How to Create a Minecraft Plugin: Java by Hand or With AI

Writing a plugin by hand starts with a small Java project. You need a JDK (Java Development Kit) that matches your server: Minecraft 1.20.5 and later require Java 21 or newer, while earlier releases run on earlier Java versions. You also need a build tool, usually Maven or Gradle, and an editor such as IntelliJ IDEA or VS Code.

In the build file, declare the server API as a provided (Maven) or compileOnly (Gradle) dependency: paper-api from the PaperMC repository, or spigot-api from the Spigot repository. Choose the API version of the server you will actually run. A plugin compiled against a newer API can call methods that do not exist on an older server.

Every plugin needs a plugin.yml at the root of the .jar. It gives the server the plugin's name, version and main class, and usually the api-version, the commands it registers and the permissions it defines. Without a valid plugin.yml, the server refuses to load the file.

The main class extends JavaPlugin. The server calls onEnable() at startup, where you register listeners and command executors, and onDisable() at shutdown, where you save data. Commands declared in plugin.yml are handled by a CommandExecutor; reactions to gameplay, such as a player joining or breaking a block, live in classes that implement Listener.

Values that server owners should be able to change, like messages, cooldowns or prices, belong in a config.yml bundled inside the plugin and read with getConfig(). When the code is ready, mvn package (or the Gradle build task) writes the .jar to the target or build/libs folder.

The AI route skips the project setup. You describe the plugin in plain language, pick the server software and the Minecraft version, and our AI writes the Java code: plugin.yml, main class, commands, listeners and config.yml. The project is then compiled with Maven on our servers.

The AI knows which version you picked: it does not use API methods newer than that version and compiles with the matching Java level. Common dependencies such as Vault, PlaceholderAPI, WorldEdit and PlotSquared are resolved automatically during the build.

Once the build succeeds, you download the .jar. You can also open the project in the online editor, read every file, request changes in plain language and go back through the version history.

Installation is identical whichever route you took. Stop the server, copy the .jar into the plugins folder next to the server jar, and start the server again. A full restart is safer than reloading plugins on a running server.

Watch the console during startup: a line saying your plugin is enabling means it loaded. In game, /plugins lists every plugin, green when enabled and red when disabled. If your plugin hooks into Vault, PlaceholderAPI or WorldEdit, those plugins must be installed on the server as well, and Vault also needs an economy plugin behind it.

Most broken plugins fall into a few cases, and the console message tells you which one.

On Spaleforce, the first two cases below are handled at build time, since the version you pick sets both the API limit and the Java target, and third-party libraries are resolved during compilation. The dependency plugins themselves still have to be installed on your server.