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. Promise, Pocket, Account, Tx, Signature, Subscription, and Order docs are canonicalized via RFC 8785 JSON, SHA-256-hashed, and content-addressed. Ledger records are bank-minted with ULIDs. In a cross-bank trade the initiator creates the record pairs (create_records), then each holder signs their own Tx (submit_tx) — lead for the initiator, follow for everyone else. From there the banks self-advance: per-record approvals, holds, then settlement — lead bank first, followers after observing upstream proof, with signatures pushed between banks via subscription fan-out. No bank ever sees the full transaction. The math binds everyone together.
See it work
git clone https://github.com/ai-1st/barter.game.git
cd barter.game
bun install
./scripts/demo.shThe 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.”