Intermediate
How to Deploy NFTs on BSC using Truffle
Non-Fungible Tokens (NFTs) are digital assets that are unique and cannot be replicated or divided. Binance Smart Chain (BSC) has gained popularity for being a fast, secure, and low-cost blockchain that supports NFTs. In this tutorial, we will be showing you how to deploy NFTs on BSC using Truffle. Truffle is a development environment, testing framework, and asset pipeline for Ethereum, which can be used to deploy smart contracts on BSC as well. With the help of this tutorial, you will learn how to set up your environment, write and deploy your NFT contract, and interact with it using Truffle. This will give you the foundation to create your own NFTs and start exploring the possibilities of the Binance Smart Chain.
ERC721 is a standard for representing ownership of non-fungible tokens, that is, where each token is unique such as in real estate or collectibles.
We will use Presets contracts in OpenZeppelin Contracts to create an ERC721 and deploy using Truffle.
Setting up the Environment
We begin by creating a new project.
$ mkdir mynft && cd mynft$ npm init -y
Then we install OpenZeppelin Contracts which has an implementation of ERC721.
$ npm i --save-dev @openzeppelin/contracts
Next, we install a development tool for deployment, for this tutorial we will use Truffle but we could use any other tools such as Buidler, Remix, or OpenZeppelin CLI.
$ npm i truffle
Getting the Contract Artifacts
We will set up our Solidity project using truffle init
to create a contracts
directory and configuration to connect to a network.
$ npx truffle init Starting init... ================ > Copying project files to Init successful, sweet!Copy
We are going to use Preset ERC721PresetMinterPauserAutoId
which is an ERC721 that is preset so it can be minted (with auto token ID and metadata URI), paused, and burned.
The Preset contracts have already been compiled, so we only need to copy the artifacts to the build/contracts
directory.
$ mkdir -p build/contracts/$ cp node_modules/ @openzeppelin/contracts/build/contracts/* build/contracts/
Using your favorite editor create 2_deploy.js
in the migrations
directory with the following contents:
// migrations/2_deploy.js // SPDX-License-Identifier: MIT const ERC721PresetMinterPauserAutoId = artifacts.require("ERC721PresetMinterPauserAutoId"); module.exports = function(deployer) { deployer.deploy(ERC721PresetMinterPauserAutoId, "My NFT","NFT", "http://my-json-server.typicode.com/huangsuyu/nft/tokens"); };
Deploy the Contract to a Local Blockchain
We will use truffle develop
to open a Truffle console with a development blockchain
Head over to Faucet and request test BNB
$ npx truffle develop Truffle Develop started at http://127.0.0.1:9545/ Accounts: (0) 0xc7e4bbc4269fdc62f879834e363173aee7895f45 Private Keys: (0) ef424b4dc91a9c9d6c1fc4ae0a50ce80668f3a955a7e982584b45577e2c70e27 Mnemonic: mechanic cannon setup general indicate people notable frown poet friend credit true ⚠️ Important ⚠️ : This mnemonic was created for you by Truffle. It is not secure. Ensure you do not use it on production blockchains, or else you risk losing funds. truffle(develop)> migrate Compiling your contracts... =========================== > Compiling ./contracts/Migrations.sol > Artifacts written to /Users/Documents/work/mynft/build/contracts > Compiled successfully using: - solc: 0.5.16+commit.9c3226ce.Emscripten.clang Starting migrations... ====================== > Network name: 'develop' > Network id: 5777 > Block gas limit: 6721975 (0x6691b7) 1_initial_migration.js ====================== Deploying 'Migrations' ---------------------- > transaction hash: 0x9a17a50e6efd52ba3e55245c76c52b065d20587add45aee732c233987033e567 > Blocks: 0 Seconds: 0 > contract address: 0x77409B688eA5461078a31450F3138EA8324F72C9 > block number: 1 > block timestamp: 1604387655 > account: 0xc7e4bBc4269fdC62F879834E363173aeE7895F45 > balance: 99.99616114 > gas used: 191943 (0x2edc7) > gas price: 20 gwei > value sent: 0 ETH > total cost: 0.00383886 ETH > Saving migration to chain. > Saving artifacts ------------------------------------- > Total cost: 0.00383886 ETH 2_deploy.js =========== Deploying 'ERC721PresetMinterPauserAutoId' ------------------------------------------ > transaction hash: 0xc1a3994c2ad2ba706ac49934b4f480c7b3d9b94241f526afa2dfe91545145a4e > Blocks: 0 Seconds: 0 > contract address: 0xEaB17D581552123695f03F12b09e378EE9463b44 > block number: 3 > block timestamp: 1604387655 > account: 0xc7e4bBc4269fdC62F879834E363173aeE7895F45 > balance: 99.92142266 > gas used: 3694586 (0x385ffa) > gas price: 20 gwei > value sent: 0 ETH > total cost: 0.07389172 ETH > Saving migration to chain. > Saving artifacts ------------------------------------- > Total cost: 0.07389172 ETH Summary ======= > Total deployments: 2 > Final cost: 0.07773058 ETH truffle(develop)>
We can deploy our new NFT to our development blockchain using migrate.
