minecraft-schematic-lab

Build Minecraft schematics by talking to Claude. Describe what you want and it produces a WorldEdit Sponge .schem with a live 3D preview in the browser. Everything runs locally — no account, no cloud.

Setup

You need Node 22+ and Claude Code (CLI or desktop app). Add the connector once — either way below works for both the CLI and the desktop app, since they share the same config.

Add it with one command  (uses the claude CLI)

macOS / Linux:

claude mcp add --scope user minecraft-schematic-lab -- npx -y github:SimoneRecchia/minecraft-schematic-lab --mcp

Windows — npx needs a cmd /c wrapper:

claude mcp add --scope user minecraft-schematic-lab -- cmd /c npx -y github:SimoneRecchia/minecraft-schematic-lab --mcp

If claude isn't found, the desktop app doesn't ship the CLI — install it, open a new terminal, and run the command again:

• macOS — brew install --cask claude-code (or curl -fsSL https://claude.ai/install.sh | bash)
• Linux — curl -fsSL https://claude.ai/install.sh | bash
• Windows — winget install Anthropic.ClaudeCode (or irm https://claude.ai/install.ps1 | iex)

Add it by hand  (edit the config file)

Add the block under mcpServers in your Claude config — ~/.claude.json for Claude Code (%USERPROFILE%\.claude.json on Windows), or claude_desktop_config.json for the Claude Desktop chat app.

macOS / Linux:

{
  "mcpServers": {
    "minecraft-schematic-lab": {
      "command": "npx",
      "args": ["-y", "github:SimoneRecchia/minecraft-schematic-lab", "--mcp"]
    }
  }
}

Windows:

{
  "mcpServers": {
    "minecraft-schematic-lab": {
      "command": "cmd",
      "args": ["/c", "npx", "-y", "github:SimoneRecchia/minecraft-schematic-lab", "--mcp"]
    }
  }
}

Restart Claude Code so it picks up the connector, then ask:

build me a 50×40×80 fantasy castle

The first run pulls the tool through npx; the 3D preview then opens at http://127.0.0.1:8765.

Using it

• Change it — "make the roof brick", "add two towers". The preview refreshes on its own.
• Export — the Export .schem button in the browser, or ask Claude (Sponge v2, or v3).
• In Minecraft — put the .schem in your world's schematics folder, then //schem load <name> and //paste.
• Versions — ask Claude to version a build in a folder (needs git).
• Updates — the connector follows main; pin a release with #v0.1.0, or clear a stale cache with npm cache clean --force.

Platform support

OS	CLI	Desktop app	Note
macOS (Intel / Apple Silicon)	✅	✅
Windows 10/11 (x64 / ARM64)	✅	✅	npx needs cmd /c (see Setup)
Linux (x64 / ARM64, incl. musl)	✅	—	no desktop app on Linux

Node 22+ on every platform; 32-bit isn't supported.

Develop

pnpm setup        # install + build
pnpm dev          # web (5173) + server (8765), hot reload
pnpm test         # vitest
pnpm bundle       # rebuild bundle/ for the npx connector (commit after server changes)

Architecture, MCP tools, the HTTP API and the BuildSpec format are documented in CLAUDE.md.

License

MIT © 2026 SimoneRecchia