Deploy Smart Contracts to TeQoin L2

Deploy your Solidity smart contracts to TeQoin L2 using your favorite development framework.

What You’ll Learn:

Deploy with Hardhat
Deploy with Foundry
Deploy with Remix
Verify deployment
Best practices

🎯 Choose Your Tool

Hardhat

Most PopularJavaScript-based frameworkDeploy →

Foundry

Fast & ModernRust-based frameworkDeploy →

Remix

Browser-BasedNo installation neededDeploy →

🔨 Deploy with Hardhat

Hardhat is the most popular Ethereum development framework.

Prerequisites

# Check Node.js installation
node --version  # Should be v18+

# Check npm
npm --version

Step 1: Create New Project

Initialize Project

    # Create project directory
    mkdir my-teqoin-project
    cd my-teqoin-project
    
    # Initialize npm
    npm init -y
    
    # Install Hardhat
    npm install --save-dev hardhat

Initialize Hardhat

    # Create Hardhat project
    npx hardhat init
    
    # Choose: "Create a JavaScript project"
    # Accept all defaults

This creates:

    my-teqoin-project/
    ├── contracts/          # Your Solidity contracts
    ├── scripts/           # Deployment scripts
    ├── test/              # Test files
    ├── hardhat.config.js  # Configuration
    └── package.json

Install Dependencies

    # Install essential plugins
    npm install --save-dev @nomicfoundation/hardhat-toolbox
    
    # Install OpenZeppelin (optional but recommended)
    npm install @openzeppelin/contracts
    
    # Install dotenv for environment variables
    npm install dotenv

Step 2: Configure for TeQoin

Create .env File

    # Create .env file
    touch .env

Add your private key:

.env

    PRIVATE_KEY=your_private_key_here

Never commit .env to Git! Add it to .gitignore:

    echo ".env" >> .gitignore

Configure hardhat.config.js

hardhat.config.js

    require("@nomicfoundation/hardhat-toolbox");
    require("dotenv").config();
    
    module.exports = {
      solidity: {
        version: "0.8.20",
        settings: {
          optimizer: {
            enabled: true,
            runs: 200
          }
        }
      },
      networks: {
        // TeQoin L2 Mainnet
        teqoin: {
          url: "https://rpc.teqoin.io",
          chainId: 420377,
          accounts: [process.env.PRIVATE_KEY]
        },
        // TeQoin L2 Testnet
        teqoinTestnet: {
          url: "https://rpc-testnet.teqoin.io",
          chainId: 420377,
          accounts: [process.env.PRIVATE_KEY]
        }
      },
      etherscan: {
        apiKey: {
          teqoin: "your-api-key-here" // Get from explorer.teqoin.io
        },
        customChains: [
          {
            network: "teqoin",
            chainId: 420377,
            urls: {
              apiURL: "https://explorer.teqoin.io/api",
              browserURL: "https://explorer.teqoin.io"
            }
          }
        ]
      }
    };

Step 3: Write Your Contract

contracts/MyToken.sol

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;

import "@openzeppelin/contracts/token/ERC20/ERC20.sol";

contract MyToken is ERC20 {
    constructor() ERC20("MyToken", "MTK") {
        _mint(msg.sender, 1000000 * 10 ** decimals());
    }
}

Step 4: Compile Contract

# Compile contracts
npx hardhat compile

# Output:
# Compiled 1 Solidity file successfully

Step 5: Create Deployment Script

scripts/deploy.js

const { ethers } = require("hardhat");

async function main() {
  // Get deployer account
  const [deployer] = await ethers.getSigners();
  
  console.log("Deploying contracts with account:", deployer.address);
  console.log("Account balance:", (await ethers.provider.getBalance(deployer.address)).toString());
  
  // Deploy contract
  const MyToken = await ethers.getContractFactory("MyToken");
  const token = await MyToken.deploy();
  
  await token.waitForDeployment();
  
  const address = await token.getAddress();
  
  console.log("MyToken deployed to:", address);
  console.log("Transaction hash:", token.deploymentTransaction().hash);
  
  // Wait for a few confirmations
  console.log("Waiting for confirmations...");
  await token.deploymentTransaction().wait(3);
  
  console.log("Deployment confirmed!");
}

main()
  .then(() => process.exit(0))
  .catch((error) => {
    console.error(error);
    process.exit(1);
  });

Step 6: Deploy to TeQoin

Deploy to Testnet
Deploy to Mainnet

    # Deploy to testnet first (recommended)
    npx hardhat run scripts/deploy.js --network teqoinTestnet
    
    # Output:
    # Deploying contracts with account: 0x...
    # Account balance: 1000000000000000000
    # MyToken deployed to: 0x5E3A9432a2D6eb0c5D362A0A2F58Bc02Db45850D
    # Transaction hash: 0x8551993d9c5625bc8e3e75afc58c0aa2998f95be9eb9bd033875157ce900afe8
    # Waiting for confirmations...
    # Deployment confirmed!

