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Interacting with Smart Contracts on Blockscout

Revealer

09 Jul 2025 • 4 min read

Blockscout features a modern, React-based interface that allows users to verify, read, write to, and interact with contracts and proxies. It automatically detects proxy patterns ([EIP-1967], [EIP-1822], Diamond) and offers separate interfaces for proxy and implementation contracts. This tutorial will guide you through effectively using Blockscout's interface to interact with smart contracts on the Optimism network.

Smart Contracts on Blockscout

Once a smart contract is verified, its methods and functions become publicly accessible, enabling users to interact with them directly. This verification process allows developers and users alike to confirm the integrity and functionality of the contract.

To verify if a contract is verified, look for a green checkmark (✅) next to the "Contract" tab on the Explorer instance. This green checkmark serves as an indicator of a verified contract, reassuring users that the code has been reviewed and matches its deployed version on the blockchain.

Blockscout blockchain explorer showing verified smart contract details for StakedLPTokenSolidlyBase4 token contract on Optimism mainnet with contract address, verification status, and source code information

Contract Tab: This tab is the heart of smart contract interaction, and it features the following tabs:

Read/Write Contract: Query contract state without gas costs and execute state-changing functions that incur gas fees.
Read Proxy/Write Proxy: For proxy contract interactions (For contracts with Proxies)
Code: Full source code with syntax highlighting
Custom ABI: You can add custom ABIs for your contract and access them when logged into your account.

Reading WETH9 Contract

Before you do this, ensure to have the following checked

Smart contract must be verified (✅ checkmark visible).
Web3 wallet connected to the Optimism network.
Understand of the contract's purpose and functions.

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The following tutorial is based on the Optimism Network. If you would prefer to use a testnet, you can use the WETH9 contract on Sepolia.

Step 1: Navigate to the Contract

Go to https://optimism.blockscout.com/
Enter the contract address (0x4200000000000000000000000000000000000006) in the search bar.

OP Mainnet explorer search results showing L2 Standard Bridged WETH token contract address with $2,572.95 value, latest blocks, transactions, and network utilization at 39.30% on Optimism blockchain

Click on the contract page result.

L2 Standard Bridged WETH token page on Blockscout showing $2,568.29 price, $82.5B market cap, 32,157 WETH max supply, and verified contract details on Optimism blockchain explorer

Check for the verification checkmark next to "Contract."

Step 2: Connect your wallet

Click the Connect Wallet button to link your wallet. Reading operations don't require gas, but a wallet connection is needed for identification.

WETH token contract page on Blockscout showing $2,572.95 price, $83.19B market cap, 303,508 holders, with Connect wallet button highlighted and contract interaction interface for L2 Standard Bridged WETH on Optimism

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Ensure your wallet is connected to the Optimism network.

Step 3: Execute Read Functions

Click the “Read/write contract” tab, then select the read tab to start browsing the methods.

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For proxy contracts, you'll see both "Read Contract" and "Read Proxy" options. Choose "Read Proxy" for proxy contracts, as it displays the implementation methods.

Smart contract read interface on Blockscout showing connected wallet and ERC-20 token contract functions including allowance, balanceOf, decimals, name, symbol, and totalSupply methods with hexadecimal values

For functions requiring parameters, fill in the required fields and click the “Read” button to execute the query.

Smart contract function interface showing allowance and balanceOf methods with Ethereum address inputs, Read and Copy calldata buttons, returning uint256 values 0 and 685654125388448733045 for ERC-20 token contract

To test the balanceOf and allowance methods, I used a random contract addresses on the Optimism network. Put in any random addresses that holds WETH and view the result.

For other methods that don't require parameters, click "Read" to execute the query. View the results displayed below the function.

ERC-20 token contract read functions showing name 'Wrapped Ether', symbol 'WETH', and totalSupply of 322729653933984883519120 with hexadecimal method IDs and Read buttons for smart contract interaction

Writing to the WETH9 Contract

Writing operations are irreversible and cost gas. Before you continue, ensure that;

Your Web3 wallet has sufficient ETH for gas fees
You understand the function you want to execute

Step 1: Navigate to the Write Methods

Click the Write tab to access the Write functions

Smart contract Write interface on Blockscout showing connected wallet with writable functions including approve, deposit, fallback, transfer, transferFrom, and withdraw methods with hexadecimal method IDs for ERC-20 token contract interaction

Step 2: Fill in the Parameters

Understand what the function will do, then carefully enter all required parameters.

For example, with the deposit function, we can send native ETH to this contract and get wrapped ETH (WETH) in return.

WETH deposit function interface showing 'Send native ETH' input field with uint256 parameter and scientific notation multiplier (×10^18) with Write button for converting ETH to Wrapped Ether on smart contract

The value of ETH is automatically converted to Wei if you paste in. If not, you can use a Wei calculator (ie https://eth-converter.com/) to enter the amount of ETH you want to convert and it will give you the value in WEI.