docs: include Hardhat project example

README.md

@@ -443,7 +443,8 @@ You can use the following checklist to make sure the new release, either integra
 - [ ] **Check `servers` list.** Make sure _Servers_ listed in <https://server-verify.hashscan.io/api-docs/> are properly set to Hedera and local servers.
 - [ ] **Verify a contract using Hashscan.** Deploy a contract with your favorite tool. Verify it using the `VERIFY CONTRACT` button in the _Contract_ view in Hashscan. Make sure the verified contract is visible from the `repository`. See [How to Verify a Smart Contract on HashScan](https://docs.hedera.com/hedera/tutorials/smart-contracts/how-to-verify-a-smart-contract-on-hashscan) for more details.
 - [ ] **Verify a contract using the Verifier UI**. Deploy a contract with your favorite tool. Verify it using the Verifier UI. Make sure the verified contract is visible from the `repository`. Make sure the verified contract is visible as such in the _Contract_ view in Hashscan.
-- [ ] **Ensure your deployed contracts are listed.**. Use the endpoint <https://server-verify.hashscan.io/files/contracts/296> (change the domain if necessary) and make sure the deployed contracts are listed here.
+- [ ] **Verify a contract using a Hardhat project**. Make sure the [`hardhat-verify`](https://hardhat.org/hardhat-runner/plugins/nomicfoundation-hardhat-verify#verifying-on-sourcify) plugin is able to verify a contract in the deployed instance. See [tools/README](./tools/README.md) for more details.
+- [ ] **Ensure your deployed contracts are listed.** Use the endpoint <https://server-verify.hashscan.io/files/contracts/296> (change the domain if necessary) and make sure the deployed contracts are listed there.
 
 Once you ensure the new release works properly, create a GitHub Release to let users and developers of what has changed.
 Go to <https://github.com/hashgraph/hedera-sourcify/releases> and follow the steps under _Draft a new release_.

tools/README.md

@@ -54,10 +54,15 @@ forge create --rpc-url http://localhost:7546 \
 
 You can also verify contracts using Hardhat with the [`hardhat-verify`](https://hardhat.org/hardhat-runner/plugins/nomicfoundation-hardhat-verify#verifying-on-sourcify) plugin using our verification service.
 
-> There is currently a minor issue that might confuse users but that does not affect Sourcify verification <https://github.com/NomicFoundation/hardhat/issues/4776>.
+> [!NOTE]
+> There is a minor issue that might confuse users but that does not affect Sourcify verification.
+> See <https://github.com/NomicFoundation/hardhat/issues/4776> for more details.
 
 Create a new Hardhat project, install its dependencies and use the following `hardhat.config.js`
 
+> [!TIP]
+> You can use the [Hardhat starter project](./hardhat/) to work with a custom Sourcify instance.
+
 ```js
 require("@nomicfoundation/hardhat-toolbox");
 
@@ -82,7 +87,7 @@ module.exports = {
 };
 ```
 
-> [!NOTE]
+> [!IMPORTANT]
 > Both `apiUrl` and `browserUrl` expect an URL without a trailing slash.
 > Having a trailing slash in the Sourcify URLs may cause unexpected errors.
 

tools/hardhat/.env.template

@@ -0,0 +1,18 @@
+# Setup your accounts for different networks
+TESTNET_PK=
+PREVIEWNET_PK=
+LOCALNET_PK=
+
+# Select the Sourcify instance you want to target
+
+# Production Hedera Sourcify instance
+SOURCIFY_API_URL=https://server-verify.hashscan.io
+SOURCIFY_BROWSER_URL=https://repository-verify.hashscan.io
+
+# Staging Hedera Sourcify instance
+# SOURCIFY_API_URL=https://server-sourcify.hedera-devops.com
+# SOURCIFY_BROWSER_URL=https://repository-sourcify.hedera-devops.com
+
+# Local Hedera Sourcify instance
+# SOURCIFY_API_URL=http://localhost:5555
+# SOURCIFY_BROWSER_URL=http://localhost:10000

tools/hardhat/.gitignore

@@ -0,0 +1,6 @@
+/node_modules/
+/.env
+
+# Hardhat output files
+/cache/
+/artifacts/

tools/hardhat/README.md

@@ -0,0 +1,22 @@
+# Sample Hardhat Project
+
+> [!IMPORTANT]  
+> Create a `.env` file
+>
+> ```sh
+> cp .env.template .env
+> ```
+>
+> and setup your accounts for different networks, and select the Sourcify instance you want to target.
+
+This project demonstrates a basic Hardhat use case. It comes with a sample contract, a test for that contract, and a script that deploys that contract.
+
+Try running some of the following tasks:
+
+```shell
+npx hardhat help
+npx hardhat test
+REPORT_GAS=true npx hardhat test
+npx hardhat node
+npx hardhat run scripts/deploy.js
+```

tools/hardhat/contracts/Lock.sol

@@ -0,0 +1,34 @@
+// SPDX-License-Identifier: UNLICENSED
+pragma solidity ^0.8.9;
+
+// Uncomment this line to use console.log
+// import "hardhat/console.sol";
+
+contract Lock {
+    uint public unlockTime;
+    address payable public owner;
+
+    event Withdrawal(uint amount, uint when);
+
+    constructor(uint _unlockTime) payable {
+        require(
+            block.timestamp < _unlockTime,
+            "Unlock time should be in the future"
+        );
+
+        unlockTime = _unlockTime;
+        owner = payable(msg.sender);
+    }
+
+    function withdraw() public {
+        // Uncomment this line, and the import of "hardhat/console.sol", to print a log in your terminal
+        // console.log("Unlock time is %o and block timestamp is %o", unlockTime, block.timestamp);
+
+        require(block.timestamp >= unlockTime, "You can't withdraw yet");
+        require(msg.sender == owner, "You aren't the owner");
+
+        emit Withdrawal(address(this).balance, block.timestamp);
+
+        owner.transfer(address(this).balance);
+    }
+}

tools/hardhat/hardhat.config.js

@@ -0,0 +1,43 @@
+require("@nomicfoundation/hardhat-toolbox");
+require("dotenv").config();
+
+const accounts = pk => pk ? [pk] : undefined;
+
+/** @type import('hardhat/config').HardhatUserConfig */
+module.exports = {
+  solidity: "0.8.19",
+
+  defaultNetwork: "testnet",
+
+  networks: {
+    testnet: {
+      url: 'https://testnet.hashio.io/api',
+      accounts: accounts(process.env.TESTNET_PK),
+      chainId: 296,
+    },
+    previewnet: {
+      url: 'https://previewnet.hashio.io/api',
+      accounts: accounts(process.env.PREVIEWNET_PK),
+      chainId: 297,
+    },
+    localnet: {
+      url: 'http://localhost:7546',
+      accounts: accounts(process.env.LOCALNET_PK),
+      chainId: 298,
+    },
+  },
+
+  etherscan: {
+    enabled: false,
+  },
+
+  sourcify: {
+    // Disabled by default
+    // Doesn't need an API key
+    enabled: true,
+    // Optional: specify a different Sourcify server
+    apiUrl: process.env.SOURCIFY_API_URL,
+    // Optional: specify a different Sourcify repository
+    browserUrl: process.env.SOURCIFY_BROWSER_URL,
+  }
+};