wflow

wflow is an offline voice-to-text tray app for Windows. Hold a global hotkey, speak, release, and wflow inserts transcribed text into the focused app.

Work in progress. Development is currently focused on ARM64 Windows, where wflow is up and running end-to-end (hotkey capture, local whisper.cpp transcription, and text injection). An AMD64 (x64) port is planned as a subsequent step.

Initial development and validation is being done on ARM64 Windows. The project can also be built and packaged for x64 Windows.

Architecture support

• ARM64: primary development target (actively validated)
• x64: supported build and packaging path
• x86 (32-bit): not currently validated in this repository

Current feature status

• Win32 hidden-window app loop
• System tray icon with status menu
• Global hotkey handling with press and release lifecycle
• WASAPI microphone capture (mono normalization and 16 kHz resampling)
• Asynchronous transcription worker pipeline
• Unicode text insertion with SendInput
• Optional clipboard fallback insertion mode
• Persistent settings in %APPDATA%/wflow/settings.ini
• Startup toggle for unpackaged runs (HKCU Run key)
• Settings window for hotkey, model path, language, threads, startup, and fallback mode
• Optional whisper.cpp integration via CMake option WFLOW_USE_WHISPERCPP
• MSIX packaging scripts for ARM64 and x64

Prerequisites

• Windows 11 (or Windows 10 with compatible SDK)
• Visual Studio with the Desktop development with C++ workload, including:
  • MSVC C++ build tools for the target architecture
  • Windows 11 SDK
  • C++ CMake tools for Windows
• CMake 3.20 or newer (the Visual Studio bundled CMake is supported)
• PowerShell (Windows PowerShell 5.1 or PowerShell 7)
• Git, only if WFLOW_USE_WHISPERCPP=ON is enabled, because CMake downloads whisper.cpp with FetchContent
• Windows 10/11 SDK packaging tools for MSIX creation/signing:
  • makeappx.exe
  • signtool.exe

For the x64 build, select the x64 MSVC tools in Visual Studio. The default build has WFLOW_USE_WHISPERCPP=OFF, so Git and the Whisper download are not needed just to compile the application.

• For ARM64 builds with WFLOW_USE_WHISPERCPP=ON (see below): the Clang toolchain via Visual Studio Installer

Build from source

Run commands from repository root.

PowerShell execution policy

If PowerShell reports that scripts\build.ps1 cannot be loaded because running scripts is disabled, allow scripts only for the current PowerShell session:

Set-ExecutionPolicy -Scope Process -ExecutionPolicy Bypass

Then run the build command again. This does not change the machine or user execution policy and is reset when the PowerShell window closes.

Alternatively, run the script in a separate process with a one-time bypass:

powershell.exe -ExecutionPolicy Bypass -File .\scripts\build.ps1 `
	-Architecture x64 `
	-BuildDir build-x64 `
	-Configuration Release

ARM64 build

./scripts/build.ps1 -Architecture ARM64 -BuildDir build-arm64 -Configuration Release

Run:

.\build-arm64\Release\wflow.exe

x64 build

./scripts/build.ps1 -Architecture x64 -BuildDir build-x64 -Configuration Release

Run:

.\build-x64\Release\wflow.exe

Enabling whisper.cpp on ARM64 (Clang toolchain required)

WFLOW_USE_WHISPERCPP is OFF by default. Turning it on pulls in whisper.cpp (via FetchContent) to enable real local transcription instead of the no-op stub.

On ARM64, whisper.cpp's ggml CPU backend does not support MSVC (cl.exe) — it requires Clang. cl.exe fails to configure with MSVC is not supported for ARM, use clang. This is unrelated to scripts/build.ps1, which does not currently expose these flags, so configure manually:

1. In Visual Studio Installer, modify your install and add these Individual components:

   • C++ Clang Compiler for Windows (provides clang-cl.exe)
   • MSBuild support for LLVM (clang-cl) toolset (both are required — the first alone is not enough to build; MSBuild needs the second to know how to invoke it)

2. Configure with the ClangCL platform toolset and the flag enabled:

   cmake -S . -B build-arm64 -G "Visual Studio 18 2026" -A ARM64 -T ClangCL -DWFLOW_USE_WHISPERCPP=ON
   cmake --build build-arm64 --config Release

   If build-arm64 was previously configured with a different toolset (e.g. plain MSVC), delete the directory first — CMake will not let you switch toolsets in place.

x64 does not have this restriction; MSVC builds whisper.cpp fine there, so -T ClangCL is not needed for x64.

Using the app

1. Launch wflow.
2. Open tray menu and go to Settings.
3. Set or confirm Whisper model path.
4. Optionally use Download Default Base Model.
5. Configure hotkey if needed.
6. In any text field: hold hotkey, speak, release to insert text.

