@kiwarilabs/contracts

A Solidity library for creating expirable tokens with time or block-based expiration.

• ERC-7818: Expirable ERC20
• ERC-7858: Expirable NFTs and SBTs

Installation

Install via npm

npm install --dev @kiwarilabs/contracts@stable

Install via yarn

yarn add --dev @kiwarilabs/contracts@stable

Usage

ERC-7818

// SPDX-License-Identifier: Apache-2.0
pragma solidity ^0.8.0;

import {ERC20EXPBase} from "@kiwarilabs/contracts/tokens/ERC20/ERC20EXPBase.sol";
import {ERC20BLSW} from "@kiwarilabs/contracts/tokens/ERC20/ERC20BLSW.sol";

contract ExpirableERC20 is ERC20BLSW {
  constructor(
        string memory _name,
        string memory _symbol,
        uint40 blocksPerEpoch_,
        uint8 windowSize_
    ) ERC20BLSW(_name, _symbol, block.number, blocksPerEpoch_, windowSize_, false) {}

    function _epochType() internal pure virtual override(ERC20EXPBase, ERC20BLSW) returns (EPOCH_TYPE) {
        return super._epochType();
    }

    function _getEpoch(uint256 pointer) internal view virtual override(ERC20EXPBase, ERC20BLSW) returns (uint256) {
        return super._getEpoch(pointer);
    }

    function _getWindowRage(
        uint256 pointer
    ) internal view virtual override(ERC20EXPBase, ERC20BLSW) returns (uint256 fromEpoch, uint256 toEpoch) {
        return super._getWindowRage(pointer);
    }

    function _getWindowSize() internal view virtual override(ERC20EXPBase, ERC20BLSW) returns (uint8) {
        return super._getWindowSize();
    }

    function _getPointersInEpoch() internal view virtual override(ERC20EXPBase, ERC20BLSW) returns (uint40) {
        return super._getPointersInEpoch();
    }

    function _getPointersInWindow() internal view virtual override(ERC20EXPBase, ERC20BLSW) returns (uint40) {
        return super._getPointersInWindow();
    }

    /// @notice In some Layer 2 (L2) use pre-compiled/system-contract to get block height instead of block.number.
    /// @dev Retrieve block.number as pointer in block-based lazy sliding window.
    /// @return uint256 return the current block height.
    function _pointerProvider() internal view virtual override(ERC20EXPBase, ERC20BLSW) returns (uint256) {
        return super._pointerProvider();
    }
}

ERC-7858

Individual Expiration

// SPDX-License-Identifier: Apache-2.0
pragma solidity ^0.8.0;

import {ERC7858BLSW} from "@kiwarilabs/contracts/tokens/ERC721/ERC7858BLSW.sol";
import {ERC7858EXPBase} from "@kiwarilabs/contracts/tokens/ERC721/ERC7858EXPBase.sol";

// Expirable ERC721 with individual expiration
contract ExpirableERC721 is ERC7858BLSW {

    constructor (string memory name_, string memory symbol_) ERC7858BLSW(name_, symbol) {}

}

Epoch Expiration

// SPDX-License-Identifier: Apache-2.0
pragma solidity ^0.8.0;

import {ERC7858EpochBLSW} from "@kiwarilabs/contracts/tokens/ERC721/extensions/ERC7858EpochBLSW.sol";
import {ERC7858EXPEpochBase} from "@kiwarilabs/contracts/tokens/ERC721/extensions/ERC7858EXPEpochBase.sol";

// Expirable ERC721 with epoch expiration
contract ExpirableERC7858 is ERC7858EpochBLSW {
    
    constructor (
        string memory name_, 
        string memory symbol_, 
        uint256 initialBlockNumber_,
        uint40 blocksPerEpoch_,
        uint8 windowSize_,
        bool development_) 
        ERC7858EpochBLSW(
            name_, 
            symbol_, 
            initialBlockNumber_,
            blocksPerEpoch_,
            windowSize_,
            development) {}

}

Contribute

Check out the contribution guide

Support and Issue

For support or any inquiries, feel free to reach out to us at github-issue or kiwarilabs@protonmail.com

Funding

If you value our work and would like to support Kiwari Labs, please visit our Open Collective page to make a donation. Thank you!

License

This repository is released under the Apache-2.0.
Copyright (C) Kiwari Labs.