NOJIRA-97B7E125: Create a Venus Improvement Proposal (VIP) targeting BNB Chai

[GitGuru7]

VIP-664 [BNB Chain Testnet] — Raise vUSDT (Core Pool) Borrow Cap +25%

What changed

• vips/vip-664/bsctestnet.ts — proposal (makeProposal, ProposalType.REGULAR) with a single command:
  _setMarketBorrowCaps([vUSDT], [65399377742237]) on the Core Pool Unitroller.
• simulations/vip-664/bsctestnet.ts — fork simulation (pre-state → testVip + expectEvents → post-state → behavioral proof).
• ABIs copied into simulations/vip-664/abi/: DiamondConsolidated.json, ERC20.json, VToken.json, ResilientOracle.json.

Supply cap note (deviation from the literal request, per approved spec)

The request asked to raise both the supply and borrow caps by 25%. On-chain, supplyCaps(vUSDT) returns type(uint256).max — the supply cap is effectively unlimited and unenforced. Raising it by 25% would overflow and have no behavioral effect, so the VIP changes only the borrow cap and documents the unlimited supply cap in the proposal description. The behavioral test proves a user can supply (mint) vUSDT under this unlimited cap. vUSDT is active on the testnet Core pool, so no alternative market was needed.

On-chain verification (broker chain.call, bsctestnet)

Item	Value	Source
vUSDT	0xb7526572FFE56AB9D7489838Bf2E18e3323b441A	symbol() → "vUSDT"; markets(vUSDT).isListed = true, CF = 0.8
USDT underlying	0xA11c8D9DC9b66E209Ef60F0C8D969D3CD988782c	vUSDT.underlying(); decimals() → 6
Core Pool Unitroller	bsctestnet.UNITROLLER = 0x94d1820b2D1c7c7452A163983Dc888CEC546b77D	networkAddresses.ts
Borrow cap (current)	52319502193790 (= 52,319,502.193790 USDT)	borrowCaps(vUSDT)
Borrow cap (new, +25%)	65399377742237 (= 65,399,377.742237 USDT)	floor(52319502193790 * 125 / 100)
Supply cap	type(uint256).max	supplyCaps(vUSDT)
MINT action paused?	false	actionPaused(vUSDT, 0)

Signature selector confirmed: _setMarketBorrowCaps(address[],uint256[]) exists in DiamondConsolidated.json. Fork block 104700000 confirmed valid with the same current cap.

Tests run + results

Command:

npx hardhat test simulations/vip-664/bsctestnet.ts --fork bsctestnet

Result: 10 passing (27s)

• Pre-VIP: borrow cap = 52,319,502.193790 USDT; supply cap = type(uint256).max
• testVip executes propose→vote→queue→execute; exactly 1 NewBorrowCap event
• Post-VIP: borrow cap = 65,399,377.742237 USDT (+25%); supply cap unchanged (type(uint256).max)
• Behavioral: an impersonated supplier (VTreasury, holds USDT) mints vUSDT supplying 1,000,000 USDT — does not revert, USDT balance decreases by exactly the supplied amount, vToken balance increases (proving supply is unbounded by a cap)

Lint/format:

npx eslint vips/vip-664/bsctestnet.ts simulations/vip-664/bsctestnet.ts   # exit 0
npx prettier --check ...                                                   # All matched files use Prettier code style!

Skill path

authoring-vips (pure VIP — all referenced contracts already deployed on-chain; no testnet deploy).

Risks / notes

• Only the borrow cap is modified (supply cap is already unlimited) — see the supply cap note above.
• Routine risk-parameter change; aggregate USDT borrow capacity increases by ~13M USDT.

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