Vibecoding the Chain: Minecraft on Cardano

Two years ago, "build a blockchain game" meant three weeks of wallet integration hell before you even drew a triangle. Last week I typed one prompt and got a playable Minecraft clone where every block you place is a real Cardano transaction.

That's not an exaggeration. That's just where we are now.

Hydra Minecraft

The idea: a voxel game in the browser (Three.js) where placing or breaking a block writes a real transaction to a Cardano Hydra L2 head — but you never feel it. No wallet popup. No "confirm in your extension." No 20-second wait. You just… mine.

The trick is a relay server that signs each NewTx and streams block deltas back fast enough to keep up with your mouse. Hydra's off-chain head does thousands of tx without touching L1 until you're done.

Here's the kicker: I didn't hand-write it. Claude Fable 5 did — end to end, from a single prompt, plus three lazy follow-ups for survival mode, TNT, mobs, caves and ores. I kept the exact prompts in PROMPT.md so anyone can rebuild it.

This isn't "AI wrote my boilerplate"

I want to be precise, because "vibecoding" gets clowned for good reasons. This wasn't autocomplete. This was: describe a genuinely hard systems problem — real-time gameplay bound to an L2 consensus layer — and get back a working architecture, not just code that compiles.

I did the same energy with Hydra Chess: wagered chess inside a Hydra head, where the pot is escrowed by an Aiken contract that makes it un-stealable and un-freezable. Turn-based games as L2 transactions, settled trustlessly.

Where the human still matters

The agent is fast, but it doesn't know what's worth building or whether the demo actually holds up under a stalling opponent. That judgment is still mine. Which is exactly why I built Loom — one CLI that weaves Claude Code, OpenCode and friends into a single shared thread per project, so the memory lives with the work, not the tool.

The takeaway for anyone my age staring at this stuff: the barrier to shipping something real just collapsed. The people who win now aren't the ones who can type the fastest — they're the ones with taste, and the guts to point an agent at a hard problem and say go.