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 skills add bartolli/kmd --skill tddgit clone --depth 1 https://github.com/bartolli/kmdWrote 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/bartolli/kmd/tdd)<a href="https://agentmods.dev/skills/bartolli/kmd/tdd"><img src="https://agentmods.dev/badge/skills/bartolli/kmd/tdd/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/bartolli/kmd/tdd"><img src="https://agentmods.dev/badge/skills/bartolli/kmd/tdd.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 | $0.00134 | $0.01988 |
| Opus 5.5 | $0.00054 | $0.00795 |
| Sonnet 5.5 | $0.00027 | $0.00398 |
| Haiku 4.5 | $0.00013 | $0.00199 |
Grade A, and why
tdd 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.
How it starts
The opening of the file, as written. The whole thing — 175 lines — stays where its author put it; the contents beside it link to each section on GitHub.
TDD — Vertical Tracer-Bullet Test-Driven Development
Take ONE ready-for-agent slice from a wiki story and implement it with the red-green-refactor loop. The story's Gherkin scenarios ARE the test specification — translate them directly into integration tests.
Prerequisites
WIKI_SCOPE: <scope>declared in the project instructions.- Target slice exists in a story file at
projects/<scope>/plan/<plan-name>/story-N-<slug>.md. - The parent story's
triage_stateisready-for-agent. Ifneeds-infoorneeds-triage, suggest/triagefirst.
Philosophy
Test behavior through public interfaces, not implementation details. Code can change entirely; tests shouldn't.
- Good tests are integration-style: they exercise real code paths through public APIs. They describe what the system does, not how. They survive refactors.
- Bad tests are coupled to implementation: mock internal collaborators, test private methods, query internals directly. Warning sign: test breaks when you refactor but behavior hasn't changed.
A story's Gherkin scenarios are your test specification. Each Scenario block translates to one integration test. Given/When/Then maps to setup/action/assertion.
Anti-pattern: Horizontal slicing — REFUSED
DO NOT write all tests first, then all implementation. This is "horizontal slicing" — treating RED as "write all tests" and GREEN as "write all code."
WRONG (horizontal):
RED: test1, test2, test3, test4, test5
GREEN: impl1, impl2, impl3, impl4, impl5
RIGHT (vertical):
RED→GREEN: test1→impl1
RED→GREEN: test2→impl2
RED→GREEN: test3→impl3
Why horizontal produces crap tests:
- Tests written in bulk test imagined behavior, not actual behavior.
- You end up testing the shape of things rather than user-facing behavior.
- Tests become insensitive to real changes.
- You outrun your headlights — committing to test structure before understanding the implementation.
If you find yourself writing test #2 before test #1's implementation passes, stop. Finish the green for #1 first.
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 Changed · -2 lines 8411c7643bd5
- 1mo ago Changed fd04e9b07aca
- 1mo ago Changed · +1 tokens per session b64cba680fdc
- 2mo ago First seen · 177 lines · 133 tokens per session scan A 829548719597
tdd is a skill published in the GitHub repository bartolli/kmd (7 stars, last pushed 1mo ago), licensed MIT. It adds 134 tokens to every session and 1,988 once invoked, about $0.0005 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 2026-08-31.
Other skills, from other repositories
engram-testing-coverage
TDD and coverage standards for Engram. Trigger: When implementing behavior changes in any package.
principle-test-behavior-not-implementation
Apply when you write, change, or keep a test. Assert what the code's users can observe, so that the test fails when that behavior breaks and keeps passing when only the internals change.
conductor-implement
Execute tasks from a track's implementation plan following TDD workflow.
tdd
This skill should be used when the user wants to implement features or fix bugs using test-driven development. Enforces the RED-GREEN-REFACTOR cycle with vertical slicing, context isolation between test writing and implementation, human checkpoints, and auto-test feedback loops. Uses multi-agent orchestration with the…
mobiai-mobile-tdd
You MUST use this before writing any implementation code for a mobile feature, bug fix, refactor, or behavior change. Tests come before implementation — no exceptions.
iterative-development
TDD iteration loops using Claude Code Stop hooks - runs tests after each response, feeds failures back automatically.