windows

WeChat Multi — Windows

A Windows tray utility to run multiple WeChat instances at once. Sibling to the macOS app at the repo root; see docs/windows-port-plan.md for the full design.

Status: in development (Phase 1–2). The tested Core and native interop are done; the tray app is a working skeleton. The concrete WeChat mutex/process names still need Phase-0 verification on a real install (see the plan).

How it works (vs. macOS)

macOS clones the .app bundle to get a fresh sandbox per instance. Windows has no equivalent and doesn't need one: WeChat's single-instance lock is a named kernel mutex, and all instances already share one install with per-account (wxid) data. So the engine is:

find WeChat's processes → close their handle to the instance mutex in all of them → launch another WeChat.exe.

Solution layout

windows/
  WeChatMulti.sln
  src/
    WeChatMulti.Core/      net8.0   — pure logic, 68 unit tests, no Windows APIs
    WeChatMulti.Native/    net8.0-windows — P/Invoke: handle scan, mutex close, locator, login
    WeChatMulti.App/       net8.0-windows — WPF tray app (H.NotifyIcon)
  tests/
    WeChatMulti.Core.Tests/ net8.0  — xUnit, gated in CI

WeChatMulti.Core is the Windows analog of the macOS WeChatMultiCore: all the bug-prone logic (version compare, ordering, settings, backup, the mutex-name registry, and the launch orchestration) lives behind interfaces (IHandleScanner, IMutexCloser, IProcessLister, IProcessLauncher) and is fully unit-tested — so the risky native bits are injected and the decisions are verified with fakes, no WeChat or admin rights required.

Build & test

On Windows:

cd windows
dotnet test  tests/WeChatMulti.Core.Tests              # the gate (68 tests)
dotnet build src/WeChatMulti.App                       # builds Core + Native + App
dotnet run  --project src/WeChatMulti.App

On macOS/Linux you can build everything (handy for CI parity) by enabling the Windows targeting pack:

cd windows
dotnet test  tests/WeChatMulti.Core.Tests                          # Core is cross-platform
dotnet build src/WeChatMulti.App -p:EnableWindowsTargeting=true     # compiles the WPF app too

The solution file is WeChatMulti.slnx (the modern XML format; needs .NET SDK 9.0.200+). Building by csproj path as above works on any .NET 8+ SDK, which is what CI does.

CI (.github/workflows/windows-build.yml) runs the test gate, builds the app (which pulls in Core + Native), and publishes self-contained x64 + arm64 on windows-latest.

Roadmap

See the port plan. Next up: Phase 0 — confirm the WeChat 3.x and 4.x mutex/process names on real installs and fill the VERIFY slots in MutexNameRegistry / BrandConventions.

Caveats

• The instance-mutex name is version-dependent and may change across WeChat releases — the maintenance surface is concentrated in MutexNameRegistry.
• Closing the mutex may require running elevated depending on WeChat's integrity level; the app detects access-denied and offers to relaunch as admin.
• Cross-process handle duplication can trip antivirus heuristics — code signing
  • open-source provenance mitigate this.
• Unaffiliated with Tencent. WeChat/Weixin are trademarks of Tencent.