Slimefun Legacy 4.1.36 — Initial Hangar Release

This is the first Slimefun Legacy release published on Hangar.

Slimefun Legacy is a community-maintained continuation of the classic Slimefun 4 experience, focused on keeping Slimefun usable, stable, and compatible with modern Minecraft servers while preserving the gameplay and addon ecosystem that made the original project popular.

🚀 Modern Server Support

• Updated for modern Paper servers
• Primary support for Paper 26.2
• Purpur 26.2 compatibility
• Experimental Folia 26.2 support
• Continued compatibility with Paper/Purpur 1.21.11
• Modern Java runtime support, including Java 25
• Updated scheduler and platform compatibility for modern Paper-family servers
• Improved startup, shutdown, chunk, task, and lifecycle handling

🧩 Slimefun Addon Compatibility

A major focus of Slimefun Legacy is preserving compatibility with the existing Slimefun addon ecosystem.

• Preserved legacy Slimefun API entry points where practical
• Added stronger public API compatibility safeguards
• Expanded addon compatibility testing
• Improved handling of missing or outdated addon dependencies
• Better diagnostics for addon linkage and runtime errors
• Preserved legacy item IDs and registration behavior
• Improved compatibility across older Slimefun-derived forks and addons
• Added automated compatibility matrices and release validation

Existing addons can continue to depend on Slimefun without needing Slimefun Legacy-specific APIs wherever possible.

🛡 Stability & Server Protection

Slimefun Legacy includes extensive stability improvements designed for long-running production servers.

• Safer machine ticker handling
• Improved machine failure isolation
• Circuit breakers to prevent broken machines or addon callbacks from repeatedly destabilizing the server
• Safer inventory and menu handling
• Improved entity lifecycle handling
• Improved chunk load/unload behavior
• Better shutdown protection
• Database and storage safeguards
• Additional runtime validation and recovery paths
• Improved handling of malformed or outdated Slimefun data
• Better protection against individual addon failures affecting the entire Slimefun runtime

⚡ Energy, Machines & Cargo

Core Slimefun systems have received compatibility, reliability, and performance work.

• Improved Energy Network handling
• Improved Cargo Network reliability
• Better machine processing safeguards
• Additional performance protections for machine-heavy servers
• Improved diagnostics for broken or stalled machines
• Safer inventory transfer behavior
• Improved recovery when machine data becomes invalid
• Better handling of machine and block storage across server upgrades

The goal remains to preserve the familiar Slimefun machine behavior rather than redesign it.

📖 Enhanced Slimefun Guide

The Slimefun Guide has been modernized while retaining the classic Slimefun structure.

• Improved item and recipe searching
• Guide bookmarks
• Better machine recipe browsing
• Improved navigation
• Safer addon integration
• Better handling of missing or broken addon items
• Improved responsiveness on large addon installations
• English-first presentation

🩺 /sf doctor

Slimefun Legacy introduces expanded diagnostics and recovery tooling through /sf doctor.

It can assist administrators with:

• Slimefun runtime health
• Addon dependency problems
• Integration status
• Item diagnosis
• Item repair
• Storage recovery
• Compatibility problems
• Legacy item migration issues
• Broken or missing Slimefun registrations

Additional stability and diagnostic commands have also been added for administrators.

💾 Legacy Data Preservation

Preserving existing servers is one of Slimefun Legacy's highest priorities.

Where practical, Legacy preserves:

• Slimefun item IDs
• Recipes
• Machine storage
• Block data
• Player data
• Backpacks
• Existing worlds
• Addon-facing behavior
• Legacy API behavior

Storage and item recovery tools have also been added for servers migrating from older Slimefun installations or translated forks.

🌎 English-First Slimefun

Slimefun Legacy provides an English-first experience without requiring a separate translation plugin.

• Cleaned and restored English-facing text
• Improved missing-message handling
• Reduced reliance on external translation systems
• Improved consistency throughout menus, machines, items, and administrator tools

🔧 Modern Development & Release Validation

The project now includes significantly stronger automated validation before releases.

• Automated build verification
• Runtime gameplay testing
• Public API verification
• Addon compatibility testing
• Paper runtime smoke testing
• Purpur validation
• Folia validation
• Legacy compatibility checks
• Release artifact verification
• Reproducible release checks
• Stronger release gating

These checks are intended to catch compatibility regressions before builds reach production servers.

🔔 Modern Update Notifications

Starting with 4.1.36, Slimefun Legacy includes its own safe update notification system.

• Checks official Slimefun Legacy GitHub Releases
• Runs asynchronously
• Rechecks periodically on long-running servers
• Notifies console operators when a newer release is available
• Can notify online server operators
• Ignores development builds, commits, drafts, and GitHub Actions artifacts
• Does not automatically replace or download over your Slimefun JAR
• The legacy upstream auto-download system has been disabled

Updates remain entirely under the server owner's control.

❤️ Preserving Slimefun

Slimefun Legacy is not intended to reinvent Slimefun.

The goal is to keep the classic Slimefun experience alive — machines, electricity, Cargo, automation, reactors, magic, backpacks, tools, equipment, and the enormous addon ecosystem — while performing the maintenance necessary for modern Minecraft servers.

Slimefun Legacy is an unofficial downstream continuation and is not an official release of the original Slimefun project, Slimefun United, or the SlimefunGuguProject.

Thank you to the original Slimefun developers, contributors, addon developers, server owners, testers, and players who built and continue to support the Slimefun ecosystem.