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name: AI SDK v6 UI description: | Build React chat interfaces with Vercel AI SDK v5/v6. Agent integration, tool approval, auto-submit.

Use when: implementing AI SDK v5/v6 chat UIs or troubleshooting "useChat failed to parse stream", "useChat no response", or "stale body values" errors.

Skill: ai-sdk-ui

Scope

• Applies to: React chat interfaces with Vercel AI SDK v5/v6, streaming UI patterns, tool approval workflows, agent integration
• Does NOT cover: Backend AI implementation (see ai-sdk-core), Generative UI/RSC

Assumptions

• AI SDK v5.0.99+ (stable) or v6.0.0-beta.108+ (beta)
• React 18+ (React 19 supported)
• Next.js 14+ (13.4+ works)
• @ai-sdk/react package

Principles

• Use useChat for chat interfaces with streaming
• Use useCompletion for text completion (non-chat)
• Use useObject for structured data generation
• Use useAssistant for OpenAI-compatible assistant APIs
• Use streaming for better UX (show tokens as they arrive)
• Handle tool approval workflows with addToolApprovalResponse (v6)
• Use controlled mode for dynamic body values (avoid stale values)
• Use toDataStreamResponse() in App Router, pipeDataStreamToResponse() in Pages Router

Constraints

MUST

• Use streaming responses (toDataStreamResponse() or pipeDataStreamToResponse())
• Use controlled mode when body values change (sendMessage with data instead of body option)
• Handle loading states (isLoading) and errors (error)

SHOULD

• Use stop function to allow users to cancel generation
• Auto-scroll to latest message during streaming
• Show loading indicators during generation
• Use InferAgentUIMessage (v6) for type-safe agent integration

AVOID

• Using body option with dynamic values (causes stale values)
• Non-streaming responses (poor UX)
• Infinite loops in useEffect (only depend on messages, not callbacks)
• Mixing v5 and v6 APIs without migration

Interactions

• Uses ai-sdk-core for backend implementation
• Works with nextjs App Router and Pages Router
• Uses Zod for schema validation (see typescript)

Patterns

Basic Chat

Copyimport { useChat } from '@ai-sdk/react'

export default function Chat() {
  const { messages, input, handleInputChange, handleSubmit, isLoading } = useChat({
    api: '/api/chat',
  })

  return (
    <form onSubmit={handleSubmit}>
      <input value={input} onChange={handleInputChange} />
      <button disabled={isLoading}>Send</button>
    </form>
  )
}

Tool Approval (v6)

Copyimport { useChat } from '@ai-sdk/react'

const { messages, addToolApprovalResponse } = useChat({
  api: '/api/chat',
})

// Handle approval
addToolApprovalResponse({
  toolCallId: 'id',
  approved: true,
})

See Templates and Next.js Integration for detailed examples.

References

• Next.js Integration - App Router and Pages Router patterns
• Streaming Patterns - UI streaming best practices
• Top UI Errors - Common error solutions

Resources

• AI SDK UI Docs
• useChat Hook
• Troubleshooting