Claude Opus 4
Anthropic's Flagship Model

Python SDK Examples

import anthropic

client = anthropic.Anthropic()  # uses ANTHROPIC_API_KEY env var

# Basic message
response = client.messages.create(
    model="claude-opus-4-20250514",
    max_tokens=1024,
    messages=[
        {"role": "user", "content": "Explain the P vs NP problem"}
    ]
)
print(response.content[0].text)

# With vision (image analysis)
import base64
with open("chart.png", "rb") as f:
    image_data = base64.standard_b64encode(f.read()).decode("utf-8")

response = client.messages.create(
    model="claude-opus-4-20250514",
    max_tokens=1024,
    messages=[{
        "role": "user",
        "content": [
            {"type": "image", "source": {
                "type": "base64",
                "media_type": "image/png",
                "data": image_data
            }},
            {"type": "text", "text": "Analyze this chart"}
        ]
    }]
)

# With tool use
response = client.messages.create(
    model="claude-opus-4-20250514",
    max_tokens=1024,
    tools=[{
        "name": "get_weather",
        "description": "Get current weather for a location",
        "input_schema": {
            "type": "object",
            "properties": {
                "location": {"type": "string"}
            },
            "required": ["location"]
        }
    }],
    messages=[
        {"role": "user", "content": "What's the weather in Tokyo?"}
    ]
)