GPT-5.4

from openai import OpenAI

client = OpenAI(
    api_key="sk-ak-...",
    base_url="https://apikey.sh/v1",
)

resp = client.chat.completions.create(
    model="gpt-5.4",
    messages=[{"role": "user", "content": "Hello!"}],
)
print(resp.choices[0].message.content)