ruby_llm

One beautiful Ruby API for GPT, Claude, Gemini, and more.

Battle tested at — Your AI coworker

[!NOTE] Using RubyLLM? Share your story! Takes 5 minutes.

---

Build chatbots, AI agents, RAG applications. Works with OpenAI, xAI, Anthropic, Google, AWS, local models, and any OpenAI-compatible API.

From zero to AI chat app in under two minutes

https://github.com/user-attachments/assets/65422091-9338-47da-a303-92b918bd1345

Why RubyLLM?

Every AI provider ships their own bloated client. Different APIs. Different response formats. Different conventions. It's exhausting.

RubyLLM gives you one beautiful API for all of them. Same interface whether you're using GPT, Claude, or your local Ollama. Just three dependencies: Faraday, Zeitwerk, and Marcel. That's it.

Show me the code

# Just ask questions
chat = RubyLLM.chat
chat.ask "What's the best way to learn Ruby?"

# Analyze any file type
chat.ask "What's in this image?", with: "ruby_conf.jpg"
chat.ask "What's happening in this video?", with: "video.mp4"
chat.ask "Describe this meeting", with: "meeting.wav"
chat.ask "Summarize this document", with: "contract.pdf"
chat.ask "Explain this code", with: "app.rb"

# Multiple files at once
chat.ask "Analyze these files", with: ["diagram.png", "report.pdf", "notes.txt"]

# Stream responses
chat.ask "Tell me a story about Ruby" do |chunk|
  print chunk.content
end

# Generate images
RubyLLM.paint "a sunset over mountains in watercolor style"

# Create embeddings
RubyLLM.embed "Ruby is elegant and expressive"

# Transcribe audio to text
RubyLLM.transcribe "meeting.wav"

# Moderate content for safety
RubyLLM.moderate "Check if this text is safe"

# Let AI use your code
class Weather < RubyLLM::Tool
  description "Get current weather"
  param :latitude
  param :longitude

  def execute(latitude:, longitude:)
    url = "https://api.open-meteo.com/v1/forecast?latitude=#{latitude}&longitude=#{longitude}&current=temperature_2m,wind_speed_10m"
    JSON.parse(Faraday.get(url).body)
  end
end

chat.with_tool(Weather).ask "What's the weather in Berlin?"

# Define an agent with instructions + tools
class WeatherAssistant < RubyLLM::Agent
  model "gpt-5-nano"
  instructions "Be concise and always use tools for weather."
  tools Weather
end

WeatherAssistant.new.ask "What's the weather in Berlin?"

# Get structured output
class ProductSchema < RubyLLM::Schema
  string :name
  number :price
  array :features do
    string
  end
end

response = chat.with_schema(ProductSchema).ask "Analyze this product", with: "product.txt"

Features

• Chat: Conversational AI with RubyLLM.chat
• Vision: Analyze images and videos
• Audio: Transcribe and understand speech with RubyLLM.transcribe
• Documents: Extract from PDFs, CSVs, JSON, any file type
• Image generation: Create images with RubyLLM.paint
• Embeddings: Generate embeddings with RubyLLM.embed
• Moderation: Content safety with RubyLLM.moderate
• Tools: Let AI call your Ruby methods
• Agents: Reusable assistants with RubyLLM::Agent
• Structured output: JSON schemas that just work
• Streaming: Real-time responses with blocks
• Rails: ActiveRecord integration with acts_as_chat
• Async: Fiber-based concurrency
• Model registry: 800+ models with capability detection and pricing
• Extended thinking: Control, view, and persist model deliberation
• Providers: OpenAI, xAI, Anthropic, Gemini, VertexAI, Bedrock, DeepSeek, Mistral, Ollama, OpenRouter, Perplexity, GPUStack, and any OpenAI-compatible API

Installation

Add to your Gemfile:

gem 'ruby_llm'

Then bundle install.

Configure your API keys:

# config/initializers/ruby_llm.rb
RubyLLM.configure do |config|
  config.openai_api_key = ENV['OPENAI_API_KEY']
end

Rails

# Install Rails Integration
bin/rails generate ruby_llm:install
bin/rails db:migrate
bin/rails ruby_llm:load_models # v1.13+

# Add Chat UI (optional)
bin/rails generate ruby_llm:chat_ui

class Chat < ApplicationRecord
  acts_as_chat
end

chat = Chat.create! model: "claude-sonnet-4"
chat.ask "What's in this file?", with: "report.pdf"

Visit http://localhost:3000/chats for a ready-to-use chat interface!

Documentation

rubyllm.com

Contributing

See CONTRIBUTING.md.

License

Released under the MIT License.