Pumpkin-Docs/docs/en/plugin-dev/migrating-from-bukkit/index.md

Migrating Overview & Architecture

Moving from Bukkit / Spigot / Paper plugin development to Pumpkin involves shifting from a Java-centric object-oriented model to a compiled, multi-language WebAssembly (WASM) component model.

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High-Level Architectural Differences

flowchart LR
    subgraph Bukkit / Paper
        A[Java Source] --> B[Java Bytecode .jar]
        B --> C[JVM / Main Server Thread]
    end
    subgraph Pumpkin
        D[Rust / Python / C# / Go / C] --> E[WASM Component .wasm]
        E --> F[WASM Sandbox / Multithreaded Engine]
    end

Concept	Bukkit / Spigot / Paper	Pumpkin
Language Support	Java / Kotlin / Scala (JVM)	Rust, Python, Kotlin, C#, Go, C
Binary Output	.jar Java Archive	.wasm WebAssembly Component
Plugin Descriptor	plugin.yml file	Programmatic PluginMetadata struct
Lifecycle Hooks	onEnable() / onDisable()	on_load(context) / on_unload(context)
Security & Isolation	Unrestricted JVM Reflection	Sandboxed WASM capability model
Concurrency	Single-threaded tick loop (BukkitScheduler)	Multithreaded native execution with Async runtime

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Detailed Migration Topics

Explore dedicated guides on migrating each major plugin subsystem:

• Migrating Commands — Transitioning from getCommand().setExecutor() and plugin.yml to Brigadier command trees.
• Migrating Events — Replacing @EventHandler and Listener interfaces with Pumpkin's blocking vs. non-blocking event system.
• Migrating Inventories & GUIs — Moving from Bukkit.createInventory() to Pumpkin container and window handlers.
• Migrating Configuration & Data — Replaces getConfig() / config.yml with native TOML, JSON, or custom storage.