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alexander-sei merged 1 commit into from
Feb 20, 2026
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add-hardhat3-support #485

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92 changes: 54 additions & 38 deletions content/evm/evm-hardhat.mdx
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Original file line number Diff line number Diff line change
Expand Up @@ -56,24 +56,41 @@ npm install --save-dev hardhat @nomicfoundation/hardhat-toolbox @openzeppelin/co
After installation, initialize a new Hardhat project:

```bash copy
npx hardhat init
npx hardhat --init
```

When prompted, select "Create a JavaScript project" and follow the setup instructions.
When prompted, select :

- Hardhat3
- A TypeScript Hardhat project using Mocha and Ethers.js

and then follow the instructions to set up your project.

If you encounter an error because of mismatch of versioning, you can try the following command with `--legacy-peer-deps` flag:

```bash copy
npm install --save-dev "@nomicfoundation/hardhat-toolbox-mocha-ethers@^3.0.2" "@nomicfoundation/hardhat-ethers@^4.0.4" "@nomicfoundation/hardhat-ignition@^3.0.7" "@types/chai@^4.2.0" "@types/chai-as-promised@^8.0.1" "@types/mocha@>=10.0.10" "@types/node@^22.8.5" "chai@^5.1.2" "ethers@^6.14.0" "forge-std@foundry-rs/forge-std#v1.9.4" "mocha@^11.0.0" "typescript@~5.8.0" --legacy-peer-deps
```

Post that, it is recommended to install some hardhat based dependencies as well for supporting Hardhat3:

```bash copy
npm i @nomicfoundation/hardhat-ethers-chai-matchers @nomicfoundation/hardhat-ignition-ethers @nomicfoundation/hardhat-keystore @nomicfoundation/hardhat-mocha @nomicfoundation/hardhat-network-helpers @nomicfoundation/hardhat-typechain @nomicfoundation/hardhat-verify
```

## Configuring Hardhat for Sei EVM

Next, we'll need to configure Hardhat to work with the Sei EVM. Update your `hardhat.config.js` file:
Next, we'll need to configure Hardhat to work with the Sei EVM. Update your `hardhat.config.ts` file:

```javascript copy filename="hardhat.config.js"
require('@nomicfoundation/hardhat-toolbox');
require('dotenv').config();
```typescript copy filename="hardhat.config.ts"
import { HardhatUserConfig } from 'hardhat/config';
import '@nomicfoundation/hardhat-toolbox';
import 'dotenv/config';

// Load environment variables
const PRIVATE_KEY = process.env.PRIVATE_KEY || '0x0000000000000000000000000000000000000000000000000000000000000000';

/** @type import('hardhat/config').HardhatUserConfig */
module.exports = {
const config: HardhatUserConfig = {
solidity: {
version: '0.8.28',
settings: {
Expand All @@ -88,15 +105,13 @@ module.exports = {
seitestnet: {
url: 'https://evm-rpc-testnet.sei-apis.com',
accounts: [PRIVATE_KEY],
chainId: 1328, // Sei testnet chain ID
gasPrice: 2000000000 // 2 gwei = 2 nsei
chainId: 1328 // Sei testnet chain ID
},
// Sei mainnet configuration
seimainnet: {
url: 'https://evm-rpc.sei-apis.com',
accounts: [PRIVATE_KEY],
chainId: 1329, // Sei mainnet chain ID
gasPrice: 2000000000 // 2 gwei = 2 nsei
chainId: 1329 // Sei mainnet chain ID
},
// Local development with Hardhat Network
hardhat: {
Expand Down Expand Up @@ -165,9 +180,9 @@ contract SeiToken is ERC20, Ownable {
}
```

Now, create a deployment script in the `ignition/modules` directory called `deploy-sei-token.js`:
Now, create a deployment script in the `ignition/modules` directory called `deploy-sei-token.ts`:

```javascript copy filename="scripts/deploy-sei-token.js"
```typescript copy filename="scripts/deploy-sei-token.ts"
import { buildModule } from '@nomicfoundation/hardhat-ignition/modules';

export default buildModule('SeiTokenModule', (m) => {
Expand All @@ -182,7 +197,7 @@ export default buildModule('SeiTokenModule', (m) => {
To deploy the token to the Sei testnet:

```bash copy
npx hardhat ignition deploy ignition/modules/deploy-sei-token.js --network seitestnet
npx hardhat ignition deploy ignition/modules/deploy-sei-token.ts --network seitestnet
```

</Tabs.Tab>
Expand Down Expand Up @@ -281,10 +296,10 @@ contract SeiNFT is ERC721, ERC721Enumerable, ERC721URIStorage, ERC721Pausable, O
}
```

