---
title: How to Mint an NFT (Part 2/3 of NFT Tutorial Series)
description: This tutorial describes how to mint an NFT on the Ethereum blockchain using our smart contract and Web3.
author: "Sumi Mudgil"
tags: ["ERC-721", "alchemy", "solidity", "smart contracts"]
skill: beginner
breadcrumb: Mint an NFT
lang: en
published: 2021-04-22
---

[Beeple](https://www.nytimes.com/2021/03/11/arts/design/nft-auction-christies-beeple.html): $69 Million
[3LAU](https://www.forbes.com/sites/abrambrown/2021/03/03/3lau-nft-nonfungible-tokens-justin-blau/?sh=5f72ef64643b): $11 Million
[Grimes](https://www.theguardian.com/music/2021/mar/02/grimes-sells-digital-art-collection-non-fungible-tokens): $6 Million

All of them minted their NFTs using Alchemy’s powerful API. In this tutorial, we’ll teach you how to do the same in \<10 minutes.

“Minting an NFT” is the act of publishing a unique instance of your ERC-721 token on the blockchain. Using our smart contract from [Part 1 of this NFT tutorial series](/developers/tutorials/how-to-write-and-deploy-an-nft/), let’s flex our Web3 skills and mint an NFT. At the end of this tutorial, you’ll be able to mint as many NFTs as your heart (and wallet) desires!

Let’s get started!

## Step 1: Install Web3 {#install-web3}

If you followed the first tutorial on creating your NFT smart contract, you already have experience using Ethers.js. Web3 is similar to Ethers, as it is a library used to make creating requests to the [Ethereum](/) blockchain easier. In this tutorial we’ll be using [Alchemy Web3](https://github.com/alchemyplatform/alchemy-web3), which is an enhanced Web3 library that offers automatic retries and robust WebSocket support.

In your project home directory run:

```
npm install @alch/alchemy-web3
```

## Step 2: Create a `mint-nft.js` file {#create-mintnftjs}

Inside your scripts directory, create a `mint-nft.js` file and add the following lines of code:

```js
require("dotenv").config()
const API_URL = process.env.API_URL
const { createAlchemyWeb3 } = require("@alch/alchemy-web3")
const web3 = createAlchemyWeb3(API_URL)
```

## Step 3: Grab your contract ABI {#contract-abi}

Our contract ABI (Application Binary Interface) is the interface to interact with our smart contract. You can learn more about [contract ABIs](/glossary/#abi). Hardhat automatically generates an ABI for us and saves it in the `MyNFT.json` file. In order to use this we’ll need to parse out the contents by adding the following lines of code to our `mint-nft.js` file:

```js
const contract = require("../artifacts/contracts/MyNFT.sol/MyNFT.json")
```

If you want to see the ABI you can print it to your console:

```js
console.log(JSON.stringify(contract.abi))
```

To run `mint-nft.js` and see your ABI printed to the console navigate to your terminal and run:

```js
node scripts/mint-nft.js
```

## Step 4: Configure the metadata for your NFT using IPFS {#config-meta}

If you remember from our tutorial in Part 1, our `mintNFT` smart contract function takes in a tokenURI parameter that should resolve to a JSON document describing the NFT's metadata— which is really what brings the NFT to life, allowing it to have configurable properties, such as a name, description, image, and other attributes.

> _Interplanetary File System (IPFS) is a decentralized protocol and peer-to-peer network for storing and sharing data in a distributed file system._

We will use Pinata, a convenient IPFS API and toolkit, to store our NFT asset and metadata to ensure our NFT is truly decentralized. If you don’t have a Pinata account, sign up for a free account [here](https://app.pinata.cloud) and complete the steps to verify your email.

Once you’ve created an account:

- Navigate to the “Files” page and click the blue "Upload" button at the top-left of the page.

- Upload an image to Pinata — this will be the image asset for your NFT. Feel free to name the asset whatever you wish

- After you upload, you'll see the file info in the table on the "Files" page. You'll also see a CID column. You can copy the CID by clicking the copy button next to it. You can view your upload at: `https://gateway.pinata.cloud/ipfs/<CID>`. You can find the image we used on IPFS [here](https://gateway.pinata.cloud/ipfs/QmZdd5KYdCFApWn7eTZJ1qgJu18urJrP9Yh1TZcZrZxxB5), for example.

For the more visual learners, the steps above are summarized here:

![How to upload your image to Pinata](./instructionsPinata.mp4#712x376)

Now, we’re going to want to upload one more document to Pinata. But before we do that, we need to create it!

In your root directory, make a new file called `nft-metadata.json` and add the following json code:

```json
{
  "attributes": [
    {
      "trait_type": "Breed",
      "value": "Maltipoo"
    },
    {
      "trait_type": "Eye color",
      "value": "Mocha"
    }
  ],
  "description": "The world's most adorable and sensitive pup.",
  "image": "ipfs://QmWmvTJmJU3pozR9ZHFmQC2DNDwi2XJtf3QGyYiiagFSWb",
  "name": "Ramses"
}
```

Feel free to change the data in the json. You can remove or add to the attributes section. Most importantly, make sure image field points to the location of your IPFS image — otherwise, your NFT will include a photo of a (very cute!) dog.

