TypeScript Smart Contract 101

Introduction

In this section, we'll provide an overview of the tutorial, including what you'll learn, the prerequisites, and the tech stack. We'll also introduce you to Azle, the TypeScript framework we'll be using to build our canisters.

What you'll learn

• Setting up your development environment: Understand the necessary tools for ICP development, such as Node.js, Node Version Manager (nvm), and DFX, and learn how to install and use them​.
• Grasping the boilerplate code: Familiarize yourself with the essential files and configurations needed to start an Azle project on the ICP platform, including the tsconfig.json, dfx.json, and package.json files.****
• Building and interacting with a messaging canister: Learn how to construct a simple messaging canister that performs CRUD (Create, Read, Update, Delete) operations. You will also learn how to interact with the canister, calling its methods and handling responses. This knowledge will allow you to build a simple message board application, enabling users to create, update, delete, and view messages​.

What is a Canister?

A canister is a fundamental building block and execution environment for deploying and running software applications on the Internet Computer Protocol (ICP) platform. Canisters bundle together code and state to create a secure and efficient execution environment. They are similar to smart contracts on other blockchain platforms. Canisters enable the development of scalable and decentralized applications, including DeFi platforms, social media applications, DAOs, and more.

What is Azle?

Azle is a TypeScript Canister Development Kit (CDK) for the Internet Computer (IC). It provides a set of libraries and tools that make it easy to build and deploy canisters on the IC platform. Azle allows web developers to bring their TypeScript/JavaScript skills to the IC and use various npm packages and VS Code intellisense. In this tutorial, you will use Azle to create and deploy your canisters.

It's important to note that Azle is currently in a beta development stage. This means while it offers a robust and valuable framework for development, it is continuously evolving and may undergo significant changes. As such, there may be occasional hiccups, and it doesn't yet have many live, successful, continuously operating applications deployed to the IC. We encourage all users to read the disclaimer.

If you want to learn more about Azle, check out the Azle documentation.

Prerequisites

While having prior coding experience is necessary, you do not need to have any prior blockchain experience to follow this tutorial. However, we do recommend that you have the following:

• Knowledge of TypeScript and Node.js: Familiarity with TypeScript and Node.js is vital, as the tutorial involves building an application using these technologies. If you're new to TypeScript or Node.js, consider going through basic tutorials for both.
• Text Editor: You will need a text editor to write and edit code. Visual Studio Code is recommended due to its excellent support for TypeScript and Node.js development, but feel free to use a text editor of your choice.
• Node.js: Although you don't need Node.js pre-installed (as we'll show you how to manage it using nvm), it's important to note that Node.js (version 18 or higher) will be necessary for running the DFINITY SDK and the project itself."

Tech Stack

Here are the key technologies and tools we'll be using:

1. Internet Computer Protocol (ICP): ICP is a decentralized computing platform that facilitates the creation of software, computation, and data that can run on the public internet. It's the platform we'll be building our application on.
2. Azle: Azle is a TypeScript framework for creating and managing smart contracts, or "canisters," on the Internet Computer Protocol (ICP).
3. Node.js: Node.js is a JavaScript runtime that allows for the execution of JavaScript outside of a web browser. We'll be using Node.js version 18 for this tutorial.
4. Node Version Manager (nvm): Nvm is a tool that enables management and switching between different Node.js versions. We'll be using it to manage our Node.js environment.
5. DFX: DFX is the command-line interface for the Internet Computer. We'll be using it to create and manage our Azle project.
6. TypeScript: TypeScript is a typed superset of JavaScript that compiles to plain JavaScript. We'll be using it for writing our application's code, and our project will include a configuration file (tsconfig.json) for setting up the TypeScript compiler options.
7. Candid: Candid is an interface description language (IDL) used by Internet Computer for defining and describing the public interfaces of services, i.e., their methods and their input/output types. We'll be using Candid in our project to describe the interface of our canisters.