The Kettle Protocol

Kettle is a JSON-based protocol used to communicate game state and player inputs for Hearthstone. It is closely modeled after the real Hearthstone protocol, but does not use Protobufs.


The main goal of Kettle is to be a portable, language-agnostic Hearthstone game protocol.

This allows:

  • Creating and playing games in Stove and be able to play them from a simulator such as Fireplace or Sabberstone.
  • Implementing a Hearthstone AI in a different language/process as the simulator it runs on.
  • Communicating games between Joust and a Kettle-compatible simulator in order to play directly from a web browser.