The developer console is a HaloScript interface accessible within Sapien and Standalone in the all games' mod tools, and in Halo Custom Edition. It allows you to enter HaloScript expressions to test and debug your custom content, including setting debug globals to visualize engine internals.


The console is opened and closed with the ~ (tilde) key, usually found above Tab on a US keyboard. The console is already enabled in Sapien and Standalone, but to use it in Custom Edition you must either launch the game with the -console argument (and optionally -devmode to access cheat commands, which will disable multiplayer) or use a mod like Chimera which can enable these features for you while retaining multiplayer functionality. For Sapien, ensure the Game window is focused first.

Commands are then entered into the console by providing their name, then their argument(s) separated by spaces. Unlike level scripts, the outermost parentheses are implicit and globals can be set like cheat_deathless_player 1 rather than (set cheat_deathless_player 1). You cannot use the console to declare new scripts or globals.

; You don't need to enclose the command in parentheses
cheat_super_jump 1
physics_set_gravity 0.5 ;h1a only
units_set_current_vitality (players) 75 75

Keys you should know are:

  • Press Enter to run a command once inputted.
  • Press Tab to see completions of partially-entered functions and global names.
  • Use and arrow keys to cycle through recently entered commands so you can re-run them. This history includes lines from your init.txt and is limited to 8 or 16 entries depending on the game.
  • Use Right Click to paste clipboard contents into the console.
  • The Home and End keys move the cursor to the start and end of the line.

Helpful commands:

  • help <function name> to get argument information.
  • cls for clearing output from the screen.


Not all functions and globals are necessarily available in all contexts, like Custom Edition's sv_ server commands not being applicable to Sapien while the radiosity_ commands are only applicable to Sapien. Custom Edition also contains a large number of globals and functions which are non-functional and were removed in the updated mod tools.

Each game will have a different set of functions and globals, so be sure to reference the scripting information for the game you're modding.


Thanks to the following individuals for their research or contributions to this topic:

  • Conscars (Documenting developer mode functions)