UniswapV4SwapperAdapter

Git Source

Inherits: ISwapper

Title: UniswapV4SwapperAdapter

Author: Golem Foundation

ISwapper adapter for Uniswap V4 exact-input swaps via the singleton PoolManager

Supports both single-hop and multi-hop (via intermediate base token) swaps, mirroring the routing logic of UniswapV3SwapperAdapter. Single-hop: tokenIn --(fee/tickSpacing/hooks)--> tokenOut Multi-hop: tokenIn --(fee/tickSpacing/hooks)--> base --(feeOut/tickSpacingOut/hooksOut)--> tokenOut The routing mode is determined by the base constructor parameter:

• base == address(0): always single-hop
• base != address(0): multi-hop unless tokenIn or tokenOut IS the base token, in which case it falls back to single-hop with the appropriate pool config Settlement uses V4's sync/transfer/settle pattern for input tokens and take() for output tokens. No ERC20 approvals are needed. Uniswap V4 PoolManager on Ethereum mainnet: 0x000000000004444c5dc75cB358380D2e3dE08A90 This contract is fully immutable and holds no tokens between calls.

Note: security-contact: [email protected]

Quick Start - What Matters Most

Uniswap V4 adapter for the ISwapper pull pattern. It uses PoolManager unlock flows and supports configured single-hop or multihop routes while returning unused balances.

State Variables

MIN_SQRT_PRICE_LIMIT

Minimum sqrt price limit for V4 swaps (TickMath.MIN_SQRT_PRICE + 1)

uint160 internal constant MIN_SQRT_PRICE_LIMIT = 4295128740

MAX_SQRT_PRICE_LIMIT

Maximum sqrt price limit for V4 swaps (TickMath.MAX_SQRT_PRICE - 1)

uint160 internal constant MAX_SQRT_PRICE_LIMIT = 1461446703485210103287273052203988822378723970341

poolManager

The Uniswap V4 PoolManager singleton address

address public immutable poolManager

fee

Fee tier for direct swaps or the first hop (tokenIn -> base)

uint24 public immutable fee

tickSpacing

Tick spacing for direct swaps or the first hop

int24 public immutable tickSpacing

hooks

Hooks address for direct swaps or the first hop (address(0) = no hooks)

address public immutable hooks

base

Optional intermediate token for multi-hop routing (address(0) = direct swap)

address public immutable base

feeOut

Fee tier for the second hop (base -> tokenOut), only used when base != address(0)

uint24 public immutable feeOut

tickSpacingOut

Tick spacing for the second hop, only used when base != address(0)

int24 public immutable tickSpacingOut

hooksOut

Hooks address for the second hop (address(0) = no hooks)

address public immutable hooksOut

Functions

constructor

Creates a UniswapV4SwapperAdapter with fixed routing configuration

constructor(
    address _poolManager,
    uint24 _fee,
    int24 _tickSpacing,
    address _hooks,
    address _base,
    uint24 _feeOut,
    int24 _tickSpacingOut,
    address _hooksOut
) ;

Parameters

Name	Type	Description
_poolManager	address	Address of the Uniswap V4 PoolManager singleton
_fee	uint24	Fee tier for direct swaps or first hop
_tickSpacing	int24	Tick spacing for direct swaps or first hop
_hooks	address	Hooks address for direct swaps or first hop (address(0) = no hooks)
_base	address	Optional base token for multi-hop routing (address(0) for direct swaps)
_feeOut	uint24	Fee tier for second hop when using multi-hop (ignored if _base is address(0))
_tickSpacingOut	int24	Tick spacing for second hop (ignored if _base is address(0))
_hooksOut	address	Hooks address for second hop (ignored if _base is address(0))

swap

Execute a token swap and send output to receiver

The caller MUST have approved this contract for at least amountIn of tokenIn before calling. The implementation pulls via transferFrom(msg.sender, this, amountIn) and returns any unused tokenIn to msg.sender before returning. Reverts if output is less than minAmountOut.

function swap(address tokenIn, address tokenOut, uint256 amountIn, uint256 minAmountOut, address receiver)
    external
    override
    returns (uint256 amountOut);

Parameters

Name	Type	Description
tokenIn	address	Address of the input token
tokenOut	address	Address of the output token
amountIn	uint256	Maximum amount of tokenIn to pull from msg.sender
minAmountOut	uint256	Minimum acceptable output amount (reverts if not met)
receiver	address	Address to receive the output tokens

Returns

Name	Type	Description
amountOut	uint256	Actual amount of tokenOut sent to receiver

unlockCallback

Callback invoked by PoolManager during unlock(); executes swaps and settles

Only callable by the PoolManager. Reverts with UnauthorizedCallback otherwise.

function unlockCallback(bytes calldata data) external returns (bytes memory);

Parameters

Name	Type	Description
data	bytes	ABI-encoded (originalCaller, tokenIn, tokenOut, amountIn, minAmountOut, receiver)

Returns

Name	Type	Description
<none>	bytes	ABI-encoded amountOut

_singleHop

Execute a single-hop exact-input swap

function _singleHop(address tokenIn, address tokenOut, uint256 amountIn)
    internal
    returns (uint256 amountOut, uint256 consumed);

Returns

Name	Type	Description
amountOut	uint256	Amount of output token received
consumed	uint256	Amount of tokenIn actually consumed by the pool

_multiHop

Execute a two-hop exact-input swap: tokenIn → base → tokenOut. Base token deltas net to zero when hop 2 consumes the full hop-1 output; otherwise the unused base is returned to the original caller.

function _multiHop(address tokenIn, address tokenOut, uint256 amountIn)
    internal
    returns (uint256 amountOut, uint256 consumed, uint256 unusedBase);

Returns

Name	Type	Description
amountOut	uint256	Final output amount
consumed	uint256	tokenIn consumed by hop 1 (may be less than amountIn on a shallow pool)
unusedBase	uint256	base token produced by hop 1 but not consumed by hop 2

Errors

InvalidPoolManager

Thrown when the PoolManager address is zero

error InvalidPoolManager();

InvalidToken

Thrown when a token address is zero

error InvalidToken();

InvalidTickSpacing

Thrown when tickSpacing is zero (invalid V4 pool configuration)

error InvalidTickSpacing();

UnauthorizedCallback

Thrown when the callback caller is not the PoolManager

error UnauthorizedCallback();

InsufficientOutput

Thrown when the swap output is less than the minimum required

error InsufficientOutput(uint256 expected, uint256 actual);

Parameters

Name	Type	Description
expected	uint256	Minimum amount expected
actual	uint256	Amount actually received