Wasi.Sdk
is an experimental package that can build .NET Core projects (including whole ASP.NET Core applications) into standalone WASI-compliant .wasm
files. These can then be run in standard WASI environments or custom WASI-like hosts.
dotnet new console -o MyFirstWasiApp
cd MyFirstWasiApp
dotnet add package Wasi.Sdk --prerelease
dotnet build
You'll see from the build output that this produces bin/Debug/net7.0/MyFirstWasiApp.wasm
.
To run it,
PATH
dotnet run
or, if you're using Visual Studio, press Ctrl+F5Alternatively you can invoke runners like wasmtime
or wasmer
manually on the command line. For example,
wasmtime bin/Debug/net7.0/MyFirstWasiApp.wasm
wasmer bin/Debug/net7.0/MyFirstWasiApp.wasm
Other WASI hosts work similarly.
dotnet new web -o MyWebApp
cd MyWebApp
dotnet add package Wasi.Sdk --prerelease
dotnet add package Wasi.AspNetCore.Server.Native --prerelease
Then:
Open your new project in an IDE such as Visual Studio or VS Code
Open Program.cs
and change the line var builder = WebApplication.CreateBuilder(args)
to look like this:
var builder = WebApplication.CreateBuilder(args).UseWasiConnectionListener();
Open Properties/launchSettings.json
and edit the applicationUrl
value to contain only a single HTTP listener, e.g.,
"applicationUrl": "http://localhost:8080"
Open your .csproj
file (e.g., in VS, double-click on the project name) and, inside a <PropertyGroup>
, add this:
<WasiRunnerArgs>--tcplisten localhost:8080 --env ASPNETCORE_URLS=http://localhost:8080</WasiRunnerArgs>
Instead of 8080
, you should enter the port number found in Properties\launchSettings.json
.
That's it! You can now run it via dotnet run
(or in VS, use Ctrl+F5)
Optionally, to add support for bundling wwwroot
files into the .wasm
file and serving them:
Add the NuGet package Wasi.AspNetCore.BundledFiles
In Program.cs
, replace app.UseStaticFiles();
with app.UseBundledStaticFiles();
In your .csproj
file, add:
<ItemGroup>
<WasmBundleFiles Include="wwwroot\**" />
</ItemGroup>
Wasi.Sdk
- a package that causes your build to produce a WASI-compliant .wasm
file. This works by:
.wasm
file. You can optionally include other native sources such as .c
files in the compilation.Wasi.AspNetCore.BundledFiles
- provides UseBundledStaticFiles
, and alternative to UseStaticFiles
, that serves static files bundled into your .wasm
file. This allows you to have single-file deployment even if you have files under wwwroot
or elsewhere.Wasi.AspNetCore.Server.Native
- a way of running ASP.NET Core on WASI's TCP-level standard networking APIs (e.g., sock_accept
). These standards are quite recent and are currently only supported in Wasmtime, not other WASI hosts.... and more
First, build the runtime. This can take quite a long time.
git submodule update --init --recursive
sudo apt-get install build-essential cmake ninja-build python python3 zlib1g-dev
cd modules/runtime/src/mono/wasm
make provision-wasm
(takes about 2 minutes)make build-all
(takes 10-15 minutes)
setlocale: LC_ALL: cannot change locale
then run sudo apt install language-pack-en
. This only happens on very bare-bones machines.cd ../wasi
make
(takes a few minutes - there are lots of warnings like "System is unknown to cmake" and that's OK)Now you can build the packages and samples in this repo:
dotnet --version
should return 7.0.100-preview.4
or later)wasm32-unknown-unknown
target (technically this is only needed for the CustomHost package)
rustup target add wasm32-unknown-unknown
dotnet build
or dotnet run
on any of the samples or src
projects, or open the solution in VS and Ctrl+F5 on any of the sample projectsThis project has adopted the code of conduct defined by the Contributor Covenant to clarify expected behavior in our community. For more information, see the .NET Foundation Code of Conduct.