truffle(develop)> migrate Compiling your contracts... =========================== > Everything is up to date, there is nothing to compile. Starting migrations... ====================== > Network name: 'develop' > Network id: 5777 > Block gas limit: 6721975 (0x6691b7) 1_initial_migration.js ====================== Replacing 'Migrations' ---------------------- > transaction hash: 0x5d71b0a45a0fe20e2ca645393bb44b83fbd47351c009c48be0b8b84b610fb3b7 > Blocks: 0 Seconds: 0 > contract address: 0x3797c825cAC4a1FA765F6D8cd7787fB195849555 > block number: 1 > block timestamp: 1590736865 > account: 0x0445c33BdCe670D57189158b88c0034B579f37cE > balance: 99.99671674 > gas used: 164163 (0x28143) > gas price: 20 gwei > value sent: 0 ETH > total cost: 0.00328326 ETH > Saving migration to chain. > Saving artifacts ------------------------------------- > Total cost: 0.00328326 ETH 2_deploy.js =========== Replacing 'ERC721PresetMinterPauserAutoId' ------------------------------------------ > transaction hash: 0x166d7b28f4afb949585b5a0e5b4151daa54acbcb70566b202fd62ab380a6650c > Blocks: 0 Seconds: 0 > contract address: 0xDEE9411430c7Dd9b67fC6DA723DE729AdAB50AD7 > block number: 3 > block timestamp: 1590736866 > account: 0x0445c33BdCe670D57189158b88c0034B579f37cE > balance: 99.92191642 > gas used: 3697675 (0x386c0b) > gas price: 20 gwei > value sent: 0 ETH > total cost: 0.0739535 ETH > Saving migration to chain. > Saving artifacts ------------------------------------- > Total cost: 0.0739535 ETH Summary ======= > Total deployments: 2 > Final cost: 0.07723676 ETH
We can then use our deployed contract.
truffle(develop)> nft = await ERC721PresetMinterPauserAutoId.deployed() undefined
Interact With Your Token
The accounts that we can use were displayed when we started truffle develop
Token Metadata
We can call the contract to read token metadata such as name
, symbol,
and baseURI
truffle(develop)> await nft.name() 'My NFT' truffle(develop)> await nft.symbol() 'NFT' truffle(develop)> await nft.baseURI()
Mint
We can send a transaction to mint tokens to a given account, from an account with the minter role. In our case, we are minting from the account which deployed the token, which is given the minter role.
We will mint 1 NFT with token ID 0.
truffle(develop)> await nft.mint("0x0445c33bdce670d57189158b88c0034b579f37ce") { tx: '0xd301a60dbb8ac187687f6639f200d4e6f2cfa065923092b3940330e35a26421d', receipt: { transactionHash: '0xd301a60dbb8ac187687f6639f200d4e6f2cfa065923092b3940330e35a26421d', transactionIndex: 0, blockHash: '0x3ad3cfcb26da0c969e9d5a5414a5e90a91a3a862c9e9082afc38a0ec0f1a5d00', blockNumber: 5, from: '0x0445c33bdce670d57189158b88c0034b579f37ce', to: '0xdee9411430c7dd9b67fc6da723de729adab50ad7', gasUsed: 156470, ...
We can check the owner of the token and the token URI for the metadata
truffle(develop)> await nft.ownerOf(1) '0x0445c33BdCe670D57189158b88c0034B579f37cE' truffle(develop)> await nft.tokenURI(1)
Metadata
EIP-721 2 includes an optional metadata extension with a name
, symbol
and for each tokenID a tokenURI
with can point to a JSON file with name
, description,
and image
for the given token ID.