✅ Contract deployed to testnet!

    # Deploy to mainnet (use with caution!)
    npx hardhat run scripts/deploy.js --network teqoin
    
    # Output:
    # Deploying contracts with account: 0x...
    # MyToken deployed to: 0x...

Double-check everything before deploying to mainnet:

Contract code audited
Tested thoroughly on testnet
Sufficient ETH for deployment
Private key is secure

Step 7: Verify Deployment

# Check contract on explorer
# Visit: https://explorer.teqoin.io/address/YOUR_CONTRACT_ADDRESS

# Or verify programmatically
npx hardhat verify --network teqoinTestnet YOUR_CONTRACT_ADDRESS

Learn more about verification →

⚒️ Deploy with Foundry

Foundry is a blazing fast, modern development framework written in Rust.

Prerequisites

# Install Foundry
curl -L https://foundry.paradigm.xyz | bash

# Run foundryup to install forge, cast, anvil
foundryup

# Verify installation
forge --version
cast --version

Step 1: Create New Project

# Create new Foundry project
forge init my-teqoin-project
cd my-teqoin-project

# Project structure:
# src/          - Contracts
# script/       - Deployment scripts
# test/         - Tests
# foundry.toml  - Configuration

Step 2: Configure for TeQoin

foundry.toml

[profile.default]
src = "src"
out = "out"
libs = ["lib"]
solc_version = "0.8.20"
optimizer = true
optimizer_runs = 200

[rpc_endpoints]
teqoin = "https://rpc.teqoin.io"
teqoin_testnet = "https://rpc-testnet.teqoin.io"

[etherscan]
teqoin = { key = "${ETHERSCAN_API_KEY}", url = "https://explorer.teqoin.io/api" }

Step 3: Write Your Contract

src/MyToken.sol

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;

import "openzeppelin-contracts/contracts/token/ERC20/ERC20.sol";

contract MyToken is ERC20 {
    constructor() ERC20("MyToken", "MTK") {
        _mint(msg.sender, 1000000 * 10 ** decimals());
    }
}

Step 4: Install Dependencies

# Install OpenZeppelin
forge install OpenZeppelin/openzeppelin-contracts

# Remappings are created automatically

Step 5: Compile Contract

# Compile
forge build

# Output:
# [⠊] Compiling...
# [⠒] Compiling 1 files with 0.8.20
# [⠢] Solc 0.8.20 finished in 1.23s
# Compiler run successful!

Step 6: Create Deployment Script

script/Deploy.s.sol

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;

import "forge-std/Script.sol";
import "../src/MyToken.sol";

contract DeployScript is Script {
    function run() external {
        // Get private key from environment
        uint256 deployerPrivateKey = vm.envUint("PRIVATE_KEY");
        
        // Start broadcasting transactions
        vm.startBroadcast(deployerPrivateKey);
        
        // Deploy contract
        MyToken token = new MyToken();
        
        console.log("MyToken deployed to:", address(token));
        
        vm.stopBroadcast();
    }
}

Step 7: Deploy to TeQoin

Deploy to Testnet
Deploy to Mainnet

    # Set your private key
    export PRIVATE_KEY=your_private_key_here
    
    # Deploy to testnet
    forge script script/Deploy.s.sol:DeployScript \
      --rpc-url teqoin_testnet \
      --broadcast \
      --verify
    
    # Output:
    # [⠊] Compiling...
    # Script ran successfully.
    # MyToken deployed to: 0x5E3A9432a2D6eb0c5D362A0A2F58Bc02Db45850D
    # 
    # ONCHAIN EXECUTION COMPLETE & SUCCESSFUL.
    # Total Paid: 0.00123 ETH (123000 gas * avg 10 gwei)

✅ Contract deployed and verified!

    # Deploy to mainnet
    forge script script/Deploy.s.sol:DeployScript \
      --rpc-url teqoin \
      --broadcast \
      --verify

Always test on testnet first before deploying to mainnet!

