Gear Sets and Brewing Mixes

Gear sets and brewing mixes

Applies to all versions. On 1.21.1 item stacks use the ItemStack codec; on 26.2 the ItemStackTemplate codec. Both accept the usual {"id": "...", "count": 1} form.

Common Toolkit ships two dynamic registries that datapacks (and other mods) can fill.

Gear sets

A gear set lists possible items for each equipment slot, with weights. Other mods use GearSetRegistry.INSTANCE to pick a random set (optionally filtered by a set of gear sets or a tag) and dress a mob with it (GearSet.apply(entity)), which picks one item per slot.

Files: data/<namespace>/common_toolkit/gear_sets/<name>.json (server-side only).

{
  "weight": 10,
  "quality": 1.5,
  "mainhands": [
    { "stack": { "id": "minecraft:iron_sword" }, "weight": 3 },
    { "stack": { "id": "minecraft:iron_axe" }, "weight": 1, "drop_chance": 0.1 }
  ],
  "helmets": [
    { "stack": { "id": "minecraft:iron_helmet" }, "weight": 1 }
  ]
}

Field	Required	Description
weight	Yes	Base weight of the set (0 or more).
quality	No (0)	How much luck increases the weight (weight + luck × quality).
mainhands, offhands, boots, leggings, chestplates, helmets	No	Weighted choices for each slot; an empty or missing list leaves the slot unchanged.

Each choice has stack (an item stack; can be empty to mean "nothing"), weight, and an optional drop_chance that sets the mob's drop chance for that slot.

Gear sets support tags in data/<namespace>/tags/common_toolkit/gear_sets/.

Brewing mixes

A brewing mix adds a brewing-stand recipe. The mixes are synced to clients when they join and after every /reload, and are re-applied to the brewing recipes on each reload.

Files: data/<namespace>/common_toolkit/brewing_mixes/<name>.json.

{
  "mix_type": "potion",
  "from": "minecraft:awkward",
  "ingredient": "minecraft:glow_berries",
  "to": "minecraft:night_vision"
}

Field	Description
mix_type	potion (turns one potion into another) or container (turns one potion container item into another, like water bottles into splash potions).
from, to	Potion ids for potion, item ids for container.
ingredient	The ingredient placed in the top slot, in the vanilla ingredient format of your Minecraft version: an item id or #tag on 26.2 (as in the example), {"item": "..."} or {"tag": "..."} on 1.21.1.