Overview

Connect useStream to any React UI component library or generative UI framework

useStream is UI-agnostic. It returns plain reactive state with messages, tool calls, loading flags, values, and thread metadata that you wire to any visual layer you choose. These pages show how different libraries integrate with LangChain frontends, each with a different philosophy for building AI chat and generative UI.

Integrations

CopilotKit

Full AI chat runtime with structured generative UI support. Add a custom CopilotKit endpoint to your LangGraph deployment, then render dynamic component trees in React.

AI Elements

Composable shadcn/ui-based components for AI chat. Drop in Conversation, Message, Tool, and Reasoning and wire them directly to stream.messages.

assistant-ui

Headless React framework with a full runtime layer. Bridge useStream to AssistantRuntimeProvider via the useExternalStoreRuntime adapter.

OpenUI

Generative UI library that lets the agent produce complete, interactive dashboards in a declarative component DSL. Purpose-built for data-rich, report-style UIs.

Choosing a library

Each library fits a slightly different integration model. The choice depends on what kind of UI you’re building:

	CopilotKit	AI Elements	assistant-ui	OpenUI
Best for	Full chat runtime plus structured generative UI	Chat with rich message types	Full-featured chat with minimal setup	Generated dashboards and reports
UI style	CopilotKit chat shell + custom message renderers	Composable shadcn/ui components	Headless slots + default theme	Prebuilt component library with declarative DSL
Customisation	Custom backend endpoint, agent context, and renderers	Edit source files directly	Override component slots	Theme via CSS custom properties
Streaming UX	Runtime-managed chat stream with structured assistant payloads	Component-level progressive render	Built-in thread management	Hoisting — shell appears immediately, data fills in
Tool calls	Via CopilotKit runtime and custom renderers	Tool / ToolHeader / ToolOutput	Custom via message slots	Inline in the generated UI
Agent format	Structured assistant responses plus optional Markdown	Any stream.messages	Any stream.messages	Agent outputs openui-lang text

All four work well with LangChain agents, and the latter three also connect directly to useStream. CopilotKit is especially useful when you want a richer runtime layer and a dedicated endpoint that can sit alongside a LangGraph deployment.

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