Defined Commands let you create powerful functionality with no code.
Defined Commands are custom made commands, defined in Oxygen's config, that players can run (if they have the correct permission).
You could use this to add things like aliases (create a simple command that runs a different, or multiple, commands), add extra messaging to existing commands, or for simple QoL like adding commands to teleport people directly to different servers.
This was created so people on Roanoke could do /skyblock to move to our Skyblock shard.
Defined Commands are placed in /config/Oxygen/DefinedCommands/<command>.json
This does replace EEssential's text-command system, but we've left that in so your existing commands keep working.
Here's the example skyblock command:
{"command":"skyblock","aliases":["is"],"actions":[{"type":"SEND-MESSAGE","message":"<gold>Sending you to the Skyblock world..."},{"type":"DELAY","delay":1.0},{"type":"MOVE-SERVER","server":"skyblock"}]}
A player requires the permission node "oxygen.defined_commands.<command>" to execute a defined command, so in this case it'd be "oxygen.defined_commands.skyblock". This Skyblock command has an alias as well, so people can use /is for identical functionality. Note that alias commands still use the "root" command in permission checks, so using /is also requires "oxygen.defined_commands.skyblock".