Verify Smart Contract

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Prerequisites

• Familiar with Block Explorers. If not, check out the Block Explorers section.
• You have previously deployed a smart contract using one of the previous tutorials (e.g. SimpleStorage.sol).

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Method 1: Subscan Verification

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1. Prepare Metadata from Remix

• Open up the artifacts/build-info/hex_value file. This contains the content we need to move to the SimpleStorage_metadata.json file.
• Copy and paste the entire content line as shown in the screenshot above.

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2. Paste content into SimpleStorage_metadata

• Navigate to the SimpleStorage_metadata.json file.
• Find the sources object where the data for contract SimpleStorage.sol is stored.
• Paste the content after the license field.

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3. Download the SimpleStorage_metadata.json file

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4. Navigate to Subscan

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5. Verify Contract

• Confirm the Contract Address field matches your Smart Contract to verify.
• Select Solidity (Standard-JSON-Input) as Compiler Type.
• Pick whether or not you would like to Include Nightly Builds.
• Choose the Compiler Version that was used when you compiled your smart contract.
• Upload the file that we downloaded from Remix earlier.
• Finally, click the Verify & Publish button.

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6. Confirm Verification

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Contract Information Displayed

• Contract Name: SimpleStorage
• Compiler Version: v0.8.26+commit.8a97fa7a
• EVM Version: cancun
• Optimization: false

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Contract ABI

• The ABI (Application Binary Interface) specifies the interface of the contract.
• It includes the function details such as:
  • Function get:
    • Inputs: None.
    • Outputs: A single uint256 value.
    • Mutability: view (read-only).
  • Function set:
    • Inputs: A single uint256 value (_data).
    • Outputs: None.
    • Mutability: nonpayable (modifies the state).

• set(uint256 _data): Stores a value.
• get(): Retrieves the stored value.

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Contract Source Code

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

contract SimpleStorage {
    uint256 private data;

    function set(uint256 _data) public {
        data = _data;
    }

    function get() public view returns (uint256) {
        return data;
    }
}

• Logic:
  • set: Allows the user to save a uint256 value in the contract’s state.
  • get: Returns the saved value without modifying the state.

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Contract Bytecode

• The bytecode is the compiled version of the Solidity source code.
• It is what gets deployed to the Ethereum blockchain.
• This bytecode matches the source code provided in the screenshot.

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Method 2: Sourcify Verification (decentralized record)

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1. Navigate to Sourcify

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2. Select Network

• From the network dropdown, select “peaq” (Chain ID: 3338)
• Ensure you’re verifying on the correct network where your contract is deployed

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3. Enter Contract Information

• Contract Address: Enter your deployed contract address
• Sourcify will automatically detect if the contract is already verified
• If unverified, you’ll proceed to the verification form

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4. Upload Contract Files

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Option A: Upload Source Files

• Drag and drop or browse to upload your main Solidity file (e.g., SimpleStorage.sol)
• Upload any imported dependencies or libraries
• Maintain the correct folder structure as used during compilation
• Include any configuration files (e.g., hardhat.config.js, foundry.toml)

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Option B: Upload Metadata JSON

• Hardhat users: Upload the complete metadata from artifacts/contracts/YourContract.sol/YourContract.json
• Foundry users: Upload the metadata from out/YourContract.sol/YourContract.json
• Remix users: Download and upload the metadata JSON from the artifacts folder

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5. Verify Compilation Settings

• Compiler Version: Must match the version used during compilation
• EVM Version: Should be set to london (required for peaq network)
• Optimization Settings: Enabled/disabled status and number of runs
• Source Maps: For debugging and verification accuracy

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6. Submit for Verification

• Review the contract details and compilation metadata
• Click “Verify” to submit your contract for verification
• Sourcify will compile the contract and compare bytecode
• Wait for the verification process to complete (usually takes 1-2 minutes)

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7. Verification Results

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Perfect Match

• Your contract achieves “Perfect Match” status
• Source code is permanently stored on IPFS
• Contract is automatically indexed by Sourcify
• Verification data is accessible across all Sourcify-compatible explorers

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Partial Match

• If you get a “Partial Match”, the core logic matches but metadata differs
• Check compilation settings, especially optimization and EVM version
• Consider re-verifying with exact compilation parameters

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8. View Verified Contract

• Visit the Sourcify repository to view your contract’s source code
• Subscan does not read Sourcify; verify there separately (Method 1) if you want decoded calls on peaq.subscan.io
• Access the contract’s IPFS hash for permanent source code storage
• Use the contract ABI for frontend integration

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Summary

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Recommended approach

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Decentralized record