What if money had an expiration date? Building an open-source UBI currency

I've been building something that I think could matter, and I want honest feedback before I go further.

The idea: A digital currency where every participant automatically receives 100 tokens per week (UBI), and balances decay over time — the more you hold, the faster they shrink. This makes it impossible to hoard wealth and forces tokens to circulate. You need 3 real people to vouch for you to participate, so bots and fake accounts can't farm the system.

Why it's designed this way:

Today's money has a fundamental problem — it flows upward and stays there. People with capital earn interest, invest, and accumulate more. People without capital stay stuck. Every cryptocurrency so far reproduces this: Bitcoin rewards miners and early holders, Ethereum rewards stakers, and every token on an exchange becomes a speculative asset where the goal is "number go up."

This is designed around the opposite principle: money should move, not sit. Demurrage (balance decay) isn't a bug — it's the core feature. It means your tokens are only useful if you spend them, which means they always end up in someone else's hands, which means they circulate through the whole community instead of pooling at the top. Combined with UBI, it creates a floor — nobody starts at zero, and nobody can passively accumulate without participating.

What makes it different from crypto: There's no blockchain, no mining, no staking rewards, no token on exchanges. You can't speculate on it. It's not trying to be a store of value — it's trying to be money that actually moves between people. Think of it as the opposite of Bitcoin: instead of rewarding people for holding, it rewards people for spending and participating.

What's built: A working prototype. The entire app is a single 1.2MB HTML file (Rust compiled to WebAssembly) — you open it in a browser and you have a wallet. Works offline. No accounts, no app store, no backend. Transfers work face-to-face via QR codes or remotely through relay servers that anyone can run. Transaction amounts are hidden using zero-knowledge proofs. If you lose your phone, 3 of your 5 chosen guardians can help you recover your wallet.

The problem: Right now it works for a local community — maybe a few hundred to a few thousand people. I want to figure out how to scale it to millions without losing the core properties (everyone gets income, nobody can hoard, no central authority, privacy by default).

I have some ideas on the roadmap (recursive zk-proofs for verification, DHT for peer discovery, relay federation) but honestly I'm not sure I'm thinking about this the right way. There might be better approaches I haven't considered.

If this sounds interesting or if you've worked on similar problems, I'd love to hear your thoughts — what would you do differently? What am I missing? DM me if you want to see the technical details or the codebase.

Not a company, not hiring, no token sale. Just an open-source project (CC0 public domain) trying to build a currency where wealth circulates instead of concentrating — and everyone starts with enough to participate.