Bitcoin commerce, woven from community trust.
Buyer, seller, and arbiter — three roles woven into one accountable trade. Pay bills, swap sats for cash, shop local stores, lend within your community. Nobody holds your money. Not even us.
No role dominates. Ever.
Every trade weaves three participants together. Sats move only when two of the three agree — cooperation enforced by mathematics, not promises.
Seller
Locks the sats
The seller has sats and wants fiat. The instant the deal is struck, their sats lock in escrow — split into three cryptographic shares. No one can move them alone. Not even Chama.
Buyer
Claims the sats
The buyer brings fiat — mobile money, bank transfer, or cash in hand — and walks away with sats. Two of three shares release the funds. Identity is a Nostr key, not a passport.
Arbiter
Justice for all
Steps in only when the two disagree, and rules for whoever is telling the truth. A reputation-staked community member: open roster, public record, calm judgment.
Teal passes over orange. Orange passes over purple. Purple passes over teal.
No role dominates forever — the weave rule lives in the logo and in the protocol.
Five products.
One trust primitive.
Everything runs on the same 2-of-3 escrow. Different flows, identical trust model: zero.
Post any bill — electricity, rent, school fees. Lock sats in escrow. A community volunteer pays it and claims the sats. No wallet required to understand it. This is how the next billion people meet Bitcoin.
Seller locks sats. Buyer sends fiat by bank, mobile money, or cash. Both confirm, escrow settles. No order books, no custody, no KYC.
Community storefronts with real reputations. Pay sats, goods ship, escrow protects both sides — ratings follow the npub, not the platform.
Lock sats as loans with trust-tiered limits. Auto-generated repayment escrows, interest tracking, arbiter-verified repayments. Microfinance on Bitcoin.
Every country gets a community.
Pick your flag at sign-in — currency, languages, payment rails, and arbiters are all local. The cryptography stays invisible plumbing.
Pay the way your neighbors already pay
A community is a currency, a culture, and the payment rails people actually use. Listings advertise the rail; your handle stays private until sats are locked.
Bring Chama home
Anyone can light up a community: claim your flag, recruit local arbiters, plug in your own Fedimint federation — or start on the default one today. No approval gate. No application form.
Open the globe →Five signed events.
One trustless trade.
The entire escrow lifecycle is a Nostr event chain. No database required — replay the chain, reconstruct the state.
Create
Trade terms published as kind:38100. NIP-44 encrypted, multi-relay broadcast. Participants only.
Join
Counterparty and arbiter sign kind:38101 events. Three present → escrow can fund. Federation validated at join, not later.
Lock
Ecash notes split into 3 Shamir shares in browser WASM. Each share encrypted to its recipient. The server never touches funds.
Vote
2-of-3 consensus resolves the trade. Agreement is instant. Disagreement goes to the arbiter — timeout, then auto-rotation.
Claim
Winner combines 2 shares, reconstructs the ecash, and withdraws over Lightning. 0.5% fee at payout. Trade complete.
Built different.
Every design decision eliminates a trust assumption.
Shamir Secret Sharing
Ecash split into 2-of-3 shares in browser WASM, each NIP-44 encrypted to its participant. The server is mathematically blind.
Fedimint underneath
Blinded tokens, instant settlement, zero routing fees. A fully client-side wallet that drains to zero after every trade.
Nostr identity
One key across every product. NIP-98 signed sessions. No passwords, no emails, no accounts to freeze.
Encrypted trade chat
Per-trade messaging between the three participants. Private during the trade, replayable as evidence in a dispute.
Arbiter marketplace
An open roster with applications and public track records. Reputation is the backbone — earned, not bought.
Multi-relay by design
Custom kinds 38100–38121. Publish to all relays, succeed on one. Any client can replay full escrow state.
Two ways in.
Play in the browser with no money on the line, then trade for real on your phone.
Walk through every flow — fund, lock, vote, claim — with simulated sats. No keys, no risk, nothing to lose.
Launch the sandbox →Install the real app and trade with your own keys. Distributed on Zapstore — a permissionless app store built on Nostr.
- Permissionless — no gatekeeper, no review board
- Every build signed by the developer’s key
- Discover and tip apps with Lightning zaps
- Android APKs delivered straight over Nostr
A coordinator.
Not a wallet.
Lightning moves value in. Ecash exists only inside the escrow window. Lightning moves value out. Sats are never parked, never pooled, never ours.
The promise: no sats stranded, ever. Every guard, every recovery path, every refusal in the codebase is that one promise wearing different clothes.
And it’s all in the open. You don’t have to read the code to trust Chama — but it’s there if you do. Every honest act is rewarded: ratings become reputation — your credibility, your superpower — and arbiters earn a direct 1% only when they settle a dispute fairly. Good behavior compounds; bad behavior goes nowhere.
Your community.
Your money.
Your rules.
Open source. No incorporation. No token. Just cryptography, community, and freedom.
Come say hi.
A place to say hi, thank someone, or share feedback — on Fedi. Scan to join every room at once, or pick yours.
