This guide demonstrates how to mint an NFT on the Polygon blockchain using the Ethers.js library and the Factory ERC-1155 contract you built in an earlier guide. With the information you learn from this guide, you'll better understand how to interact with other smart contracts using Ethers.js.
Prerequisites
Node.js installed
A text editor
Terminal
MATIC tokens (Polygon mainnet)
Deployed Factory ERC-1155 Contract (found in this QuickNode guide)
What is Ethers.js?
Ethers.js is a complete Ethereum library and wallet implementation in Javascript. It has recently become the library of choice for dApp developers due to its efficient codebase, ease of use, and well-written documentation.
Ethers.js has several different modules. We will be using the Providers, Signers, Contract Interact, and Utility modules in this guide.
Providers - read-only abstraction to access the blockchain data.
Signers - an abstraction of an Ethereum Account
Contract Interaction - an abstraction of a smart contract
Utilities - Useful tools for application developers (i.e., convert hex to number)
Other Libraries - Ethers ASM Dialect, Hardware Wallets (i.e., Ledger)
Experimental - experimental features
Smart Contract Recap
As a reminder, the act of "minting an NFT" is calling the mint function on an ERC-721 or ERC-1155 contract.
Let us quickly review the solidity code for the function we will be calling to mint our ERC-1155 Tokens:
function mintERC1155(uint _index, string memory _name, uint256 amount) public {
uint id = getIdByName(_index, _name);
tokens[_index].mint(indexToOwner[_index], id, amount);
emit ERC1155Minted(tokens[_index].owner(), address(tokens[_index]), amount);
}
function mintERC1155(uint _index, string memory _name, uint256 amount) public {
uint id = getIdByName(_index, _name);
tokens[_index].mint(indexToOwner[_index], id, amount);
emit ERC1155Minted(tokens[_index].owner(), address(tokens[_index]), amount);
}
function mintERC1155(uint _index, string memory _name, uint256 amount) public {
uint id = getIdByName(_index, _name);
tokens[_index].mint(indexToOwner[_index], id, amount);
emit ERC1155Minted(tokens[_index].owner(), address(tokens[_index]), amount);
}
Line 1: a public function named mintERC1155 that requires three arguments
Line 2: A require statement is meant to validate a statement before executing the remaining body of code. In this example, we're checking to ensure the sending address matches the owner's address from the ERC-1155 contract. If the condition is not met, the transaction will throw an error.
Line 3: The variable id is assigned to the output of a mapping. The mapping gets an ID by it's name. In our example, we'll mint Earth NFTs, which map to ID three in the factory contract. We'll explain how we got this info in a bit.
Line 4: The mint function from the token being indexed is called. There are three required parameters in the mint function we are calling.
Line 5: An Event log is emitted with our mint details, including the contract address of the token, the owner of the token, and the number of tokens minted.
Step 1: Booting your Polygon Node
We will deploy our contract on Polygon main-net. We can get a free trial node from QuickNode, which is easier than investing time in looking at different custom configurations to launch your own node. Copy the HTTP URL, which we will need in the next step.
Step 2: Creating the Project
Time to write the code! Start by opening a terminal window and navigating to the directory you'd like to have this project live in. Then, run the following commands:
Our project directory should now look similar to this:
We will start by pasting our private key into the .secret. file. To find out how to export your private key, check out this MetaMask Exporting Private Key Guide.
After, we will need to retrieve the ABI (application binary interface) of the contract we want to interact with. The ABI defines the methods and structures used to interact with the contract. It is represented in JSON format. Since the factory smart contract we want to interact with is deployed on Polygon, we will navigate to Polygonscan (a block explorer) and search this address: 0xB0C35A41994b75B98fA148b24Fcf0a84db21751D. Once you locate the page, click on the Contract tab and scroll down to the bottom to find the contract ABI. Click the copy button and paste the contents into your abi.json file.
Now it's time to write the script that will interact with our Factory ERC-1155 smart contract. We will go over each section of code piece by piece and tie it all together in the end.
Open your mint.js file and start by adding the dependencies.
