Retrieving Interchain Messenger from the Registry

Use Registry in a Cross-Chain dApp.

Let's now integrate the registry into a smart contract. Let's go back to the very simple string sending contract from the beginning:

src/3-registry/SenderOnCChainWithRegistry.sol

pragma solidity ^0.8.18;
 
import "@teleporter/upgrades/TeleporterRegistry.sol"; 
import "@teleporter/ITeleporterMessenger.sol";
 
contract SenderOnCChain {
    // The Interchain Messaging registry contract manages different Interchain Messaging contract versions.
    TeleporterRegistry public immutable teleporterRegistry = TeleporterRegistry(0x827364Da64e8f8466c23520d81731e94c8DDe510);
 
    /**
     * @dev Sends a message to another chain.
     */
    function sendMessage(address destinationAddress, string calldata message) external {
        ITeleporterMessenger messenger = teleporterRegistry.getLatestTeleporter();  
 
        messenger.sendCrossChainMessage(
            TeleporterMessageInput({
                // Replace with blockchainID of your Avalanche L1 (see instructions in Readme)
                destinationBlockchainID: 0x92756d698399805f0088fc07fc42af47c67e1d38c576667ac6c7031b8df05293,
                destinationAddress: destinationAddress,
                feeInfo: TeleporterFeeInfo({feeTokenAddress: address(0), amount: 0}),
                requiredGasLimit: 100000,
                allowedRelayerAddresses: new address[](0),
                message: abi.encode(message)
            })
        );
    }
}

Don't forget to replace the destinationBlockchainID with Blockchain ID (HEX) from your Avalanche L1!

The key things to understand:

We are importing the ITeleporterRegistry.sol interface
We have a variable for the registry address instead of the messenger address
Before sending the message we get the latest version from the registry

Interact with the ICM Registry

Verify if Sender is Interchain Messaging

Retrieving Interchain Messenger from the Registry

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