ERC20 Swaps were designed by the developers in the Frictionless protocol to risk off permissionless stablecoins such as USDC or USDT.

Permissionless are a great innovation from the crypto markets which were designed for permissionless crypto referencing to US Dollars, however handling stablecoins for traditional institutional partners is still a risky proposition.

The principle of an ERC20 Swap is simple.

1. The PROTOCOL_ADMIN defines the valid token pairs which are convertible on a 1:1 basis.

2. Fees can be optionally defined for the conversion to/from the ERC20 token.

3. The holder (Investor) of ERC20 tokens invokes the convertFromERC20function of the smart contract, the ERC20 tokens are sent to the PROTOCOL_TREASURY and a matching amount of FrictionlessFundDepositToken is minted and sent to the holder (Investor).

4. If the Investor wishes to convert their FrictionlessFundDepositToken to a valid configured ERC20 token, such as USDC/USDT, then they can invoke the convertToERC20function of the smart contract. In this case, the PROTOCOL_TREASURY will receive the FrictionlessFundDepositToken and burn it, transferring the matching amount of ERC20 (less any fees) to the Investor.

An example of two live ERC20 swaps on the Avalanche C-Chain are;

• USDC swapped for fsUSD

• fsUSD swapped for USDC

In these swaps, you can observe the collection of optional fees and the atomic settlement of the swap of the fsUSD tokens with USDC into the PROTOCOL_TREASURY.

Git Source

Inherits: IAbstractFeeModule

Author: DEFYCA Labs S.à.r.l

Copyright © 2023 DEFYCA Labs S.à.r.l Permission is hereby granted, free of charge, to any person obtaining a copy of the Frictionless protocol smart contracts (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice (including the next paragraph) shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL DEFYCA LABS S.à.r.l BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

Interface defining the frictionless conversion and atomic swapping of ERC-20 tokens for FrictionlessFundDepositToken on the Frictionless protocol. The conversion of tokens is considered frictionless as the protocol does not impose any fee structures on the conversion itself.

Functions

pause

See {PausableUpgradeable-_pause}

function pause() external;

unpause

See {PausableUpgradeable-_unpause}

function unpause() external;

setConvertTokensFees

Set the conversion fees for the token pair. The fees can be any combination of zero (0%) or upto 10000 bps (100%) on any directional transfer. Fees can only be set by the Owner (PROTOCOL_ADMIN).

function setConvertTokensFees(address erc20Token_, address fundDepositToken_, FeeInfo calldata feeInfo_) external;

Parameters

setConvertTokensFee

Set the conversion fees for the token pair using the tokenFeeKey_. The fees can be any combination of zero (0%) or upto 10000 bps (100%) on any directional transfer. Fees can only be set by the Owner (PROTOCOL_ADMIN).

function setConvertTokensFee(bytes32 tokenFeeKey_, FeeInfo calldata feeInfo_) external;

Parameters

removeFrictionlessTokensConvertInfo

Removes the conversion fees for the token pair using the tokenFeeKey_. Fees can only be set by the Owner (PROTOCOL_ADMIN).

function removeFrictionlessTokensConvertInfo(address erc20Token_, address fundDepositToken_) external;

Parameters

addFrictionlessTokensConvertInfo

Sets the mapping for the convertible tokens in the contract, calling this will add a new conversion pair to the contract.

function addFrictionlessTokensConvertInfo(FrictionlessTokensConvertInfo[] calldata tokensConvertInfoArr_) external;

Parameters

convertFromERC20

Converts from an ERC20 token to a FrictionlessFundDepositToken, using the safe precision conversion. The ERC20 token is transferred to configured treasuryAddress in the conversion and the minted FrictionlessFundDepositToken is sent to the msg.sender

function convertFromERC20(address erc20Token_, address fundDepositToken_, uint256 erc20TokensAmount_)
    external
    returns (uint256);

Parameters

convertFromERC20

Converts from an ERC20 token to a FrictionlessFundDepositToken, using the safe precision conversion. The ERC20 token is transferred to configured treasuryAddress in the conversion and the minted FrictionlessFundDepositToken is sent to the convertedTokensRecipient_

function convertFromERC20(
    address erc20Token_,
    address fundDepositToken_,
    address convertedTokensRecipient_,
    uint256 erc20TokensAmount_
) external returns (uint256);

