Infura: Create an NFT Contract Factory with Metadata stored on IPFS
Learn how to create an NFT Contract Factory that stores metadata on IPFS.
A Smart Contract is a program that is stored and executed on the blockchain. It contains the NFT's metadata, such as the name of the NFT, a URL to the NFT data file, a description of the NFT, and any other data the creator has included. If the NFT is part of a collection, sometimes there will be metadata stating its position in the collection and its rarity compared to other NFTs in the collection.
Metadata is simply data that provides additional data about other data. Metadata of an object stored on Filebase typically includes the owner’s account email, size, ETag, object key or name, time and date last modified, and if the object is stored on an IPFS bucket, the IPFS CID is included in the object’s metadata.
In this guide, we’ll use Truffle, Ganache, and Infura to create a local development environment using the Ropsten blockchain network that enables us to use a series of scripts to mint NFTs and their metadata using a single command and their IPFS CID.
- Have an IDE or text editor for making changes to snippets of code.
This guide was written and tested using Ubuntu 20.04. Commands and workflow may vary depending on your operating system.
For this project, we’ll be uploading 3 images to Filebase for us to use. To do this, navigate to console.filebase.com. If you don’t have an account already, sign up, then log in.
Select ‘Create Bucket’ in the top right corner to create a new bucket for your NFTs.

Bucket names must be unique across all Filebase users, be between 3 and 63 characters long, and can contain only lowercase characters, numbers, and dashes.


Once uploaded, they will be listed in the bucket.

Take note of the IPFS CID for each object.

mkdir nft-factory
cd nft-factory
npm init
Provide any necessary configuration options for your workspace, or accept the default configuration settings for your npm workspace.
npm install -g truffle
npm install ganache --global
truffle unbox react
Your project will have the following files and directories:
- contracts/
- migrations/
- test/
- truffle-config.js
Do not remove any of the files that already exist in these directories, such as Migrations.sol or SimpleStorage.sol.
Then, open an IDE such as VSCode, and enter the following piece of code into a new file called
nftFactory.sol
in your contracts directory:// SPDX-License-Identifier: MIT
pragma solidity ^0.8.1;
import "@openzeppelin/contracts/token/ERC721/extensions/ERC721URIStorage.sol";
import "@openzeppelin/contracts/utils/Counters.sol";
contract nftFactory is ERC721URIStorage {
using Counters for Counters.Counter;
Counters.Counter private _tokenIds;
event CreatedNFT(uint256 indexed tokenId, string tokenURI);
constructor() ERC721("My NFT Collection", "MNC") {}
function mint(string memory _tokenURI) public returns (uint256) {
uint256 newItemId = _tokenIds.current();
_safeMint(msg.sender, newItemId);
_setTokenURI(newItemId, _tokenURI);
emit CreatedNFT(newItemId, _tokenURI);
_tokenIds.increment();
return newItemId;
}
}
This code imports the ERC721 token standard using an open source contract from Openzeppelin. Then, it creates the function that is responsible for minting our contract, which is a public function, meaning it can be called by any contract or wallet address, though whoever calls the function will be paying the gas fees.




