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/jakubsuplicki/codument/tddnpx skills add jakubsuplicki/codument --skill tddgit clone --depth 1 https://github.com/jakubsuplicki/codumentWrote 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/jakubsuplicki/codument/tdd)<a href="https://agentmods.dev/skills/jakubsuplicki/codument/tdd"><img src="https://agentmods.dev/badge/skills/jakubsuplicki/codument/tdd.svg" alt="Measured on agentmods" height="20"></a>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 | $0.00023 | $0.00336 |
| Opus 5 | $0.00012 | $0.00168 |
| Sonnet 5 | $0.00005 | $0.00067 |
| Haiku 4.5 | $0.00002 | $0.00034 |
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 5d 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.
What it actually says
Test-Driven Development
Use this when implementing a planned step or fixing a bug. The principle is feedback first: build the fastest reliable loop that proves the behavior.
Workflow
- Read the approved plan step and its mapped docs.
- Identify the public interface or user-observable behavior to verify.
- Choose the strongest practical feedback loop:
- Unit test for pure logic
- Integration test for module boundaries
- CLI invocation for command behavior
- Browser or UI harness for interface behavior
- Repro script for a bug when a proper test seam does not exist yet
- Prefer red-green-refactor:
- Red: write one failing behavior test
- Green: add the smallest code change that passes it
- Refactor: improve structure only while tests are green
- Repeat one behavior at a time.
- Update docs and registry when behavior or source ownership changes.
Test Quality
Good tests verify behavior through public interfaces. They should survive internal refactors.
Avoid tests that:
- Assert private implementation details
- Mock internal collaborators when a real boundary is cheap enough
- Encode imagined future behavior before the current slice teaches you what matters
- Pass while the user-visible behavior is broken
Rules
- Do not write all tests first and then all implementation.
- Do not refactor while red.
- Do not add speculative behavior for later steps.
- If no correct test seam exists, document that finding and use the best available feedback loop.
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.
- 5d ago First seen · 43 lines · 23 tokens per session scan A 121de0703b9f
tdd is a skill published in the GitHub repository jakubsuplicki/codument (47 stars, last pushed 14d ago), licensed Apache-2.0. It adds 23 tokens to every session and 336 once invoked, about $0.0001 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 2026-08-30.
Other skills, from other repositories
tdd-cycle
Execute full TDD red-green-refactor cycle with validation gates. Use when saying "TDD cycle", "test-driven development", or "full TDD workflow".
tdd
Drive a change through a red-green-refactor loop - failing test first, minimal code to pass, then clean up. Use when implementing a feature or fixing a bug where correctness matters and a test can pin the behavior. Says "TDD", "test first", "red green refactor", "write the test first".
test-guide
Test-writing guide for Backend.AI — propose success/exception/edge scenarios first, refine them with the user, then implement while reporting per-scenario verification status. Covers fixtures, withtables, mock repositories, pants test, optional TDD cadence.
lfe-tdd
Red-green-refactor quality pass on code the Builder just wrote. Use in the Builder sub-pipeline after lfe-builder completes implementation.
init-pipeline
Infrastructure skill for scaffolding pipeline enforcement into a project. Sets up Claude Code hooks (TDD classification gate, git guardrails, optional quality gate), pre-commit hooks (detects existing tools, defaults to Lefthook + Biome + pnpm if none found). Run when setting up a project for pipeline work, and again…
triage-issue
Invoked helper skill for deep bug diagnosis, usually delegated from /qa when a reported issue needs root-cause analysis and a TDD fix plan before implementation. Use when the cause is unclear, the bug is a regression, or the user explicitly wants diagnosis. Not for lightweight QA intake (use /qa) or already-clear…