Create a Modded Minecraft Server with AI Code

8/11/2025

So, You Want An "MCP Server" with Claude-Generated Code? The REAL 2025 Guide

Hey there! So you've got this idea buzzing in your head. You want to set up an "MCP Server," maybe get some "Claude Code" running on it to create your own custom Minecraft experience. I get it. The idea of bending one of the world's most popular games to your will, using cutting-edge AI to do the heavy lifting, is INCREDIBLY cool.

But here’s the thing, and I'm telling you this as a friend who's spent way too many nights wrestling with Java code & server configs: the terms you're using, "MCP Server" & "Claude Code," are like a secret handshake from a bygone era mixed with a glimpse into the far future.

And honestly? That's what makes this so exciting.

You’re on the right track, but the map you're holding is a little old. Let's get you the new one. In this guide, I'm going to break down everything. We'll translate that "MCP" idea into its modern, much more powerful equivalent. We'll dive into how you can ACTUALLY use AI like Claude to write Minecraft mods without being a Java expert. & we'll put it all together by setting up a server to run it all.

This is the ultimate guide to what you're really asking for. Let's do this.

Part 1: What Even Is an "MCP Server"? A Quick History Lesson

Okay, first things first. There's no such thing as an "MCP Server" today, not really. What you're likely thinking of is the Mod Coder Pack, or MCP.

Back in the day, Minecraft wasn't open source. Its code was obfuscated, meaning it was a jumbled, unreadable mess to the outside world. MCP was a collection of tools & scripts that clever developers created to de-obfuscate Minecraft's code. It essentially translated the game's code into something human-readable, allowing people to go in, change things directly, & create what were known as "jar mods." You were literally modifying the core game files. It was the wild west of modding—powerful, but messy & extremely prone to breaking. Every mod directly edited the same source code, so incompatibilities were a nightmare.

From MCP to Modern Mod Loaders: Forge & Fabric

Thankfully, things have evolved. The community developed APIs (Application Programming Interfaces) to make modding cleaner, more stable, & easier. Instead of everyone changing the game's core files, you use a "mod loader" that acts as a middleman. It loads the base game & then "injects" your mods' changes in a structured way.

The two giants in this space are Forge & Fabric.

Forge: This is the old guard, the heavyweight champion. It's been around for ages & has a massive library of complex, game-altering mods. Think industrial machinery, magic systems, new dimensions—the big stuff. It’s robust & powerful, but sometimes it can be a bit slower to update when a new version of Minecraft comes out.
Fabric: The newer, lightweight challenger. Fabric is designed to be lean & fast. It updates VERY quickly, often having a version ready the same day a new Minecraft snapshot is released. It’s fantastic for performance-focused mods, smaller enhancements, & staying on the absolute cutting edge of Minecraft versions.

For this guide, we're going to focus on Forge. It has a rich history & is a fantastic platform for the kind of custom, AI-generated mods you’re probably dreaming of. The principles, however, will be similar for Fabric.

So, when you say "MCP Server," what you really mean in 2025 is a Modded Minecraft Server, likely running Forge. See? We're already speaking the right language.

Part 2: Let's Build It! Setting Up Your Forge Server Step-by-Step

Alright, time to get our hands dirty. We're going to set up a Forge server from scratch on your own computer. This is perfect for testing your own mods & playing with a few friends.

Step 1: The One Prerequisite - Java

Minecraft, & by extension Forge, runs on Java. You need to have the right version of the Java Development Kit (JDK) installed. The specific version depends on the Minecraft version you're modding, but for anything modern (like 1.20+), you'll generally need Java 17 or newer.

Not sure if you have it? Open your command prompt or terminal & type

java -version

. If you get an error or the version is old, you'll need to install it. A quick search for "Java JDK 17 download" will get you to the official Oracle website. Just download & run the installer.

Step 2: Download the Forge Installer

Head over to the official Minecraft Forge website. You'll see a list of Minecraft versions. Pick the version you want to build for (e.g., 1.20.1 is a popular & stable choice). On the download page, click the "Installer" button. You might be taken to an ad page—just wait a few seconds & click the "Skip" button in the top right. Don't click the ads! The file will download.

Step 3: Create Your Server Folder & Run the Installer

This is important for staying organized. Create a new folder somewhere on your computer. Call it something like "My Forge Server." Move the Forge installer file you just downloaded into this folder.

Now, double-click the Forge installer file. A little window will pop up with three options:

Install client
Install server
Extract

Choose "Install server". A red box will appear asking you to specify the location. Make sure it's pointing to the "My Forge Server" folder you created. Click "OK."

The installer will chug away for a minute, downloading all the necessary files. When it's done, you'll see a success message. Pretty cool, right? Your folder should now have a bunch of new files & folders in it.

Step 4: The EULA (The One Legal Thing)

You can't start the server just yet. First, you have to agree to Minecraft's End User License Agreement (EULA).

In your server folder, you'll see a new file called

run.bat

(for Windows) or

run.sh

(for Mac/Linux). Double-click it. It will try to start, fail, & then close immediately. This is supposed to happen!

If you look in the folder now, you'll see a new text file:

eula.txt

. Open it. Inside, you'll see a line that says

eula=false

. Change it to

eula=true

& save the file. That's you telling Mojang you agree to their terms.

Step 5: Start Your Server!

Now for the magic moment. Double-click that

run.bat

run.sh

file again. A new window will pop up—the server console. You'll see it start loading the world, preparing spawn areas... all the good stuff.

