Build Arena

A voxel building desk in the browser. A person places blocks by hand. An AI agent can use the same live world through WebMCP tools (look, lock, then build). Live demo: TODO (paste your Vercel URL)
Demo video: TODO (paste your YouTube link)

Why WebMCP

Block coordinates and circuit layout are exact. Clicking around is slow and easy to mess up. Tools let an agent read slices, place shapes, and undo, while you watch and take over.

Typical loop: lock → context → summary → query/slice → one write → re-read → unlock.

Related MCP server: Brainstorm

Run locally

Needs Node.js 22+ (or 20+).

cd MINECRAFT_BUILD_ARENA
npm install
npm run dev

Open the URL Vite prints (usually http://localhost:5173). Title in the tab is Build Arena.

npm run build    # output is dist/
npm test

Try the agent tools

1. Open the live site (not only localhost) in ChatGPT's in-app browser, or Google Chrome 149+ with chrome://flags/#enable-webmcp-testing turned on, then restart Chrome.

2. Load Build Arena.

3. The agent should see tools such as list_tools, get_arena_context, and set_blocks.

The agent cannot if WebMCP is off .

Tools

Platform size and blueprint save stay human-only.

Warning: The docs and some md in this repo are old and were made during a premature state of the project.

Credits

• First-person play space starts from maoxin1234/redstone-world (MIT). Wiki/Mojang art is not included.

• UI font: Press Start 2P (SIL OFL 1.1), self-hosted.

• Music: ansimuz, "Going Up" (see public/public-license.txt).

License

MIT. See LICENSE.md at the repo root.