from openai import OpenAI

client = OpenAI(
    base_url="https://openrouter.ai/api/v1",
    api_key="your-openrouter-key"
)

# You can call any model, just modify the model parameters
response = client.chat.completions.create(
    model="anthropic/claude-3.5-sonnet", # or any other model
    messages=[{"role": "user", "content": "Hello"}],
    extra_headers={
        "HTTP-Referer": "https://your-site.com",
        "X-Title": "Your App Name"
    }
)
print(response.choices[0].message.content)

# Just change one line to switch models
# model="openai/gpt-4o"
# model="google/gemini-pro-1.5"
# model="meta-llama/llama-3.1-70b-instruct"

Free model on #OpenRouter (2025)
free_models = [
    "google/gemini-flash-1.5-8b", # Google Free
    "meta-llama/llama-3.2-3b-instruct:free", # Meta free
    "mistralai/mistral-7b-instruct:free", #Mistral free
    "deepseek/deepseek-r1:free", # DeepSeek free
]

# Use free models
response = client.chat.completions.create(
    model="deepseek/deepseek-r1:free",
    messages=[{"role": "user", "content": "Explaining Machine Learning"}]
)

# Use "auto" routing, OpenRouter automatically selects the optimal model
response = client.chat.completions.create(
    model="openrouter/auto",
    messages=[{"role": "user", "content": "Write a poem"}]
)

# View the actual used model
print(response.model)

#Set cost cap
response = client.chat.completions.create(
    model="openai/gpt-4o",
    messages=[{"role": "user", "content": "Hello"}],
    extra_body={
        "provider": {
            "order": ["OpenAI", "Azure"], # Priority order
            "allow_fallbacks": True # Allow downgrades
        }
    }
)