iron-horse-opencode

Iron Horse — OpenCode Plugin + Skill Pack for Rails 8

Deep Rails 8 domain intelligence for AI coding agents.

What This Is

Iron Horse is an OpenCode plugin and skill pack that gives AI agents deep Rails 8 domain knowledge. It ships 23 domain skills covering everything from migrations to WebSockets, plus a bootstrap plugin that loads core context at session start.

Your agent harness (oh-my-opencode, Superpowers, or any compatible process layer) handles orchestration, TDD, debugging loops, and planning. Iron Horse handles the domain layer — the Rails-specific patterns, conventions, and gotchas that generic models don't know well.

Quick Install

bunx iron-horse-opencode install

That's it. This adds two entries to your opencode.json:

• "iron-horse-opencode" in the plugin array (bootstrap prompt injection)
• A skills.urls entry pointing to the skill catalog on GitHub (23 on-demand skills)

After install, OpenCode loads using-iron-horse automatically at every session start.

Manual install

If you prefer, add these to your opencode.json by hand:

{
  "plugin": ["iron-horse-opencode"],
  "skills": {
    "urls": ["https://raw.githubusercontent.com/pelletencate/iron-horse/main/skills/"]
  }
}

Uninstall

bunx iron-horse-opencode uninstall

Default Stack

Iron Horse assumes this stack unless you say otherwise:

Layer	Choice
Framework	Rails 8
Frontend	Hotwire (Turbo + Stimulus)
Background jobs	SolidQueue
Caching	SolidCache
WebSockets	SolidCable
Database	SQLite (dev/test), PostgreSQL (prod)
Testing	Minitest
Assets	Propshaft
Styling	Tailwind CSS + DaisyUI

How It Works

• Session start — the using-iron-horse plugin bootstraps core Rails domain context automatically.
• On-demand skills — individual skills load via OpenCode's native skill tool (e.g., skill("hotwire")). Each skill provides deep, focused guidance for its domain.
• Process layer — your agent harness (oh-my-opencode, Superpowers, or similar) handles TDD, debugging loops, code review, and planning workflows. Iron Horse skills slot in alongside it, not replacing it.

Skill Catalog

23 domain skills. Load any of them with skill("<name>").

Skill	Description
action-cable	Implement real-time features with Action Cable, WebSockets, channels, broadcasting, and SolidCable for Rails 8
active-storage	Configure Active Storage for file uploads with variants, direct uploads, and secure attachment handling
api-versioning	Implement RESTful API versioning with namespace-based routing, versioned controllers, authentication, and deprecation strategies
architecture	Guide Rails code organization decisions — where code belongs, layer interactions, and when to extract patterns like service objects, query objects, and presenters
authentication	Implement authentication using Rails 8 built-in generator — session-based auth, password resets, token generation, remember-me, and OAuth integration
caching-strategies	Implements Rails caching patterns — fragment, Russian doll, HTTP, low-level, and SolidCache — for performance optimization
controllers	Build Rails controllers with RESTful actions, strong parameters, skinny architecture, concerns, and nested resources
debugging	Rails-specific debugging tools and techniques for logs, console, breakpoints, SQL inspection, and performance profiling
form-objects	Build form objects for complex form handling — multi-model forms, search forms, wizards, and non-persisted forms using ActiveModel::API
frame-problem	Use this skill BEFORE writing code or creating a plan to detect XY problems early
hotwire	Use when adding interactivity to Rails views — Turbo (Drive, Morphing, Frames, Streams) and Stimulus controllers
i18n	Implement Rails internationalization with locale files, lazy lookups, pluralization, date/currency formatting, and locale switching
mailers	Send emails with ActionMailer — async delivery via SolidQueue, templates, previews, attachments, and testing
migrations	Create safe, reversible database migrations with zero-downtime strategies, proper indexing, and strong_migrations patterns
models	Design Rails models with ActiveRecord patterns, associations, validations, scopes, concerns, and query objects
project-setup	Initialize and configure new Rails 8+ projects with the default stack, living documentation, and development environment
security	Prevent critical security vulnerabilities in Rails — XSS, SQL injection, CSRF, file uploads, and command injection
solid-stack	Use when setting up background jobs, caching, or WebSockets — SolidQueue, SolidCache, SolidCable (never Sidekiq/Redis)
styling	Style Rails views with Tailwind CSS utilities, DaisyUI components, and theme-aware responsive design
testing	Test Rails applications with Minitest — models, controllers, jobs, mailers, fixtures, mocking, and test helpers
using-iron-horse	Provides core Rails domain knowledge, architecture patterns, and an overview of available iron-horse skills
views	Build Rails views with partials, layouts, helpers, forms, nested forms, and WCAG 2.1 AA accessibility
writing-plans	Write convention-lean implementation plans that trust the executor's Rails knowledge by focusing on what and why, not how

Convention-Lean Planning

Plans only specify deviations from Rails conventions. Trust the agent's Rails knowledge. Only include implementation detail when it's non-obvious.

This means a plan says "add soft-delete to User" rather than "add a deleted_at:datetime column, add a default_scope, add a discard method...". The executor knows Rails. The plan focuses on intent and constraints, not steps the agent can infer from convention.

Load writing-plans when you need a plan written this way.

Attribution

This project adapts domain skills from two MIT-licensed repositories. See ATTRIBUTION.md for full details.

• zerobearing2/iron-horse — 12 adapted domain skills
• ThibautBaissac/rails_ai_agents — 8 adapted domain skills

License

MIT