Building Minecraft Plugins with Claude | A Bukkit/Spigot Introduction

What's the Difference Between "Plugins" and "Mods"?

When looking for information about using Claude with Minecraft, the first thing to understand is the difference between plugins and Mods. Mods use loaders like Forge, Fabric, or NeoForge to modify the game itself — they can add new blocks and entities, but require every player to install the same Mod on their client, not just the server.

Plugins, by contrast, run on the API of server software like Bukkit, Spigot, or Paper. They're placed in the server's plugins/ folder, and players can connect using a completely unmodified Minecraft client. Plugins handle things like rank systems, minigames, protection mechanics, and economy systems — anything that extends how the server is played. If you're running a multiplayer server and want to add features, plugins are almost always what you need. If you want to modify the game itself, see How to Create Minecraft Mods with Claude.

It's also worth knowing that Bukkit, Spigot, and Paper are not separate products — they form a single lineage. Bukkit is the original server API, Spigot improved on it in terms of performance and features, and Paper is a fork of Spigot with further optimizations and its own additional APIs. Paper is largely backward-compatible with Spigot plugins and also offers better performance. If you're not sure which to choose, go with the latest version of Paper — most plugins covered in this article run on Paper without any issues.

Three Approaches to Building Minecraft Plugins with Claude

There are three main approaches to plugin development with Claude, depending on your goal:

1. Write Java code with Claude Code: Load a skill with Bukkit/Spigot/Paper development knowledge and implement full-featured plugins.
2. Operate a live server with DeveloperMCP: Use the Model Context Protocol (MCP) to have Claude check logs and install plugins on a real server.
3. Use no-code or building tools: Generate buildings or simple plugins from natural language, with no coding required.

If you want to build a distributable, production-quality plugin, approach 1 is your best bet. For maintaining an existing server more efficiently, go with approach 2. And if you want to experiment without writing any code, approach 3 is the way to start. Let's look at each one in detail.

① Writing Code with Claude Code and a Plugin Development Skill

The most versatile approach is giving Claude Code knowledge of Minecraft plugin development. The community-published minecraft-bukkit-pro skill in the antigravity-awesome-skills repository provides Claude with a structured set of guidelines for working with the Bukkit, Spigot, and Paper APIs.

This skill covers a wide range of topics, organized into three main areas:

• Core features (commands / events / GUIs): Event-driven design, command systems using Brigadier (Minecraft's standard command parsing library), inventory GUIs, world generation, custom entity AI, and text formatting with Paper's Adventure / MiniMessage.
• Advanced features (NMS / packets / reflection): Low-level access to NMS (net.minecraft.server — a technique for directly accessing Minecraft's internal server classes), packet manipulation, and reflection for version compatibility (dynamically calling classes and methods at runtime).
• Quality (testing / optimization): Performance areas like hot event optimization, async processing, and memory profiling; testing with MockBukkit (a test framework that lets you verify plugins without starting a server).

The skill also encourages a "research first" approach — looking up the latest best practices before implementation — which tends to produce well-structured code designed for production use, not just one-off snippets.

How to Install and Use the Development Skill

Here's how to load this kind of skill into Claude Code:

1. Run /plugin in Claude Code and add the target repository from the Marketplace.
2. Select the relevant skill from the Discover tab and install it.
3. Open your plugin's source code and make a request like "Add a command that tracks player kill counts."
4. Build the generated code with Maven or Gradle, place it in the server's plugins/ folder, and restart.

The exact install command varies by repository, so always check the latest instructions in the README. Most skills are designed to activate automatically in the context of plugin code, so you generally don't need to invoke them explicitly every time.

② DeveloperMCP: Operating a Live Server from Claude

If you want to do more than just generate code — if you want to control an actively running server directly from Claude — that's where DeveloperMCP comes in. It's a plugin for Spigot/Paper servers that implements the Model Context Protocol (MCP), bridging AI clients like Claude Desktop or Cursor with the server via JSON-RPC over SSE.

The plugin exposes eight types of operations: command execution with output capture, file management for reading and writing config files and logs, binary transfer of JARs and world data via Base64, a list of installed plugins with version info, log viewing, and directory exploration with file size information. This lets Claude analyze server errors and diagnose issues, install new plugins, monitor performance metrics, and handle other maintenance tasks — all without you needing to sit at the console.

How to Install DeveloperMCP

Follow these steps to install DeveloperMCP:

1. Download the JAR matching your server's version from the Versions tab on Modrinth.
2. Place the JAR in the server's plugins/ folder.
3. Restart the server to generate the initial config file.
4. Set the security token and listening port in plugins/MCPMinecraft/config.yml.
5. Add the connection details to the mcp.json on the client side (Claude, etc.) to link them.

Because this plugin allows operations equivalent to administrator-level access to your server, it's essential to use a strong, random token and never expose the port to the public internet without a firewall. This is a hard requirement.

③ No-Code Options: Promptcraft and Kodari AI

For those who want to avoid programming altogether, there are more options than ever. Promptcraft is a Claude Code plugin that converts natural language instructions into Minecraft Java Edition building data. You describe something like "a medieval castle with a moat," and Claude generates and runs a Python script that outputs a WorldEdit-compatible .schem file and automatically copies it to the schematic folder. From there, just run //schem load and //paste in-game to place it. After setup with /promptcraft:setup, it handles everything from verifying Python 3.8+, installing dependencies, and configuring folders. This tool is specifically focused on automating construction, not server logic.

If you want to generate actual server functionality, services like Kodari AI let you generate plugins or Fabric Mods entirely in the browser, with automatic compilation, error fixing, and deployment. It's a great entry point for beginners who want working results without writing a single line of code.

Costs and Operational Considerations

All of these approaches consume Claude or Claude Code usage. The larger the plugin you're generating, the more each interaction costs, so it's wise to start with small features to get a feel for the behavior and consumption before scaling up. Tools like DeveloperMCP that interact directly with a server should be treated with care — they have administrator-level power. Always use a strong token, keep the port closed to the public, and test with MockBukkit or similar tools before deploying to production.

Also keep in mind that plugins are tightly coupled to the Minecraft and server software version. If the api-version in plugin.yml doesn't match the Paper version you're running, the plugin may fail to load or throw errors on startup. Always check the version compatibility table before installing anything, make sure you have a world backup, and get into the habit of testing in a separate environment first — that's the surest path to stable server operation.