Ethers.js has several provider classes. We will be using the JsonRpcProvider, a popular method for interacting with Ethereum which is available in all major Ethereum node implementations. Add the following bit of code to your mint.js script:
async function getGasPrice() {
let feeData = await provider.getFeeData()
return feeData.gasPrice
}
async function getWallet(privateKey) {
const wallet = await new ethers.Wallet(privateKey, provider)
return wallet
}
async function getChain(_provider) {
let chainId = await _provider.getNetwork()
return chainId.chainId
}
async function getContractInfo(index, id) {
let contract = await contractInstance.getERC1155byIndexAndId(index, id)
return contract;
}
async function getNonce(signer) {
return (await signer).getTransactionCount()
}
async function getGasPrice() {
let feeData = await provider.getFeeData()
return feeData.gasPrice
}
async function getWallet(privateKey) {
const wallet = await new ethers.Wallet(privateKey, provider)
return wallet
}
async function getChain(_provider) {
let chainId = await _provider.getNetwork()
return chainId.chainId
}
async function getContractInfo(index, id) {
let contract = await contractInstance.getERC1155byIndexAndId(index, id)
return contract;
}
async function getNonce(signer) {
return (await signer).getTransactionCount()
}
async function getGasPrice() {
let feeData = await provider.getFeeData()
return feeData.gasPrice
}
async function getWallet(privateKey) {
const wallet = await new ethers.Wallet(privateKey, provider)
return wallet
}
async function getChain(_provider) {
let chainId = await _provider.getNetwork()
return chainId.chainId
}
async function getContractInfo(index, id) {
let contract = await contractInstance.getERC1155byIndexAndId(index, id)
return contract;
}
async function getNonce(signer) {
return (await signer).getTransactionCount()
}
For example, the getGasPrice() function calls the getFeeData() method on a provider object which returns its response in hexadecimal format. We will then convert this hex value to gwei for useability in our script. The getWallet() function takes a private key and returns an Ethers Wallet object. The remaining functions utilize retrieving the chainId of the network and state information from one of the factory contract's functions.
Next, we will create a mint function that will utilize all the helper functions we created above to send and sign a transaction. Let us dive a bit into the explanation of the code below:
This function takes three inputs and is designed with a Try-Catch block for better error handling. When the function runs, it first attempts to run the code in the Try statement. The Try statement checks if the Provider is connected to the Polygon network (ID 137), then if that statement passes, it will create a wallet instance, get the gas price, and continue setting the transaction.
async function mintERC1155(index, name, amount) {
try {
if (await getChain(provider) === 137) {
const wallet = getWallet(privateKey)
const nonce = await getNonce(wallet)
const gasFee = await getGasPrice()
let rawTxn = await contractInstance.populateTransaction.mintERC1155(index, name, amount, {
gasPrice: gasFee,
nonce: nonce
})
console.log("...Submitting transaction with gas price of:", ethers.utils.formatUnits(gasFee, "gwei"), " - & nonce:", nonce)
let signedTxn = (await wallet).sendTransaction(rawTxn)
let reciept = (await signedTxn).wait()
if (reciept) {
console.log("Transaction is successful!!!" + '\n' + "Transaction Hash:", (await signedTxn).hash + '\n' + "Block Number: " + (await reciept).blockNumber + '\n' + "Navigate to https://polygonscan.com/tx/" + (await signedTxn).hash, "to see your transaction")
} else {
console.log("Error submitting transaction")
}
}
else {
console.log("Wrong network - Connect to configured chain ID first!")
}
} catch (e) {
console.log("Error Caught in Catch Statement: ", e)
}
}
async function mintERC1155(index, name, amount) {
try {
if (await getChain(provider) === 137) {
const wallet = getWallet(privateKey)
const nonce = await getNonce(wallet)
const gasFee = await getGasPrice()
let rawTxn = await contractInstance.populateTransaction.mintERC1155(index, name, amount, {
gasPrice: gasFee,
nonce: nonce
})
console.log("...Submitting transaction with gas price of:", ethers.utils.formatUnits(gasFee, "gwei"), " - & nonce:", nonce)
let signedTxn = (await wallet).sendTransaction(rawTxn)
let reciept = (await signedTxn).wait()
if (reciept) {
console.log("Transaction is successful!!!" + '\n' + "Transaction Hash:", (await signedTxn).hash + '\n' + "Block Number: " + (await reciept).blockNumber + '\n' + "Navigate to https://polygonscan.com/tx/" + (await signedTxn).hash, "to see your transaction")
} else {
console.log("Error submitting transaction")
}
}
else {
console.log("Wrong network - Connect to configured chain ID first!")
