CraftPlan

A browser-based, Minecraft-style multiplayer voxel world where an in-world player named Claude builds anything you ask. Type @Claude build a dragon, here in chat and watch the LLM stream blocks into the world over ~10 seconds. Dragons, Hogwarts, pirate ships, whatever you can describe.

Demo video: https://youtu.be/GDJijs-ZlSk

CraftPlan started life as a JIRA-backlog visualizer — story points became tower sizes, status became color, parent links became spatial clusters. Then the AI builder bot landed and quietly took over the project. The JIRA import still works (see below), but the fun part is asking Claude to build you a castle.

A note on how this was built: every line of code in this repo was written by Claude. So were the cached LLM builds, the recording pipeline, and the demo video itself (shot list, fades, audio cues, the lot). I drove, Claude typed. The whole thing is a vibe-coding experiment — I wanted to see how far Claude could be pushed on a real multi-component project, end to end.

Try it without installing anything

The static demo is on GitHub Pages: https://loathwine.github.io/craftplan/

• Fly around a finished demo world, no server required.
• Pick from 16 cached builds (dragon, Hogwarts, pirate ship, …); a small Claude avatar appears and places blocks visibly over ~10 s.
• Works on desktop (WASD + mouse-look) and mobile (virtual joystick, drag-to-look, on-screen Spawn button).

Run locally

Dependencies

What you want to run	Needs
The static demo above	A browser. That's it.
Live multiplayer server	Nix (with flakes). The flake pins Node 22 and resolves all npm deps via buildNpmPackage, so there's no host-level npm install and no global packages on your $PATH.
AI builder bot	Nix plus the Claude Code CLI on $PATH. The bot shells out to claude -p --model claude-opus-4-7 to turn freeform prompts into block-placement scripts.

Server

./craftplan.sh start          # WebSocket + Express server on :3000
./craftplan.sh status         # show server + bot state
./craftplan.sh stop
./craftplan.sh tunnel         # public Cloudflare URL (no account needed)
./craftplan.sh ngrok          # public ngrok URL (needs free token once)

Then open http://localhost:3000, pick a name, and play. Controls: WASD move · mouse look · Space jump · F fly · LMB break · RMB place · T task panel · Enter chat · G/R carry + rotate a task.

AI builder bot

./craftplan.sh bot            # connects as @Claude

In chat:

@Claude build a dragon, here
@Claude build castle here
@Claude come

Preset builds (castle, tower, sphere, …) run instantly from scripts/builders.mjs. Freeform prompts ask the LLM for a build plan, which is then run inside vm.createContext and streamed to the world at ~40 blocks/sec so the build is visibly placed.

JIRA import

Open the task panel (T), click Import from JIRA, supply your Atlassian URL + email + API token + JQL. Story points → tower size, status category → color, parent/child links → spatial clusters.

Architecture

See CLAUDE.md — full breakdown of the world generator, task rendering, networking, bot pipeline, and the things I learned the hard way.

server.js               WebSocket + Express. In-memory state, auto-saves
                        to data.json every 30 s.
public/js/              Three.js client (~2500 LOC, no bundler — three.js
                        loads from a CDN via importmap).
scripts/bot.mjs         AI player, listens for @Name in chat.
scripts/builders.mjs    Reusable building primitives.