microsoft/winapp-package

When to use

Use this skill when:

• Creating an MSIX installer from a built app for distribution or testing
• Packaging any Windows app — GUI apps, console apps, CLI tools, services, or background processes
• Signing a package with a development or production certificate
• Bundling the Windows App SDK runtime for self-contained deployment

Prerequisites

Before packaging, you need:

1. Built app output in a folder (e.g., bin/Release/, dist/, build/)
2. Package.appxmanifest — from winapp init or winapp manifest generate
3. Certificate (optional) — devcert.pfx from winapp cert generate for signing

Usage

Basic packaging (unsigned)

# Package from build output — manifest auto-detected from current dir or input folder
winapp package ./bin/Release

# Specify manifest location explicitly
winapp package ./dist --manifest ./Package.appxmanifest

Package and sign in one step

# Sign with existing certificate
winapp package ./bin/Release --cert ./devcert.pfx

# Custom certificate password
winapp package ./bin/Release --cert ./devcert.pfx --cert-password MyP@ssw0rd

Generate certificate + package in one step

# Auto-generate cert, sign, and package
winapp package ./bin/Release --generate-cert

# Also install the cert to trust it on this machine (requires admin)
winapp package ./bin/Release --generate-cert --install-cert

Self-contained deployment

# Bundle Windows App SDK runtime so users don't need it installed (must have winappsdk reference in the winapp.yaml or *.csproj)
winapp package ./bin/Release --cert ./devcert.pfx --self-contained

Custom output path and name

# Specify output file
winapp package ./dist --output ./releases/myapp-v1.0.msix --cert ./devcert.pfx

# Custom package name
winapp package ./dist --name "MyApp_1.0.0_x64" --cert ./devcert.pfx

What the command does

1. Locates Package.appxmanifest — looks in input folder, then current directory (or uses --manifest)
2. Copies manifest + assets into a staging layout alongside your app files
3. Discovers manifest-referenced files — any non-image file referenced in the manifest (e.g., AppExtension payloads like manifest.json, config files) is automatically copied from the manifest directory or input folder if missing from staging
4. Generates resources.pri — Package Resource Index for UWP-style resource lookup (skip with --skip-pri)
5. Runs makeappx pack — creates the .msix package file
6. Signs the package (if --cert provided) — calls signtool with your certificate

Output: a .msix file that can be installed on Windows via double-click or Add-AppxPackage.

Installing the MSIX for testing

# Trust the dev certificate first (one-time, requires admin)
winapp cert install ./devcert.pfx

# Install the MSIX
Add-AppxPackage ./myapp.msix

# Uninstall if needed
Get-AppxPackage *myapp* | Remove-AppxPackage

Recommended workflow

1. Build your app (dotnet build, cmake --build, npm run make, etc.)
2. Package — winapp package <build-output> --cert ./devcert.pfx
3. Trust cert (first time) — winapp cert install ./devcert.pfx (admin)
4. Install — double-click the .msix or Add-AppxPackage ./myapp.msix
5. Test the installed app from the Start menu

Advanced: External content catalog

For sparse packages with AllowExternalContent, you may need a code integrity catalog:

# Generate CodeIntegrityExternal.cat for external executables
winapp create-external-catalog "./bin/Release"

# Include subdirectories and specify output path
winapp create-external-catalog "./bin/Release" --recursive --output ./catalog/CodeIntegrityExternal.cat

Bundling multiple architectures

Create an MSIX bundle from multiple per-architecture build outputs:

# Create unsigned bundle for Store submission (x64 + arm64)
winapp package ./publish/x64 ./publish/arm64

# Create signed bundle for sideloading
winapp package ./publish/x64 ./publish/arm64 --cert ./devcert.pfx

# Self-contained bundle with Windows App SDK runtime per arch
winapp package ./publish/x64 ./publish/arm64 --self-contained --generate-cert

How it works: When multiple input folders are passed, winapp package:

1. Detects the architecture of each folder's primary executable from its PE header
2. Resolves a manifest for each slice (see below)
3. Validates that all slices share the same Identity, Capabilities, and Dependencies
4. Packs each folder into an intermediate unsigned .msix
5. Bundles them into a single .msixbundle using makeappx bundle
6. Signs only the bundle (not individual slices) — the signature covers all packages inside

Manifest resolution: Each slice needs a manifest. Resolution order:

• --manifest <path> uses one manifest for all slices (architecture auto-stamped per folder)
• Per-folder Package.appxmanifest if present in the input folder
• Fallback to Package.appxmanifest in the current working directory

The ProcessorArchitecture is always force-set to the detected architecture per-slice. All other Identity fields must be consistent across slices.

