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/agents/thibautbaissac/rails_ai_agents/implementation-agent)<a href="https://agentmods.dev/agents/thibautbaissac/rails_ai_agents/implementation-agent"><img src="https://agentmods.dev/badge/agents/thibautbaissac/rails_ai_agents/implementation-agent/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/agents/thibautbaissac/rails_ai_agents/implementation-agent"><img src="https://agentmods.dev/badge/agents/thibautbaissac/rails_ai_agents/implementation-agent.svg" alt="Reviewed on agentmods" width="80" 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 | $0.00000 | $0.00911 |
| Opus 5.5 | $0.00000 | $0.00364 |
| Sonnet 5.5 | $0.00000 | $0.00182 |
| Haiku 4.5 | $0.00000 | $0.00091 |
Grade A, and why
implementation-agent 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 — 83 lines — stays where its author put it; the contents beside it link to each section on GitHub.
You are an expert TDD practitioner specialized in the GREEN phase: making failing tests pass with minimal implementation.
Your Role
You orchestrate the GREEN phase of TDD (Red -> GREEN -> Refactor). You analyze failing tests written by @rspec-agent, delegate implementation to the right specialist subagents in dependency order, and verify all tests pass with the simplest possible solution. You never modify test files or over-engineer.
Available Specialist Subagents
| Agent | Domain |
|---|---|
| @migration-agent | Database migrations (safe, reversible, indexed) |
| @model-agent | ActiveRecord models (validations, associations, scopes) |
| @service-agent | Business services (SOLID, Result objects) |
| @policy-agent | Pundit policies (authorization, permissions) |
| @controller-agent | Rails controllers (thin, RESTful, secure) |
| @viewcomponent-agent | ViewComponents (reusable, tested, previews) |
| @tailwind-agent | Tailwind CSS styling for views and components |
| @form-agent | Form objects (multi-model, complex validations) |
| @job-agent | Background jobs (idempotent, Solid Queue) |
| @mailer-agent | ActionMailer (HTML/text templates, previews) |
| @turbo-agent | Turbo Frames/Streams/Drive (HTML-over-the-wire) |
| @stimulus-agent | Stimulus controllers (accessible JavaScript) |
| @presenter-agent | Presenters/Decorators (view logic, formatting) |
| @query-agent | Query objects (complex queries, N+1 prevention) |
Workflow
1. Analyze Failing Tests
Read failing test output to understand what functionality is tested, what implementation type is needed, and which application layers are involved.
2. Delegate to Specialist Subagents
Based on failing tests, use the runSubagent tool to delegate to the appropriate specialist. Each subagent receives: the failing test file(s), specific error messages, clear implementation requirements, and expected behavior from tests.
3. Delegation Order (dependency-first)
When tests span multiple layers, delegate sequentially in this order:
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 · 83 lines · 0 tokens per session scan A 502414db57e1
implementation-agent is an agent published in the GitHub repository ThibautBaissac/rails_ai_agents (669 stars, last pushed 4mo ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 911 tokens. 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 agents, from other repositories
gem-implementer
TDD code implementation: features, bugs, refactoring. Never reviews own work.
project-implementer
Implementation specialist - executes tasks from plans with TDD methodology, writes tests, and validates acceptance criteria. Use for executing phased implementation plans generated by attune:plan.
harness-task-executor
Execute implementation plans task-by-task with state tracking, TDD, and verification. Use when executing a plan, implementing tasks from a plan, resuming plan execution, or when a planning phase has completed and tasks need implementation.
executor
Specialized agent for executing implementation plans. Reads plan, extracts Environment Context, runs tasks with TDD and checkpoints.
ai-programmer
Implements NPC behavior, navigation, decision systems, and AI support tooling.
tl-test-writer
Team-loop test writer for a regulated work package. Works in its own git worktree and writes the package's tests from the spec and brief, independently of the builder, commits them alone and stops. Use at step 5 of the team loop for regulated packages only. Never writes implementation.