Verify smart contracts with Foundry

This page outlines the steps for verifying contracts on Neon EVM using the Foundry tool.

This tutorial is based on the example located in this repository.

info

Foundry doesn't support custom explorers and only support Blockscout, Sourcify and Etherscan.

By the end of this tutorial, you will learn to verify a contract that deploys an ERC-20 token to Neon EVM Devnet on Blockscout explorer.

Step 1: Configure .env

Create a .env file in the project's root directory to feed in the required variables.

RPC_URL_DEVNET=https://devnet.neonevm.org
CHAIN_ID_DEVNET=245022926
RPC_URL_MAINNET=https://neon-proxy-mainnet.solana.p2p.org
CHAIN_ID_MAINNET=245022934
PRIVATE_KEY=<YOUR_PRIVATE_KEY>
VERIFIER_URL_BLOCKSCOUT=https://neon-devnet.blockscout.com/api

Run source .env to save the .env variables.

Step 2: Deploy the contract

To deploy a contract, please follow this page describing how to deploy contracts with Foundry.

Step 3: Verify the deployed contract

To verify the deployed contract from the above step, let's take an example of a deployed contract with address 0x93adb347065949a90a7f2e198f94c2fadeb7dbbd on Neon EVM Devnet.

After running the following command to verify -

forge verify-contract --chain-id $CHAIN_ID_DEVNET 0x93adb347065949a90a7f2e198f94c2fadeb7dbbd src/TestERC20/TestERC20.sol:TestERC20 --verifier-url $VERIFIER_URL_BLOCKSCOUT --verifier blockscout

The output should look like this -

Start verifying contract `0x93Adb347065949a90a7f2e198F94c2FADeb7dBbd` deployed on 245022926

Submitting verification for [src/TestERC20/TestERC20.sol:TestERC20] "0x93Adb347065949a90a7f2e198F94c2FADeb7dBbd".
Submitted contract for verification:
	Response: `OK`
	GUID: `93adb347065949a90a7f2e198f94c2fadeb7dbbd661584d8`
	URL:
        https://neon-devnet.blockscout.com/api?/address/0x93adb347065949a90a7f2e198f94c2fadeb7dbbd

The verified contract source code can be found here https://neon-devnet.blockscout.com/address/0x93Adb347065949a90a7f2e198F94c2FADeb7dBbd?tab=contract.

important

If the deployed contract consists of constructor arguments to be passed, then the constructor arguments are ABI-encoded. For example -

forge verify-contract --chain-id $CHAIN_ID_DEVNET 0x93adb347065949a90a7f2e198f94c2fadeb7dbbd src/TestERC20/TestERC20.sol:TestERC20 --verifier-url $VERIFIER_URL_BLOCKSCOUT --verifier blockscout --constructor-args $(cast abi-encode "constructor(string,string)" "TestToken" "TEST")

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If you want to verify on NeonScan, then please follow this page which describes the steps to verify smart contracts manually on NeonScan