Add to your Claude Desktop config file:

{
  "mcpServers": {
    "minecraft-dev": {
      "command": "minecraft-dev-mcp"
    }
  }
}

{
  "mcpServers": {
    "minecraft-dev": {
      "command": "node",
      "args": ["/path/to/minecraft-dev-mcp/dist/index.js"]
    }
  }
}

In Claude Desktop, you can now ask questions like:

Get decompiled source code for a specific Minecraft class.

{
  "version": "1.21.10",
  "className": "net.minecraft.world.entity.Entity",
  "mapping": "yarn"
}

Decompile an entire Minecraft version (runs once, then cached).

{
  "version": "1.21.10",
  "mapping": "yarn"
}

{
  "cached": ["1.21.10"],
  "available": ["1.21.10", "1.21.9", "..."],
  "total_available": 800
}

Get Minecraft registry data (blocks, items, entities, etc.).

{
  "version": "1.21.10",
  "registry": "blocks"
}

Remap Fabric mod JARs from intermediary to human-readable mappings.

{
  "inputJar": "/mnt/c/mods/mymod.jar",
  "outputJar": "/mnt/c/mods/mymod-remapped.jar",
  "mcVersion": "1.21.10",
  "toMapping": "yarn"
}

Look up symbol mappings between different mapping systems.

{
  "symbol": "Entity",
  "version": "1.21.10",
  "sourceMapping": "yarn",
  "targetMapping": "mojmap"
}

Search decompiled Minecraft source code using regex patterns.

{
  "version": "1.21.10",
  "query": "onBlockBreak",
  "searchType": "method",
  "mapping": "yarn",
  "limit": 20
}

Compare two Minecraft versions to find differences.

{
  "fromVersion": "1.21.10",
  "toVersion": "1.21.11",
  "mapping": "yarn",
  "category": "all"
}

Analyze and validate Mixin code against Minecraft source.

{
  "source": "/path/to/MyMixin.java",
  "mcVersion": "1.21.10",
  "mapping": "yarn"
}

Validate Fabric Access Widener files against Minecraft source.

{
  "content": "/path/to/mymod.accesswidener",
  "mcVersion": "1.21.10"
}

Compare versions with detailed AST-level analysis.

{
  "fromVersion": "1.21.10",
  "toVersion": "1.21.11",
  "mapping": "yarn",
  "packages": ["net.minecraft.entity"]
}

Create a full-text search index for fast searching.

{
  "version": "1.21.10",
  "mapping": "yarn"
}

Fast full-text search using pre-built index (requires index_minecraft_version first).

{
  "query": "entity AND damage",
  "version": "1.21.10",
  "mapping": "yarn",
  "types": ["method"],
  "limit": 50
}

Get documentation for Minecraft classes and concepts.

{
  "className": "Entity"
}

Search for documentation across all Minecraft/Fabric topics.

{
  "query": "block entity"
}

Analyze third-party mod JARs to extract comprehensive metadata.

Supports: Fabric, Quilt, Forge, and NeoForge mods

Returns: Mod ID, version, dependencies, entry points, mixin configurations, class statistics, and more

{
  "jarPath": "C:\\mods\\meteor-client.jar",
  "includeAllClasses": false,
  "includeRawMetadata": true
}

All data is cached in a platform-specific directory:

Supported Minecraft Versions: 1.14+ (any version with available mappings)

{
  "mcpServers": {
    "minecraft-dev": {
      "command": "minecraft-dev-mcp",
      "env": {
        "CACHE_DIR": "/custom/cache/path",
        "LOG_LEVEL": "DEBUG"
      }
    }
  }
}

When you request source code for the first time:

When you request another class from the same version: