Skip to main content

TransferLibrary

This utility abstracts away the differences between transferring native ETH and ERC20 tokens by introducing a unified interface for both sending and receiving assets. It also standardizes how native ETH is represented on-chain to simplify integration logic across different components.

ETH Representation​

The constant ETH = 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE (EIP-7528) is used as a sentinel value to distinguish native ETH from ERC20 tokens.

Errors​

  • InvalidValue(): Thrown when the contract expects a specific msg.value (for native ETH transfers) but receives a different amount.

Constants​

  • ETH: Reserved address used to represent native Ether. When passed to sendAssets or receiveAssets, the function will process ETH instead of calling token functions.

Functions​

sendAssets(address asset, address to, uint256 assets)​

Sends the specified asset (assets amount) to the recipient to.

  • If asset == ETH, the function uses Address.sendValue to transfer native ETH.
  • If asset is an ERC20 token, it uses IERC20.safeTransfer.

Parameters:

  • asset: Address of the asset to transfer. Use ETH for native Ether or the ERC20 token address.
  • to: Address to send the asset to.
  • assets: Amount of the asset to transfer.

Reverts if the ETH transfer fails or the ERC20 transfer fails via SafeERC20.

receiveAssets(address asset, address from, uint256 assets)​

Receives assets from the caller (or a third party) into the current contract.

  • If asset == ETH, verifies that msg.value == assets.
  • If asset is an ERC20 token, calls IERC20.safeTransferFrom from from to the current contract.

Parameters:

  • asset: Address of the asset to receive. Use ETH for native Ether or an ERC20 token address.
  • from: Address sending the ERC20 tokens (ignored for ETH).
  • assets: Expected amount of the asset to receive.

Reverts if the contract receives an incorrect msg.value for ETH or the ERC20 transfer fails.

note

Calling receiveAssets(0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE, from, assets) multiple times within a single function call will result in incorrect asset accounting. Do not use this function in scenarios like the following:

function func() external payable {
    TransferLibrary.receiveAssets(0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE, msg.sender, 1 ether);
    TransferLibrary.receiveAssets(0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE, msg.sender, 1 ether);
    ...
}