USDai

USDai, sUSDai and CHIP occupy different legal and technical seats. USDai is the transferable synthetic dollar at 0x0A1a…82EF. sUSDai at 0x0B2b…5ef9 is the vault share that absorbs loan income, expenses and impairment. CHIP votes on protocol matters; it is not a higher-yield version of USDai.

This distinction corrects the seductive shorthand “GPU-backed stablecoin.” A USDai holder does not receive title to a rack of servers. The June terms place loan participations into Depositor NFTs held by the sUSDai vault, with distributions and enforcement proceeds flowing through that layer.

Early USD.AI material described USDai as an M-backed token. A December 18, 2025 partnership announced PYUSD integration, and the March 26, 2026 mint-and-redeem notice said the wM-to-PYUSD collateral transition had finished and every USDai was backed 1:1 by PYUSD. The older M wording remains visible in technical documentation.

The current published implementation makes the distinction concrete. USDai accepts only the immutable base token embedded in that implementation, scales it into 18-decimal USDai, burns USDai on withdrawal and sends base-collateral yield to a designated recipient. “AI yield” therefore does not automatically accumulate to a wallet merely holding USDai.

sUSDai stakes the liquid token into a vault whose value is tied to GPU-backed lending. The terms say loan payments accrue pro rata through Depositor NFTs held by the vault. That is a structured-credit exposure: borrower performance, fees and recoveries can move the share price, and the terms expressly allow yield to be zero or negative.

The protective layer changed on February 6, 2026. Traditional FiLo put junior capital ahead of sUSDai losses. For new loans, USD.AI removed the mandatory FiLo tranche and announced Barker valuation warranties backed by reinsurance; existing FiLo positions remain, and the announcement leaves room for traditional FiLo in future deals.

The May underwriting account sets a maximum 80% LTV, at least 20% borrower equity and usually three-year straight-line amortization. It requires a three-month debt-service reserve and tests a 1.15x DSCR quarterly. Two consecutive failures open a 30-day cure before acceleration and enforcement.

Collateral is not liquidated by an oracle in one block. The described structure uses bankruptcy-remote SPVs, liens over hardware and SPV equity, offtake step-in rights, and GPU Finance Ltd. as administrative and collateral agent. Barker’s 80%-of-warranted-value protection costs 150 bps a year from interest, but the project and terms both preserve model, insolvency, jurisdiction and recovery shortfall risks.

The March 26, 2026 notice announced that from April 6 only KYC-whitelisted market makers and approved institutions could mint or redeem directly, and that redemptions would incur a 10-basis-point fee. Current depositor and technical pages repeat the institutional restriction; the announcement does not by itself establish its implementation.

The reviewed Arbitrum v1.6 implementation tells a different execution story: deposit and withdraw check the immutable PYUSD base token, pause state and blacklist status, but contain no whitelist test and no 10-bps deduction. The restriction may live at the interface, in operations or elsewhere, but these public sources do not prove where.

sUSDai has a separate clock. Its current specification uses 30-day global FIFO epochs, with partial fills and carry-forward when cash is short; active loans are not force-liquidated. The 2025 QEV essay proposed priority bidding and urgency premiums, but the present page marks QEV as not implemented.

Terms modified June 4 identify USD.AI Foundation as a Cayman foundation company and GPU Finance Ltd., its BVI subsidiary, as loan and collateral agent. They deny deposit insurance, guarantee neither dollar value nor yield, apply Cayman law and generally require individual AAA arbitration for Service disputes.

Code creates another authority map. A two-day timelock controls proxy upgrades. Separate 3-of-3 Safes hold default administration, a 2-of-3 Safe holds pause authority, and a 3-of-4 Safe services sUSDai strategy functions. Default admins can grant new roles, including blacklist power; USDai and sUSDai were unpaused when reviewed.

The evidence fixes identity but refuses one tidy diagram. Official pages preserve M and PYUSD backing, open code and KYC-only direct redemption, 70% FiLo and 80% Barker underwriting, and a QEV proposal beside implemented FIFO exits. This account treats dated changes, current docs, current code and direct chain state as separate evidence rather than silently choosing the most convenient claim.