Promptly

Opinionated Rails integration for reusable AI prompt templates. Build maintainable, localized, and testable AI prompts using ERB or Liquid templates with Rails conventions.

Features

• Template rendering: ERB (via ActionView) and optional Liquid support
• I18n integration: Automatic locale fallback (welcome.es.erb → welcome.en.erb → welcome.erb)
• Rails conventions: Store prompts in app/prompts/ with organized subdirectories
• Render & CLI: Test prompts in Rails console or via rake tasks
• Minimal setup: Auto-loads via Railtie, zero configuration required
• Prompt caching: Configurable cache store, TTL, and cache-bypass options
• Schema Validation: Ensure all locals passed to templates match a defined schema.

Documentation

For detailed documentation, please visit the Promptly Wiki.

Install

Add to your Gemfile:

gem "promptly"

For Liquid template support, also add:

gem "liquid"

Then run:

bundle install

Quick Start

# In a controller, service, or anywhere in Rails
prompt = Promptly.render(
  "user_onboarding/welcome_email",
  locale: :es,
  locals: {
    name: "María García",
    app_name: "ProjectHub",
    user_role: "Team Lead",
    features: ["Create projects", "Invite team members", "Track progress", "Generate reports"],
    days_since_signup: 2
  }
)

# Send to your AI service (OpenAI, Anthropic, etc.)
ai_response = openai_client.completions(
  model: "gpt-4",
  messages: [{role: "user", content: prompt}]
)

puts ai_response.dig("choices", 0, "message", "content")
# => AI-generated personalized welcome email in Spanish

Development

# Install dependencies
bundle install

# Run tests
bundle exec rspec

# Run linter
bundle exec standardrb

# Build gem
rake build

Contributing

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request

License

MIT