Trustless rotating savings circles (Ajo/Esusu/Chama/Tanda) on Stellar/Soroban. No backend, no custodian.
# Ajo — Rotating Savings Circles on Stellar
**A trustless Ajo/Esusu/Chama/Tanda circle, held by a smart contract instead of a person.**
Ajo digitizes the rotating savings and credit association (ROSCA) — the informal
savings circle known by dozens of names across the world (Ajo/Esusu in
Nigeria, Chama in Kenya, Tanda in Mexico, Susu in Ghana and the Caribbean,
committee/kameti in South Asia). A fixed group of members each contribute the
same amount every cycle; one member takes the full pot per cycle, in
rotation, until everyone's had a turn.
The mechanic works. What's always been fragile is the trust model: an
organizer, or whoever's turn it is to collect, physically holds everyone's
money until payout. If they vanish, get sick, or spend it, there's no
recourse — which is why these circles rarely extend past people who already
know and trust each other.
Ajo keeps the mechanic and removes that single point of failure. A Soroban
smart contract custodies the pot instead of a person, enforces the
contribution schedule, and pays out automatically — trustless by
construction, not by promise.
- **Network:** Stellar / Soroban, testnet
## How it works
1. **Start or join a circle.** Set a contribution amount, a cycle length, and
a member count. Join order becomes payout order — fixed the moment the
circle fills, verifiable on-chain, no separate randomization step to
trust.
2. **Contribute every cycle.** Once full, every member pays their fixed
contribution into the contract each cycle. Wallets sign directly — Ajo
never takes custody of a private key.
3. **The contract pays out automatically.** As soon as every member has
contributed (or the cycle deadline passes, so one non-payer can't freeze
everyone else's money), the contract releases the full pot to that
cycle's member. No organizer collects or distributes anything by hand.
## Why this belongs on Stellar
- **Fees in fractions of a cent.** A weekly contribution shouldn't cost more
in gas than the amount being sa …