Contract Verification with Blockscout

The following guide walks you through the process of contract verification using the Blockscout explorer.

Prerequisites

• A deployed smart contract on Filecoin mainnet or Calibration testnet
• Your contract source code, either as a flattened .sol file or the same source files and metadata used at compile time
• The deployed contract address
• The Solidity compiler version used for deployment
• The license, optimization settings, optimizer runs, EVM version, and viaIR setting used for deployment
• Constructor arguments, if the contract was deployed with any

Step-by-Step Verification Process

Step 1: Prepare Your Contract Source Code

1. Open Remix IDE if you are using Blockscout's single-file Solidity verification method:

1. Flatten your contract:

   • In the File Explorer sidebar, under contracts, right-click on your contract
   • Select Flatten from the menu
   • This creates a <contract-name>_flattened.sol file with all dependencies included

2. Verify contract details:

   • Ensure the license and Solidity version match your original contract
   • Click Save to save the flattened contract

3. Download the flattened contract:

   • Right-click on <contract-name>_flattened.sol
   • Select Download to save the file locally

4. Gather required information:

   • Contract deployment address
   • Contract license type (optional)
   • Solidity compiler version used for deployment
   • Optimization settings, including enabled/disabled and runs count
   • EVM version and viaIR setting, if your deployment used non-default values
   • ABI-encoded constructor arguments, if your contract constructor used arguments

Step 2: Submit for Verification

1. Access Blockscout verification page:

   • For Filecoin mainnet, navigate to Filecoin Blockscout Contract Verification. Mainnet uses chain ID 314.
   • For Calibration testnet, navigate to Calibration Blockscout Contract Verification. Calibration uses chain ID 314159.

2. Fill in contract information:

   • Enter your contract's deployment address
   • Select the appropriate license type (optional)
   • Choose verification method: Solidity (Single file)
   • Select the compiler version used for deployment
   • Paste the source code from your <contract-name>_flattened.sol file
   • Configure the Optimization enabled checkbox to match your deployment settings
   • Enter optimizer runs, constructor arguments, and any advanced compiler settings if the form prompts for them

1. Submit for verification:
   • Click Verify & Publish to submit your contract

Step 3: Verification Complete

Upon successful verification, Blockscout will display a success message and redirect you to your verified contract dashboard where you can view the source code and interact with your contract.