ICM Basics

Teleporter enables you to send messages from one blockchain to another blockchain in the Avalanche network by simply calling the sendCrossChainMessage on the TeleporterMessenger contract. This invokes a smart contract on another Avalanche L1, where the called contract implements the ITeleporterReceiver interface to receive messages on the destination Avalanche L1. We will look at what happens under the hood in a later chapter.

What You Will Learn

In this section, you will go through the following topics:

• Recap: Bytes, Encoding, and Decoding: Understand how data is encoded and decoded in bytes
• Sending messages: Write your first simple sender contract
• Receiving messages: Write your first simple receiver contract

Exercise

You will apply your learned knowledge by building your first Cross-Chain application! This application will be deployed on two chains: C-chain and your own Avalanche L1, both running on a Local Network.

Therefore, you will deploy two contracts:

• Sender on Local C-Chain: Send a message with a simple string
• Receiver on your Avalanche L1: Receives the message and saves the most recent string

At the end of the section, you will be adapting the example to build an 'Adder'. This application is similar to the example above, but will the message will include a number. The receiving contract keeps track of the sum of all sent numbers.