An auto-compounding USDG vault. Harvested interest lands in a spendable layer called the white, and the card draws from the white and nowhere else. Your principal, the yolk, has no code path to a checkout.
Illustration on a 10,000 USDG deposit. One harvest here represents one protocol day.
Every other yield card blends principal and interest into one number, then asks you to have the discipline not to spend it down. Yolk splits the number in two at the contract level, and only one half is reachable.
Your principal. It compounds, and it is the only thing the withdrawal function can return to you.
The spendable layer. Each harvest deposits interest here, and the card draws here and nowhere else.
Shell, white, yolk. Three layers, and value only ever moves inward or out through the white. Every render below is the same object under a different cut.
Whole
Cut away
The yolk
LayersA keeper calls harvest. Interest accrued since the last cycle is realised, and the dial you set decides how it is divided. Both destinations are inside your own vault. Nothing leaves.
Lending interest from an on-chain money market. No emissions, no validator staking, no rewards token that has to be sold to be worth anything.
Your chosen share is credited to the spendable layer. This is the only balance the card processor can ever see or draw against.
The remainder compounds into principal. Set the dial to zero and Yolk is a plain auto-compounding vault with a card you simply never use.
Deposit once. Everything after that runs without you, and every stage moves value in the same direction: toward the yolk, or toward the white. Never out.
Send USDG. You receive ERC-4626 shares that represent your slice of the yolk.
A keeper realises accrued interest on a cycle. Capped gas, public calldata, anyone can watch it.
Your dial divides the harvest between the white and the yolk. Change it whenever you like.
The card authorises against the white. If the white is empty the card declines. That is the whole safety model.
The only decision Yolk asks you to make. Everything to the left compounds, everything to the right is spendable. Move it and see what you are choosing.
Illustrative only. The yield figure is an assumption you set on these sliders, not a rate Yolk quotes, offers or guarantees. Real returns are whatever the underlying money market pays, and can be lower.
Yolk runs on the USDG-native L2, an Arbitrum Orbit rollup, chain id 4663, fully EVM equivalent. The yield is lending interest from an on-chain money market and nothing else: no emissions, no validator staking, no rewards token.
Nothing here is exotic. The novelty is entirely in which balance the card is allowed to see.
A card authorisation can only debit the white. There is no code path from a swipe to the yolk.
An empty white declines the card. It never borrows against, liquidates or dips into principal to approve a payment.
Withdrawal returns the full yolk plus whatever is unspent in the white, in the same block you ask.
The dial only ever routes new harvest. Moving it cannot retroactively move value that has already settled.
Harvests are permissionless to trigger and identical for every depositor. No priority, no preferred tier.
If the oracle is stale or the market is paused, the cycle skips itself rather than harvesting on bad data.
Card spending is denominated in USDG and settled out of the white. The token governs the protocol and captures its fees. It is deliberately not part of the payment path, so a volatile day in the market cannot change what your card does at a checkout.
Dates get missed and the queue dies with them. These ship in order, and each one is announced when it is live and not before.
ERC-4626 vault, harvest keeper and the split dial, live on Robinhood Chain with the white and the yolk fully separated in the contract.
Authorisation against the white only, with declines instead of overdrafts. Spend history readable on-chain against the same shares you already hold.
Multiple cards drawing on one white, each with its own cap, over a single shared yolk. For households and for teams that want one treasury and many spenders.
Third-party strategies competing to fill the white, chosen per vault, with the same invariant enforced on every one of them.
The card processor is only ever shown the white balance. The debit function takes the white as its argument and reverts if the amount exceeds it. There is no fallback branch that reaches into the yolk, so it is not a matter of discipline or of a setting you could turn off.
Yes, in full, in the block you ask. Withdrawal burns your shares and returns the underlying yolk plus anything unspent in the white. There is no lock, no notice period, no queue and no exit fee.
The authorisation declines. That is the intended behaviour rather than a failure. Yolk would rather your card say no at a checkout than quietly sell down the position you spent a year building.
Lending interest from an on-chain money market on Robinhood Chain. No emissions, no validator staking, and no rewards token that has to be sold to be worth anything.
Not announced. When there is one it will be published here and on the project account first, and anything circulating before that is not from us.