Interest and repayment
Fixed terms
Fuel Credit uses a fixed 10% APY, prorated when the loan opens.
| Term | Approximate upfront fee at 10% APY |
|---|---|
| 6 months | 4.93% of principal |
| 9 months | 7.40% of principal |
| 12 months | 9.86% of principal |
The LTV schedule remains 20% for six months, 22.5% for nine months, and 25% for twelve months.
Upfront FUEL fee
The oracle attests the current FUEL/USD price. The contract uses that price and the selected term to compute the USDC principal and complete prorated fee. The borrower sends collateral and fee together in FUEL; the contract records them separately and transfers the USDC principal atomically.
The fee is fully paid at opening. Repayment therefore covers USDC principal only; no interest or fee is collected again.
Signed price attestation
A configurable Fuel secp256k1 oracle address signs the versioned FuelCredit:PriceAttestation:v1 domain bound to chain ID, contract ID, FUEL/USD price, and price timestamp.
The timestamp uses Fuel's TAI64 block time in seconds. Attestations expire after 300 seconds and are intentionally reusable across borrowers and terms while current. The contract independently enforces the borrower, supported term, LTV, principal, fee, exact payment, and liquidity. This keeps the signing service oracle-like and does not require Stork, although governance may replace or supplement the signer later.
Repayment deadline
All USDC principal must be returned before maturity. Partial principal repayments are accepted only while the loan is active and before maturity. Each partial payment returns collateral pro rata; a final payment returns all remaining collateral, including rounding dust.
At maturity, an unpaid position is terminal: repayment closes, remaining USDC principal is recorded as defaulted, and all unreleased FUEL collateral is claimed into the managed vault. The borrower cannot cure or repay it afterward. There is no extension or grace period.
Deployment status
The release build is deployed on testnet and local Fuel Core end-to-end tests pass. Testnet pools remain unfunded. The production price-oracle service, real app transaction wiring, production pool funding, independent audit, and mainnet deployment remain pending.
Original accounting
Every loan permanently retains its original FUEL collateral, USDC principal, upfront FUEL fee, attested price, price timestamp, and maturity. Separate mutable fields track USDC repaid, USDC defaulted, FUEL collateral released, and FUEL collateral claimed by the vault. This preserves original and remaining obligations for reconciliation.