You can add a package reference with the .NET SDK:

$ dotnet add package wasmtime 

For this introduction, we'll be using a simple WebAssembly module that imports a hello function and exports a run function:

(module (func $hello (import "" "hello")) (func (export "run") (call $hello)) )

To use this module from .NET, create a new console project:

$ mkdir wasmintro $ cd wasmintro $ dotnet new console 

Next, add a reference to the Wasmtime package:

$ dotnet add package wasmtime 

Replace the contents of Program.cs with the following code:

using System; using Wasmtime; using var engine = new Engine(); using var module = Module.FromText( engine, "hello", "(module (func $hello (import \"\" \"hello\")) (func (export \"run\") (call $hello)))" ); using var linker = new Linker(engine); using var store = new Store(engine); linker.Define( "", "hello", Function.FromCallback(store, () => Console.WriteLine("Hello from C#!")) ); var instance = linker.Instantiate(store, module); var run = instance.GetAction("run")!; run();

An Engine is created and then a WebAssembly module is loaded from a string in WebAssembly text format.

A Linker defines a function called hello that simply prints a hello message.

The module is instantiated and the instance's run export is invoked.

To run the application, simply use dotnet:

$ dotnet run 

This should print Hello from C#!.