from openai import OpenAI
 
client = OpenAI(
    base_url="https://openrouter.ai/api/v1",
    api_key="sk-or-v1-...",  # OpenRouter API key
)
 
# Model adı olarak provider/model formatı
response = client.chat.completions.create(
    model="anthropic/claude-sonnet-4.6",  # ← provider/model
    messages=[{"role": "user", "content": "Merhaba"}],
)
print(response.choices[0].message.content)

response = client.chat.completions.create(
    model="anthropic/claude-sonnet-4.6",
    messages=[
        {
            "role": "system",
            "content": [
                {
                    "type": "text",
                    "text": LONG_KB,
                    "cache_control": {"type": "ephemeral"},  # ← Anthropic format
                }
            ],
        },
        {"role": "user", "content": "Soru"}
    ],
)

response = client.chat.completions.create(
    model="anthropic/claude-sonnet-4.6",
    messages=messages,
    extra_body={
        "models": [
            "anthropic/claude-sonnet-4.6",     # 1. tercih
            "openai/gpt-4o",                    # fallback 1
            "google/gemini-2.5-pro",            # fallback 2
        ],
        "route": "fallback",
    },
)
# Kullanılan modeli response'da gör
print(f"Model used: {response.model}")