Python Anthropic integration

pip install lunary anthropic

import os

from anthropic import Anthropic
import lunary

client = Anthropic(api_key=os.environ["ANTHROPIC_API_KEY"])

lunary.monitor(client)

import pydantic


class Answer(pydantic.BaseModel):
    answer: int
    confidence: str


parsed = client.messages.parse(
    model="claude-sonnet-4-5-20250929",
    max_tokens=256,
    messages=[
        {
            "role": "user",
            "content": "Return JSON with `answer` and `confidence` for 2 + 2.",
        }
    ],
    output_format=Answer,
    tags=["support", "structured-output"],
    user_id="user_123",
    user_props={"plan": "pro"},
    metadata={"user_id": "user_123"},
)

raw_stream = client.messages.create(
    model="claude-sonnet-4-5-20250929",
    max_tokens=256,
    stream=True,
    messages=[{"role": "user", "content": "Write one sentence about Lunary tracing."}],
)

for event in raw_stream:
    pass

with client.messages.stream(
    model="claude-sonnet-4-5-20250929",
    max_tokens=256,
    messages=[{"role": "user", "content": "Write one more sentence about Lunary tracing."}],
) as stream:
    for event in stream:
        pass

    final_message = stream.get_final_message()

from anthropic import beta_tool


@beta_tool
def get_weather(city: str) -> str:
    """Returns a canned weather response for the requested city."""

    return f"The weather in {city} is sunny and 20C."


runner = client.beta.messages.tool_runner(
    model="claude-sonnet-4-5-20250929",
    max_tokens=256,
    max_iterations=3,
    messages=[
        {
            "role": "user",
            "content": "Call the weather tool and summarize the result.",
        }
    ],
    tools=[get_weather],
)

for message in runner:
    print(message)