UtilityTokenContract

An Ethereum smart contract which issues and trades a more regulator-friendly utility token. It is published in 2 versions: with external token(UtilityToken) and using ETH as external funds(UtilityTokenETHOnly).

Deploy

when deploy it is need to pass parameters in to constructor

name	type	description
name	string	name utility token. see ERC20 interface
symbol	string	symbol utility token. see ERC20 interface
community	address	address of community contract. can be zero then reward mechanism will not work
inviterCommission	uint256	commission (mul by 1e6) to the inviting user, if the user who was invited by the inviter sent a reserve token. can be zero then reward mechanism will not work
reserveToken	address	address for external token. used only in UtilityToken.sol

Overview

once installed will be use methods to exchange Note that contract accept tokens, it should be approve before

Settings

name	type	value	description
DECIMALS	uint256	1e18	Fraction part.
maxGasPrice	uint256	1*DECIMALS	maximum Gas Price(in wei) used for transaction. Transaction fail if reached limit
claimMorePerSeconds	uint256	10*DECIMALS	how many tokens available to claim after each second after contract deployed
claimInitialMax	uint256	1000000*DECIMALS	initial amount that can be claimed by contract without transactions failing
claimMaxLimit	uint256	1000000*DECIMALS	amount that can be claimed one-time by contract
claimReserveMinPercent	uint256	20	Reserve min percent. Grant fails if we would have new nativeTokensOutstanding * exchangeRate > reserveTokensbalance * (100 - this number) / 100
claimMaxPercent	uint256	2	claim fails if nativeTokensbeingSent * exchangeRate > reserveTokensbalance * this number / 100
claimDeficitMax	uint256	1000000 * DECIMALS	Grant fails if claimDeficitMax exceeds (nativeTokensOutstanding * exchangeRate - reserveTokensbalance)
claimLockupPeriod	uint256	100	added limit in seconds for each claim
claimLockupPercent	uint256	100e4	100% mul 1e6. percent that would be lockup for each claim
claimGradual	bool	true	if true then limit is gradually decreasing
reserveTokenLimitPerDay	uint256	20e4	limit for reserve token

Methods

method name	called by	contract	description
receiveReserveToken	anyone	UtilityToken.sol	method received Reserve Tokens.
receive	anyone	UtilityToken.sol	internal method triggered if contract getting ETH. but is not supported and through an exception
donateETH	anyone	UtilityTokenETHOnly.sol	Method used for donate ETH without receiving token
receive	anyone	UtilityTokenETHOnly.sol	internal method triggered if contract getting ETH
setMaxGasPrice	owner	boths	setting Gas Price(in wei) used for transactions
claimingTokenAdd	owner	boths	method add token for claiming
claimingTokensView	anyone	boths	returned list of claiming tokens
claimingTokensWithdraw	owner	boths	method to withdraw all claiming tokens
claim	anyone	boths	getting own tokens instead claimed tokens
transfer	anyone	boths	Overrode {ERC20-transfer} method. with rectrictions
amountLockUp	anyone	boths	Calculate amount of tokens need to be left at recipient's account
whitelistAdd	owner	boths	Adding addresses list to whitelist
whitelistRemove	owner	boths	Removing addresses list from whitelist
isWhitelisted	anyone	boths	Checks if a address already exists in a whitelist

for UtilityToken.sol only

receiveReserveToken

method received reserve tokens. Note that tokens need to approved before

receive

internal method triggered if contract getting ETH. but is not supported and through an exception

for UtilityTokenETHOnly.sol only

donateETH

Method used for donate ETH without receiving token

receive

internal method triggered if contract getting ETH

for boths (UtilityTokenETHOnly.sol and UtilityToken.sol

setMaxGasPrice

Params:

name	type	description
gasPrice	uint256	maximum Gas Price(in wei) used for transaction

claimingTokenAdd

Params:

name	type	description
tokenForClaiming	address	added token for claiming
maxClaimingSpeed	uint256	percent that we can claim from participant. mul by 1e6
maxClaimingFrequency	uint256	frequency in seconds that user can be able to claim
ownerCanWithdraw	bool	if true owner can withdraw clamed tokens
ownerThrottleWithdraw	uint256	period than owner can withdraw clamed tokens (if ownerCanWithdraw param set true)
exchangeRate	uint256	exchange rate claimed to native tokens. mul by 1e6

claimingTokensView

Returned list of claimng tokens

claimingTokensWithdraw

allow owner to withdraw all claimingTokens

claim

getting utility tokens instead claimed tokens

transfer

Params:

name	type	description
recipient	address	recipient
amount	uint256	amount

Overrode {ERC20-transfer} method. There are added some features:

1. added validation of restriction limit to transfer
2. if recipient is self contract than we will get tokens, burn it and transfer eth to sender (if whitelisted) In all over cases its simple ERC20 Transfer

amountLockUp

Params:

name	type	description
recipient	address	recipient

Calculate amount of tokens need to be left at recipient's account

whitelistAdd

Params:

name	type	description
_addresses	address[]	array of addresses which need to be added to whitelist

whitelistRemove

Params:

name	type	description
_addresses	address[]	array of addresses which need to be removed from whitelist

isWhitelisted

Params:

name	type	description
addr	address	address which need to be check

Examples

contract can be used in two ways:

• if ReserveToken is exernal ERC20 token (UtilityToken.sol)(UT)
• if ReserveToken is ETH currency (UtilityTokenETHOnly.sol)(UT_eth)

• want to exchange external Token to our Utility Token(UT)
  • approve some external erc20 tokens to UT contract (.approve('<UT.address>', '')
  • call method receiveReserveToken of UT contract (.receiveReserveToken('false'))
• want to exchange ETH to our Utility Token(UT_eth)
  • send directly to UT_eth contract some ETH
• want to manage whitelist (owner option)
  • call method whitelistAdd to add some addresses
  • call method whitelistRemove to remove some addresses
• want to send UT back to contract (whitelisted user option)
  • call method transfer of UT token to UT address (.transfer('<UT.address>', ''))
• want to send UT to some user (whitelisted user option)
  • call method transfer of UT token (.transfer('', ''))