A simple timelock smart contract which locks ERC20 tokens for a specific time period and then allows users to unlock when that time period has elapsed.
Connecting to blockchain and accounts:
- Open https://remix.ethereum.org/
- Connect MetaMask
- Select owner’s account
- Fund owner’s account with ETH as gas for the following transactions
Make sure that the “environment” in Remix is set to “Injected Web3” and that the owner's account is selected in Remix’s “account” section
Compile an ERC20 contract of your choice.
IMPORTANT: Please ensure that the ERC20 contract has 18 decimal places and conforms fully to the ERC20 standard. This is a requirement which will allow this token to be traded on DEXs on Ethereum mainnet.
Deploy your ERC20 contract; making sure that Remix’s “contract” dropdown section is set to “YourERC20Contract.sol” (the drop down resets to other inherited contracts so you have to manually/deliberately choose the correct contract to deploy each time).
Once deployed, please record the ERC20 contract’s address and tx hash for future use.
Make sure that the “environment” in Remix is set to “Injected Web3” and that the owner's account is selected in Remix’s “account” section
Compile the simple timelock contract
Deploy the Timelock contract; making sure that Remix’s “contract” dropdown section is set to “SimpleTimelock.sol”
You must put the address of the ERC20 token as the one and only parameter for the constructor.
Set the time stamp of the contract by calling the setTimestamp function. There is only one function parameter called _timePeriodInSeconds; which reflects the amount of time (in seconds) for which you want the time lock period to exist.
timestampSet
Check that the timestampSet variable is true
initialTimestamp
Check the initialTimestamp variable, and confirm its value in proper date format by using an online epoch to date converter
For example, the value in the above image, 1642993044 is equivalent to Monday, 24 January 2022 12:57:24 GMT+10:00
Checking the associated ERC20 contract.
First of all, please check to make absolutely sure that the ERC20 contract associated with this timelock contract is correct. This can be done by calling the erc20Contract variable, as shown below.
Allocating user tokens into the timelock contract.
Tokens can be allocated to users one at a time using the depositToken function, as shown below.
Tokens can also be allocated in bulk using the bulkDepositTokens function. This is done using a third-party script. Please contact via an issue for access to this script.
Always keep an exact record of how many tokens (sum total of all ERC20 tokens) which you allocated to the users. This sum total figure is required for the next step (and ensures that there will be the exact amount of tokens in the timelock contract to service all of the users, who will be performing the unlock).
Transfer ERC20 tokens to the timelock contract.
From the ERC20 token contract, use the transfer function to transfer ERC20 tokens to the timelock smart contract's address.
You can confirm that these tokens have been transferred by pasting the timelock contract's address into the ERC20 contract's balanceOf function, as shown below.
Finalize owner participation.
Once all allocations have been made and the ERC20 tokens have been transferred into the timelock contract, the owner can call the timelock contract's finalizeAllIncomingDeposits() function. This makes the timelock non-custodial, whereby the contract owner has no ability to alter token amounts and so forth. The operation of the timelock contract is purely based on the math in the transferTimeLockedTokensAfterTimePeriod function from this point forward.
This simple timelock smart contract has an open source front end user interface. Please follow the instructions there to deploy this on the open web.