Once you’re done editing the JSON file, save it and upload it to Pinata, following the same steps we did for uploading the image.

![How to upload your nft-metadata.json to Pinata](./uploadPinata.mp4#1280x676)

## Step 5: Create an instance of your contract {#instance-contract}

Now, to interact with our contract, we need to create an instance of it in our code. To do so we'll need our contract address which we can get from the deployment or [Blockscout](https://eth-sepolia.blockscout.com/) by looking up the address you used to deploy the contract.

![View your contract address on Etherscan](./view-contract-etherscan.png)

In the above example, our contract address is 0x5a738a5c5fe46a1fd5ee7dd7e38f722e2aef7778.

Next we will use the Web3 [contract method](https://docs.web3js.org/api/web3-eth-contract/class/Contract) to create our contract using the ABI and address. In your `mint-nft.js` file, add the following:

```js
const contractAddress = "0x5a738a5c5fe46a1fd5ee7dd7e38f722e2aef7778"

const nftContract = new web3.eth.Contract(contract.abi, contractAddress)
```

## Step 6: Update the `.env` file {#update-env}

Now, in order to create and send transactions to the Ethereum chain, we’ll use your public Ethereum account address to get the account nonce (will explain below).

Add your public key to your `.env` file — if you completed part 1 of the tutorial, our `.env` file should now look like this:

```js
API_URL = "https://eth-sepolia.g.alchemy.com/v2/your-api-key"
PRIVATE_KEY = "your-private-account-address"
PUBLIC_KEY = "your-public-account-address"
```

## Step 7: Create your transaction {#create-txn}

First, let’s define a function named `mintNFT(tokenData)` and create our transaction by doing the following:

1. Grab your _PRIVATE_KEY_ and _PUBLIC_KEY_ from the `.env` file.

1. Next, we’ll need to figure out the account nonce. The nonce specification is used to keep track of the number of transactions sent from your address — which we need for security purposes and to prevent replay attacks. To get the number of transactions sent from your address, we use [getTransactionCount](https://www.alchemy.com/docs/chains/ethereum/ethereum-api-endpoints/eth-get-transaction-count).

1. Finally we’ll set up our transaction with the following info:

- `'from': PUBLIC_KEY` — The origin of our transaction is our public address

- `'to': contractAddress` — The contract we wish to interact with and send the transaction

- `'nonce': nonce` — The account nonce with the number of transactions sent from our address

- `'gas': estimatedGas` — The estimated gas needed to complete the transaction

- `'data': nftContract.methods.mintNFT(PUBLIC_KEY, md).encodeABI()` — The computation we wish to perform in this transaction — which in this case is minting a NFT

Your `mint-nft.js` file should look like this now:

```js
   require('dotenv').config();
   const API_URL = process.env.API_URL;
   const PUBLIC_KEY = process.env.PUBLIC_KEY;
   const PRIVATE_KEY = process.env.PRIVATE_KEY;

   const { createAlchemyWeb3 } = require("@alch/alchemy-web3");
   const web3 = createAlchemyWeb3(API_URL);

   const contract = require("../artifacts/contracts/MyNFT.sol/MyNFT.json");
   const contractAddress = "0x5a738a5c5fe46a1fd5ee7dd7e38f722e2aef7778";
   const nftContract = new web3.eth.Contract(contract.abi, contractAddress);

   async function mintNFT(tokenURI) {
     const nonce = await web3.eth.getTransactionCount(PUBLIC_KEY, 'latest'); //get latest nonce

   //the transaction
     const tx = {
       'from': PUBLIC_KEY,
       'to': contractAddress,
       'nonce': nonce,
       'gas': 500000,
       'data': nftContract.methods.mintNFT(PUBLIC_KEY, tokenURI).encodeABI()
     };
   }​
```

## Step 8: Sign the transaction {#sign-txn}

Now that we’ve created our transaction, we need to sign it in order to send it off. Here is where we’ll use our private key.

