CoolCatLib

v8.0.0 Release | Oct 26, 2026

✨ New Features

• More common events (api.event.v2.common), fired the same on Fabric and Forge:

  • BlockEvents.PLACE: a block is about to be placed, by any block item (players, dispensers, other mods' machines) or an enderman; interrupt and it isn't, and the item isn't used up.
  • PlayerEvents.PICKUP_ITEM (interrupt to leave the item on the ground), TRAVEL_TO_DIMENSION (before any teleport to another dimension: portals, commands, other mods' teleporters; interrupt to stay), CRAFTED and SMELTED (an item taken from a crafting or furnace result slot).
  • PlayerEvents.CLONE (the new player object after death or the End, to carry data over), RESPAWN and CHANGE_DIMENSION.
  • LivingEvents.EQUIPMENT_CHANGE: what an entity wears or holds in a slot changed.
  • RecipeEvents.CRAFT_RESULT: a crafting recipe's result for a crafting grid; interrupt with another stack, or an empty one so nothing can be crafted. On this version it gets the game's Recipe and CraftingContainer (there is no crafter block).

• Game tests from common code (api.gametest), as on 26.1.2 and the same on Fabric and Forge: GameTests.register(modId, SomeTests.class) registers every @GameTest method (as <modid>:<class>/<method>), and GameTests.register(id, options, helper -> ...) one test by hand. GameTestOptions sets the structure, time limit, setup ticks, rotation, retries and batch (one per mod by default; there are no test environments on this version); without a structure of their own, tests run on CoolCatLib's coolcatlib:gametest/platform, an empty 8 × 6 × 8 space on a stone floor. Positions count from the structure's corner, as on newer versions. Tests are added in a development environment or with -Dcoolcatlib.gametest=true (or the loader's own game test switch), then run with /test run <modid>.<class>.<method>, /test runall <modid> or on a game test server.

• Attachments on levels and on the server: get, set, update, modify, has and reset take a Level or the MinecraftServer, saved in the level's data folder (the server's in the overworld's) and synced (SyncPolicy.ALL) to the players in the level, or to everyone. getGlobal(level) reads the server's values on either side.

• Offline players' attachments: getOffline, setOffline, updateOffline and resetOffline read and write a player's saved values whether or not they're online (an offline player's data file is written at once).

• Sound filters (api.client.sound): muffle, roughen and echo the game's sounds, as heard through a wall, under a spell or in a cave.

  • A SoundFilter is how loud a sound stays, how much of its high end it keeps, and how much of it goes through a distortion and into a reverb. muffled, quieter, distorted and echoing make the usual ones; then combines two and lerp goes part of the way, for fades.
  • SoundFilters.register(provider) adds a SoundFilterProvider, asked about each sound as it starts and as it moves, with a SoundContext: where it plays, which sound event it is, its category and whether it is relative to the listener (music, the menus; the menus' clicks are relative MASTER sounds here, as this version has no UI category). SoundFilterProvider.inWorld makes one for the sounds in the world only, by their place. register gives back a Registration to remove() it again.
  • Named filters for every sound at once (but the menus' clicks): SoundFilters.set(id, filter, fadeTicks) fades one in, clear(id, fadeTicks) out again; isSet(id). From the server, SoundFilterControl.set and clear (api.sound) do the same for a player.
  • SoundFilters.refresh() filters the sounds already playing again, when a provider's answers change.
  • Through OpenAL's EFX extension (a low-pass filter on each sound, sent to a distortion and a reverb effect); without it, sounds are left as they are.

• Items drawn in a GUI at an opacity (api.client.gui.ItemOpacityRenderer), flat and solid ones alike, where the game draws them only fully opaque: render and renderWithDecorations (with the count and durability bar) at an opacity or an OpacityTween (in, out, between, eased over ticks and smooth at any frame rate), and withOpacity(opacity, draw) for anything that draws items, fading the text and bars drawn with them too. Any item drawn while the shader color's alpha is under 1 fades with it, the game's own included.

• Placing GUI elements out of the way of everything else (api.client.gui.placement): GuiAreas.hud() and screen() give the boxes of what the HUD (every mod's HUD layers too: minimaps, block tooltips, boss bars) and the open screen drew last frame, the screen's widgets included but not its background or the tooltip under the mouse; GuiAreas.unrecorded(draw) draws your own element without it counting. GuiPlacement.hud() / screen() take a size, where you'd like it (at), a gap, the bounds to stay within and the directions it may slide in, leave out overlays and whatever you ignore, and find() the nearest clear place.

• World effect layers: frame.draw(material, VfxLayer.of(n)) draws in a layer, lowest first, so a higher layer always covers a lower one. A VfxLayer.sorted(n) layer draws its painted-over shapes of every material back to front, so shapes of different textures cover each other as their distance says. Materials in a layer now draw in the order they were first used each frame, where before they drew in no set order.

🔧 Changes

• Config screens call configs by their own name ("Client", "Server"), after their mod's name where it matters ("Testing Mod › Client"), instead of a title made from the mod id ("Testingmod Client"): in a config's screen, its category popups, the config cards' tooltips and search results, and saved notices. Translate a config's name with config.<modid>.<name>.label.
• New version numbers: <version>+<minecraft>, this one 8.0.0+1.20.1, the same for every Minecraft version and loader. They follow on from 2001.4.0.1; the part before the + is what launchers and loaders compare, the Minecraft version after it is only a label. Depending on CoolCatLib: ask for >=8.0.0, and the Maven artifacts are coolcatlib-<loader>:8.0.0+1.20.1.