🦑 Kraken Minecraft Server

Ultra-fast, sub-10ms startup Minecraft Java Edition proxy/server backend built in Rust with Bevy ECS and Pumpkin Protocol.

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Overview

Kraken is a high-performance Rust-based Minecraft server engine designed for low latency and high throughput. It features an ultra-fast asynchronous boot pipeline (starting in ~10ms), a protocol-aware proxy bridge (via the ViaKraken plugin), and a modular Bevy ECS backend utilizing Pumpkin Protocol primitives.

✨ Features

• ⚡ Ultra-Fast Startup: Asynchronous hardware diagnostic polling allows the server to fully initialize and bind to network ports in under 10ms.
• 🦀 Core: Built on Rust with optimized memory management and concurrent task execution.
• ⚙️ Network Engine: Native Minecraft Java protocol implementation powered by Pumpkin Protocol & pumpkin-data, supporting multi-version client connections (up to 1.21.11 / 26.1).
• 🧩 Architecture: Driven by Bevy ECS with a cleanly modularized backend (src/viakraken/java/backend/) separated into dedicated state management, packet handlers, and session loops.
• ⚔️ Combat & PvP: Real-time entity interactions including 1-heart melee punch damage, realistic fall damage mechanics, hurt animations (CEntityStatus), and broadcasted sound effects (EntityPlayerHurt).
• 🔄 Player Lifecycle: Instant respawns, persistent inventory & health tracking, real-time multiplayer tablist synchronization, and interactive /gamemode autocompletion.
• 💾 Persistence: Embedded Sled storage for player state, compressed generated chunks, biome climate, and block modifications.
• 🌍 World Generation: Contextual biome borders, temperature, caves, depth-aware ores, and cross-chunk trees with on-demand chunk streaming.
• 👁️ View Distance: Honors each client's render-distance preference up to the configurable view-distance server limit (default 16).
• ☀️ Daylight Mobs: Summoned zombies burn and die when exposed to daytime sky; husks remain sunlight-immune.

🚀 Getting Started

First Launch — EULA Gate

Before any network listeners or game loops start, Kraken validates the EULA:

• If eula.txt does not exist, the server creates it with eula=false, generates a default server.properties, logs an alert, and halts immediately.
• The engine will not bind to port 25565 or initialize internal systems until eula=true is set. Edit eula.txt to accept the Mojang EULA before starting.

Installation & Running

1. Clone the repository:

   git clone https://github.com/itarqos5/KrakenMC.git
   cd KrakenMC

2. Build and run:

   cargo run --release

Operators

Kraken creates an empty ops.json beside the executable on first login. Add operators using the standard Minecraft format, then reconnect the player:

[
  {
    "uuid": "8667ba71-b85a-4004-af54-457a9734eed7",
    "name": "Player",
    "level": 4,
    "bypassesPlayerLimit": false
  }
]

Only operators receive in-game command permission and may use /gamemode or the game-mode switcher. Console /op and /deop changes apply immediately.

Console Commands

Commands may be entered with or without the leading slash:

Command	Description
/help	Show console command usage.
/list	List online players.
/op <player> [level]	Grant an online player operator level 1–4.
/deop <player>	Remove operator status.
/kill <player>	Kill an online player.
/gamemode <mode> <player>	Change an online player's game mode.
/summon <entity> [x y z]	Summon a registered entity; console defaults to 0 0 0. In-game use defaults to the executing player's position.

🏗️ Technical Architecture

Modular Backend Structure (src/viakraken/java/backend/)

To prevent monolithic file bloat, the Java backend is divided into specialized modules:

• mod.rs: Manages TCP listener loops, status ping responses, and the initial login handshake state machine.
• state.rs: Thread-safe global registries (HashMap<Uuid, OnlinePlayer>) and tokio broadcast channels (PlayerEvent, chat, and block updates).
• handler.rs: Decodes incoming ServerPacket payloads (interact/attack, digging, block placement, chat commands) and processes combat physics.
• play.rs: Handles the active session loop, entity spawning/despawning, tablist updates, keep-alives, and chunk broadcasting.

Startup Latency Optimization

By moving synchronous sysinfo hardware queries (OS memory and CPU enumeration) out of the critical bootstrap path and into a detached asynchronous thread, Kraken bypasses OS blocking calls during boot, consistently achieving start times around 10ms.

📁 Generated Files

File	Purpose
eula.txt	Mojang EULA acceptance flag. Must be eula=true to boot.
server.properties	Bind IP, port, target protocol, max players, MOTD, and maximum view distance.
ops.json	Operator UUIDs, names, permission levels, and player-limit bypass settings.
world_data/	Sled database directory for player and chunk persistence.

📜 License

This project is licensed under the MIT License - see the LICENSE file for details.