How to generate files in a Vercel AI SDK chatbot

import { anthropic } from "@ai-sdk/anthropic"
import { convertToModelMessages, isStepCount, jsonSchema, streamText, tool, type UIMessage } from "ai"
import { Doconda } from "@doconda/sdk"

const doconda = new Doconda()
const tools = Object.fromEntries(
  doconda.tools().map((t) => [
    t.name,
    tool({ description: t.description, inputSchema: jsonSchema(t.inputSchema), execute: (input) => t.run(input as Record<string, unknown>) }),
  ]),
)

export async function POST(req: Request) {
  const { messages }: { messages: UIMessage[] } = await req.json()
  const result = streamText({
    model: anthropic("claude-sonnet-5-5"),
    system: "If the user asks for a document, create it and give them the download link.",
    messages: await convertToModelMessages(messages),
    tools,
    stopWhen: isStepCount(5),
  })
  return result.toUIMessageStreamResponse()
}

"use client"

import { useChat } from "@ai-sdk/react"
import { useState } from "react"

export default function Chat() {
  const { messages, sendMessage } = useChat()
  const [input, setInput] = useState("")

  return (
    <main>
      {messages.map((m) => (
        <p key={m.id}>
          <b>{m.role}:</b> {m.parts.map((p) => (p.type === "text" ? p.text : "")).join("")}
        </p>
      ))}
      <form
        onSubmit={(e) => {
          e.preventDefault()
          sendMessage({ text: input })
          setInput("")
        }}
      >
        <input value={input} onChange={(e) => setInput(e.target.value)} placeholder="Ask for a document…" />
      </form>
    </main>
  )
}