ag-ui: an open event-based protocol for standardizing agent-human interaction in user-facing applications

What it solves

AG-UI provides a standardized, open protocol for connecting AI agents to user-facing applications. It eliminates the need for custom, one-off integrations between agent backends and frontends, allowing agents to interact with users through a consistent set of event types and inputs.

How it works

AG-UI is an event-based protocol that uses a flexible middleware layer to ensure compatibility across different environments. Agent backends emit events compatible with approximately 16 standard event types, and accept simple AG-UI compatible inputs. This system works with any event transport (such as SSE, WebSockets, or webhooks) and allows for loose event format matching to maintain interoperability between diverse agents and apps.

Who it’s for

Developers building AI agents and user interfaces that need a seamless, standardized way to synchronize state, stream chat, and implement human-in-the-loop collaboration.

Highlights

• Bi-directional state synchronization: Keeps the agent and the user interface in sync.
• Generative UI: Supports structured messages and dynamic UI components.
• Broad Framework Support: Integrations available for LangGraph, CrewAI, Pydantic AI, LlamaIndex, and others.
• Multilingual SDKs: Community-supported SDKs for Kotlin, Golang, Dart, Java, Rust, Ruby, and C++.
• Real-time context enrichment: Enhances agent interactions with real-time user context.