[V4-SDK] maxHopSlippage added to action SWAP_EXACT_IN makes the swap consumes incorrect amount of input token

[juroberttyb]

Issue

• v4-sdk from 1.22.1 to 1.23.0 introduces maxHopSlippage to action SWAP_EXACT_IN, yet the swap consumes uncertain amount of input token after adding it.
  • amountOutMinimum = minAmountOut.quotient, the swap fails.
  • amountOutMinimum = 0, the swap passes, yet the consumed amount of input token is incorrect. (<2% in the given example)

Environment

• Anvil fork of unichain mainnet at block number 34779300

Example

Code

  route = await router.route(
    amountIn,
    USDC,
    EXACT_INPUT,
    {
type: SwapType.UNIVERSAL_ROUTER,
version: UniversalRouterVersion.V2_0,
...
    },
    {
protocols: [Protocol.V4],
maxSplits: 1,
maxSwapsPerPath: 2,
    }
  );

  ...

v4Planner.addAction(Actions.SWAP_EXACT_IN, [{
  currencyIn: wbtcAddr,
  path: pathKeys,
  maxHopSlippage: [],
  amountIn: wbtcAmount.toString(),
  amountOutMinimum: "0"
}]);
v4Planner.addAction(Actions.SETTLE_ALL, [wbtcAddr, wbtcAmount.toString()]);
v4Planner.addAction(Actions.TAKE_ALL, [usdcAddr, "0"]);

...

const tx = await universalRouter.execute(commands, inputs, swapDeadline, {
  gasPrice,
  gasLimit,
  value: 0,
});

Log

[2025-12-12T08:22:45.250Z]  Route details: 1 route(s), protocols: V4
[2025-12-12T08:22:45.250Z]  Route type: MULTI-HOP (2 pools)
[2025-12-12T08:22:45.250Z]  Complete routing path:
[2025-12-12T08:22:45.250Z]    Start: WBTC (0x0555E30da8f98308EdB960aa94C0Db47230d2B9c)
[2025-12-12T08:22:45.250Z]    → Pool 1:
[2025-12-12T08:22:45.250Z]        token0: ETH (0x0000000000000000000000000000000000000000)
[2025-12-12T08:22:45.250Z]        token1: WBTC (0x0555E30da8f98308EdB960aa94C0Db47230d2B9c)
[2025-12-12T08:22:45.250Z]        fee: 500, tickSpacing: 10
[2025-12-12T08:22:45.250Z]        hooks: 0x0000000000000000000000000000000000000000
[2025-12-12T08:22:45.250Z]        output: ETH (0x0000000000000000000000000000000000000000)
[2025-12-12T08:22:45.250Z]    → Pool 2:
[2025-12-12T08:22:45.250Z]        token0: ETH (0x0000000000000000000000000000000000000000)
[2025-12-12T08:22:45.250Z]        token1: USDC (0x078D782b760474a361dDA0AF3839290b0EF57AD6)
[2025-12-12T08:22:45.250Z]        fee: 500, tickSpacing: 10
[2025-12-12T08:22:45.250Z]        hooks: 0x0000000000000000000000000000000000000000
[2025-12-12T08:22:45.250Z]        output: USDC (0x078D782b760474a361dDA0AF3839290b0EF57AD6)
[2025-12-12T08:22:45.250Z]    End: USDC (0x078D782b760474a361dDA0AF3839290b0EF57AD6)
[2025-12-12T08:22:45.250Z] [INFO] Route found: 30.697809 USDC output, price impact: 0.1000%
[2025-12-12T08:22:45.250Z]    PathKey 1: intermediateCurrency=0x0000000000000000000000000000000000000000, fee=500
[2025-12-12T08:22:45.250Z]    PathKey 2: intermediateCurrency=0x078D782b760474a361dDA0AF3839290b0EF57AD6, fee=500
[2025-12-12T08:22:45.250Z]  SWAP_EXACT_IN params: amountIn=32893, amountOutMinimum=30393870
[2025-12-12T08:22:45.251Z]  TAKE_ALL: currency=0x078D782b760474a361dDA0AF3839290b0EF57AD6, minAmount=30393870
[2025-12-12T08:22:45.251Z]  SETTLE_ALL: currency=0x0555E30da8f98308EdB960aa94C0Db47230d2B9c, maxAmount=32893
[2025-12-12T08:22:45.255Z]  Balances BEFORE swap: WBTC=0.00032893, USDC=0.0
[2025-12-12T08:22:47.365Z]  Swap confirmed in block 34779406
[2025-12-12T08:22:47.369Z]  Balances AFTER swap: WBTC=0.00032253, USDC=0.596664
[2025-12-12T08:22:47.369Z]  ===== SWAP DELTA ANALYSIS =====
[2025-12-12T08:22:47.369Z]  Expected WBTC consumed: 0.00032893 WBTC
[2025-12-12T08:22:47.369Z]  Actual WBTC consumed:   0.0000064 WBTC
[2025-12-12T08:22:47.369Z]  Consumption ratio:      1.94%
[2025-12-12T08:22:47.369Z]  Expected USDC received: ~30.697809 USDC
[2025-12-12T08:22:47.369Z]  Actual USDC received:   0.596664 USDC
[2025-12-12T08:22:47.369Z]  ================================
[2025-12-12T08:22:47.369Z]  ⚠️  WARNING: Less than 99% of WBTC was consumed! This suggests the swap did not execute as expected.

[juroberttyb]

Note the same setting works fine if v4-sdk version is set to 1.22.1.

[2025-12-12T08:51:22.776Z] Balances BEFORE swap: WBTC=0.00032893, USDC=0.0
[2025-12-12T08:51:24.884Z] Swap confirmed in block 34781124
[2025-12-12T08:51:24.887Z] Balances AFTER swap: WBTC=0.0, USDC=30.658518
[2025-12-12T08:51:24.887Z] ===== SWAP DELTA ANALYSIS =====
[2025-12-12T08:51:24.887Z] Expected WBTC consumed: 0.00032893 WBTC
[2025-12-12T08:51:24.887Z] Actual WBTC consumed:   0.00032893 WBTC
[2025-12-12T08:51:24.887Z] Consumption ratio:      100%
[2025-12-12T08:51:24.887Z] Expected USDC received: ~30.658518 USDC
[2025-12-12T08:51:24.888Z] Actual USDC received:   30.658518 USDC
[2025-12-12T08:51:24.888Z] ================================
[2025-12-12T08:51:24.888Z] Swap completed successfully ✓

[anumukul]

Hi, I’d like to take this issue and can deliver a fix within 24 hours.
I’ve worked on similar projects before and have relevant experience, so I should be able to handle this efficiently.