Open Source

Halite is an open source project. We encourage you to check out our source code on Github. Here are some of the ways you can contribute:

Create a New Starter Kit

Thank you for your interest in creating a new Halite III starter kit! Starter kits help players develop Halite bots in their preferred language. We have put together this guide to help you create a new starter kit that will work with our game engine and be easy to use for other players. If you have any questions, feel free to reach out via email at

API Design

Please adhere as best you can to the API design used in the Python3 starter kit. Our API documentation is here.

Game Communication Overview

Bots communicate with the environment via JSON, stdin, and stdout using a stream of space-separated integers. There are two stages of communication: initialization and turn formats.



At the beginning of the game, the bot must parse a blob of JSON constants from the game environment.

  • If your language doesn’t support JSON parsing easily, you can treat all of the special JSON characters as separators and parse the resulting flat key-value stream (the Java and C++ starter kits handle the constants this way, for reference).
  • Your starter kit should silently ignore unknown constants.

Game Data

The game environment also sends a stream of space-separated integers representing:

  1. The number of players and their player IDs.
  2. The location of each players’ shipyards.
  3. A full list of each map cell’s location and halite amount.


Each turn, every bot is sent:

  1. The turn number.
  2. Each player in the game.
    • A list of this player’s ships.
    • A list of this player’s dropoffs.
  3. The changed cells on the game map, represented by an update count (how many cells have changed) and the details of changed cells (x, y, halite amount).

Submitting your new starter kit

To submit your starter kit, fork our repo, place your starter package in the starter-kits/ folder, and send us a pull request! The Halite repo is licensed under the MIT License; please ensure that your code does not include copyright language. If we accept your PR, your starter package will be added to the site.

Note: please include the and run_game.bat scripts, following the Python3 starter kit as a template.


  • Adhere to the Python 3 starter kit design, function/object/variable names, and class structure as much as possible. The Python 3 kit is the most fully documented, and the online API documentation refers to the Python 3 starter kit.
  • Support seeding the internal bot RNG from the command line, as it’s helpful for debugging.
  • The game environment allows time to analyze the initial game map before your bot returns its name. Make sure that your starter kit bot can take advantage of this time by keeping analysis functions separate, as in existing kits.