Savings that keep themselves. Every USDC payment splits on-chain into spend and keep; savings wait before they can leave, and you can take an advance against them. Passkey wallet on Arbitrum.
The problem. Freelancers and web3 contributors paid in USDC have no tool that saves for them. The money lands in a wallet next to a card and an exchange, and most of it is gone within days. Saving depends on willpower, and willpower loses at 2am.
What Keep Yours does.
Auto-split: every incoming payment splits on-chain into "to spend" and "kept" (for example 60/40). No tap needed.
Waiting period: kept savings can only leave after a waiting period you choose (for example 72 hours). Withdrawals go only to your own wallet and can be cancelled while they wait. You get a push and a Telegram alert, so if someone else got into your phone you'd know.
Advance: if a client pays late, borrow up to half your savings. Free for 30 days, then 1.5%, then 3%. Your next payment repays it automatically before the split. After 90 days it is settled from your savings, with no penalty.
Rules that protect you: saving more applies at once. Saving less or a shorter wait has to wait out the current waiting period.
How it's built. One vault contract per user (EIP-1167 clone from a factory), never a shared pool. Advances come from a separate pool funded by the builder, never from other users' savings. No admin key can move user funds, and nothing can pause withdrawals. Wallets are ZeroDev passkey smart accounts (Face ID, no seed phrase) with sponsored gas. The app is an installable PWA, and a keeper sends closed-app push notifications and Telegram alerts.
Security. Solidity 0.8.28 and OpenZeppelin 5. 64 unit tests plus a stateful invariant suite: mutation-tested, so 5 planted bugs are all caught. The Slither findings are reviewed. The contracts are not yet audited, so deposits are capped at $200 per vault.
Who it's for. Freelancers paid in stablecoins, starting with the SL Web3 Builders Club community in Sri Lanka.
Everything was built during the Buildathon: first commit 24 Sep 2026, 142 commits since.
Contracts: KeepVault, KeepVaultFactory and AdvancePool. Unit and invariant tests, Slither review, deployed and verified on Arbitrum Sepolia.
App: an installable PWA with a passkey wallet, auto-split, withdraw with waiting period and cancel, advance and repay, settings changes on-chain, activity, and auto-lock.
A keeper on a VPS: closed-app push notifications, Telegram alerts, and automatic settlement.
Testing with a tester group so far: 7 vaults created, 9 payments auto-split, 5 advances taken and all repaid or settled, 3 withdrawals requested and 3 cancelled.
Not raised. Bootstrapped: the advance pool is seeded with the builder's own funds. Next: an audit and a capped Arbitrum One launch, for which we'd apply for the milestone grants.