}
} catch (e) {
console.log("Error Caught in Catch Statement: ", e)
}
}
async function mintERC1155(index, name, amount) {
try {
if (await getChain(provider) === 137) {
const wallet = getWallet(privateKey)
const nonce = await getNonce(wallet)
const gasFee = await getGasPrice()
let rawTxn = await contractInstance.populateTransaction.mintERC1155(index, name, amount, {
gasPrice: gasFee,
nonce: nonce
})
console.log("...Submitting transaction with gas price of:", ethers.utils.formatUnits(gasFee, "gwei"), " - & nonce:", nonce)
let signedTxn = (await wallet).sendTransaction(rawTxn)
let reciept = (await signedTxn).wait()
if (reciept) {
console.log("Transaction is successful!!!" + '\n' + "Transaction Hash:", (await signedTxn).hash + '\n' + "Block Number: " + (await reciept).blockNumber + '\n' + "Navigate to https://polygonscan.com/tx/" + (await signedTxn).hash, "to see your transaction")
} else {
console.log("Error submitting transaction")
}
}
else {
console.log("Wrong network - Connect to configured chain ID first!")
}
} catch (e) {
console.log("Error Caught in Catch Statement: ", e)
}
}
All that's left is to add the function call at the bottom of your script. In our example, we will be minting a Saturn NFT. To do this, we will call the mintERC1155 function with the following parameters:
The first argument (0) refers to the specific contract we want to interact with within our smart contracts token array. Since we have only deployed one ERC-1155 token via this Factory contract, only the zero index has a contract we can interact with. The second argument specifies which NFT we want to mint, and the third is the amount of Saturn NFTs.
In the end, your complete script should look like:
const { ethers } = require("ethers")
const fs = require('fs')
const privateKey = fs.readFileSync(".secret").toString().trim()
const QUICKNODE_HTTP_ENDPOINT = "YOUR_QUICKNODE_HTTP_ENDPOINT"
const provider = new ethers.providers.JsonRpcProvider(QUICKNODE_HTTP_ENDPOINT)
const contractAddress = "0xB0C35A41994b75B98fA148b24Fcf0a84db21751D"
const contractAbi = fs.readFileSync("abi.json").toString()
const contractInstance = new ethers.Contract(contractAddress, contractAbi, provider)
async function getGasPrice() {
let feeData = await provider.getFeeData()
return feeData.gasPrice
}
async function getWallet(privateKey) {
const wallet = await new ethers.Wallet(privateKey, provider)
return wallet
}
async function getChain(_provider) {
let chainId = await _provider.getNetwork()
return chainId.chainId
}
async function getContractInfo(index, id) {
let contract = await contractInstance.getERC1155byIndexAndId(index, id)
return contract;
}
async function getNonce(signer) {
return (await signer).getTransactionCount()
}
async function mintERC1155(index, name, amount) {
try {
if (await getChain(provider) === 137) {
const wallet = getWallet(privateKey)
const nonce = await getNonce(wallet)
const gasFee = await getGasPrice()
let rawTxn = await contractInstance.populateTransaction.mintERC1155(index, name, amount, {
gasPrice: gasFee,
nonce: nonce
})
console.log("...Submitting transaction with gas price of:", ethers.utils.formatUnits(gasFee, "gwei"), " - & nonce:", nonce)
let signedTxn = (await wallet).sendTransaction(rawTxn)
let reciept = (await signedTxn).wait()
if (reciept) {
console.log("Transaction is successful!!!" + '\n' + "Transaction Hash:", (await signedTxn).hash + '\n' + "Block Number:" + (await reciept).blockNumber + '\n' + "Navigate to https://polygonscan.com/tx/" + (await signedTxn).hash, "to see your transaction")
} else {
console.log("Error submitting transaction")
}
}
else {
console.log("Wrong network - Connect to configured chain ID first!")
