Open source, on Stellar
Add a little, or skip.
Before they sign, an app can ask if they want to add a little for a foundation, or round up. They decide. Spare never takes custody of the funds.
Open source · MIT · No custody · The registry is public
The idea
A short question at checkout, in wallets they already use.
What this is
Simple, transparent donations in the payment flow.
Open source
The kit, the interface, the registry, and the indexer are public.
Transparent
Every foundation has a record anyone can read.
No custody
The gift goes to the foundation. Spare never holds the funds.
Flexible
A fixed amount or a round-up, in classic wallets, Soroban, or Ledger.
Add it to your app
Add the question to checkout with the SDK and Spare Wallets Kit.
Give, if they want
A fixed amount or a round-up. They can always continue without giving.
Foundations receive
The gift goes straight to the foundation. The movement stays in view.
How it works
The app asks
When they sign, they see the option to add a little or round up.
They decide
They accept, change the amount, or continue. Nothing moves without their signature.
The registry is public
The foundation receives the gift. The movement is recorded in the registry.
FAQ
Questions, answered
Does Spare hold the money?
No. Funds go from the user to the foundation in a normal Stellar payment. Spare never holds funds and takes no cut.
Who pays the fee?
A classic donation is one more payment operation in the same transaction, so the transaction fee is raised by one operation. The Soroban follow-up is its own payment transaction with its own fee. Spare checks the user can cover the donation and the fee before it offers anything.
How does round-up work?
Round-up adds what it takes to reach the next whole dollar, and only when the whole transaction is a Circle-USDC purchase (payments, pathPaymentStrictSend, sell offers). If the amount is already whole, or the real spend is unknown up front, only a fixed amount is offered.
Why does a Soroban call need a second signature?
A Soroban transaction holds only one operation, so the donation cannot ride along. Spare sends a separate payment after the call succeeds, and the confirmation says so before the user accepts.
Does the dashboard show who donated?
No. The public dashboard aggregates by app and foundation and never lists donor addresses.
How is a foundation verified?
A foundation registers its account in the Spare registry contract and lists the same account in the ACCOUNTS field of its website's stellar.toml (SEP-1). Nobody approves it by hand. “Domain-verified” means exactly that, nothing more.