by ombulabs
A Claude Code Skill to Upgrade Rails
# Add to your Claude Code skills
git clone https://github.com/ombulabs/claude-code_rails-upgrade-skillA Claude Code skill that helps you upgrade Ruby on Rails applications from version 2.3 through 8.1.
The Rails Upgrade Assistant analyzes your Rails application and generates:
rails app:updateThe skill follows a sequential upgrade strategy—you upgrade one minor/major version at a time (e.g., 5.2 → 6.0 → 6.1 → 7.0), never skipping versions.
This skill is built on real-world experience, not just documentation:
We've encountered (and solved) edge cases that don't appear in any documentation. This skill encapsulates that hard-won knowledge.
This skill depends on the following skills. Install them first:
1. rails-load-defaults skill — incremental verification and updates:
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load_defaultsgit clone https://github.com/ombulabs/claude-code_rails-load-defaults-skill.git
cp -r claude-code_rails-load-defaults-skill ~/.claude/skills/rails-load-defaults
2. dual-boot skill — dual-boot setup and management with next_rails:
git clone https://github.com/ombulabs/claude-code_dual-boot-skill.git
cp -r claude-code_dual-boot-skill/dual-boot ~/.claude/skills/dual-boot
Add this skill to your Claude Code configuration:
# Clone the repository
git clone https://github.com/ombulabs/claude-code_rails-upgrade-skill.git
# Add to your Claude Code skills directory
cp -r claude-code_rails-upgrade-skill/rails-upgrade ~/.claude/skills/
In Claude Code, navigate to your Rails application directory and use natural language:
"Upgrade my Rails app to 7.2"
"Help me upgrade from Rails 6.1 to 7.0"
"What breaking changes are in Rails 8.0?"
"Create a detection script for Rails 7.1"
rails_{version}_upgrade_findings.txt| Command | Description |
|---------|-------------|
| /rails-upgrade | Start the upgrade assistant |
| "Upgrade to Rails X.Y" | Generate detection script for target version |
| "Here's my findings.txt" | Generate reports from detection results |
| "Show app:update changes" | Preview configuration file changes |
| "Plan upgrade from X to Y" | Get multi-hop upgrade strategy |
This skill implements the FastRuby.io upgrade methodology, which includes:
Run your application with two versions of Rails simultaneously using the next_rails gem. This allows you to test both versions during the transition and deploy backwards-compatible changes before the version bump.
See the dual-boot skill for setup, code patterns, CI configuration, and post-upgrade cleanup.
We never skip versions. Each Rails minor/major version introduces changes that build on previous versions. Skipping creates compound issues that are nearly impossible to debug.
✅ Correct: 6.0 → 6.1 → 7.0 → 7.1
❌ Wrong: 6.0 → 7.1 (skipping 6.1 and 7.0)
Before upgrading:
This reduces the upgrade to a single Gemfile change.
Be aware of these limitations:
| Limitation | Explanation | |------------|-------------| | Gradual deployments | This skill focuses on code changes, not deployment strategies. Rolling deployments, canary releases, and feature flags are outside its scope. | | Debugging monkeypatching issues | If gems or your code monkeypatch Rails internals, you may encounter weird issues that require manual investigation. | | Accurate time estimates | The difficulty ratings and time estimates are rough guidelines based on typical applications. Your mileage will vary based on codebase size, test coverage, and custom code complexity. | | Automated code changes | The skill provides guidance and examples, but you implement the changes. It won't automatically refactor your code. | | Gem compatibility resolution | While we note common gem version requirements, resolving complex dependency conflicts requires manual intervention. |
We welcome contributions! Here's how you can help:
git checkout -b add-rails-X-Y-guideversion-guides/This project is licensed under the MIT License. See LICENSE for details.
This project is sponsored by:
We build custom AI solutions that integrate with your existing workflows. From Claude Code skills to full AI agent systems.
The Rails upgrade experts. We've been upgrading Rails applications professionally since 2017, helping companies stay current and secure.
Questions? Open an issue or reach out to us at hello@ombulabs.com