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Overview

MakxYieldPadHook is a stateless Uniswap V4 hook attached to every pool created by MakxYieldPad. Its sole purpose is to intercept swaps and route the creator’s hook fee to YieldPad. It holds no funds and no rental state. All fee accounting is done in YieldPad via recordHookFee().

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Immutables

VariableDescription
poolManagerUniswap V4 PoolManager
yieldPadMakxYieldPad — source of pool config, receiver of fees

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Hook flags

BEFORE_SWAP                (0x80)
AFTER_SWAP                 (0x40)
BEFORE_SWAP_RETURNS_DELTA  (0x08)
AFTER_SWAP_RETURNS_DELTA   (0x04)

Required address suffix: 0xCC
The hook address must end in 0xCC for the Uniswap V4 router to recognize and enforce the required flags.

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Fee architecture

Two independent fee layers per pool: LP fee — Fixed per pool (fee: 3000 = 0.3%), overridden on every swap via OVERRIDE_FEE_FLAG. Goes entirely to liquidity providers. Never changes for a given pool. Hook fee — Flat bps set by the token creator (hookFeeBps). Applied to ETH on every swap. Routed to YieldPad and accrued in launchFeeBalance, claimable by the creator.

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beforeSwap — ETH → Token swaps

function beforeSwap(
    address,
    PoolKey calldata key,
    SwapParams calldata params,
    bytes calldata
) external returns (bytes4, BeforeSwapDelta, uint24)
Triggered on every swap. For ETH → token exact-input swaps (zeroForOne = true, amountSpecified < 0):
  1. Reads hookFeeBps from YieldPad via getPoolConfig(poolId).
  2. Calculates fee = -amountSpecified × hookFeeBps / 10_000.
  3. Returns a BeforeSwapDelta that reduces the ETH sent to the pool by fee.
  4. Calls poolManager.take(ETH, yieldPad, fee) — transfers the fee directly to YieldPad.
  5. Calls yieldPad.recordHookFee(poolId, fee) — YieldPad credits it to launchFeeBalance.
The pool only sees ethIn - hookFee. The LP fee applies to the reduced input.

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afterSwap — Token → ETH swaps

function afterSwap(
    address,
    PoolKey calldata key,
    SwapParams calldata params,
    BalanceDelta delta,
    bytes calldata
) external returns (bytes4, int128)
For token → ETH swaps (zeroForOne = false):
  1. Reads hookFeeBps from YieldPad.
  2. Calculates fee = delta.amount0() × hookFeeBps / 10_000 (where amount0 is positive ETH output).
  3. Returns a negative afterSwapDelta reducing the ETH the swapper receives by fee.
  4. Calls poolManager.take(ETH, yieldPad, fee).
  5. Calls yieldPad.recordHookFee(poolId, fee).

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Pool currency convention

All Makx pools use:
  • currency0 = address(0) (native ETH) — always sorted first
  • currency1 = ERC-20 token address
ETH is always the “specified” or “output” side depending on swap direction. The hook always takes its fee from the ETH side.

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What the hook does NOT do

  • Does not hold ETH or tokens.
  • Does not track rental state or prepaidUntil.
  • Does not restrict who can swap.
  • Does not implement beforeInitialize, afterInitialize, beforeAddLiquidity, afterAddLiquidity, beforeRemoveLiquidity, afterRemoveLiquidity, beforeDonate, or afterDonate — all revert with HookNotImplemented.