Foundry Useful Commands

# Check gas usage
forge test --gas-report

# Run tests
forge test

# Format code
forge fmt

# Get contract size
forge build --sizes

# Interact with contract
cast call CONTRACT_ADDRESS "totalSupply()" --rpc-url teqoin

🌐 Deploy with Remix

Remix is a browser-based IDE - no installation required!

Step 1: Open Remix

Visit https://remix.ethereum.org

Step 2: Create Contract

Create New File

In the File Explorer, click ”+” to create new file
Name it MyToken.sol

Write Contract

    // SPDX-License-Identifier: MIT
    pragma solidity ^0.8.20;
    
    contract MyToken {
        string public name = "MyToken";
        string public symbol = "MTK";
        uint256 public totalSupply = 1000000 * 10**18;
        
        mapping(address => uint256) public balanceOf;
        
        constructor() {
            balanceOf[msg.sender] = totalSupply;
        }
        
        function transfer(address to, uint256 amount) public returns (bool) {
            require(balanceOf[msg.sender] >= amount, "Insufficient balance");
            balanceOf[msg.sender] -= amount;
            balanceOf[to] += amount;
            return true;
        }
    }

Step 3: Compile

Select Compiler

Click “Solidity Compiler” tab (left sidebar)
Select compiler version: 0.8.20
Click “Compile MyToken.sol”

Verify Compilation

✅ Green checkmark appears when compilation succeeds

Step 4: Connect Wallet

Open Deploy Tab

Click “Deploy & Run Transactions” tab

Select Environment

In “ENVIRONMENT” dropdown, select:

“Injected Provider - MetaMask”

Connect MetaMask

MetaMask popup appears
Select account
Click “Connect”
Make sure you’re on TeQoin L2 network in MetaMask

Step 5: Deploy

Select Contract

In “CONTRACT” dropdown, select MyToken

Click Deploy

Click orange “Deploy” button
MetaMask popup appears
Review transaction
Click “Confirm”

Verify Deployment

Contract appears under “Deployed Contracts”
You can interact with it directly in Remix
Copy contract address for use in your dApp

✅ Contract deployed!

💰 Deployment Costs

Estimated Gas Costs

Contract Type	Gas Used	Estimated Cost (TeQoin L2)
Simple Storage	~100,000	< $0.01
ERC20 Token	~1,200,000	~ $0.05 -$ 0.10
ERC721 NFT	~2,500,000	~ $0.10 -$ 0.20
Complex DeFi	~4,000,000	~ $0.20 -$ 0.40

Much cheaper than Ethereum L1 where the same deployments would cost $50-500+!

✅ Post-Deployment Checklist

Save Contract Address

    # Save to a file
    echo "CONTRACT_ADDRESS=0x..." >> .env
    
    # Or create deployment record
    echo "MyToken: 0x5E3A9432a2D6eb0c5D362A0A2F58Bc02Db45850D" >> deployments.txt

Verify on Explorer

Visit https://explorer.teqoin.io/address/YOUR_ADDRESSVerify:

✅ Contract created successfully
✅ Transaction shows “Success”
✅ Contract code is visible (after verification)

Test Contract Functions

    # Using Hardhat console
    npx hardhat console --network teqoinTestnet
    
    > const MyToken = await ethers.getContractFactory("MyToken")
    > const token = await MyToken.attach("0x...")
    > await token.totalSupply()
    1000000000000000000000000n

Or use Foundry:

    cast call 0x... "totalSupply()" --rpc-url teqoin_testnet

Verify Contract Source

Verify your contract source code on the explorer:Contract Verification Guide →

🔧 Troubleshooting

'Insufficient funds' error

You don’t have enough ETH to pay for deployment gas.Solution:

For testnet: Get ETH from faucet
For mainnet: Bridge ETH from L1 to L2
Check balance: cast balance YOUR_ADDRESS --rpc-url teqoin

'Nonce too high' error

Your wallet’s nonce is out of sync.Solution:

Reset MetaMask: Settings → Advanced → Clear activity tab data
Or wait a few minutes and try again

Contract deployed but not showing on explorer

The explorer indexer might be delayed.Solution:

Wait 1-2 minutes
Refresh the explorer page
Check the transaction hash directly

'Contract creation code storage out of gas'

Your contract is too large (> 24KB limit).Solution:

