red/green/refactor cycle (TDD mode only)

## Workflow Integration

Operates in **Phase 2 (Test)** and **Phase 3 (Build)**. Output supports the `developer` and `tester` agents.

TDD enforcement (`tdd-enforcement.md` reference) is OPT-IN as of the TDD-optional migration. Default mode skips RED-phase enforcement; enable with `--tdd` or `MEOWKIT_TDD=1`.

## References

| Reference | When to load | Content |
|-----------|-------------|---------|
| **[code-patterns.md](./references/code-patterns.md)** | During implementation | Coding patterns, architecture patterns, file organization |
| **[tdd-enforcement.md](./references/tdd-enforcement.md)** | Phase 2-3 | RED/GREEN/REFACTOR cycle, test-first rules, coverage requirements |
| **[skill-loader.md](./references/skill-loader.md)** | Skill activation | How to load skills on-demand, lazy loading patterns |

## Gotchas

- **TDD enforcement blocking exploratory prototyping**: Strict red-green cycle slows rapid iteration → Default mode (TDD off) is now the right choice for prototypes; opt into `--tdd` only when shipping production-quality work
- **200-line file rule on generated code**: Auto-generated files (migrations, schemas) exceed limit by design → Exempt generated files explicitly in plan constraints