Anthropic SDKを使用してFlatkey経由でClaudeリクエストをルーティングする

pip install anthropic

import os
import anthropic

client = anthropic.Anthropic(
    api_key=os.environ["FLATKEY_API_KEY"],
    base_url="https://router.flatkey.ai",
)

message = client.messages.create(
    model="claude-sonnet-4-5",
    max_tokens=1024,
    messages=[
        {"role": "user", "content": "Write a Python function to reverse a linked list."}
    ],
)

print(message.content[0].text)

message = client.messages.create(
    model="claude-opus-4-5",
    max_tokens=2048,
    system="You are a senior software engineer. Provide concise, idiomatic code.",
    messages=[
        {"role": "user", "content": "Implement a rate limiter in Python."}
    ],
)

print(message.content[0].text)

with client.messages.stream(
    model="claude-haiku-4-5-20251001",
    max_tokens=512,
    messages=[{"role": "user", "content": "Explain how HTTPS works."}],
) as stream:
    for text in stream.text_stream:
        print(text, end="", flush=True)
print()

conversation = [
    {"role": "user", "content": "What is the capital of France?"},
    {"role": "assistant", "content": "The capital of France is Paris."},
    {"role": "user", "content": "What is its population?"},
]

response = client.messages.create(
    model="claude-sonnet-4-5",
    max_tokens=256,
    messages=conversation,
)

print(response.content[0].text)