Multicalls

Build and execute multicalls in Solidity.

For SDK multicall helpers, see Multicalls.

The MultiCall Structure

struct MultiCall {
    address target;   // CreditFacade or allowed Adapter
    bytes callData;   // Encoded function call
}

ICreditFacadeV3Multicall Operations

All multicall operations are defined in ICreditFacadeV3Multicall:

import {ICreditFacadeV3Multicall} from "@gearbox-protocol/core-v3/contracts/interfaces/ICreditFacadeV3Multicall.sol";

Protocol Operations

Function	Signature
addCollateral	(address token, uint256 amount)
addCollateralWithPermit	(address token, uint256 amount, uint256 deadline, uint8 v, bytes32 r, bytes32 s)
withdrawCollateral	(address token, uint256 amount, address to)
increaseDebt	(uint256 amount)
decreaseDebt	(uint256 amount)
updateQuota	(address token, int96 quotaChange, uint96 minQuota)

Safety Operations

Function	Signature
onDemandPriceUpdate	(address token, bool reserve, bytes data)
storeExpectedBalances	(BalanceDelta[] deltas)
compareBalances	()
setFullCheckParams	(uint256[] hints, uint16 minHF)
setBotPermissions	(address bot, uint192 permissions)

Encoding Multicalls

Use abi.encodeCall for type-safe encoding:

MultiCall[] memory calls = new MultiCall[](3);

// Add collateral
calls[0] = MultiCall({
    target: creditFacade,
    callData: abi.encodeCall(
        ICreditFacadeV3Multicall.addCollateral,
        (usdc, 10_000 * 10**6)
    )
});

// Borrow
calls[1] = MultiCall({
    target: creditFacade,
    callData: abi.encodeCall(
        ICreditFacadeV3Multicall.increaseDebt,
        (40_000 * 10**6)
    )
});

// Set quota
calls[2] = MultiCall({
    target: creditFacade,
    callData: abi.encodeCall(
        ICreditFacadeV3Multicall.updateQuota,
        (weth, 50_000 * 10**6, 50_000 * 10**6)
    )
});

Adapter Calls

External protocol calls go through adapters. Get the adapter address from Credit Manager:

// Get adapter for Uniswap V3
address uniswapV3Adapter = ICreditManagerV3(creditManager).contractToAdapter(UNISWAP_V3_ROUTER);
require(uniswapV3Adapter != address(0), "Adapter not found");

// Encode adapter call
calls[4] = MultiCall({
    target: uniswapV3Adapter,
    callData: abi.encodeCall(
        IUniswapV3Adapter.exactInputSingle,
        (ISwapRouter.ExactInputSingleParams({
            tokenIn: usdc,
            tokenOut: weth,
            fee: 500,
            recipient: address(0), // Adapter overrides to credit account
            deadline: block.timestamp + 3600,
            amountIn: 50_000 * 10**6,
            amountOutMinimum: 0, // Using Gearbox slippage check instead
            sqrtPriceLimitX96: 0
        }))
    )
});

Complete Multicall Example

8-call strategy: price update, collateral, borrow, slippage setup, swap, deposit, slippage check, quota:

address accountOwner;
address creditManager;
address creditFacade;
address usdc;
address weth;
address yvWETH;
address uniswapV3Router;
bytes memory yvWETH_priceData;

// Assume exchange rate: 2000 USDC/yvWETH

MultiCall[] memory calls = new MultiCall[](8);

// 1. On-demand price update (must be first)
calls[0] = MultiCall({
    target: creditFacade,
    callData: abi.encodeCall(
        ICreditFacadeV3Multicall.onDemandPriceUpdate,
        (yvWETH, false, yvWETH_priceData)
    )
});

// 2. Add collateral
calls[1] = MultiCall({
    target: creditFacade,
    callData: abi.encodeCall(
        ICreditFacadeV3Multicall.addCollateral,
        (usdc, 10_000 * 10**6)
    )
});

// 3. Borrow
calls[2] = MultiCall({
    target: creditFacade,
    callData: abi.encodeCall(
        ICreditFacadeV3Multicall.increaseDebt,
        (40_000 * 10**6)
    )
});

// 4. Store expected balances for slippage check
// Min output: (50000 / 2000) * 0.995 = 24.875 yvWETH
BalanceDelta[] memory deltas = new BalanceDelta[](1);
deltas[0] = BalanceDelta({
    token: yvWETH,
    amount: (25 * 10**18) * 995 / 1000
});

calls[3] = MultiCall({
    target: creditFacade,
    callData: abi.encodeCall(
        ICreditFacadeV3Multicall.storeExpectedBalances,
        (deltas)
    )
});

// 5. Swap via Uniswap
address uniswapV3Adapter = ICreditManagerV3(creditManager).contractToAdapter(uniswapV3Router);

ISwapRouter.ExactInputSingleParams memory params = ISwapRouter.ExactInputSingleParams({
    tokenIn: usdc,
    tokenOut: weth,
    fee: 500,
    recipient: address(0), // Adapter overrides
    deadline: block.timestamp + 3600,
    amountIn: 50_000 * 10**6,
    amountOutMinimum: 0, // Using Gearbox slippage check
    sqrtPriceLimitX96: 0
});

calls[4] = MultiCall({
    target: uniswapV3Adapter,
    callData: abi.encodeCall(IUniswapV3Adapter.exactInputSingle, (params))
});

// 6. Deposit to Yearn using diff pattern
address yvWETHAdapter = ICreditManagerV3(creditManager).contractToAdapter(yvWETH);

calls[5] = MultiCall({
    target: yvWETHAdapter,
    callData: abi.encodeCall(IYearnV2Adapter.depositDiff, (1)) // Leave 1 wei
});

// 7. Compare balances (slippage check)
calls[6] = MultiCall({
    target: creditFacade,
    callData: abi.encodeCall(ICreditFacadeV3Multicall.compareBalances, ())
});

// 8. Set quota for yvWETH
calls[7] = MultiCall({
    target: creditFacade,
    callData: abi.encodeCall(
        ICreditFacadeV3Multicall.updateQuota,
        (yvWETH, 50_000 * 10**6, 50_000 * 10**6)
    )
});

// Approve collateral to Credit Manager (not Facade!)
IERC20(usdc).approve(creditManager, 10_000 * 10**6);

// Execute
ICreditFacadeV3(creditFacade).openCreditAccount(accountOwner, calls, 0);

The "Diff" Pattern

Adapters implement *_diff functions for handling unknown amounts:

• Standard function: Requires exact amountIn

• Diff function: Calculates amountIn = currentBalance - leftoverAmount

This is essential when the exact output of a previous operation is unknown.

// After a swap, deposit all WETH except 1 wei to Yearn
calls[5] = MultiCall({
    target: yvWETHAdapter,
    callData: abi.encodeCall(IYearnV2Adapter.depositDiff, (1))
});

Best Practices

1. Price updates first: Always put onDemandPriceUpdates at the start if using pull-based oracles

2. Slippage protection: Always use storeExpectedBalances before swaps and compareBalances after

3. Approve to Credit Manager: Token approvals go to Credit Manager, not Credit Facade

4. Gas optimization: Use setFullCheckParams with hints for accounts with many tokens

5. Dust management: Use type(uint256).max in withdrawCollateral to empty balances

Next Steps

• Pool Operations - Direct pool interaction

For architectural background, see Multicall System.