Please report a security problem in this client, or in EyalSec itself, to security@eyalsec.com rather than in a public issue. We will reply to confirm we have it and keep you updated until it is fixed. The EyalSec security page is at https://eyalsec.com/security.
This library sends your API key only to the address you configure, only over HTTPS (plain HTTP is accepted for localhost alone), and never includes it in a repr or an error message.