Haiku 5.5 API & SDK Quickstart

import anthropic

client = anthropic.Anthropic()

with client.messages.stream(
    model="claude-5-5-haiku-latest",
    max_tokens=1024,
    temperature=0.7,
    system="You are an expert low-latency AI coding assistant.",
    messages=[
        {"role": "user", "content": "Write an asynchronous token bucket rate limiter in Python."}
    ]
) as stream:
    for text in stream.text_stream:
        print(text, end="", flush=True)

import Anthropic from '@anthropic-ai/sdk';

const anthropic = new Anthropic();

async function main() {
  const message = await anthropic.messages.create({
    model: 'claude-5-5-haiku-latest',
    max_tokens: 1024,
    system: [
      {
        type: 'text',
        text: 'Massive 50,000-word product documentation text here...',
        cache_control: { type: 'ephemeral' } // 90% discount on cache read!
      }
    ],
    messages: [
      { role: 'user', content: 'What is the return policy outlined in section 4?' }
    ]
  });

  console.log(message.content[0].text);
}

main();