rails-dev-plugin: Instructions file for Claude Code

CLAUDE.md

rails-dev-plugin CLAUDE.md is an instructions file for Claude Code from ag0os/rails-dev-plugin. It costs 2,050 tokens per session, scanned A, original, MIT.

A set of instructions for using a Claude Code plugin focused on Ruby on Rails application development. It describes the project structure and separate guidance for models, controllers, views, services, jobs, tests, and Hotwire.

In plain words
What is it for?
Use it when working in the described Rails plugin repository and needing guidance for common Rails components, testing, or Hotwire features.
Why use it?
It gives a coding agent project-specific Rails guidance instead of leaving it to infer the repository’s structure and design rules.

Instructions file for Claude Code

Written for Claude Code: Claude Code plugin machinery. Also seen: mentions .claude-plugin; mentions CLAUDE.md; mentions Claude Code.

This is ag0os/rails-dev-plugin's own configuration. It tells Claude Code how to work on rails-dev-plugin itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything rails-dev-plugin configures →

Reuse

Borrowing it

Nothing to install: this file belongs to ag0os/rails-dev-plugin. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/ag0os/rails-dev-plugin/main/CLAUDE.md
Clone the repo
git clone --depth 1 https://github.com/ag0os/rails-dev-plugin

Made for: Claude Code.

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Per session 2,050 This file is loaded in full into every session.
When invoked 2,050 The same file — it is already loaded in full.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5.1 $0.02050 $0.02050
Opus 5.5 $0.00820 $0.00820
Sonnet 5.5 $0.00410 $0.00410
Haiku 4.5 $0.00205 $0.00205

Measured 1mo ago against content hash 4573a62dbc84, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

rails-dev-plugin CLAUDE.md 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.

CLAUDE.md · 160 lines

How it starts

The opening of the file, as written. The whole thing — 160 lines — stays where its author put it; the contents beside it link to each section on GitHub.

CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

Project Overview

This is a Claude Code plugin that provides specialized agents and portable skills for Rails application development. Agents are lean orchestrators that load domain-specific skills via the skills frontmatter field. Skills are independently usable and exportable to other platforms.

Repository Structure

rails-dev-plugin/
├── .claude-plugin/
│   └── plugin.json                     # Plugin metadata (name, version, description)
├── agents/                              # lean agents (reference skills for knowledge)
│   ├── rails-model.md                   # skills: [rails-model-patterns]
│   ├── rails-controller.md              # skills: [rails-controller-patterns]
│   ├── rails-views.md                   # skills: [rails-views-patterns]
│   ├── rails-service.md                 # skills: [rails-service-patterns]
│   ├── rails-jobs.md                    # skills: [rails-jobs-patterns]
│   ├── rails-test.md                    # skills: [rails-testing-patterns]
│   ├── rails-hotwire.md                 # skills: [hotwire-patterns]
│   ├── rails-graphql.md                 # skills: [rails-graphql-patterns]
│   ├── rails-architect.md               # skills: [rails-architecture-patterns]
│   ├── rails-devops.md                  # skills: [rails-devops-patterns]
│   └── rails-api.md                     # skills: [rails-api-patterns, rails-controller-patterns]
└── skills/                              # portable skills (domain knowledge)
    ├── rails-model-patterns/            # ActiveRecord, associations, migrations
    ├── rails-controller-patterns/       # RESTful controllers, routing, params
    ├── rails-views-patterns/            # ERB, partials, helpers, caching
    ├── rails-service-patterns/          # Service objects, result pattern, DI
    ├── rails-jobs-patterns/             # ActiveJob, Sidekiq, idempotency
    ├── rails-testing-patterns/          # RSpec, Minitest, system tests
    ├── hotwire-patterns/                # Stimulus, Turbo frames/streams
    ├── rails-graphql-patterns/          # Schema, mutations, DataLoader
    ├── rails-architecture-patterns/     # Planning, design decisions, skill directory
    ├── rails-devops-patterns/           # Docker, CI/CD, monitoring, security
    ├── rails-api-patterns/              # API controllers, serialization, JWT
    ├── rails-stack-profiles/            # Architecture axis detection (logic placement, delivery)
    ├── rails-mailer-patterns/           # Action Mailer, email delivery, previews
    ├── rails-auth-patterns/             # Authentication (built-in vs Devise)
    ├── rails-caching-patterns/          # Fragment, low-level, HTTP caching
    ├── ruby-refactoring/                # Code smells, refactoring patterns
    ├── ruby-object-design/              # Class vs module, Struct, Data
    └── project-conventions/             # Auto-detect project-specific coding conventions

Read the full file on GitHub · 160 lines

Changes

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.

  1. 1mo ago First seen · 160 lines · 2,050 tokens per session scan A 4573a62dbc84

Subscribe to this mod's changes

rails-dev-plugin CLAUDE.md is an instructions file published in the GitHub repository ag0os/rails-dev-plugin (5 stars, last pushed 4mo ago), licensed MIT. It adds 2,050 tokens to every session, about $0.0082 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.

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