Once you see a line that says something like

[Server thread/INFO]: Done! ... For help, type "help"

, your server is officially running! To join it yourself, launch Minecraft (with the corresponding Forge profile installed on your client), go to Multiplayer, click "Add Server," & for the server address, just type

localhost

. You should be able to connect to your very own server.

To stop the server, just go to the console window & type

stop

& press Enter. NEVER just close the window, as this can corrupt your world save.

Part 3: "Claude Code" - Using AI To Write Your First Mod

Okay, the server is ready. Now for the futuristic part. We're going to create a mod. But we're not going to write the code ourselves. We're going to be the director, & Claude is going to be our coder.

The Concept: You're the Architect, AI is the Builder

Using an AI like Claude for coding is a game of prompts. Your job is to describe what you want, as clearly & specifically as possible. Claude's job is to translate your request into functional Java code. You don't need to know the complex syntax, but you need to know what to ask for.

For this, you'll want to have an IDE (Integrated Development Environment) like VS Code or IntelliJ IDEA with a Java extension. They make managing code files much easier. You'll also need to set up a basic Forge MDK (Mod Development Kit), which you can find on the Forge download site. The MDK gives you the basic file structure for a mod.

Let's Make a Mod: The "Sunstone"

We're going to create a simple new item called a "Sunstone." When a player holds it, it will give them the Night Vision effect.

Here’s how you'd ask Claude to do this. Open up Claude's chat interface & give it this prompt:

"Hey Claude, I need you to act as an expert Minecraft modder. I am creating a mod for Minecraft Forge version 1.20.1.
I want to create a new basic item called 'Sunstone'.
Here are its properties:
The item ID should be 'sunstone'.
The English name should be 'Sunstone'.
It should be in its own custom Creative Tab called 'Sunstone Mod'.
When a player holds the Sunstone in their main hand or off-hand, they should receive the Night Vision I potion effect. The effect should be removed when they are no longer holding the item.
Please provide me with the full Java code for the main mod file, the item registration, & the custom item class needed to make this work. Please add comments to the code to explain what each part does."

Breaking Down That Prompt:

Set the Context: "act as an expert Minecraft modder" & "for Minecraft Forge version 1.20.1." This is SUPER important. It tells the AI which rules & libraries to use.
Be Specific: I didn't just say "make a cool item." I gave it a name, an ID, a creative tab, & a VERY specific function (
1Night Vision I
when held).
Ask for Everything: I asked for all the necessary files & for comments, making my job of understanding & organizing the code much easier.

Claude will now generate the Java code, likely broken into a few different files. Your job is to copy this code & paste it into the correct files within your Forge MDK project structure in your IDE.

Compiling Your Mod

Once the code is in place, you'll "compile" it. This is the process of turning the human-readable Java code into a

.jar

file that Minecraft can understand. In most IDEs set up with the Forge MDK, this is as simple as opening a terminal panel & running a command like

./gradlew build

After it's finished, you'll find your brand new mod file inside the

build/libs

folder. It'll be named something like

sunstone-mod-1.0.0.jar

Part 4: Bringing It All Together

This is the final step. You have a server. You have an AI-generated mod. Let's combine them.

Stop your server (by typing
1stop
in the console).
Find your server folder. Inside, there's a folder named
1mods
.
Copy your
1sunstone-mod-1.0.0.jar
file & paste it into that
1mods
folder.
Start your server again using the
1run.bat
or
1run.sh
file.

Watch the console. You'll likely see it mention that it's loading your Sunstone Mod. Now, launch your Minecraft client, connect to

localhost

, go into Creative mode, & you should see your new "Sunstone Mod" creative tab. Inside, you'll find your Sunstone. Grab it, wait for night to fall, & watch the world light up.

You just created a custom Minecraft mod using AI & deployed it to your own server. How AMAZING is that?

Part 5: The Next Step - Managing Your Awesome New Server

Okay, so you've done it. You have a modded server. You invite your friends. They love it. Soon, you have a small community. This is the dream! But it also comes with new challenges. You'll get the same questions over & over:

"What's the server address?"
"How do I install the mods?"
"What are the server rules?"
"Why did the Sunstone stop working?" (Because you're probably already thinking of the next AI-generated mod to add).

Answering these questions can become a full-time job. & honestly, it's not the fun part. The fun part is creating things.

Here’s where things get REALLY interesting. Once your server gets popular, you need a way to automate support. This is where a tool like Arsturn becomes a complete game-changer. Arsturn helps businesses create custom AI chatbots trained on their own data. For you, your "business" is your server community.

Imagine this: you take all your server rules, your mod list, a step-by-step connection guide, & a list of common questions, & you put them all into a text document. You then use Arsturn to build a no-code AI chatbot trained on that specific information.

Now, you can put this chatbot on a simple website for your server or link to it in your Discord. When a new player has a question, they don't have to ping you. They can just ask the chatbot & get an instant, accurate answer, 24/7. This frees you up to focus on what really matters: dreaming up the next insane, AI-powered feature for your world. Arsturn helps you build that meaningful connection with your audience by providing a personalized, instant experience, which is exactly what you want for your player base.

Wrapping it all up

Hope this was helpful! We went on a pretty big journey here. We translated the old-school idea of an "MCP Server" into a modern Forge setup, walked through how to actually build that server, & then did the coolest part: we acted as the director for an AI coder to create a brand new mod from scratch.

The world of AI-assisted development is just getting started, & you're officially a part of it. You've seen how easy it can be to take an idea & turn it into a real, playable experience.

Now go build something awesome. Let me know what you think.