}
} catch (e) {
console.log("Error Caught in Catch Statement: ", e)
}
}
mintERC1155(0, "Saturn", 1)
const { ethers } = require("ethers")
const fs = require('fs')
const privateKey = fs.readFileSync(".secret").toString().trim()
const QUICKNODE_HTTP_ENDPOINT = "YOUR_QUICKNODE_HTTP_ENDPOINT"
const provider = new ethers.providers.JsonRpcProvider(QUICKNODE_HTTP_ENDPOINT)
const contractAddress = "0xB0C35A41994b75B98fA148b24Fcf0a84db21751D"
const contractAbi = fs.readFileSync("abi.json").toString()
const contractInstance = new ethers.Contract(contractAddress, contractAbi, provider)
async function getGasPrice() {
let feeData = await provider.getFeeData()
return feeData.gasPrice
}
async function getWallet(privateKey) {
const wallet = await new ethers.Wallet(privateKey, provider)
return wallet
}
async function getChain(_provider) {
let chainId = await _provider.getNetwork()
return chainId.chainId
}
async function getContractInfo(index, id) {
let contract = await contractInstance.getERC1155byIndexAndId(index, id)
return contract;
}
async function getNonce(signer) {
return (await signer).getTransactionCount()
}
async function mintERC1155(index, name, amount) {
try {
if (await getChain(provider) === 137) {
const wallet = getWallet(privateKey)
const nonce = await getNonce(wallet)
const gasFee = await getGasPrice()
let rawTxn = await contractInstance.populateTransaction.mintERC1155(index, name, amount, {
gasPrice: gasFee,
nonce: nonce
})
console.log("...Submitting transaction with gas price of:", ethers.utils.formatUnits(gasFee, "gwei"), " - & nonce:", nonce)
let signedTxn = (await wallet).sendTransaction(rawTxn)
let reciept = (await signedTxn).wait()
if (reciept) {
console.log("Transaction is successful!!!" + '\n' + "Transaction Hash:", (await signedTxn).hash + '\n' + "Block Number:" + (await reciept).blockNumber + '\n' + "Navigate to https://polygonscan.com/tx/" + (await signedTxn).hash, "to see your transaction")
} else {
console.log("Error submitting transaction")
}
}
else {
console.log("Wrong network - Connect to configured chain ID first!")
}
} catch (e) {
console.log("Error Caught in Catch Statement: ", e)
}
}
mintERC1155(0, "Saturn", 1)
const { ethers } = require("ethers")
const fs = require('fs')
const privateKey = fs.readFileSync(".secret").toString().trim()
const QUICKNODE_HTTP_ENDPOINT = "YOUR_QUICKNODE_HTTP_ENDPOINT"
const provider = new ethers.providers.JsonRpcProvider(QUICKNODE_HTTP_ENDPOINT)
const contractAddress = "0xB0C35A41994b75B98fA148b24Fcf0a84db21751D"
const contractAbi = fs.readFileSync("abi.json").toString()
const contractInstance = new ethers.Contract(contractAddress, contractAbi, provider)
async function getGasPrice() {
let feeData = await provider.getFeeData()
return feeData.gasPrice
}
async function getWallet(privateKey) {
const wallet = await new ethers.Wallet(privateKey, provider)
return wallet
}
async function getChain(_provider) {
let chainId = await _provider.getNetwork()
return chainId.chainId
}
async function getContractInfo(index, id) {
let contract = await contractInstance.getERC1155byIndexAndId(index, id)
return contract;
}
async function getNonce(signer) {
return (await signer).getTransactionCount()
}
async function mintERC1155(index, name, amount) {
try {
if (await getChain(provider) === 137) {
const wallet = getWallet(privateKey)
const nonce = await getNonce(wallet)
const gasFee = await getGasPrice()
let rawTxn = await contractInstance.populateTransaction.mintERC1155(index, name, amount, {
gasPrice: gasFee,
nonce: nonce
})
console.log("...Submitting transaction with gas price of:", ethers.utils.formatUnits(gasFee, "gwei"), " - & nonce:", nonce)
let signedTxn = (await wallet).sendTransaction(rawTxn)
let reciept = (await signedTxn).wait()
if (reciept) {
console.log("Transaction is successful!!!" + '\n' + "Transaction Hash:", (await signedTxn).hash + '\n' + "Block Number:" + (await reciept).blockNumber + '\n' + "Navigate to https://polygonscan.com/tx/" + (await signedTxn).hash, "to see your transaction")
} else {
console.log("Error submitting transaction")
}
}
else {
console.log("Wrong network - Connect to configured chain ID first!")
}
} catch (e) {
console.log("Error Caught in Catch Statement: ", e)
}
}
mintERC1155(0, "Saturn", 1)
The last line of code calls the mintERC1155 function with some input data.
Step 3: Minting our NFT
Note, you will need some MATIC on Polygon main-net in order to proceed with this mint transaction
One command away from minting our Saturn NFT! Navigate to your terminal into your project's main directory and run the command `node mint.js`. The output should look like this:
We can verify the NFT was minted by checking a Polygonscan and OpenSea:
Conclusion
That’s it! You have minted an NFT using Ethers.js! To learn more about Ethers, you can check out some of our other Web3 SDK guides or take a look at the Ethers documentation.