`web3.eth.sendSignedTransaction` will give us the transaction hash, which we can use to make sure our transaction was mined and didn't get dropped by the network. You'll notice in the transaction signing section, we've added some error checking so we know if our transaction successfully went through.

```js
require("dotenv").config()
const API_URL = process.env.API_URL
const PUBLIC_KEY = process.env.PUBLIC_KEY
const PRIVATE_KEY = process.env.PRIVATE_KEY

const { createAlchemyWeb3 } = require("@alch/alchemy-web3")
const web3 = createAlchemyWeb3(API_URL)

const contract = require("../artifacts/contracts/MyNFT.sol/MyNFT.json")
const contractAddress = "0x5a738a5c5fe46a1fd5ee7dd7e38f722e2aef7778"
const nftContract = new web3.eth.Contract(contract.abi, contractAddress)

async function mintNFT(tokenURI) {
  const nonce = await web3.eth.getTransactionCount(PUBLIC_KEY, "latest") //get latest nonce

  //the transaction
  const tx = {
    from: PUBLIC_KEY,
    to: contractAddress,
    nonce: nonce,
    gas: 500000,
    data: nftContract.methods.mintNFT(PUBLIC_KEY, tokenURI).encodeABI(),
  }

  const signPromise = web3.eth.accounts.signTransaction(tx, PRIVATE_KEY)
  signPromise
    .then((signedTx) => {
      web3.eth.sendSignedTransaction(
        signedTx.rawTransaction,
        function (err, hash) {
          if (!err) {
            console.log(
              "The hash of your transaction is: ",
              hash,
              "\nCheck Alchemy's Mempool to view the status of your transaction!"
            )
          } else {
            console.log(
              "Something went wrong when submitting your transaction:",
              err
            )
          }
        }
      )
    })
    .catch((err) => {
      console.log(" Promise failed:", err)
    })
}
```

## Step 9: Call `mintNFT` and run node `mint-nft.js` {#call-mintnft-fn}

Remember the `metadata.json` you uploaded to Pinata? Get its hashcode from Pinata and pass the following as parameter to the function `mintNFT` `https://gateway.pinata.cloud/ipfs/<metadata-hash-code>`

Here’s how to get the hashcode:

![How to get your nft metadata hashcode on Pinata](./metadataPinata.mp4#1280x676)_How to get your nft metadata hashcode on Pinata_

> Double check that the hashcode you copied links to your **metadata.json** by loading `https://gateway.pinata.cloud/ipfs/<metadata-hash-code>` into a separate window. The page should look similar to the screenshot below:

![Your page should display the json metadata](./metadataJSON.png)_Your page should display the json metadata_

Altogether, your code should look something like this:

```js
require("dotenv").config()
const API_URL = process.env.API_URL
const PUBLIC_KEY = process.env.PUBLIC_KEY
const PRIVATE_KEY = process.env.PRIVATE_KEY

const { createAlchemyWeb3 } = require("@alch/alchemy-web3")
const web3 = createAlchemyWeb3(API_URL)

const contract = require("../artifacts/contracts/MyNFT.sol/MyNFT.json")
const contractAddress = "0x5a738a5c5fe46a1fd5ee7dd7e38f722e2aef7778"
const nftContract = new web3.eth.Contract(contract.abi, contractAddress)

async function mintNFT(tokenURI) {
  const nonce = await web3.eth.getTransactionCount(PUBLIC_KEY, "latest") //get latest nonce

  //the transaction
  const tx = {
    from: PUBLIC_KEY,
    to: contractAddress,
    nonce: nonce,
    gas: 500000,
    data: nftContract.methods.mintNFT(PUBLIC_KEY, tokenURI).encodeABI(),
  }

  const signPromise = web3.eth.accounts.signTransaction(tx, PRIVATE_KEY)
  signPromise
    .then((signedTx) => {
      web3.eth.sendSignedTransaction(
        signedTx.rawTransaction,
        function (err, hash) {
          if (!err) {
            console.log(
              "The hash of your transaction is: ",
              hash,
              "\nCheck Alchemy's Mempool to view the status of your transaction!"
            )
          } else {
            console.log(
              "Something went wrong when submitting your transaction:",
              err
            )
          }
        }
      )
    })
    .catch((err) => {
      console.log("Promise failed:", err)
    })
}

mintNFT("ipfs://QmYueiuRNmL4MiA2GwtVMm6ZagknXnSpQnB3z2gWbz36hP")
```

Now, run `node scripts/mint-nft.js` to deploy your NFT. After a couple of seconds, you should see a response like this in your terminal:

    The hash of your transaction is: 0x301791fdf492001fcd9d5e5b12f3aa1bbbea9a88ed24993a8ab2cdae2d06e1e8

    Check Alchemy's Mempool to view the status of your transaction!

Next, visit your [Alchemy mempool](https://dashboard.alchemy.com/mempool) to see the status of your transaction (whether it’s pending, mined, or got dropped by the network). If your transaction got dropped, it’s also helpful to check [Blockscout](https://eth-sepolia.blockscout.com/) and search for your transaction hash.

![View your NFT transaction hash on Etherscan](./view-nft-etherscan.png)_View your NFT transaction hash on Etherscan_

And that’s it! You’ve now deployed AND minted with a NFT on the Ethereum blockchain <Emoji text=":money_mouth_face:" size={1} />

Using the `mint-nft.js` you can mint as many NFTs as your heart (and wallet) desires! Just be sure to pass in a new tokenURI describing the NFT's metadata (otherwise, you'll just end up making a bunch of identical ones with different IDs).

Presumably, you’d like to be able to show off your NFT in your wallet — so be sure to check out [Part 3: How to View Your NFT in Your Wallet](/developers/tutorials/how-to-view-nft-in-metamask/)!