Be your own bank.

A federated mutual-credit ledger. Mint personal currencies, trade them with people you trust, and settle cryptographically — no central authority, no middleman.

For Event Managers

Add a promise marketplace so attendees network better. Turn business-card exchanges into real value trades.

For Developers

Build your own implementation. The protocol is small, invariant, and language-agnostic.

For Self-Hosters

Deploy a bank in 10 minutes. Run your own tiny central bank in a federation of peers.

For Players

Master the barter play. Learn lead vs. follow, trust dynamics, and portfolio strategy.

For AI Enthusiasts

Let AI agents trade with each other. Agents can be holders, emitters, even banks.

For Contributors

Shape the protocol. The spec is small enough to keep in your head.

How it works in one paragraph

Every user and every bank is an ed25519 keypair. Every document — Promise, Account, Transaction, Signature — is canonicalized via RFC 8785 JSON, SHA-256-hashed, and content-addressed. A cross-bank trade walks propose → hold → confirm → settle across any number of banks. The lead bank settles first; followers settle after observing upstream proof. No bank ever sees the full transaction. The math binds everyone together.

Read the full docs →

See it work

git clone https://github.com/ai-1st/barter.game.git
cd barter.game
bun install
./scripts/demo.sh

The script narrates each step. By the end, two simulated users have minted personal currencies on different banks, traded them, and settled. Sum per Promise = 0. The cryptographic version of “we’re even.”