Subscribe to our newsletter for more articles and guides on Ethereum. If you have any feedback, feel free to reach out to us via Twitter. You can always chat with us on our Discord community server, featuring some of the coolest developers you'll ever meet :)
PHP is very popular in developing the backend of websites or web applications. PHP has a huge crowd of developers trusting it as their go-to language. In this guide, we will see how we can...
Private keys are one of the most sensitive pieces of data when it comes to cryptography and the blockchain. However, there has always been debate/confusion about choosing between custodial...
With high usage in web applications and straightforward syntax, Ruby is used by a vast number of people. This guide will cover creating an Ethereum address in Ruby using
In this tutorial we will look at how we can setup a basic NEAR project from scratch, installing and configuring dependencies and customizing the project to work well with...
To send a transaction on the Ethereum network, you need to pay fees for including the transaction in a block as well as the computation necessary in the transaction; this fee is called gas....
When building a smart contract on the Ethereum blockchain, new developers tend to reach out to tools like truffle and web3.js in building their smart contracts. This tutorial will look at how...
We can say that Java is one of the most versatile languages out there, and it continues to be relevant in today's time. Java is so popular because of its massive user base and use cases. In...
Ever wanted to get a list of all the owners of a particular NFT collection? Or wanted to fetch all the metadata for an NFT collection? From experience, you may know that compiling all this NFT...
Bitcoin is the father of blockchain technology. With Bitcoin started a new era of blockchain and decentralization. Bitcoin enabled everyone to make the peer-to-peer transactions they enjoy...
When someone thinks of developing a dApp the first tool that comes to their mind is web3.js which is pretty common because of its popularity in the community and wide use cases, dApp...
Stacks is an open-source layer-1 blockchain that utilizes the Proof of Transfer (PoX) consensus mechanism. The Stacks blockchain leverages Bitcoin's security and allows direct read access to...
On Ethereum, when a transaction is sent, before being added to a block, it resides in what is called a Mempool. To receive information about this transaction, the Mempool must be queried. This...
A developer stack is a bag of technologies a developer possesses. For example, MEAN (MongoDB, Express.js, AngularJS/Angular, and Node.js) and MERN (MongoDB, Express.js, React, and Node.js) are...
If you are building on Ethereum, you may run into scenarios where you need to fetch transaction history for a given address. Unfortunately, the current design for Ethereum lacks an easy way to...
Building on web3 is sometimes seen as a challenge greater than building on web2. The majority of web2 development features and technologies are well-documented and have stood the test of time,...
Developing applications involves juggling several moving pieces like front-ends, back-ends, and databases. But developing a decentralized application on a blockchain adds a few more elements...
To do any type of transaction on the Bitcoin blockchain, you’ll need a public key or a Bitcoin address. In this guide, we’ll cover how to generate a new Bitcoin address in JavaScript using
Avalanche is an open-source, proof-of-stake blockchain with smart contract functionality that uses the Snow family of consensus protocols. The Avalanche...
Blockchain provides us with the power of decentralization. Decentralization means the transfer of power to users/members rather than having a single centralized authority governing everything;...
In our dApp, we will have a simple react user interface that has a material button asking the user to connect to MetaMask. And if they do not have an account, they can create one or log in to...
Sometimes, you submit a transaction on Ethereum without enough gas due to network congestion or too many pending transactions offering a higher gas price than you have offered on your...
PHP is a very popular choice among developers and has a vast community due to its long presence in web development. In this guide, we’ll cover how to connect to Ethereum with PHP using the
Making a dApp that requires ERC20 token data can be tedious since there are numerous tokens, and one needs to query each token contract to get the data. This guide will show how we can build a...
In this guide, we'll understand a bit about reactive development and how to use Subspace with QuickNode.JavaScript is the programming language behind most of the internet apps and...
Social logins: we have all seen them, we have all used them. "Login with Facebook". "Login with Github".If you have been around the Web3 community you may have come across a...
Golang is very popular among backend developers for building infrastructures and microservices. Go is a procedural programming language. Developed in 2007 by...
Python is one of the most versatile programming languages out there with an abundance of use cases; We can build many applications with Python from client-side to back end. In this guide, we...
NFTs are great for creators to monetize their artwork and for people to get ownership of an item. But since gas prices are usually high given the highly in-demand space on Ethereum, minting an...
Today we will be building a sample app in Svelte, and connecting it to a smart contract that we deploy on the Ropsten Network.Our frontend will be able to do the...
If you’ve interacted with smart contracts on Ethereum before, you might have noticed that your transaction includes a long hexadecimal value in its data field. As a user (or developer), you...
.png)
.png)
.png)
.png)
