## Getting Started: Creating Your First Noir Project with Nargo Noir is a powerful domain-specific language designed for crafting and verifying zero-knowledge proofs. To begin your journey with Noir, you'll need its official command-line tool, `nargo`. This lesson will guide you through the process of creating a new Noir project, setting up the foundational structure for your circuits. We'll primarily use a terminal for these operations. Ensure you have `nargo` installed and your terminal open and ready. ### Understanding `nargo init` vs. `nargo new` Before we jump into creating a project, it's important to understand the two primary `nargo` commands for project initialization: * **`nargo init`**: This command initializes a new Noir project *within your current working directory*. If you already have a directory set up and want to transform it into a Noir project, `nargo init` is the command you'd use. * **`nargo new <project_name>`**: This command creates a new Noir project by first creating a *new directory* named after your specified `<project_name>`. The project files are then initialized within this new directory. This is generally the preferred method for starting a fresh, standalone project as it keeps your workspace organized. For this guide, we will use `nargo new` to demonstrate a clean project setup. ### Creating a New Project with `nargo new` Let's create our first Noir project. We'll name it `simple_circuit`. 1. **Open your terminal.** You'll see a prompt, for example: ```bash yourusername@yourmachine current_directory % ``` 2. **Execute the `nargo new` command:** Type the following command and press Enter: ```bash nargo new simple_circuit ``` * `nargo`: Invokes the Noir package manager and build tool. * `new`: The subcommand to create a new project. * `simple_circuit`: The name for your new project. `nargo` will create a directory with this name. **A quick note on typos:** It's common to make mistakes when typing commands. For instance, if you accidentally typed `nrgo new simple_circuit` (missing the 'a'), your terminal would likely respond with an error: ```bash zsh: command not found: nrgo ``` If this happens, simply correct the typo and try the command again. 3. **Observe the output:** Upon successful execution, `nargo` will confirm the project creation: ``` Project successfully created! It is located at /path/to/your/current_directory/simple_circuit ``` The exact path will reflect your system's directory structure. ### Verifying Project Creation To confirm that the project directory was indeed created, you can list the contents of your current directory. 1. **Use the `ls` command (or `dir` on Windows):** ```bash ls ``` 2. **Check the output:** You should see `simple_circuit` listed among the files and directories: ``` simple_circuit other_files_and_directories... ``` This confirms that `nargo` successfully created the `simple_circuit` directory. ### Navigating into Your Project Directory Now that your project directory exists, let's move into it to inspect its contents. 1. **Use the `cd` (change directory) command:** ```bash cd simple_circuit ``` Your terminal prompt should update to reflect that you are now inside the `simple_circuit` directory. ### Inspecting the Default Noir Project Structure Every new Noir project created with `nargo new` comes with a standard, minimal structure. Let's see what `nargo` has set up for us. 1. **List the contents of the `simple_circuit` directory:** ```bash ls ``` 2. **Examine the output:** You will see two items: ``` Nargo.toml src ``` Let's break down what these are: * **`src/`**: This is the source directory. All your Noir code, which defines the circuits for your zero-knowledge proofs, will reside here. Typically, Noir source files have a `.nr` extension. * **`Nargo.toml`**: This is the manifest file for your Noir project. It's analogous to `Cargo.toml` in Rust projects or `package.json` in Node.js projects. The `Nargo.toml` file contains crucial metadata about your project, such as its name, version, author, dependencies on other Noir libraries (crates), and compiler configurations. You have now successfully created a new Noir project using `nargo`! This basic structure provides the foundation for you to start writing your Noir circuits and exploring the world of zero-knowledge proofs.