Ruby SDK for the Agent-User Interaction (AG-UI) Protocol.

ag-ui-protocol provides Ruby developers with strongly-typed data structures and event encoding for building AG-UI compatible agent servers. Built on Sorbet for robust validation and automatic camelCase serialization for seamless frontend integration.

Install bundle:

gem install bundler

Add the gem:

bundle add ag-ui-protocol

• 🐍 Ruby-native – Ruby APIs with full type hints and validation
• 📋 Sorbet Runtime – Runtime validation scheme
• 🔄 Streaming events – 16 core event types for real-time agent communication
• ⚡ High performance – Efficient event encoding for Server-Sent Events

require "ag_ui_protocol"

event = AgUiProtocol::Core::Events::TextMessageContentEvent.new(
    message_id: "msg_123",
    delta: "Hello from Ruby!",
)

encoder = AgUiProtocol::Encoder::EventEncoder.new
encoded_event = encoder.encode(event)

require "ag_ui_protocol/core/types"

message = AgUiProtocol::Core::Types::UserMessage.new(
    id: "user-123",
    content: [
        { type: "text", text: "Please describe this image" },
        { type: "binary", mimeType: "image/png", url: "https://example.com/a.png" }
        # or
        AgUiProtocol::Core::Types::TextInputContent.new(text: "Please describe this image"),
        AgUiProtocol::Core::Types::BinaryInputContent.new(mime_type: "image/png", url: "https://example.com/cat.png"),
    ],
)

• AgUiProtocol::Core::Types – Message types, tools, and data models
• AgUiProtocol::Core::Events – Event types and event handling
• AgUiProtocol::Encoder – Event encoding utilities for HTTP streaming

• Concepts & architecture: docs/concepts
• Full API reference: docs/sdk/ruby

See the example/ directory for:

• Simple use case
• Minimal Rails example

To sync the documentation of YARD with the path docs/sdk/ruby, run the following command:

cd sdks/community/ruby
rake doc

cd sdks/community/ruby
rake test

Bug reports and pull requests are welcome! Please read our contributing guide first.

MIT © 2025 AG-UI Protocol Contributors