Verify a Smart Contract on the XRPL EVM

After deploying your smart contract on the XRPL EVM, it is essential to verify the contract source code on the XRPL EVM Explorer. Verification ensures transparency and allows users to interact with your contract directly through the explorer.

This guide provides step-by-step instructions for verifying a smart contract using Remix IDE, Hardhat, and Foundry, with a recommended approach of using Standard JSON Input for seamless verification.

Step 1: Access the XRPL EVM Explorer

Step 2: Select Verification Method

The XRPL EVM Explorer supports multiple methods. For the most reliable results, use Standard JSON Input exported from Remix, Hardhat, or Foundry.

Why Standard JSON Input?

• Captures all compiler settings (version, optimizer, metadata).
• Minimizes bytecode mismatches.

Step 3: Verification with Remix IDE

Generate Standard JSON Input

1. Open your contract in Remix IDE (remix.ethereum.org).

2. Compile under Solidity Compiler:

   • Match the compiler version and optimizer settings from deployment.

3. Under Compilation Details, copy COMPILER INPUT.

4. Save it as input.json locally.

Upload & Verify

1. In the XRPL EVM Explorer’s Verify & Publish page, choose Standard JSON Input.
2. Upload input.json.
3. Select your License Type.
4. Click Verify.

Step 4: Verification with Hardhat

Two approaches—Standard JSON Input and the Hardhat Verify Plugin—each work on Mainnet, and Testnet.

A) Standard JSON Input

1. Compile:

   npx hardhat compile

2. Locate your JSON at:

   artifacts/solc-input/standard-input.json

3. On the Verify & Publish page, choose Standard JSON Input, upload, pick license, and click Verify.

B) Hardhat Verify Plugin

Automate via CLI. Configuration varies per network:

// hardhat.config.ts
import "@nomicfoundation/hardhat-toolbox";
import "@nomicfoundation/hardhat-verify";
import * as dotenv from "dotenv";
dotenv.config();

export default {
  solidity: "0.8.24",
  networks: {
    xrplEVM: {
      url: process.env.XRPL_EVM_URL,    // https://rpc.xrplevm.org
      chainId: 1440000,
      accounts: [process.env.PRIVATE_KEY!],
    },
  },
  etherscan: {
    apiKey: { xrplEVM: "mainnet-key" },
    customChains: [{
      network: "xrplEVM",
      chainId: 1440000,
      urls: {
        apiURL:    "https://explorer.xrplevm.org/api",
        browserURL:"https://explorer.xrplevm.org"
      }
    }]
  }
}

Verify via CLI

Replace <ADDRESS> and [args]:

# Mainnet
npx hardhat verify --network xrplEVM <ADDRESS> [constructorArg1] …

# Testnet
npx hardhat verify --network xrplEVMTestnet <ADDRESS> …

If no constructor parameters, omit the args. Use --force to reverify.

Step 5: Verification with Foundry

Foundry’s forge can both generate Standard JSON and invoke on-chain verification via Etherscan-compatible API.

A) Export Standard JSON Input

1. Build:

   forge build

2. Generate JSON input:

   forge inspect src/HelloWorld.sol:HelloWorld --pretty-json > input.json

3. On the Explorer’s Verify & Publish, choose Standard JSON Input, upload input.json, pick license, and click Verify.

B) CLI Verification with forge verify-contract

Use your .env for RPC, key, and chain ID:

# .env
PRIVATE_KEY=0xYOUR_KEY
CHAIN_ID=1440000           # 1440000=Mainnet, 1449000=Testnet
RPC_URL=https://rpc.xrplevm.org  # switch URL per network

Run:

# Install etherscan support if needed:
forge install foundry-rs/forge-etherscan

# Then verify:
forge verify-contract \
  --chain-id $CHAIN_ID \
  --constructor-args "Hello, XRPL EVM!" \
  --etherscan-api-key any-string \
  <DEPLOYED_ADDRESS> \
  HelloWorld \
  $RPC_URL

• Replace <DEPLOYED_ADDRESS> and HelloWorld with your contract’s name.
• For Testnet, set CHAIN_ID and RPC_URL accordingly.

Additional Tips

• Compiler Settings: Match version & optimizer exactly.
• License: Choose MIT, GPL, or Unlicense.
• Explorer Indexing: Wait ~10–15 s or retry on “no bytecode” errors.
• Cross-chain Ready: Plan for Cosmos IBC or Axelar GMP if you need interoperability.

Why Verify?

1. Transparency: Users can audit your code on-chain.
2. Trust: Builds community confidence.
3. Interaction: Enables Read/Write directly in the explorer UI.

By following these steps—across Mainnet and Testnet, and with Remix, Hardhat, or Foundry—you’ll have a fully verified contract visible and interactable on the XRPL EVM Explorer.