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/tommymorgan/claude-plugins/tdd-executionnpx skills add tommymorgan/claude-plugins --skill tdd-executiongit clone --depth 1 https://github.com/tommymorgan/claude-pluginsWrote 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/tommymorgan/claude-plugins/tdd-execution)<a href="https://agentmods.dev/skills/tommymorgan/claude-plugins/tdd-execution"><img src="https://agentmods.dev/badge/skills/tommymorgan/claude-plugins/tdd-execution.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 | $0.00050 | $0.01911 |
| Opus 5 | $0.00025 | $0.00955 |
| Sonnet 5 | $0.00010 | $0.00382 |
| Haiku 4.5 | $0.00005 | $0.00191 |
Grade A, and why
tdd-execution 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 4d 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 — 372 lines — stays where its author put it; the contents beside it link to each section on GitHub.
TDD Execution
Workflow for executing plan tasks autonomously using Test-Driven Development, with code review gates and root cause analysis for failures.
Core Principles
Test-First: Write the failing test before any implementation. The test defines what "done" looks like.
Atomic Tasks: Each task = one test file = one commit. Keep changes small and reviewable.
Evidence-Based: Never guess at failures. Use root-cause-analysis before declaring anything blocked.
Continuous Progress: Update the plan file after each task. Progress survives session interruption.
Execution Loop
┌─────────────────────────────────────────────────────────┐
│ VERIFICATION SWEEP │
│ (establish ground truth) │
└─────────────────────────┬───────────────────────────────┘
│
▼
┌─────────────────────────────────────────────────────────┐
│ SELECT NEXT TASK │
│ (first pending task by number) │
└─────────────────────────┬───────────────────────────────┘
│
▼
┌─────────────────────────────────────────────────────────┐
│ RED PHASE │
│ Write failing test from Gherkin │
└─────────────────────────┬───────────────────────────────┘
│
▼
┌─────────────────────────────────────────────────────────┐
│ GREEN PHASE │
│ Implement minimum code to pass test │
└─────────────────────────┬───────────────────────────────┘
│
▼
┌─────────────────────────────────────────────────────────┐
│ CODE REVIEW │
│ Loop until approved │
└─────────────────────────┬───────────────────────────────┘
│
▼
┌─────────────────────────────────────────────────────────┐
│ COMMIT │
│ Conventional commit message │
└─────────────────────────┬───────────────────────────────┘
│
▼
┌─────────────────────────────────────────────────────────┐
│ UPDATE PLAN │
│ Status: pending → complete │
└─────────────────────────┬───────────────────────────────┘
│
▼
More pending? ──yes──► SELECT NEXT TASK
│
no
│
▼
DONE
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.
- 4d ago First seen · 372 lines · 50 tokens per session scan A f1e984d0c71f
tdd-execution is a skill published in the GitHub repository tommymorgan/claude-plugins (4 stars, last pushed 1mo ago), licensed MIT. It adds 50 tokens to every session and 1,911 once invoked, about $0.0003 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.
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Execute tasks from a track's implementation plan following TDD workflow.
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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.
python
Python development with ruff, mypy, pytest - TDD and type safety.