Vercel AI SDK useChat in Production: Streaming, Errors, and the Patterns Nobody Writes About

The Vercel AI SDK's useChat hook makes streaming AI responses look trivially easy. Five lines of code and you have a ChatGPT clone. Then you add it to a real product and discover the parts the README skips. I've shipped useChat-based interfaces in two production apps. Here's the complete picture. The basic setup (you know this part) // app/api/chat/route.ts import { streamText } from 'ai'; import { anthropic } from '@ai-sdk/anthropic'; export async function POST(req: Request) {...