Parameters

Returns

convertToERC20

Converts to an ERC20 token from a FrictionlessFundDepositToken, using the safe precision conversion. The FrictionlessFundDepositToken is burned in the conversion and the ERC20 is sent to the msg.sender from the treasuryAddress.

function convertToERC20(address erc20Token_, address fundDepositToken_, uint256 fundDepositTokensAmount_)
    external
    returns (uint256);

Parameters

Returns

convertToERC20

Converts to an ERC20 token from a FrictionlessFundDepositToken, using the safe precision conversion. The FrictionlessFundDepositToken is burned in the conversion and the ERC20 is sent to the convertedTokensRecipient_ from the treasuryAddress.

function convertToERC20(
    address erc20Token_,
    address fundDepositToken_,
    address convertedTokensRecipient_,
    uint256 fundDepositTokensAmount_
) external returns (uint256);

Parameters

Returns

getConvertTokenInfo

Returns the FrictionlessTokensConvertInfo for the given conversion key

function getConvertTokenInfo(bytes32 convertInfoKey_) external view returns (FrictionlessTokensConvertInfo memory);

Parameters

Returns

getConvertTokenKeysByToken

Returns the conversion keys for the given tokenAddr_

function getConvertTokenKeysByToken(address tokenAddr_) external view returns (bytes32[] memory);

Parameters

Returns

getConvertTokenKeysCountByToken

Returns the count of conversion keys for the given tokenAddr_

function getConvertTokenKeysCountByToken(address tokenAddr_) external view returns (uint256);

Parameters

Returns

getConvertTokenInfosByToken

Returns the FrictionlessTokensConvertInfo for the given tokenAddr_

function getConvertTokenInfosByToken(address tokenAddr_)
    external
    view
    returns (FrictionlessTokensConvertInfo[] memory);

Parameters

Returns

isTokenSupported

Returns true if the token specified by the tokenAddr_ has been registered as a valid convertible pair.

function isTokenSupported(address tokenAddr_) external view returns (bool);

Parameters

Returns

isTokenPairSupported

Returns true if the token pair specified have been registered as a valid convertible pair.

function isTokenPairSupported(address erc20Token_, address fundDepositToken_) external view returns (bool);

Parameters

Returns

isConvertTokenKeySupported

Returns true if the conversion key is supported.

function isConvertTokenKeySupported(bytes32 convertTokenKey_) external view returns (bool);

Parameters

Returns

getConvertTokensKey

Returns the conversion key for the given token pair.

function getConvertTokensKey(address token0_, address token1_) external pure returns (bytes32);

Parameters

Returns

Events

FrictionlessTokensConverted

Event emitted when a successful conversion occurs between an ERC20 and a FrictionlessFuncDepositToken.

event FrictionlessTokensConverted(
    address fromToken, address toToken, address toTokensRecipient, uint256 fromAmount, uint256 toAmount
);

Errors

FrictionlessERC20ConverterManagerInvalidTokenConvertInfo

thrown during addFrictionlessTokensConvertInfo if the tokensConvertInfoArr_ contains zero addresses

error FrictionlessERC20ConverterManagerInvalidTokenConvertInfo(FrictionlessTokensConvertInfo);

FrictionlessERC20ConverterManagerUnableToUpdateConvertInfo

thrown during addFrictionlessTokensConvertInfo if the tokensConvertInfoArr_ cannot be updated

error FrictionlessERC20ConverterManagerUnableToUpdateConvertInfo(FrictionlessTokensConvertInfo);

FrictionlessERC20ConverterManagerUnsupportedPair

error FrictionlessERC20ConverterManagerUnsupportedPair(address, address);

FrictionlessERC20ConverterManagerInvalidTokensAmountAfterConversion

thrown during a convert to/from an ERC20 if the conversion resolves to zero

error FrictionlessERC20ConverterManagerInvalidTokensAmountAfterConversion();

FrictionlessERC20ConverterManagerIdenticalAddresses

thrown during a convert to/from an ERC20 if the conversion is attempted for the same token

error FrictionlessERC20ConverterManagerIdenticalAddresses();

FrictionlessERC20ConverterManagerZeroAddress

thrown if the IFrictionlessERC20ConverterManager is configured as a zero address

error FrictionlessERC20ConverterManagerZeroAddress();

Structs

FrictionlessTokensConvertInfo

Struct to represent the conversion between an ERC20 token and a FrictionlessFundDepositToken on the Frictionless protocol

struct FrictionlessTokensConvertInfo {
    address erc20Token;
    address fundDepositToken;
    address treasuryAddress;
}