The Level API uses API keys to authenticate requests. You can view and manage your API keys in the settings for your account.
Authentication to the API is performed via an authorization header value. Provide your API key as the authorization value.
curl https://api.level.io/v1/groups \
-H "Authorization: APIKEY"
All API requests must be made over HTTPS. Calls made over plain HTTP will fail. API requests without authentication will also fail.