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The Filecoin EVM runtime allows developers to use Ethereum tooling, like Remix, with the Filecoin network.
As a simple introduction, we’re going to use Remix to create an ERC-20 token on the Filecoin network. In this guide, we’re using the Calibration testnet, but this process is the same for mainnet.
In Remix, workspaces are where you can create a contract, or group of contracts, for each project. Let’s create a new workspace to create our new ERC-20 token.
- 2.Click the
+icon next to Workspaces to create a new workspace.
- 3.In the Choose a template dropdown, select ERC20.
- 4.Select the Mintable checkbox.
- 5.Enter a fun name for your token in the Workspace name field. Something like
- 6.Click OK to create your new workspace.
The contract template we’re using is pretty simple. We just need to modify a couple of variables.
- 1.Under the contract directory, click MyToken.sol.
- 2.In the editor panel, replace
MyTokenwith whatever you’d like to name your token. In this example, we’ll use
- 3.On the same line, replace the second string with whatever you want the symbol of your token to be. In this example, we’ll use
That’s all we need to change within this contract. You can see on line 4 that this contract is importing another contract from
@openzeppelinfor us, meaning that we can keep our custom token contract simple.
- 1.Click the green play symbol at the top of the workspace to compile your contract. You can also press
son MacOS or
son Linux and Windows.
- 2.Remix automatically fetches the two
importcontracts from the top of our
.solcontract. You can see these imported contracts under the
.depsdirectory. You can browse the contracts there, but Remix will not save any changes you make.
Now that we’ve successfully compiled our contract, we need to deploy it somewhere! This is where our previous MetaMask setup comes into play.
- 1.Click the Deploy tab from the left.
- 2.Under the Environment dropdown, select Injected Provider - MetaMask.
- 3.MetaMask will open a new window confirming that you want to connect your account to Remix.
- 4.Click Next:
- 5.Click Connect to connect your
tFILaccount to Remix.
- 6.Back in Remix, under the Account field, you’ll see that it says something like
0x11F... (5 ether). This value is 5
tFIL, but Remix doesn’t support the Filecoin network, so it doesn’t understand what
tFILis. This isn’t a problem; it’s just a little quirk of using Remix.
- 7.Under the Contract dropdown, ensure the contract you created is selected.
- 8.Click Deploy.
- 9.MetaMask will open a window and as you to confirm the transaction. Scroll down and click Confirm to have MetaMask deploy the contract. If you’re deploying to mainnet, we advise you to adjust your gas fees for a cheaper deployment.
- 10.Back in Remix, a message at the bottom of the screen shows that the creation of your token is pending.
- 11.Wait around 90 seconds for the deployment to complete.
On the Filecoin network, a new set of blocks, also called a tipset, is created every thirty seconds. When deploying a contract, the transaction needs to be received by the network, and then the network needs to confirm the contract. This process takes around one to two tipsets to process – or around 60 to 90 seconds.
Now that we’ve compiled and deployed the contract, it’s time to actually interact with it!
Let’s call a method within the deployed contract to mint some tokens.
- 1.Back in Remix, open the Deployed Contracts dropdown, within the Deploy sidebar tab.
- 2.Expand the
mintmethod. You must fill in two fields here:
tofield specifies where address you want these initial tokens sent. Open MetaMask, copy your address, and paste it into this field.
- 4.This field expects an
FILis equal to 1,000,000,000,000,000,000
attoFil. So if you wanted to mint 100
FIL, you would enter
100followed by 18 zeros:
- 5.Click Transact.
- 6.MetaMask will open a window and ask you to confirm the transaction:
Again, you must wait for the network to process the transaction, which should take about 90 seconds. You can move on to the next section while you’re waiting.
Currently, MetaMask has no idea what our token is or what it even does. We can fix this by explicitly telling MetaMask the address of our contract.
- 1.Go back to Remix and open the Deploy sidebar tab.
- 2.Under Deployed Contracts, you should see your contract address at the top. Click the copy icon to copy the address to your clipboard.
- 3.Open MetaMask, select Assets, and click Import your tokens.
- 4.In the Token contract address field, paste the contract address you just copied from Remix and then click Add custom token. MetaMask should autofill the rest of the information based on what it can find from the Filecoin network.
- 5.Click Import token:
- 6.You should now be able to see that you have 100 of your tokens within your MetaMask wallet!
And that’s it! Deploying an ERC-20 token on Filecoin is simple!
Remix uses a default of 2.5 nanoFIL per gas as a priority fee, which is usually too high for the Filecoin network. If you don’t adjust this, you may end up overpaying when deploying to mainnet. We recommend that you switch from the site-suggested gas fees to oracle-supplied gas fees when deploying your contract.
- 1.When the deployment transaction confirmation pop-up window shows up, click on Site suggested.
- 2.Switch to Market, Aggressive, or Low. The Market option is generally suitable for most situations.