How you create and host this metadata is up to you. I would suggest using a domain that you control to point to where you host the data so that you can move it as required.
For this tutorial, we will use My JSON Server where we can store a single JSON file in a GitHub repository that we can access via a fake JSON server.
For production, we need to store our metadata in a permanent location that can exist for the life of the token.
A sample JSON for tokenID 1 is: http://my-json-server.typicode.com/huangsuyu/nft/tokens/1
Deploy to a Public Testnet
Next, we will deploy to the BNB Smart Chain testnet.
To deploy, we will use the instructions for Connecting to Public Test Networks with Truffle
You will need the following:
-
An Infura project ID (or a public node provider of your choice)
-
@truffle/hdwallet-provider
installed -
Configure
truffle-config.js
for Rinkeby network -
A funded testnet account and mnemonic
-
A
secrets.json
or another secret-management solution. Make sure you don’t commit this to GitHub!
My truffle-config.js
has the following rinkeby
configuration:
testnet: { provider: () => new HDWalletProvider(mnemonic, `https://data-seed-prebsc-1-s1.binance.org:8545`), network_id: 97, confirmations: 10, timeoutBlocks: 200, skipDryRun: true }, bsc: { provider: () => new HDWalletProvider(mnemonic, `https://bsc-dataseed1.binance.org`), network_id: 56, confirmations: 10, timeoutBlocks: 200, skipDryRun: true },
Deploy to BSC Testnet
$ npx truffle migrate --network testnet Compiling your contracts... =========================== > Everything is up to date, there is nothing to compile. Starting migrations... ====================== > Network name: 'develop' > Network id: 5777 > Block gas limit: 6721975 (0x6691b7) 1_initial_migration.js ====================== Deploying 'Migrations' ---------------------- > transaction hash: 0x9a17a50e6efd52ba3e55245c76c52b065d20587add45aee732c233987033e567 > Blocks: 0 Seconds: 0 > contract address: 0x77409B688eA5461078a31450F3138EA8324F72C9 > block number: 1 > block timestamp: 1604387655 > account: 0xc7e4bBc4269fdC62F879834E363173aeE7895F45 > balance: 99.99616114 > gas used: 191943 (0x2edc7) > gas price: 20 gwei > value sent: 0 ETH > total cost: 0.00383886 ETH > Saving migration to chain. > Saving artifacts ------------------------------------- > Total cost: 0.00383886 ETH 2_deploy.js =========== Deploying 'ERC721PresetMinterPauserAutoId' ------------------------------------------ > transaction hash: 0xc1a3994c2ad2ba706ac49934b4f480c7b3d9b94241f526afa2dfe91545145a4e > Blocks: 0 Seconds: 0 > contract address: 0xEaB17D581552123695f03F12b09e378EE9463b44 > block number: 3 > block timestamp: 1604387655 > account: 0xc7e4bBc4269fdC62F879834E363173aeE7895F45 > balance: 99.92142266 > gas used: 3694586 (0x385ffa) > gas price: 20 gwei > value sent: 0 ETH > total cost: 0.07389172 ETH > Saving migration to chain. > Saving artifacts ------------------------------------- > Total cost: 0.07389172 ETH Summary ======= > Total deployments: 2 > Final cost: 0.07773058 ETH
Mint
We can send a transaction to mint tokens to a given account, from an account with the minter role.
truffle(develop)> nft = await ERC721PresetMinterPauserAutoId.deployed() undefined
In our case, we are minting from the account which deployed the token, which is given the minter role.
To see configured accounts run the command accounts
.
truffle(rinkeby)> accounts [ '0x133d144f52705ceb3f5801b63b9ebccf4102f5ed',
We will mint 1 NFT with token ID 1. Specify the address that you want to be the token holder (0xc7e4bBc4269fdC62F879834E363173aeE7895F45
is one of my test accounts)
truffle(rinkeby)> await nft.mint("0x133d144f52705ceb3f5801b63b9ebccf4102f5ed") { tx: '0x0d90d4a2a4ac3f33d5220deb11e8f65adf14a6669afd18abd4cce8ca7ab58e04', receipt: { blockHash: '0x724ba66bc1d799820c05a93ae67991b21bb769fd1e9dddd5db9f725f5f633331', blockNumber: 3333746, contractAddress: null, cumulativeGasUsed: 164785, from: '0x77737a65c296012c67f8c7f656d1df81827c9541', gasUsed: 164785, ...