The Adaptive Engine API uses API keys for authentication. You can find your personal API key on the bottom left of the Adaptive UI by clicking your user profile icon.

You can copy your API key from the bottom left of the Adaptive UI.

All API requests should include your API key in an Authorization HTTP Header as such: 
Authorization: Bearer ADAPTIVE_API_KEY
The Adaptive Python SDK allows you configure your API key on instantiation of the Adaptive client, as such:
Adaptive SDK
from adaptive_sdk import Adaptive

adaptive = Adaptive(base_url="ADAPTIVE_URL", api_key="ADAPTIVE_API_KEY")
You can also set an environment variable $ADAPTIVE_API_KEY instead of explicitly passing it to the Adaptive client. If you are using the OpenAI Python library to make inference requests, you can configure the OpenAI Client as such:
OpenAI Python
from openai import Client

oai_client = Client(
   base_url="ADAPTIVE_URL/api/v1",
   api_key="ADAPTIVE_API_KEY",
)