flow-credit-markets

Users holding an asset are seeking higher returns than the direct yield opportunities of that asset. Using the asset as collateral to borrow a debt token can gain those higher yields, but requires permanent user interaction to keep asset exposure, maximize yield and prevent liquidation. We utilize flow's unique feature of scheduled transactions to automate this process, constantly adjusting the position to keep asset exposure at 100%, maximizing the potential debt to maximize yield while making sure the user doesn’t get liquidated. This will bring TVL and users to Flow, provide a revenue stream through fees, and demonstrate a practical application of Flow’s unique feature of scheduled transactions.

Installation

curl -L https://foundry.paradigm.xyz | bash
source ~/.zshenv   # or restart your shell
foundryup

Build & Test

make ci             # fmt check + build + tests (solidity + cadence)
make solidity-test  # solidity tests only
make cadence-test   # cadence tests only (requires the Flow CLI)

Architecture

See Architecture

Deployment

Deployments are manual and target Flow mainnet directly — see the mainnet-* targets in the Makefile (every one has a -dry variant that fork-simulates against live state first). EVM deployments sign with a Foundry encrypted keystore account (set it up once with make setup-evm-deployer); the Cadence rebalancer signs with the mainnet-deployer Flow account (see below). Dependency addresses used at deploy time are pinned in solidity/deployments/mainnet.json.

Cadence contract (VaultRebalancer)

Automates FCMVault.rebalance() on an interval via FlowTransactionScheduler. The signer is the mainnet-deployer account in flow.mainnet.json. This account becomes the resource owner and pays scheduling fees. The overlay is loaded only by the rebalancer make targets (via -f), so flow test / make ci never touch it. For -dry, start a forked emulator in a separate terminal with make mainnet-fork-emulator.

VAULT is the FCMVault EVM address from the EVM deploy above:

make mainnet-deploy-rebalancer
make mainnet-setup-rebalancer VAULT=0x… TICK_INTERVAL=3600.0 EVM_GAS_LIMIT=200000 EXECUTION_EFFORT=20000
make mainnet-schedule-rebalancer VAULT=0x…

mainnet-deploy-rebalancer is idempotent (--update): re-running it ships an additive contract change in place, subject to Cadence contract-update validation.

To tear a rebalancer down — cancel its pending tick (refunding the fee to the deployer's FlowToken vault), destroy the resource, and free its storage path so the same target can be re-created — use the remove target. This is the way to stop fee drain on an unused or misconfigured rebalancer:

make mainnet-remove-rebalancer VAULT=0x…

Calldata is hardcoded to rebalance() and scheduler priority to Medium. The deployer must hold enough FLOW for the per-tick scheduling fee plus the account storage minimum.

Deployed contracts (Flow EVM mainnet)

Contract	Address
FCMVault	not yet deployed
YieldTokenOracle	not yet deployed

Deployed contracts (Flow mainnet — Cadence)

Contract	Account
VaultRebalancer	not yet deployed

Morpho market (WETH collateral / PYUSD0 loan, LLTV 86%): 0xe9c0fc2a0c62a6e5cdee4bc4d06d571850a2add3bb7c96d8c3a75997cae6b866

Dependencies (Flow EVM mainnet)

Morpho Blue

Contract	Address
Morpho	0x9a094eA4AbE343D908E1bDE9fC478D71b41D665f
Morpho IRM	0xdFC4f7951EcDd2D505b6406e9c886c0dB9393546

Pyth oracles

Feed	Address
Pyth Oracle Factory	0x32130316E1Fc503F8a6c8DEbA8320A9d45B3D135
WBTC/USD	0x5B3e0BA14443B444D557C0C2F85592d88B88f5c8
WETH/USD	0xD744044044C0Dd0c73BeA440747115674Ebae030
WFLOW/USD	0xd8848Ccc8beA82046Da0B144844118db17086af4

Update these Pyth feeds with the Foundry script. The script requires curl; --ffi lets Foundry invoke it to fetch the latest update from Hermes. Run without --broadcast first to simulate the update:

cd solidity
forge script script/UpdatePythPrices.s.sol:UpdatePythPrices \
  --rpc-url https://mainnet.evm.nodes.onflow.org \
  --account "$ACCOUNT" \
  --ffi

Then broadcast it:

forge script script/UpdatePythPrices.s.sol:UpdatePythPrices \
  --rpc-url https://mainnet.evm.nodes.onflow.org \
  --account "$ACCOUNT" \
  --ffi \
  --broadcast

Foundry prompts for the account's keystore password. Add --sender "$SENDER" if the sender cannot be inferred from the account. The account must hold enough FLOW to cover the dynamic Pyth update fee printed by the script plus gas. Per Price Feed is 0.5 FLOW.

ERC-20 tokens

Token	Address
WETH	0x2F6F07CDcf3588944Bf4C42aC74ff24bF56e7590
PYUSD0	0x99aF3EeA856556646C98c8B9b2548Fe815240750
FUSDEV	0xd069d989e2F44B70c65347d1853C0c67e10a9F8D

FlowSwap V3 (Uniswap V3 fork)

Contract	Address
Factory	0xca6d7Bb03334bBf135902e1d919a5feccb461632
SwapRouter02	0xeEDC6Ff75e1b10B903D9013c358e446a73d35341
QuoterV2	0x370A8DF17742867a44e56223EC20D82092242C85

Pools used by the vault (fetched via Factory.getPool(tokenA, tokenB, fee)):

Pool	Fee tier
PYUSD0 / Yield token	100 (0.01%)
WETH / PYUSD0	3000 (0.30%)