Borrowing it
Nothing to install: this file belongs to KbWen/agentic-os. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/KbWen/agentic-os/main/.agents/skills/test-driven-development/SKILL.mdgit clone --depth 1 https://github.com/KbWen/agentic-osWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/kbwen/agentic-os/test-driven-development)<a href="https://agentmods.dev/skills/kbwen/agentic-os/test-driven-development"><img src="https://agentmods.dev/badge/skills/kbwen/agentic-os/test-driven-development/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/kbwen/agentic-os/test-driven-development"><img src="https://agentmods.dev/badge/skills/kbwen/agentic-os/test-driven-development.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
What 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 5.1 | $0.00023 | $0.00207 |
| Opus 5.5 | $0.00009 | $0.00083 |
| Sonnet 5.5 | $0.00005 | $0.00041 |
| Haiku 4.5 | $0.00002 | $0.00021 |
Grade A, and why
test-driven-development 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 1mo ago.
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.
Copies of this mod
1 near-identical copy found in the catalogue:
- test-driven-development — 100% identical, 0 lines differ
What it actually says
Test-Driven Development
Overview
TDD uses the Red → Green → Refactor micro-cycle. First, define expected behavior. Next, use a minimal implementation to pass the test. Finally, organize the code structure.
When to Use
- Adding or modifying core logic.
- Fixing bugs and needing regression protection.
- Requirements can be written as explicit input/output acceptance tests.
Workflow
- Red: Write a failing test describing the expected behavior.
- Green: Write the minimal code to make the test pass.
- Refactor: Clean up naming, structure, and duplication.
- Repeat the cycle until acceptance criteria are met.
Ironclad Rules
- Do NOT write massive amounts of features before writing tests.
- Focus on one small goal per cycle.
- All tests MUST pass after refactoring.
What ships with it
1 file 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.
- 1mo ago First seen · 30 lines · 23 tokens per session scan A 762ab7b7099c
test-driven-development is a skill published in the GitHub repository KbWen/agentic-os (221 stars, last pushed yesterday), licensed MIT. It adds 23 tokens to every session and 207 once invoked, about $0.0001 per session on Opus 5.5. 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 2026-08-30.
Other skills, from other repositories
tdd
AI DevKit · Test-driven development — write a failing test before writing production code. Use when implementing new functionality, adding behavior, or fixing bugs during active development.
tdd
A Test-Driven Development guide. TDD means writing a failing test first, adding the smallest implementation that passes it, and then improving the code while keeping the tests passing.
test-audit
Audit test suites for T1-T4 violations using AST analysis, mock detection, and multi-stage synthesis. Invoke when user asks to audit tests, check test quality, find mock violations, review test effectiveness, or inspect test suites for over-mocking. Triggers automatic rewrites when quality gates fail.
agnostic-ai-gh-issue
Take one GitHub issue from branch to merged PR with TDD. Use when asked to work, fix, or implement an issue by number.
debugging
A structured method for finding and fixing software bugs. It starts by writing a test that reproduces the failure, then investigates its underlying cause before making a small fix.
test-driven-development
Use when implementing any feature or bugfix, before writing implementation code.