Installation & Configuration

RubyLLM is a Ruby gem that gives you a single, elegant interface to work with multiple AI providers — OpenAI, Anthropic, Google Gemini, and more. Instead of learning a different SDK for each provider, you learn one API and swap models freely.

Installing the Gem

In any Ruby project, add RubyLLM to your Gemfile:

gem "ruby_llm"

Then run bundle install. That’s it — no provider-specific gems needed.

Configuration

Open setup.rb in the editor. RubyLLM needs API keys to talk to providers. Complete the configure block:

RubyLLM.configure do |config|
  # Add your API key configuration here
  config.openai_api_key = ENV.fetch("OPENAI_API_KEY", nil)
  config.anthropic_api_key = ENV.fetch("ANTHROPIC_API_KEY", nil)
  config.gemini_api_key = ENV.fetch("GEMINI_API_KEY", nil)
end

You only need keys for providers you plan to use:

Run the script to verify:

$ ruby setup.rb

What Makes RubyLLM Different?

• One interface, many providers — switch from GPT to Claude by changing a model name
• Conversation history is automatic — no manual message array management
• Tools are just Ruby classes — no JSON schema boilerplate
• Streaming, embeddings, and image generation — all built in