Create a deployment script `deploy-sei-nft.js`:
Create a deployment script `deploy-sei-nft.ts`:

```javascript copy filename="scripts/deploy-sei-nft.js"
const { ethers } = require('hardhat');
```typescript copy filename="scripts/deploy-sei-nft.ts"
import { ethers } from 'hardhat';

async function main() {
const [deployer] = await ethers.getSigners();
Expand Down Expand Up @@ -320,7 +335,7 @@ main()
Deploy the NFT contract to the Sei testnet:

```bash copy
npx hardhat run scripts/deploy-sei-nft.js --network seitestnet
npx hardhat run scripts/deploy-sei-nft.ts --network seitestnet
```

</Tabs.Tab>
Expand All @@ -333,12 +348,13 @@ First, ensure you have installed the necessary upgrade plugins as mentioned in t
npm install @openzeppelin/contracts-upgradeable @openzeppelin/hardhat-upgrades
```

And make sure your `hardhat.config.js` includes the upgrades plugin:
And make sure your `hardhat.config.ts` includes the upgrades plugin:

```javascript copy filename="hardhat.config.js"
require('@nomicfoundation/hardhat-toolbox');
require('@openzeppelin/hardhat-upgrades');
require('dotenv').config();
```typescript copy filename="hardhat.config.ts"
import { HardhatUserConfig } from 'hardhat/config';
import '@nomicfoundation/hardhat-toolbox';
import '@openzeppelin/hardhat-upgrades';
import 'dotenv/config';

// ... rest of your config
```
Expand Down Expand Up @@ -390,10 +406,10 @@ contract UpgradeableSeiToken is Initializable, ERC20Upgradeable, OwnableUpgradea

Note the use of `Initializable`, `initializer` modifier, `__ERC20_init`, `__Ownable_init`, `__UUPSUpgradeable_init`, and the `_authorizeUpgrade` function override. These are crucial for upgradeable contracts.

Create a deployment script `scripts/deploy-upgradeable-token.js`:
Create a deployment script `scripts/deploy-upgradeable-token.ts`:

```javascript copy filename="scripts/deploy-upgradeable-token.js"
const { ethers, upgrades } = require('hardhat');
```typescript copy filename="scripts/deploy-upgradeable-token.ts"
import { ethers, upgrades } from 'hardhat';

async function main() {
const [deployer] = await ethers.getSigners();
Expand Down Expand Up @@ -423,7 +439,7 @@ main()
Deploy this to the testnet:

```bash copy
npx hardhat run scripts/deploy-upgradeable-token.js --network seitestnet
npx hardhat run scripts/deploy-upgradeable-token.ts --network seitestnet
```

**Upgrading the Contract**
Expand Down Expand Up @@ -456,10 +472,10 @@ contract UpgradeableSeiTokenV2 is UpgradeableSeiToken {
}
```

Now, create an upgrade script `scripts/upgrade-token.js`. **Replace `PROXY_ADDRESS` with the address printed when you deployed the proxy.**
Now, create an upgrade script `scripts/upgrade-token.ts`. **Replace `PROXY_ADDRESS` with the address printed when you deployed the proxy.**

```javascript copy filename="scripts/upgrade-token.js"
const { ethers, upgrades } = require('hardhat');
```typescript copy filename="scripts/upgrade-token.ts"
import { ethers, upgrades } from 'hardhat';

// !! REPLACE WITH YOUR PROXY ADDRESS !!
const PROXY_ADDRESS = '0xYOUR_PROXY_CONTRACT_ADDRESS_HERE';
Expand Down Expand Up @@ -494,7 +510,7 @@ main()
Run the upgrade script:

```bash copy
npx hardhat run scripts/upgrade-token.js --network seitestnet
npx hardhat run scripts/upgrade-token.ts --network seitestnet
```

You have now successfully deployed and upgraded a UUPS contract on the Sei network using Hardhat and OpenZeppelin!
Expand All @@ -504,11 +520,11 @@ You have now successfully deployed and upgraded a UUPS contract on the Sei netwo

## Testing Your Smart Contracts

Hardhat makes it easy to test your contracts before deploying them. Create a test file `test/sei-token-test.js`:
Hardhat makes it easy to test your contracts before deploying them. Create a test file `test/sei-token-test.ts`:

```javascript copy filename="test/sei-token-test.js"
const { expect } = require('chai');
const { ethers } = require('hardhat');
```typescript copy filename="test/sei-token-test.ts"
import { expect } from 'chai';
import { ethers } from 'hardhat';

describe('SeiToken', function () {
let SeiToken;
Expand Down Expand Up @@ -594,11 +610,11 @@ Once you've tested your contracts, you can deploy them to the Sei testnet or mai
Deploy to the testnet:

```bash copy
npx hardhat ignition deploy ignition/modules/deploy-sei-token.js --network seitestnet
npx hardhat ignition deploy ignition/modules/deploy-sei-token.ts --network seitestnet
```

Deploy to the mainnet (only when you're ready for production):

```bash copy
npx hardhat ignition deploy ignition/modules/deploy-sei-token.js --network seimainnet
npx hardhat ignition deploy ignition/modules/deploy-sei-token.ts --network seimainnet
```