GitHub - Kuberwastaken/minicraft: A playable copy of Minecraft Classic hidden inside a single X thread that's self-decoding, runs in your browser.

A playable copy of Minecraft Classic, hidden inside a single X thread.

I found this rather cool trick from @rebane2001 on twitter yesterday that reminded me that I was working on this "hard problem" I left 3 months ago of running Minectaft from a tweet.

If you do x.com/compose followed by the URL string on your post itself, it'll open up the compose box with those words clearly printed out! Using this I was able to truncade the instructions and my custom decoder (because it's ~20 tweets that need to be consolidated) base64 encoded

Is it useful? No, is it a really fun sunday hack that made me smile? sure

▶️ See it live on X →

Play it

Three ways, easiest first:

1. Just play → kuber.studio/minicraft
2. From the thread: open tweet 2's link, copy the data:text/html;base64,… line it shows, and paste it into your browser's address bar → that's the decoder. Hit auto-fill from github, then Play.
3. By hand: in the decoder, paste tweets 3–20 (the raw chunks) yourself, then Play.

How it works

The game is ~9 MB of HTML/JS. A thread is ~20 posts. The squeeze:

The layout of the thread:

• Tweet 1 — the intro (a compose link that opens the write-up).
• Tweet 2 — the decoder: a data:text/html page, deflate-compressed and wrapped in a self-inflating bootstrap so the whole thing (a UI plus an embedded LZMA engine) fits in one post. Works fully offline.
• Tweets 3–20 — the game itself, as raw base64url(LZMA) text. X Premium's 25 K-char limit lets each post carry a big chunk directly — no links needed.

The decoder gathers the parts (paste them, or one-click auto-fill from github), base64url-decodes, LZMA-decompresses, and document.writes the game. A localStorage shim is injected first, because the game needs storage and data: URLs disable it.

What's where

game-shaken.html          the shipped game — Babylon tree-shaken, crypto-stripped, Elon-grass
index.html                original monolithic Minecraft Classic (unminified, 9 MB)
minified-index.html       the full game, re-minified with a JS-aware minifier
tweet.txt                 the v1 approach — bytes hidden as invisible Unicode variation selectors
font/                     bitmap font the game uses
TWEETS/                   the postable thread — tweet-001..020.txt + manifest.txt
unlinked-tweets/          the decoded text= of each tweet (for local testing without X)
FINDINGS.md               empirical notes (WAF behaviour, URL limits, compression)

scripts/
  build_thread.py         game.lzma  ->  TWEETS/ + unlinked-tweets/  (builds the thread)
  build_decoder.mjs       decoder_page.html  ->  self-inflating decoder_bootstrap.html
  decoder_page.html       decoder source (UI + embedded LZMA engine)
  decoder_bootstrap.html  the built decoder, embedded in tweet 2
  lzma-d-min.js           LZMA decode engine (shipped inside the decoder)
  intro.txt               tweet 1 text  (edit this — not the generated TWEETS/)
  compose_link.py         any text/file  ->  an x.com/compose/post link
  encode.py / decode.py   v1: hide bytes as Unicode variation selectors
  thread_pack.py / _unpack generic file <-> deflate-thread helpers

Editable sources: scripts/intro.txt (tweet 1), scripts/decoder_page.html (the decoder), and game-shaken.html (the game — e.g. textures). TWEETS/ and unlinked-tweets/ are generated — regenerate them with build_thread.py.

The journey (a.k.a. everything that went wrong)

It started as "can we make the broken minified build run" and turned into a compression / X-limits rabbit hole. Highlights:

• The minifier that ate a regex. minified-index.html threw Uncaught SyntaxError: Invalid regular expression flags. A naïve minifier had seen the // inside a /\//g regex, mistaken it for a line comment, and deleted the rest of the line. Re-minified with a JS-aware tool.

• The compose-link rabbit hole. A link to x.com/compose/post?text=… opens a pre-filled composer. But X's WAF 403s any URL containing <script (so payloads are base64), and the URL 431s past ~14 K chars — dropping to ~10 K once a logged-in browser's cookies are added. All measured against x.com directly.

• base64url. Standard base64's + / = get %-expanded 3× inside a URL. base64url (A–Z a–z 0–9 - _) is URL-safe with zero expansion — 6 bits/char, the density ceiling.

• The white screen. The decoder booted from file:// in tests but white-screened as a real data: URL — the game reads localStorage, which is disabled in opaque data: origins. Fixed by injecting an in-memory storage shim before the game runs.

• Babylon.js is 69% of the game. The bundle's biggest module is Babylon.js 4.0.3 (2.37 MB), but the game only touches 26 of its APIs. Tree-shaking it to that surface (→ 806 KB), plus stripping a dead crypto polyfill (elliptic / bn.js, dragged in by a single randomBytes call), roughly halved the game — verified still booting, rendering, and opening menus in headless Chrome.

• Beating deflate. Browsers only inflate gzip/deflate natively — but the decoder ships its own engine, so LZMA (−25% vs deflate) does the compression, wrapped so the decoder still fits in one tweet.

• The Premium plot twist. The compose-link trick beats the 280-char free limit — but X Premium already grants 25 K chars per post. So for the game data, posting raw text directly beats links (no ~10 K URL cap): 45 → 20 tweets.

• GitHub Pages hated us. Legacy Jekyll choked on the huge inlined-HTML files (stuck builds, failed deploys). A one-line .nojekyll → serves static, builds in ~15 s.

• Elon grass. Because why not. Swapped the grass entry (16×16 green) in the game's __TEX__ table for a 64×64 render and re-ran the pipeline. Cost: +1 tweet.

The full measured notes live in FINDINGS.md.

Credits & legal

• Minecraft is © Mojang / Microsoft. This is an unaffiliated technical-art demo, not endorsed by them.
• The compose-link trick: @rebane2001.
• Minecraft Classic Forever - Goats for helping me find the actual source to play with
• Made with funmaxxing by Kuber Mehta.