DeerFolia

Introduction

DeerFolia is a Minecraft server core maintained by LunaDeerMC and developed on top of Folia’s regionized multithreading architecture. It is not a plugin: it replaces the server core used to start the server. This page is based on the repository’s 26.2.0-bbeb1d1 tag, Minecraft 26.2, and its Java 25 build configuration.

DeerFolia keeps changes to Folia and Paper upstream focused, restores selected vanilla behavior, and exposes several expensive workloads as administrator-controlled configuration. It is a better fit for survival, skyblock, and community servers whose players naturally spread across multiple active regions. A small server with everyone concentrated in one area may not benefit from the Folia architecture itself.

Current capabilities

• Restores sand-duplication-related vanilla behavior and adjusts relevant End teleport handling for the regionized environment.
• Adds Dynamic Activation of Brain to reduce unnecessary AI work for distant entities.
• Adds asynchronous pathfinding backed by virtual threads.
• Adds Kaiiju entity throttling, which controls update frequency for excessive entities per region and can gradually remove entities above a removal threshold.
• Adds VarInt and frame-encoding optimizations, POI optimizations, Lithium-derived hot-path work, and AFK network suppression.
• Keeps DeerFolia-specific settings in config/deer-folia.yml; entity throttling uses config/kaiiju-entity-throttling.yml.

Read this before using it

DeerFolia inherits Folia’s core constraints. There is no traditional single Bukkit/Paper main thread, and plugins should be explicitly Folia-compatible before being used. Check every plugin, script, and management panel before switching cores, and make a complete backup of worlds, configuration, and databases.

Start with Installation and first start, then read Configuration overview and DeerFolia configuration. Tune performance settings only after a backup and a small-scope test.

Documentation entry points

• Installation and first start: Java, downloads, directories, startup, upgrades, and building.
• Configuration overview: file responsibilities, edit order, and restart boundaries.
• DeerFolia configuration: every default in deer-folia.yml, its effect, and tuning guidance.
• Entity throttling: limits and removal rules in kaiiju-entity-throttling.yml.
• Features and optimizations: what each optimization does, its default state, and possible gameplay effects.
• Troubleshooting: startup failures, plugin compatibility, farms, YAML errors, and AFK resynchronization.