HOT Swap

To configure an HOT swap correctly, one needs to set the following two parameters in _swapParams.swapContext:

1. swapFeeModuleContext - Set this to any value that is not empty. The exact value does not matter, the only requirement is that the length of this array should not be 0. Any value such as “0x01” will work.

2. externalContext - The value should be the concatenation of the ABI-encoded HOT struct and signature received from the HOT signer. For example: bytes memory externalContext = abi.encode(hotParams, signature)

Hybrid Order Type Params

/**
    @notice The struct with all the information for a HOT swap. 

    This struct is signed by `signer`, and put onchain via HOT swaps.

    * amountInMax: Maximum amount of input token which `authorizedSender` is allowed to swap.
    * sqrtHotPriceX96Discounted: sqrtPriceX96 to quote if the HOT is eligible to update AMM state (see HOT).
    * sqrtHotPriceX96Base: sqrtPriceX96 to quote if the HOT isn't eligible to update AMM (can be same as above).
    * sqrtSpotPriceX96New: New sqrt spot price of the AMM, in Q96 format.
    * authorizedSender: Address of authorized msg.sender in `pool`.
    * authorizedRecipient: Address of authorized recipient of tokenOut amounts.
    * signatureTimestamp: Offchain UNIX timestamp that determines when this HOT intent has been signed.
    * expiry: Duration, in seconds, for the validity of this HOT intent.
    * feeMinToken0: Minimum AMM swap fee for token0.
    * feeMaxToken0: Maximum AMM swap fee for token0.
    * feeGrowthE6Token0: Fee growth in pips, per second, of AMM swap fee for token0.
    * feeMinToken1: Minimum AMM swap fee for token1.
    * feeMaxToken1: Maximum AMM swap fee for token1.
    * feeGrowthE6Token1: Fee growth in pips, per second, of AMM swap fee for token1.
    * nonce: Nonce in bitmap format (see AlternatingNonceBitmap library and docs).
    * expectedFlag: Expected flag (0 or 1) for nonce (see AlternatingNonceBitmap library and docs).
    * isZeroToOne: Direction of the swap for which the HOT is valid.
 */
struct HybridOrderType {
    uint256 amountInMax;
    uint160 sqrtHotPriceX96Discounted;
    uint160 sqrtHotPriceX96Base;
    uint160 sqrtSpotPriceX96New;
    address authorizedSender;
    address authorizedRecipient;
    uint32 signatureTimestamp;
    uint32 expiry;
    uint16 feeMinToken0;
    uint16 feeMaxToken0;
    uint16 feeGrowthE6Token0;
    uint16 feeMinToken1;
    uint16 feeMaxToken1;
    uint16 feeGrowthE6Token1;
    uint8 nonce;
    uint8 expectedFlag;
    bool isZeroToOne;
}

This is the HOT struct, exact descriptions of all the fields can be found in the Natspec documentation above. Here we shall discuss the important things to keep in mind and common reverts. Most of these checks can be found in the src/libraries/HOTParams.sol file, we will only discuss some common ones in this document.