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Quick Start

Get up and running with Wasmrun in just a few minutes. This guide will walk you through creating and running your first WebAssembly project.

Prerequisites​

Before you begin, make sure you have:

  • Wasmrun installed (see Installation)
  • Basic knowledge of command-line tools

Your First WASM Project​

Let's create a simple WebAssembly project using Rust. Don't worry if you prefer another language - the process is similar for all supported languages.

Step 1: Install the Rust Plugin​

# Install the Rust plugin for Wasmrun
wasmrun plugin install wasmrust

This downloads and installs the wasmrust plugin, which adds Rust support to Wasmrun.

Step 2: Create a New Project​

Create a new directory for your project:

mkdir my-first-wasm
cd my-first-wasm

Create a Cargo.toml file:

[package]
name = "my-first-wasm"
version = "0.1.0"
edition = "2021"

[lib]
crate-type = ["cdylib"]

[dependencies]
wasm-bindgen = "0.2"

Create src/lib.rs with a simple function:

use wasm_bindgen::prelude::*;

#[wasm_bindgen]
pub fn greet(name: &str) -> String {
    format!("Hello, {}! Welcome to WebAssembly.", name)
}

#[wasm_bindgen]
pub fn add(a: i32, b: i32) -> i32 {
    a + b
}

Step 3: Run the Development Server​

Start the development server with live reload:

wasmrun run . --watch

Wasmrun will:

  1. Detect that this is a Rust project
  2. Compile your code to WebAssembly
  3. Start a development server at http://localhost:8420
  4. Watch for file changes and auto-reload

Step 4: Test Your WASM Module​

Open your browser to http://localhost:8420 and you'll see the Wasmrun interface. You can test your functions in the browser console:

// Load the WASM module
import init, { greet, add } from './my_first_wasm.js';

await init();

// Call your functions
console.log(greet('World'));  // "Hello, World! Welcome to WebAssembly."
console.log(add(5, 3));        // 8

Step 5: Try Native Execution​

You can also run WASM modules natively without a browser. First, compile a standalone WASM module:

wasmrun compile .

Then execute it natively:

wasmrun exec ./target/wasm32-unknown-unknown/release/my_first_wasm.wasm --call add 10 20

Running Existing Examples​

Wasmrun comes with several example projects that demonstrate different features and languages. Clone the repository to try them:

# Clone the repository
git clone https://github.com/anistark/wasmrun.git
cd wasmrun/examples

Rust Examples​

# Simple Rust hello world
cd rust-hello
wasmrun run .

# Rust web application with Leptos
cd ../web-leptos
wasmrun run . --watch

Go Examples​

# Install Go plugin first
wasmrun plugin install wasmgo

# Simple Go example
cd go-hello
wasmrun run .

# Native execution example
cd ../native-go
wasmrun run .
wasmrun exec ./path/to/compiled.wasm --call main

Python Example​

# Install Python plugin first
wasmrun plugin install waspy

# Python example
cd python-hello
wasmrun run .

C/C++ Example​

# C example (no plugin needed - built-in support)
cd c-hello
wasmrun run .

AssemblyScript Examples​

# Install AssemblyScript plugin first
wasmrun plugin install wasmasc

# Simple AssemblyScript example
cd asc-hello
wasmrun run .

# Web application example
cd ../web-asc
wasmrun run . --watch

Common Commands​

Here are the most common commands you'll use:

Development Server​

# Run with auto-reload
wasmrun run ./my-project --watch

# Run on a specific port
wasmrun run ./my-project --port 3000

# Specify language explicitly
wasmrun run ./my-project --language rust

Compilation​

# Compile project
wasmrun compile ./my-project

# Compile with optimization
wasmrun compile ./my-project --optimization release

# Verbose output
wasmrun compile ./my-project --verbose

Native Execution​

# Execute WASM file
wasmrun exec myfile.wasm

# Execute with arguments
wasmrun exec myfile.wasm arg1 arg2

# Call specific function
wasmrun exec myfile.wasm --call add 5 3

Plugin Management​

# List all plugins
wasmrun plugin list

# Get plugin info
wasmrun plugin info wasmrust

# Install plugin
wasmrun plugin install wasmrust

# Uninstall plugin
wasmrun plugin uninstall wasmrust

Inspection & Verification​

# Verify WASM file
wasmrun verify myfile.wasm

# Detailed verification
wasmrun verify myfile.wasm --detailed

# Inspect WASM structure
wasmrun inspect myfile.wasm

Next Steps​

Now that you've created your first WebAssembly project, here's what to explore next:

Learn More About Your Language​

Explore Features​

Reference Documentation​

Tips for Success​

  1. Use Live Reload - The --watch flag makes development much faster
  2. Start Simple - Begin with basic examples before complex applications
  3. Check Plugin Status - Use wasmrun plugin list to see what's installed
  4. Read Error Messages - Wasmrun provides helpful error messages and suggestions
  5. Explore Examples - The example projects demonstrate best practices

Getting Help​

If you run into issues:

Happy WebAssembly development!