Create MSIX installer

The same flow works for ARM64 and x64 by changing the architecture and build directory.

1) Preflight checks

ARM64:

./packaging/msix/check-packaging-prereqs.ps1 -Mode pack -Architecture arm64 -BuildDir build-arm64
./packaging/msix/check-packaging-prereqs.ps1 -Mode sign -Architecture arm64

x64:

./packaging/msix/check-packaging-prereqs.ps1 -Mode pack -Architecture x64 -BuildDir build-x64
./packaging/msix/check-packaging-prereqs.ps1 -Mode sign -Architecture x64

2) Build executable

ARM64:

./scripts/build.ps1 -Architecture ARM64 -BuildDir build-arm64 -Configuration Release

x64:

./scripts/build.ps1 -Architecture x64 -BuildDir build-x64 -Configuration Release

3) Create unsigned MSIX

ARM64:

./packaging/msix/build-msix.ps1 -Architecture arm64 -BuildDir build-arm64 -Configuration Release -Publisher "CN=YourPublisher" -Version "0.1.0.0" -PackageName "wflow_0.1.0.0_arm64.msix"

x64:

./packaging/msix/build-msix.ps1 -Architecture x64 -BuildDir build-x64 -Configuration Release -Publisher "CN=YourPublisher" -Version "0.1.0.0" -PackageName "wflow_0.1.0.0_x64.msix"

Output files are created under packaging/msix/out.

4) Sign MSIX

ARM64:

./packaging/msix/sign-msix.ps1 -Architecture arm64 -MsixPath ./packaging/msix/out/wflow_0.1.0.0_arm64.msix -PfxPath C:/path/to/cert.pfx

x64:

./packaging/msix/sign-msix.ps1 -Architecture x64 -MsixPath ./packaging/msix/out/wflow_0.1.0.0_x64.msix -PfxPath C:/path/to/cert.pfx

The sign script prompts securely for the PFX password.

For local development, a self-signed certificate can be used. The certificate subject must match the package publisher (CN=YourPublisher). Windows must trust the certificate in the Local Computer > Trusted People store; installing the certificate by double-clicking it may place it in the wrong store. From an elevated PowerShell, run:

$cert = "C:\path\to\wflow-dev-signing.cer"
certutil.exe -addstore -f TrustedPeople $cert
certutil.exe -addstore -f Root $cert

The .cer file contains only the public certificate and is safe to distribute with a development build. Do not distribute the private .pfx file. A production package should use a certificate issued by a trusted publisher instead of a self-signed development certificate.

5) Install

Install the certificate before installing a self-signed package, then run:

Add-AppxPackage `
  -Path ".\packaging\msix\out\wflow_0.1.0.0_x64.msix"

Alternatively, double-click the signed .msix file after the certificate is trusted.

SDK path override (optional)

If auto-discovery cannot find SDK tools, set explicit paths:

$env:WFLOW_MAKEAPPX_PATH = "C:\Program Files (x86)\Windows Kits\10\bin\10.0.26100.0\arm64\makeappx.exe"
$env:WFLOW_SIGNTOOL_PATH = "C:\Program Files (x86)\Windows Kits\10\bin\10.0.26100.0\arm64\signtool.exe"

For x64 packaging, point these to the x64 tool binaries.

Notes

• Startup currently uses HKCU Run key for unpackaged development runs.
• For production packaged behavior, use MSIX startup task extensions.

CI command matrix

Use these command sets in CI release jobs.

ARM64 release job:

./scripts/build.ps1 -Architecture ARM64 -BuildDir build-arm64 -Configuration Release
./packaging/msix/check-packaging-prereqs.ps1 -Mode pack -Architecture arm64 -BuildDir build-arm64
./packaging/msix/build-msix.ps1 -Architecture arm64 -BuildDir build-arm64 -Configuration Release -Publisher "CN=YourPublisher" -Version "0.1.0.0" -PackageName "wflow_0.1.0.0_arm64.msix"
./packaging/msix/sign-msix.ps1 -Architecture arm64 -MsixPath ./packaging/msix/out/wflow_0.1.0.0_arm64.msix -PfxPath C:/path/to/cert.pfx

x64 release job:

./scripts/build.ps1 -Architecture x64 -BuildDir build-x64 -Configuration Release
./packaging/msix/check-packaging-prereqs.ps1 -Mode pack -Architecture x64 -BuildDir build-x64
./packaging/msix/build-msix.ps1 -Architecture x64 -BuildDir build-x64 -Configuration Release -Publisher "CN=YourPublisher" -Version "0.1.0.0" -PackageName "wflow_0.1.0.0_x64.msix"
./packaging/msix/sign-msix.ps1 -Architecture x64 -MsixPath ./packaging/msix/out/wflow_0.1.0.0_x64.msix -PfxPath C:/path/to/cert.pfx