Anthropic SDK Pro -- Claude AI for Next.js 16

When to Use

Trigger on any mention of: anthropic, claude, claude api, ai sdk, ai enhancement, streaming response, tool use, function calling, prompt engineering, token counting, ai rate limit, claude sonnet, claude haiku.

Reference Files

Load the relevant file(s) from references/ based on the task:

Error Quick Lookup

Key Patterns

CV Bullet Enhancement

// app/api/ai/enhance/route.ts
const response = await anthropic.messages.create({
  model: 'claude-sonnet-4-6',
  max_tokens: 1024,
  system: 'You are an expert CV writer. Rewrite bullet points to be impactful and ATS-friendly.',
  messages: [{ role: 'user', content: `Rewrite these bullets:\n${bullets.join('\n')}` }]
})

Streaming in Route Handler

export async function POST(req: Request) {
  const stream = await anthropic.messages.stream({
    model: 'claude-sonnet-4-6',
    max_tokens: 1024,
    messages: [{ role: 'user', content: prompt }]
  })
  return new Response(stream.toReadableStream())
}

Usage Tracking (Free/Pro Gating)

if (user.plan === 'FREE' && user.aiUsageThisMonth >= 3) {
  return NextResponse.json({ error: 'AI limit reached' }, { status: 429 })
}
await db.user.update({ where: { id: user.id }, data: { aiUsageThisMonth: { increment: 1 } } })