Enable optimizer in compiler settings
Split contract into multiple contracts
Use libraries to reduce size

    // hardhat.config.js
    solidity: {
      settings: {
        optimizer: {
          enabled: true,
          runs: 200  // Increase for smaller bytecode
        }
      }
    }

Private key not found / Invalid private key

Environment variable not set correctly.Solution:

    # Make sure .env is loaded
    cat .env  # Should show PRIVATE_KEY=...
    
    # Try exporting manually
    export PRIVATE_KEY=your_key_here
    
    # For Hardhat, check dotenv is required
    # Add to hardhat.config.js:
    require("dotenv").config();

📊 Deployment Comparison

Feature	Hardhat	Foundry	Remix
Setup Time	5 minutes	3 minutes	0 minutes
Speed	Medium	Fast	Slow
Testing	Excellent	Excellent	Basic
Gas Reports	Yes	Yes	No
Best For	Teams	Advanced devs	Beginners
Language	JavaScript	Rust/Solidity	Browser

🎯 Next Steps

Verify Your Contract

Verify source code on block explorer

Integrate with Frontend

Connect your contract to a dApp

Write Tests

Test your contract thoroughly

Deploy to Mainnet

After testing, deploy to production

💡 Best Practices

Always Deploy to Testnet First

Deploy to testnet
Test all functions
Get community feedback
Audit if handling significant value
Only then deploy to mainnet

Use Environment VariablesNever hardcode private keys in your code:

// ❌ NEVER DO THIS
const privateKey = "0x1234...";

// ✅ ALWAYS DO THIS
const privateKey = process.env.PRIVATE_KEY;

Keep Deployment RecordsMaintain a file with all your deployments:

deployments.txt

# TeQoin Testnet
MyToken: 0x5E3A9432a2D6eb0c5D362A0A2F58Bc02Db45850D
MyNFT: 0x1234567890abcdef1234567890abcdef12345678

# TeQoin Mainnet
MyToken: 0xabcdef1234567890abcdef1234567890abcdef12

Contract deployed? Now verify it on the block explorer →

Documentation Index

​Deploy Smart Contracts to TeQoin L2

​🎯 Choose Your Tool

Hardhat

Foundry

Remix

​🔨 Deploy with Hardhat

​Prerequisites

​Step 1: Create New Project

​Step 2: Configure for TeQoin

​Step 3: Write Your Contract

​Step 4: Compile Contract

​Step 5: Create Deployment Script

​Step 6: Deploy to TeQoin

​Step 7: Verify Deployment

​⚒️ Deploy with Foundry

​Prerequisites

​Step 1: Create New Project

​Step 2: Configure for TeQoin

​Step 3: Write Your Contract

​Step 4: Install Dependencies

​Step 5: Compile Contract

​Step 6: Create Deployment Script

​Step 7: Deploy to TeQoin

​Foundry Useful Commands

​🌐 Deploy with Remix

​Step 1: Open Remix

​Step 2: Create Contract

​Step 3: Compile

​Step 4: Connect Wallet

​Step 5: Deploy

​💰 Deployment Costs

​Estimated Gas Costs

​✅ Post-Deployment Checklist

​🔧 Troubleshooting

​📊 Deployment Comparison

​🎯 Next Steps

Verify Your Contract

Integrate with Frontend

Write Tests

Deploy to Mainnet

​💡 Best Practices

Deploy Smart Contracts to TeQoin L2

🎯 Choose Your Tool

🔨 Deploy with Hardhat

Prerequisites

Step 1: Create New Project

Step 2: Configure for TeQoin

Step 3: Write Your Contract

Step 4: Compile Contract

Step 5: Create Deployment Script

Step 6: Deploy to TeQoin

Step 7: Verify Deployment

⚒️ Deploy with Foundry

Prerequisites

Step 1: Create New Project

Step 2: Configure for TeQoin

Step 3: Write Your Contract

Step 4: Install Dependencies

Step 5: Compile Contract

Step 6: Create Deployment Script

Step 7: Deploy to TeQoin

Foundry Useful Commands

🌐 Deploy with Remix

Step 1: Open Remix

Step 2: Create Contract

Step 3: Compile

Step 4: Connect Wallet

Step 5: Deploy

💰 Deployment Costs

Estimated Gas Costs

✅ Post-Deployment Checklist

🔧 Troubleshooting

📊 Deployment Comparison

🎯 Next Steps

💡 Best Practices