Windows — MSIX (Microsoft Store / sideloading)

format = "msix" packs the runtime image into a Windows .msix package. The launchers are packaged as full-trust Win32 apps (runFullTrust), one <Application> per launcher.

appdist/<target>/dist/<name>-<version>.msix — the package.

Only platform = "windows-x86_64" may use this format.

Build requirements

MSVC C++ build tools (cl.exe / rc.exe) — to compile the launcher .exe (same as MSI; see its install steps).
makeappx (Windows SDK) — located automatically, or set PYAPPDIST_MAKEAPPX to its path. It is included in the Windows SDK that the MSVC Build Tools install pulls in; standalone, it comes with the Windows SDK installer or
```
winget install --id Microsoft.WindowsSDK.10.0.26100 -e
```

No WiX is needed.

Configuration

manufacturer: Vendor name; used as the launcher’s version-resource company name and as the default publisher (CN=<manufacturer>; when unset, the app name is used instead).
identity-name: Package Identity Name (for the Store, the reserved Publisher.AppName). Defaults to [project].name.
publisher: Package Identity Publisher DN (e.g. "CN=Contoso"). For the Store or signing it must match. Defaults to CN=<manufacturer>, or CN=<app name> when manufacturer is also unset.
display-name: App display name. Defaults to [tool.pyappdist].name.
logo: Path to a source .png used for the package logos. A placeholder is generated if omitted.

[[tool.pyappdist.targets]]
name = "store"
platform = "windows-x86_64"
format = "msix"
manufacturer = "Example Inc."
# identity-name = "Contoso.MyApp"   # from Partner Center for the Store
# publisher = "CN=Contoso"
# display-name = "My App"
# logo = "assets/logo.png"

Signing and install

The package is left unsigned: the Microsoft Store signs it for free on submission (company registration is also free), and auto-updates are handled by the Store.

To test an unsigned .msix locally, enable Developer Mode (Settings → For developers; one-time, requires admin), then:

Add-AppxPackage -Register <image>\AppxManifest.xml   # loose, from the built image
# or:  Add-AppxPackage -AllowUnsigned <app>.msix

Without the Store or Developer Mode, an unsigned MSIX cannot be installed (it would need your own trusted code-signing certificate). For sideloading, the signing certificate’s subject must match the manifest Publisher.

MSIX is not covered by the MSI code-sign key: the package is signed only when the PYAPPDIST_SIGN_CMD environment variable is set. The command receives the artifact’s file name via the {file} token and runs from the artifact’s directory, exactly as described in Code signing.