Add CCIP Networks for Cross-Chain Token Tutorials (Foundry)

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The smart-contract-examples repository includes default configurations for common CCIP testnet networks. This guide shows how to add support for additional networks.

Add a Network

Add the network configuration to script/HelperConfig.s.sol

// Rest of the code...

constructor() {
    // Rest of the existing networks...

    else if (block.chainid == 11155420) {
        activeNetworkConfig = getOptimismSepoliaConfig();
    } else {
        revert("Unsupported network");
    }
}

// Rest of the existing network configurations...

function getOptimismSepoliaConfig() public pure returns (NetworkConfig memory) {
    NetworkConfig memory optimismSepoliaConfig = NetworkConfig({
        chainSelector: 5224473277236331295,
        router: 0x114A20A10b43D4115e5aeef7345a1A71d2a60C57,
        rmnProxy: 0xb40A3109075965cc09E93719e33E748abf680dAe,
        tokenAdminRegistry: 0x1d702b1FA12F347f0921C722f9D9166F00DEB67A,
        registryModuleOwnerCustom: 0x49c4ba01dc6F5090f9df43Ab8F79449Db91A0CBB,
        link: 0xE4aB69C077896252FAFBD49EFD26B5D171A32410,
        confirmations: 2,
        nativeCurrencySymbol: "ETH"
    });
    return optimismSepoliaConfig;
}

function getNetworkConfig(uint256 chainId) public pure returns (NetworkConfig memory) {
    // Rest of the existing networks...

    else if (chainId == 11155420) {
        return getOptimismSepoliaConfig();
    } else {
        revert("Unsupported chain ID");
    }
}

Set the RPC URL:

RPC_URL_OPTIMISM_SEPOLIA="INSERT_YOUR_RPC_URL_HERE"

Save the .env file, then load the environment variable into the terminal session:

source .env

The network is now available in all Foundry commands using --rpc-url $RPC_URL_OPTIMISM_SEPOLIA.

Configuration Fields

Field	Required	Description	Source
`chainSelector`	Yes	CCIP identifier for the network	CCIP Directory
`router`	Yes	CCIP Router contract address	CCIP Directory
`rmnProxy`	Yes	RMN Proxy contract address	CCIP Directory
`tokenAdminRegistry`	Yes	Token Admin Registry address	CCIP Directory
`registryModuleOwnerCustom`	Yes	Registry Module Owner address	CCIP Directory
`link`	Yes	LINK token contract address	CCIP Directory
`confirmations`	No	Number of block confirmations before considering transaction final	Blockchain's finality characteristics and your risk tolerance
`nativeCurrencySymbol`	No	Native gas token symbol (e.g., `"ETH"`, `"AVAX"`, `"POL"`)	Blockchain's official documentation

Find all CCIP addresses in the CCIP Directory - Testnet or CCIP Directory - Mainnet.

Test

Deploy a token to verify the configuration:

forge script script/DeployToken.s.sol --rpc-url $RPC_URL_OPTIMISM_SEPOLIA --private-key $PRIVATE_KEY --broadcast

Contract Verification (Optional)

Most networks are natively supported. Add --verify when deploying:

forge script script/DeployToken.s.sol --rpc-url $RPC_URL_OPTIMISM_SEPOLIA --private-key $PRIVATE_KEY --broadcast --verify

For networks not in Foundry's StdChains.sol::StdChains::initializeStdChains() function, include the --verifier, --verifier-url, and --verifier-api-key flags together with --verify when deploying:

forge script script/DeployToken.s.sol --rpc-url $RPC_URL_CUSTOM_NETWORK --private-key $PRIVATE_KEY --broadcast --verify --verifier custom --verifier-url $CUSTOM_EXPLORER_API_URL --verifier-api-key $CUSTOM_EXPLORER_API_KEY

With Etherscan API V2, a single ETHERSCAN_API_KEY works across all Etherscan-compatible networks.