InitialTwitterOffering

Introduction

Initial Twitter Offering (ITO) is a Dapplet based on the Mask browser extension. It consists of two components, the browser extension and the Ethereum smart contract. This repo covers the design and the implementation of the smart contract only.

Overview

ITO is basically a token swap pool that can be initiated by any Ethereum user. Users can transfer an amount of a target token (now supporting ETH and ERC20 tokens) into the pool and set the swap ratios, e.g. {1 ETH: 10000 TOKEN, 1 DAI: 10 TOKEN}. Users can also set the swap limit (ceiling) to control how many tokens to be swapped by a single address, e.g. 10000 TOKEN. After the pool is expired (also set on initiation) or the target token is out of stock, the pool creator can withdraw any target token left and all the swapped tokens. The pool will be destructed after the withdraw.

Participants only need to approve one of the specified tokens according to the pool ratio and call the swap() function to swap the target token out. The swapped amount is automatically calculated by the smart contract and the users can receive the target token instantly after a successful call of the swap(). Pool creator can also set an unlock time for ITO which means to receive the target token participants need to wait after that unlock time by calling claim() function.

Getting Started

This is a standard truffle project. To install:

npm ci

To build the project:

npm run compile

To test the project:

npm test

To deploy contract on ropsten:

npm run deploy ropsten

To debug:

//...
import "hardhat/console.sol";

function debug_param (address _token_addr) public {
    console.log('_token_addr', _token_addr);
}

Deployed Contract

ITO Contract

The ITO smart contract adopts the Proxy Upgrade Pattern to improve user experience. Hence, the addresses in later section are actually the deployed TransparentUpgradeableProxy smart contract addresses.

Qualification

Another smart contract interface IQLF (source code) is also introduced to provide an API logQualified() that returns a boolean indicating if the given address is qualified. Custom qualification contract SHOULD implement contract IQLF rather than ERC-165 to further ensure the required interface is implemented since IQLF is compliant with ERC-165 and has implemented the details of supportsInterface function.

To prevent a malicious attack, you can set a swap_start_time in your custom qualification contract, then add accounts who swap before that time to a blacklist, they will no longer be able to access your ITO. Please confirm the swap_start_time carefully, it must be less than the end time of ITO, otherwise, nobody can access your ITO at all. To let Mask browser extension help you check if swap_start_time is less than the end time of ITO. You need to append interfaceId == this.get_start_time.selector; to supportsInterface()(Notice the getter function MUST be named get_start_time() to keep the same with the browser extension code), just copy the implementation of our default qualification contract.

Contract Addresses

Chain	ITO	Dummy Qualification
Mainnet	0xc2CFbF22	0x4dC5f343
Ropsten	0xcdE281B3	0xd5e6434b
Rinkeby	0xBe62f180	0x8440b99B
BSC	0x96c7D011	0xAb7B1bE4
BSC_test	0xbc558E76	0xaaC2362f
Matic	0xF9F7C149	0x2cf91AD8
Arbitrum_rinkeby	0x9b3649eC	0xEbd753E6
Arbitrum	0x71834a3F	0x913975af
xDai	0x913975af	0x71834a3F
Goerli	0x3475255F	0x957DCb39
Fantom	0x981be454	0x83D6b366
Celo	0x54a0A221	0x2cB220F9
Avalanche	0x02Ea0720	0x54a0A221
Optimism_kovan	0x88edAC7a	0x57E2AAB7
Optimism	0x71834a3F	0x913975af
Aurora	0x2cf91AD8	0x578a7Fee
Fuse	0xF9F7C149	0x2cf91AD8
Boba	0x981be454	0x83D6b366
Moonriver	0x981be454	0x83D6b366
Conflux_espace_test	0x83D6b366	0x96c7D011
Conflux_espace	0x066804d9	0x05ee315E
Harmony	0x5B966f3a	0x02Ea0720
Harmony_test	0x578a7Fee	0x81246335
Metis_test	0x71834a3F
Metis	0x5B966f3a
Kardia	0x224e8327	0x0cE6df81
Astar	0x1D720657	0xdd2Cf3fF

Implementation block number (required by frontend developers)

Chain	v1.0	v2.0
Mainnet	12689616	12766513
Ropsten	10468221	10572050
BSC	8508077	8885927
Matic	16002769	16516643
Arbitrum_rinkeby		708696
Arbitrum		102022
xDai		17865755
Goerli		6028660
Fantom		25071597
Celo		10406511
Avalanche		8289892
Optimism_kovan		47716
Optimism		8994
Aurora		57350598
Fuse		14951572
Boba		290600
Moonriver		1314566
Conflux_espace_test		66092470
Conflux_espace		37722805
Harmony		24133305
Harmony_test		22744597
Metis_test		5207086
Metis		1701875
Kardia		7566530
Astar		915536

Security Audit

The Solidity code in this repository has been audited by blockchain security experts from SlowMist. If you are interested, here are the audit reports:

• Audit Report
• 审计报告

If you have any security issue to report, please send to security@mask.io.

Contribute

Any contribution is welcomed to make it more secure and powerful. Had you any questions, please do not hesitate to create an issue to let us know.

License

InitialTwitterOffering is released under the MIT LICENSE.