const path = require("path");
module.exports = {
// See <http://truffleframework.com/docs/advanced/configuration>
// to customize your Truffle configuration!
compilers:{
solc: {
version: "0.8.1",
optimizer: {
enabled: true,
runs: 200
}}},
contracts_build_directory: path.join(__dirname, "client/src/contracts"),
networks: {
development:{ host: "127.0.0.1",
port: 8545, network_id: "*" // Match any network id
},
ropsten:{
provider: function() {
return new HDWalletProvider(mnemonic, // Project secret key
"https://ropsten.infura.io/v3/INFURA_PROJECT_ID")
}},
}
};
Replace the
INFURA_PROJECT_ID
with the project ID you copied down in the last step.var nftFactory = artifacts.require("./nftFactory.sol");
module.exports = function(deployer) {
deployer.deploy(nftFactory);
};
truffle develop
migrate –-reset
Your output should resemble the following:
truffle(develop)> migrate --reset
Compiling your contracts...
===========================
> Compiling ./contracts/nftFactory.sol
> Artifacts written to /home/filebase/client/src/contracts
> Compiled successfully using:
- solc: 0.8.1+commit.df193b15.Emscripten.clang
Starting migrations...
======================
> Network name: 'develop'
> Network id: 5777
> Block gas limit: 6721975 (0x6691b7)
1_initial_migration.js
======================
Replacing 'Migrations'
----------------------
> transaction hash: 0xbb354a7275da5af90f0ff462bbbcfbdfb529554cdb7cc2432541bb16668aac17
> Blocks: 0 Seconds: 0
> contract address: 0x6aaea605d6a1e07BD1A2cd7CAe6dE8dB569aa5FB
> block number: 25
> block timestamp: 1646682139
> account: 0x2D99E145805912f2964b4A8636291133fe03e4Ba
> balance: 99.99007346984352138
> gas used: 271700 (0x42554)
> gas price: 2.540819307 gwei
> value sent: 0 ETH
> total cost: 0.0006903406057119 ETH
> Saving migration to chain.
> Saving artifacts
-------------------------------------
> Total cost: 0.0006903406057119 ETH
2_deploy_contracts.js
=====================
Deploying 'nftFactory'
----------------------
> transaction hash: 0xe21306f9915ba9509bcfab324037c10e5616860e42ad9687e64b9cee023e2e69
> Blocks: 0 Seconds: 0
> contract address: 0x4Dd6153057B939b882992fa96F529687ba7a60a0
> block number: 27
> block timestamp: 1646682140
> account: 0x2D99E145805912f2964b4A8636291133fe03e4Ba
> balance: 99.983540351487302762
> gas used: 2534533 (0x26ac85)
> gas price: 2.531674926 gwei
> value sent: 0 ETH
> total cost: 0.006416613645219558 ETH
> Saving migration to chain.
> Saving artifacts
-------------------------------------
> Total cost: 0.006416613645219558 ETH
Summary
=======
> Total deployments: 2
> Final cost: 0.007106954250931458 ETH
let nft = await nftFactory.deployed();
Replace the
IPFS_CID
with one of the IPFS CIDs you recorded from your Filebase upload at the beginning of this tutorial.nft.mint("ipfs://IPFS_CID");
A successful minting output should be:
truffle(develop)> nft.mint("ipfs://bafkreiha6dsjkd3jsdwdlla35aud3gzcykrvlhv4uxqnmxawsxefq75tjm");
{ tx:
'0xd2b7e7ef5e85f3908c9a862d8a2a1eb1ec36cbac52233f386201eb605e391d73',
receipt:
{ transactionHash:
'0xd2b7e7ef5e85f3908c9a862d8a2a1eb1ec36cbac52233f386201eb605e391d73',
transactionIndex: 0,
blockNumber: 29,
blockHash:
'0x3877a2563a0440d58f7f2d995d88aa966c56ce85f8ad89ec8361c6ebb9b6abba',
from: '0x2d99e145805912f2964b4a8636291133fe03e4ba',
to: '0x4dd6153057b939b882992fa96f529687ba7a60a0',
cumulativeGasUsed: 186050,
gasUsed: 186050,
contractAddress: null,
logs: [ [Object], [Object] ],
logsBloom:
'0x00000000000000010000000000002000000000000000000000000000000000008000000000000000000000000000000000000000000000000000000000000000020000000000000000000008000000000000000000000000000000000001000000000000020000000000000000000800040000000000000000000010000000000000000000000000000000000000000000000002040000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000002000000000000000000000000000020000000000000000000000020000000000000000000000000000000000000000000000000000000000000000000',
status: true,
effectiveGasPrice: '0x969d61d3',
type: '0x2',
rawLogs: [ [Object], [Object] ] },
logs:
[ { address: '0x4Dd6153057B939b882992fa96F529687ba7a60a0',
blockHash:
'0x3877a2563a0440d58f7f2d995d88aa966c56ce85f8ad89ec8361c6ebb9b6abba',
blockNumber: 29,
logIndex: 0,
removed: false,
transactionHash:
'0xd2b7e7ef5e85f3908c9a862d8a2a1eb1ec36cbac52233f386201eb605e391d73',
transactionIndex: 0,
id: 'log_b2fa89a7',
event: 'Transfer',
args: [Result] },
{ address: '0x4Dd6153057B939b882992fa96F529687ba7a60a0',
blockHash:
'0x3877a2563a0440d58f7f2d995d88aa966c56ce85f8ad89ec8361c6ebb9b6abba',
blockNumber: 29,
logIndex: 1,
removed: false,
transactionHash:
'0xd2b7e7ef5e85f3908c9a862d8a2a1eb1ec36cbac52233f386201eb605e391d73',
transactionIndex: 0,
id: 'log_66393441',
event: 'CreatedNFT',
args: [Result] } ] }
From here, you can create as many NFTs as you’d like, simply by changing the IPFS CID in each iteration of the command:
nft.mint("ipfs://IPFS_CID");
If you have any questions, please join our Discord server, or send us an email at [email protected]
Last modified 8mo ago