Behind-the-Scenes Mods
Plumbing: shared code libraries, compatibility patches, and bugfixes. You’ll never open a menu for any of these — listed here purely for completeness.
Core libraries & APIs
Fabric API, Architectury, Cloth Config v11, Bookshelf, Fabric Language Kotlin, Iceberg, Necronomicon, OctoLib, Obscure API, Ash API, Athena, Cardinal Components API, CICADA, Collective, Common Network, CoroUtil, Dawn API, EpheroLib, fakerlib, FTB XMod Compat, Fzzy Config, Integrated API, JamLib, Konkrete, LibZ, MidnightLib, oωo (owo-lib), Player Animator, Puzzles Lib, Resourcefulconfig, Resourceful Lib, SuperMartijn642’s Config Lib, Thermoo, TxniLib, YetAnotherConfigLib, Balm, Cupboard, Melody, Cristel Lib, Lithostitched, Structure Pool API, Structure Essentials Mod, Moog’s Structure Lib, TerraBlender, Botarium, Reborn Core, BCLib, RecipeSplitter, recipeessentials Mod, CreativeCore. Patchouli is the in-game guidebook engine several other mods use to render their own tutorial books. Paxi lets the pack’s developers drop in extra datapacks.
Animation & AI libraries
GeckoLib 4, AzureLib, AzureLib Armor, SmartBrainLib, Pehkui (entity resizing), Moonlight (villager AI/map markers) — power the mods in Creatures, Bosses & Mobs.
Compatibility & integration glue
BetterCompatibilityChecker, Forge Config API Port, Forge Config Screens, AutoTag Convention, Item Filters, Item Obliterator, Modpack Update Checker, Bad Packets, Extra Thicc Packets, Packet Fixer, Common Networking, Offhand Tick Fix, Despawn Tweaks, lootintegrations Mod (+ companions), Immersive Messages API, Ad Astra Cable Fix, Faux-Custom-Entity-Data, Transparent, Load My F***ing Tags.
Bugfixes and stability patches
BoatBreakFix, DEUF Refabricated, Debugify, Neruina, NightConfigFixes, Chunk Save Fix, Smooth chunk save Mod, Alternate Current, NetherPortalFix, Wither Spawn Fix, Vitality Fix, Simple Snowy Fix, Legendary Tooltips x Traveler’s Backpack Fix, Log Begone, Crash Assistant, MixinTrace, StackDeobfuscator, Unsafe World Random Access Detector.
Performance mods
Faster Random, FerriteCore, Lithium, ModernFix, Immersive Optimization, CreateBetterFps, Clumps, Redirected, TooFast, Memorysettings Mod, Not Enough Recipe Book. Chunky and spark are admin-facing tools (chunk pregen, server profiling). You Shall Not Spawn is admin-facing mob-spawn tuning.