Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx agentmods add skills/hculap/better-code/tdd-methodologynpx skills add hculap/better-code --skill tdd-methodologygit clone --depth 1 https://github.com/hculap/better-codeWhat it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5 | $0.00085 | $0.01603 |
| Opus 5 | $0.00043 | $0.00801 |
| Sonnet 5 | $0.00017 | $0.00321 |
| Haiku 4.5 | $0.00009 | $0.00160 |
Grade A, and why
TDD Methodology scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured yesterday.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 225 lines — stays where its author put it; the contents beside it link to each section on GitHub.
TDD Methodology
Transform coding behavior into strict Test-Driven Development practice. Enforce the Red→Green→Refactor cycle where no behavior-changing code is written without a failing test first.
Core Philosophy
TDD is not about testing—it is about design through tests. Tests drive the implementation, not the other way around.
The Iron Rules
- No production code without a failing test - Write a test that fails for the right reason before writing any implementation
- Minimal code to pass - Write only enough code to make the failing test pass, nothing more
- Refactor only when green - Clean up code only after all tests pass
- Small increments - Each cycle should be minutes, not hours
The Red→Green→Refactor Loop
┌─────────────────────────────────────────────────┐
│ │
│ RED: Write a failing test │
│ ↓ │
│ GREEN: Write minimal code to pass │
│ ↓ │
│ REFACTOR: Clean up while staying green │
│ ↓ │
│ (repeat) │
│ │
└─────────────────────────────────────────────────┘
Strictness Modes
Strict Mode (Default)
Block any behavior-changing implementation without a failing test:
- Refuse to write/edit source files until a failing test exists
- Enforce test-first for every behavior change
- No exceptions without explicit user override
Standard Mode
Warn and prompt for confirmation:
- Alert when attempting to write code without a failing test
- Ask: "No failing test exists. Proceed anyway? (yes/no)"
- Log violations for awareness
Relaxed Mode
Coach and suggest without blocking:
- Recommend writing tests first
- Provide guidance on TDD approach
- Allow user to proceed without tests
TDD Workflow Execution
What ships with it
4 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- yesterday First seen · 225 lines · 85 tokens per session scan A efe0fc692705
TDD Methodology is a skill published in the GitHub repository hculap/better-code (2 stars, last pushed 7mo ago), licensed MIT. It adds 85 tokens to every session and 1,603 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.
Other skills, from other repositories
golden-jupyter-dir
Use when testing the goldenjupyterdir golden build.
golden-man-kw
Use when testing the man golden build.
skill-builder
Automatically detect source types and build AI skills using Skill Seekers. Use when the user wants to create skills from documentation, repos, PDFs, videos, or other knowledge sources.
golden-rss
Use when testing the rss golden build.
golden-chat-topics
Use when testing the goldenchattopics golden build.
golden-chat-single
Use when testing the goldenchatsingle golden build.