Fuel Credit development plan

Goal

Build an open-source Fuel-native credit facility where FUEL holders lock FUEL and borrow USDC on fixed terms without mark-to-market liquidation.

Loan product

Term	Advance rate	Interest
6 months	20%	10% APY on borrowed USDC
9 months	22.5%	10% APY on borrowed USDC
12 months	25%	10% APY on borrowed USDC

Target onchain rules:

• A user deposits FUEL collateral and receives USDC if pool liquidity exists.
• The borrower sends FUEL collateral plus the complete upfront FUEL fee and receives USDC atomically in the same transaction.
• There are no price-triggered liquidations.
• Maturity is the final repayment deadline; there is no additional grace period or post-maturity repayment window.
• Partial USDC principal repayment is accepted only before maturity and returns collateral pro rata.
• No interest or fee is due during repayment because the fixed, prorated fee was charged upfront.
• At maturity, unpaid positions become terminal defaults: repayment closes, remaining USDC is recorded as defaulted, and all unreleased FUEL collateral is claimed into the managed vault.
• A reusable five-minute Fuel secp256k1 oracle attestation signs only FUEL price and timestamp; the contract computes and enforces principal, fee, borrower, term, payment, and liquidity.
• Permissionless FUEL and USDC top-ups and owner-only idle withdrawals support lending, repayments, strategy operations, and accounting.

Production currently provides quoting and an explicitly browser-only Burner simulation. Real deposit, borrow, repayment, and collateral-release transactions are not wired yet.

Phases

Phase 0 — planning and skeleton

• Keep the protocol, application, deployment tooling, and documentation minimal.
• Document addresses, architecture, UX, risks, and tickets.
• Confirm Fuel asset IDs and Sway standards to use.

Phase 1 — local/testnet MVP

• Single Sway lending contract.
• Local FUEL/USD price-attestation signer for development only.
• React app with Fuel wallet connector.
• Deposit, borrow, view loans, repay, and claim collateral.
• Protocol metrics are derived from contract events and reconciled against contract reads.
• Local/testnet deploy scripts write artifacts into deployments/.
• Testnet faucet helper links users to the Fuel faucet after wallet connect.

Phase 2 — production hardening

• Harden oracle key custody, price-attestation monitoring, and rotation; Stork remains an optional future signer/input.
• Add contract audit checklist and invariant tests.
• Add permissionless automation-bot runbook for matured loan finalization.
• Prepare a guarded public application release after contract deployment approval.
• Add mainnet guarded deploy flow with balance warnings and address confirmations.

Phase 3 — bridge and growth UX

• Add LayerSwap bridge option for Ethereum-held FUEL.
• Detect EVM FUEL balance where possible.
• Add richer historical stats export, managed-vault strategy reporting, and confidence metrics.
• Add docs site polish and public launch material.

Deliberate MVP cuts

• No automated LayerSwap bridge in Phase 1.
• No mandatory external oracle integration in Phase 1; the configured oracle signs current FUEL price attestations.
• No multi-contract architecture unless tests prove the single-contract path is unsafe.
• No complex admin UI; permissionless maturity-finalization bots can be CLI scripts first.