World Config

Every world has its own Origins config at <world>/origins/config.json. It lists every origin layer, every origin and every power those origins grant, each with a switch, so a server owner can take something out of one world without touching the data packs that add it.

Origins writes the file when the world starts and fills in anything new whenever the data packs change, so the list is always complete. Nothing is disabled until you set a switch to false.

{
  "layers": {
    "origins:origin": {
      "enabled": true,
      "origins": {
        "origins:elytrian": false,
        "origins:human": true,
        "origins:merling": true
      }
    }
  },
  "origins": {
    "origins:merling": {
      "enabled": true,
      "powers": {
        "origins:merling/aqua_affinity": true,
        "origins:merling/water_breathing": false
      }
    },
    "origins:phantom": {
      "enabled": false,
      "powers": {}
    }
  }
}

The switches

In the example above, nobody can choose Elytrian from the origin layer or Phantom from anywhere, and Merlings lose their gills, so they breathe air like everyone else.

When changes apply

The file is read when the world starts and again on every /reload, so edit it and run /reload without restarting.

A player who already has an origin that is now switched off keeps it on record but loses its powers, and gets them back if it is switched on again. Give them something else with /origin set if the change is meant to stay.

Switches for layers, origins or powers that no data pack provides any more are kept while they are false, so a pack that is removed and added back returns the way it was configured. Switches left at true for something that no longer exists are dropped.