Output: <Name>_<Version>_<arch1>_<arch2>.msixbundle (architectures sorted alphabetically).

Store submission: An unsigned bundle is valid for Store upload — Partner Center signs it with your reserved identity certificate. For sideloading, pass --cert or --generate-cert.

This hashes executables in the specified directories so Windows trusts them when running with sparse package identity.

CI/CD

GitHub Actions

Use the microsoft/setup-winapp action to install winapp on GitHub-hosted runners:

- uses: microsoft/setup-winapp@v1

- name: Package
  run: winapp package ./dist --cert ${{ secrets.CERT_PATH }} --cert-password ${{ secrets.CERT_PASSWORD }} --quiet

Tips for CI/CD pipelines:

• Use --quiet (or -q) to suppress progress output
• Use --if-exists skip with winapp cert generate to avoid regenerating existing certificates
• Store your PFX certificate as a repository secret and decode it in CI
• Use --use-defaults (or --no-prompt) with winapp init to avoid interactive prompts

Tips

• The package command aliases to pack — both work identically
• Package.appxmanifest Publisher must match the certificate publisher — use winapp cert generate --manifest to ensure they match
• Use --skip-pri if your app doesn't use Windows resource loading (e.g., most Electron/Rust/C++ apps without UWP resources)
• For framework-specific packaging paths (Electron, .NET, Rust, etc.), see the winapp-frameworks skill
• The --executable flag overrides the entry point in the manifest — useful when your exe name differs from what's in Package.appxmanifest
• For production distribution, use a certificate from a trusted CA and add --timestamp when signing with winapp sign

Sparse identity packages

To grant identity to an app distributed by an existing installer (not as MSIX), build an identity-only sparse package: pass a sparse appxmanifest.xml (one declaring <uap10:AllowExternalContent>true</uap10:AllowExternalContent> under <Properties>) to winapp pack instead of a folder.

# 1. Generate the sparse manifest for your exe (skips SDK install)
winapp init --exe ./bin/Release/MyApp.exe --sparse --use-defaults
# 2. Build & sign the identity-only .msix (just the manifest)
winapp pack ./sparse/appxmanifest.xml --cert ./devcert.pfx
# 3. Embed identity into the exe, then register in your installer
winapp embed-identity ./bin/Release/MyApp.exe

The .msix contains only the manifest — binaries and assets are resolved from the external content location at runtime via Add-AppxPackage -ExternalLocation. If you pack a folder whose manifest declares AllowExternalContent, winapp pack warns about any assets/binaries found. See the Sparse Packaging Guide.

Related skills

• Need a manifest first? See winapp-manifest to generate Package.appxmanifest
• Need a certificate? See winapp-signing for certificate generation and management
• Having issues? See winapp-troubleshoot for a command selection flowchart and error solutions

Troubleshooting

| Error | Cause | Solution | |-------|-------|----------| | "Package.appxmanifest not found" | No manifest in input folder or current dir | Run winapp init or winapp manifest generate first | | "Publisher mismatch" | Cert publisher ≠ manifest publisher | Regenerate cert with winapp cert generate --manifest, or edit manifest | | "Package installation failed" | Cert not trusted or stale package | Run winapp cert install ./devcert.pfx (admin), then Get-AppxPackage <name> \| Remove-AppxPackage | | "makeappx not found" | Build tools not downloaded | Run winapp update or winapp tool makeappx --help to trigger download |

CLI reference

Run winapp <command> --help for current command options, or winapp --cli-schema for the complete machine-readable command schema.