PayMaster

Introduction

PayMaster handles payment and relayer cost management for crosschain transactions. Callers pay in native tokens on the source chain directly through SuperformRouter entry functions (_forwardPayment) and this payment is used to fund Keepers making cross-chain transactions including retrying of messages. To rebalance funds across chains when they get low, PayMaster integrates LiquidityHandler.

Core Concepts

Users making additional payments

While estimations try to estimate the amount paid in SuperformRouter as accurately as possible, it is possible that transactions are underpaid, especially in custom integrations not using the Superform API. Underpaid transactions will become stuck. Users can pay more native tokens to PayMaster on any chain Superform supports through the makePayment() function by specifying which address the payments should be used for. Once completed, Superform Keepers will recognize this and attempt to retry the action.

makePayment

function makePayment(
    address user_) external payable;

Name	Description
user_	Address of the user to make a payment for

Superform managing payments

Payments can only be withdrawn by the Superform PaymentAdmin and tokens can only be sent to core infrastructure in the Superform ecosystem, associated with a hashed superRegistryId.

withdrawTo

This function is utilized to withdraw native tokens from PayMaster to the appropriate contract on the same chain.

function withdrawTo(
    bytes32 superRegistryId_,
    uint256 nativeAmount_) external;

Name	Description
superRegistryId_	bytes hash of the superRegistryId
nativeAmount_	Amount of the native token to withdraw

rebalanceTo

These functions are used to withdraw and bridge native tokens from PayMaster to the appropriate contract on other chains. Bridge Validators ensure that bridged data sends funds to the intended contract.

function rebalanceTo(
    bytes32 superRegistryId_,
    LiqRequest memory req_,
    uint64 dstChainId_) external;

Name	Description
superRegistryId_	bytes id of the superRegistryId
liqRequest	LiquidityRequest struct
dstChainId_	uint64 EVM chain ID of where the funds are going

Retrying Messages

The retrying of messages, either payloads or proofs, is specific to the AMB implementation and can be triggered by users directly in AMB Implementations.

treatAMB

This function allows PaymentAdmin to use funds in PayMaster to retry messages automatically.

function treatAMB(
    uint8 ambId_,
    uint256 nativeValue_,
    bytes memory data_) external

Name	Description
ambId_	uint8 AMBid of the AMB Implementations.
nativeValue_	uint256 native tokens to send in the transaction
data_	bytes data specific to the AMB implementation required to retry the message