Vercel AI SDK v6 Streaming Chat in Practice

Vercel AI SDK v6 is currently the most elegant toolkit for building AI-powered applications, with built-in streaming responses, tool calling, structured output, and deep integration with Next.js.

The core of streaming chat is the streamText() function. Combined with toDataStreamResponse(), it converts AI responses directly into streaming responses for Next.js Route Handlers, consumed seamlessly on the client via the useChat() hook.

AI SDK v6 introduces an improved Tool Calling system with type-safe tool definitions and execution, automatically handling the streaming return of tool execution results.

Multi-model support is a key feature—switching between OpenAI, Anthropic, Google Gemini, and other models only requires changing the provider; business logic code needs no modification, greatly reducing vendor lock-in risk.

In production, it's recommended to deploy AI routes on Edge Runtime for minimal latency, while configuring error retries and timeout handling to ensure a stable user experience.