DeepSlate

An MCP (Model Context Protocol) server that renders Minecraft structure files (NBT / Sponge schematic / Litematic) into PNG preview images using vanilla Minecraft resources.

deepslate-mcp wraps the misode/deepslate rendering engine (MIT-licensed) inside a small MCP server, so any MCP-aware agent — including Hermes Agent — can call a tool and get a PNG back.

Tools

Tool	Description
render_structure	Load a .nbt/.schem/.litematic file from disk and render to PNG
render_blocks	Build a structure from a programmatic block list and render to PNG
inspect_structure	Read structure metadata (size, palette, block count) without rendering
render_item	Render a single Minecraft item/block as an icon

Each tool supports configurable camera angles (isometric, top, front, side, and custom rotation), background colour, output dimensions, and zoom level.

At a glance

Language	TypeScript / Node.js ≥ 20
License	MIT (inherits upstream deepslate)
Upstream	misode/deepslate v0.26.0
Protocol	MCP 2025-06-18 spec (stdio transport)
Renderer	headless WebGL via gl
Resources	Vanilla Minecraft assets from Mojang's client.jar
Tests	Vitest — 65 unit + integration tests across 9 modules

Example call (from an MCP client)

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "render_structure",
    "arguments": {
      "nbt_path": "examples/fixtures/tiny_house.nbt",
      "angle": "isometric",
      "width": 1024,
      "height": 768
    }
  }
}

Response includes a text summary and an inline base64-encoded PNG image.

Quick start

# Dependencies
npm install

# Build
npm run build

# Run (stdio MCP server)
node bin/deepslate-mcp.js

# Development (hot-reload via tsx)
npm run dev

# Smoke test (starts the server and exercises all tools)
npm run smoke

# Tests
npm test

# Lint (TypeScript strict check)
npm run lint

System dependencies

On Linux, headless-gl requires Mesa libraries:

apt install libgl1-mesa-dev

The server expects an X display or virtual framebuffer (Xvfb :99 -screen 0 1024x768x24).

Architecture

See ARCHITECTURE.md for the full technical design.

M0 — Foundation (scaffold, build, basic MCP server) M1 — Render core (headless WebGL, camera presets, PNG encoding) M2 — Resource pipeline (Mojang client.jar extraction, blockstate/model/texture parsing) M3 — Multi-format loaders (.nbt, .schem, .litematic) M4 — MCP tools (4 tools wrapping the pipeline) M5 — Hermes integration (MCP config, end-to-end tool calls from Hermes Agent) M6 — Hardening (error UX, cache invalidation, progress reporting, unit tests, smoke test, lint, packaging, README polish)

All milestones complete — ready for v0.1.0 publication.

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🏗️ Building Design Toolkit

This repository also includes a Minecraft building design toolkit as a Hermes Agent skill — minecraft-building-design.

It provides:

• Format specifications for all three major Minecraft structure formats: Vanilla NBT, Create Mod schematic, and Litematica
• Python generators (zero external dependencies) to produce .nbt, .litematic files from code
• Design helpers (fill_cuboid, hollow_cuboid, mirror, rotate, etc.)
• Example — a modern villa generated in all three formats

To install:

# Via install script
bash skill/install.sh

# Or manually copy
cp -r skill/minecraft-building-design ~/.hermes/skills/creative/

Then in Hermes:

skill_view(name='minecraft-building-design')

The skill complements deepslate-mcp perfectly:

• deepslate-mcp renders existing .nbt/.schem/.litematic files to PNG
• minecraft-building-design builds those files from scratch

See skill/minecraft-building-design/SKILL.md for full documentation.

Resource caching

Vanilla resources (~3,500 blockstates, ~10,000 models, ~1,500 textures) are extracted from Mojang's client.jar and cached to disk on first build. Subsequent loads take ~0.2s instead of ~7s. Purge the cache with:

rm -rf ~/.cache/deepslate-mcp

Environment variables

Variable	Purpose
DEEPSLATE_JAR_PATH	Point to a pre-downloaded client.jar (skips network)
DEEPSLATE_CACHE_DIR	Override the cache directory (default: ~/.cache/deepslate-mcp)
DISPLAY	X display for headless-gl (e.g. :99)

Credits

This project is built on top of misode/deepslate by Misode, licensed under MIT. See ATTRIBUTION.md for full upstream credits and license obligations.

Minecraft content and assets are © Mojang AB; this project never distributes Mojang-owned assets — all resources are fetched at runtime from official sources.

License

MIT — see LICENSE.