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.
git clone --depth 1 https://github.com/ThibautBaissac/rails_ai_agentsWrote 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/commands/thibautbaissac/rails_ai_agents/feature-tdd-implementation)<a href="https://agentmods.dev/commands/thibautbaissac/rails_ai_agents/feature-tdd-implementation"><img src="https://agentmods.dev/badge/commands/thibautbaissac/rails_ai_agents/feature-tdd-implementation.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 5.1 | $0.00051 | $0.00676 |
| Opus 5 | $0.00026 | $0.00338 |
| Sonnet 5 | $0.00010 | $0.00135 |
| Haiku 4.5 | $0.00005 | $0.00068 |
Grade A, and why
feature-tdd-implementation 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 8d 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 — 59 lines — stays where its author put it; the contents beside it link to each section on GitHub.
TDD Cycle Skill
Overview
Guides the Red-Green-Refactor TDD cycle: write a failing test describing desired behavior,
implement the minimum code to pass it, then improve the code while keeping tests green.
See references/testing-patterns.md for code examples, common patterns, and anti-patterns.
Test Type Selection
| Test Type | Use For | Location |
|---|---|---|
| Model spec | Validations, scopes, instance methods | spec/models/ |
| Request spec | API endpoints, HTTP responses | spec/requests/ |
| System spec | Full user flows with JavaScript | spec/system/ |
| Service spec | Business logic, complex operations | spec/services/ |
| Job spec | Background job behavior | spec/jobs/ |
Workflow Steps
- Choose Test Type -- Pick the appropriate spec type from the table above based on what you are testing.
- Write Failing Spec (RED) -- Write a spec that describes the desired behavior. Follow the structure template in the references file.
- Verify Failure -- Run
bundle exec rspec path/to/spec.rb --format documentation. The spec must fail with a clear message. If it passes immediately, either the behavior already exists or the spec is wrong. - Implement Minimal Code (GREEN) -- Write the minimum code to make the spec pass. No optimization, no extra edge-case handling, no refactoring yet.
- Verify Pass -- Run the spec again. It must pass. If it fails, read the error, fix the implementation (not the spec unless it was wrong), and re-run.
- Refactor -- Improve the code one change at a time: extract methods, improve naming, remove duplication, simplify logic. Run specs after each change. Undo if specs fail.
- Final Verification -- Run all related specs. All must pass. If any fail, undo recent changes and try a different approach.
Good Spec Characteristics
- One behavior per example: each
itblock tests one thing - Clear description: reads like a sentence with
describe/context - Minimal setup: only create data needed for the specific test
- Fast execution: prefer
buildovercreate, mock external services - Independent: tests do not depend on order or shared state
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.
- 8d ago First seen · 59 lines · 51 tokens per session scan A 33cb9ce440f8
feature-tdd-implementation is a command published in the GitHub repository ThibautBaissac/rails_ai_agents (659 stars, last pushed 3mo ago), licensed MIT. It adds 51 tokens to every session and 676 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 2026-08-30.
Other commands, from other repositories
bugfix
Bug fix workflow: root cause analysis → user review → regression test + fix via TDD.
usage-add
PitWay: Accumulate measured planning or qa token usage onto a milestone.
dashboard
Generar dashboard HTML local con métricas de eficiencia del proyecto SDD.
hub-tdd
TDD workflow for MCP Hub implementation. Types → Tests (red) → Implementation (green) with git gates.
eval
Evaluate and improve one healthcare agent's system prompt. Run up to 5 iterations of: prepare fixed questions -> answer -> judge -> improve -> re-score -> commit if better.
tdd
A command that follows test-driven development (TDD), a method where you write tests before the code they check. It moves through writing a failing test, adding the smallest implementation, and then improving the code.