description	Rotating savings on Stellar, enforced by a smart contract instead of a collector you have to trust.

Introduction

OpenAjo brings Nigeria's rotating savings groups — ajo, esusu, adashe — on-chain. A group agrees to contribute a fixed amount on a schedule; each cycle, the whole pot pays out to the next member in turn. OpenAjo replaces the trusted human collector with a Soroban smart contract on Stellar that no one controls.

The problem

Rotating savings is how a large share of Nigeria saves. Per EFInA's Access to Financial Services survey, 14.6 million Nigerian adults relied on informal mechanisms only in 2018 — savings groups, esusu, ajo, and collectors — up from 9.4 million in 2016. These groups work on trust, and that trust is the weak point:

• The collector holds everyone's money between cycles. "The ajo collector ran away with our money" is a loss story millions of people know first-hand.
• Records are on paper or in one person's head. Disputes have no source of truth.
• A member who collects their payout early has no reason to keep contributing.

Existing apps — AjoMoney, Thrifto, Alajo, KoloPay — digitize the ledger, but they replace the collector with a company you must trust instead. The custodian changes; the custody problem doesn't.

How OpenAjo is different

There is no custodian. A Soroban contract holds the funds and enforces the rules:

• Escrow — contributions and deposits are locked in the contract, not in anyone's account.
• Enforced order — payout order is fixed at activation and executed by code.
• Priced default — every member posts a security deposit. Miss a contribution and the shortfall is slashed from your deposit into the pot, so the group is made whole.
• Portable reputation — a member who defaults is recorded permanently in an on-chain registry, visible to every future circle.
• No trusted operator — anyone can trigger a due settlement (settle_cycle is permissionless), so circles keep moving without a middleman.

Why Stellar

• Fees are fractions of a cent. A contribution can be as small as ₦1,000-worth of USDC without fees eating the savings — the difference between viable and not for this use case.
• USDC has real on/off-ramps in Nigeria, so the value in a circle is spendable, not stuck.
• Soroban gives the contract the escrow, authorization, and cross-contract calls the protocol needs.

Live on testnet

The contracts are deployed and verified on the Stellar test network.

Contract	ID
circle	CCLVOHGHDH32GWFAMCEMVHLNJSF6ENVHERYWU2OHUYWWLAOKLVR3HGKS
reputation	CDXPH2PYUTRW7GV57X6CJH3E3JOPROSC23NXPMAXOO3EOBI5UTCB2GTQ

Where to go next

• New to the protocol? Read Circle lifecycle.
• Want to use it? Start with Set up a wallet.
• Building on it? See Architecture and the SDK reference.

OpenAjo is unaudited and deployed to testnet only. Do not use it with mainnet funds.