---

name: vercel-ai-sdk

IMPORTANT: Keep description on ONE line for Claude Code compatibility

prettier-ignore

description: Vercel AI SDK v5: generateText, streamText, useChat, tool calling (use tool() helper + inputSchema), embeddings. v5: sendMessage vs append, message.parts, string models. allowed-tools: Read, Write, Edit, Glob, Grep, Bash, WebFetch

Vercel AI SDK v5

Quick Start

Copy// Chat API route
import { streamText, convertToModelMessages } from 'ai';

export async function POST(req: Request) {
  const { messages } = await req.json();
  const result = streamText({
    model: 'openai/gpt-4o',
    messages: convertToModelMessages(messages),
  });
  return result.toUIMessageStreamResponse();
}

// Chat component
'use client';
import { useChat } from 'ai/react';
const { messages, sendMessage } = useChat();

⚠️ CRITICAL: Tool Calling

MUST use tool() helper with inputSchema (not parameters):

Copyimport { tool } from 'ai';
import { z } from 'zod';

tools: {
  weather: tool({
    description: 'Get weather',
    inputSchema: z.object({ city: z.string() }),
    execute: async ({ city }) => ({ temp: 72 }),
  })
}

v4 → v5 Key Changes

• append → sendMessage({ text: input })
• message.content → message.parts.map(...)
• parameters → inputSchema (with tool() wrapper)

Reference Files

• core-apis.md - generateText, streamText, useChat, tool calling, embeddings
• tool-calling.md - ⚠️ tool() helper requirement, inputSchema vs parameters
• migration.md - v4 to v5 migration guide
• patterns.md - Common implementation patterns
• quick-reference.md - API reference table, pitfalls, TypeScript types

Notes

• v5 useChat: Manage input state separately (useState)
• Model format: Prefer string 'openai/gpt-4o' over function
• Last verified: 2025-01-11