Mac WeChat Dual Open
Create a second WeChat instance on macOS for running two accounts simultaneously.
Core Method
The underlying mechanism is simple — macOS distinguishes apps by their bundle
identifier. By copying WeChat, changing the copy's bundle ID, and re-signing
it locally, macOS treats the copy as a separate app that can run alongside the
original:
- Copy
/Applications/WeChat.app to ~/Applications/WeChat-2.app.
- Change the copy's
CFBundleIdentifier (e.g., to com.tencent.xin2).
- Re-sign the copy with
codesign --force --deep --sign -.
- Launch the copy via its executable directly.
No third-party injection tools or modified binaries required.
Prerequisites
- macOS 12+ with WeChat installed at
/Applications/WeChat.app
- Python 3.10+ (system python works)
- Pillow (
pip3 install Pillow) — required only for recolor-icon
- Xcode Command Line Tools (
xcode-select --install) for codesign, iconutil, sips
Locating the Script
The helper script lives at scripts/wechat_dual_open.py relative to this skill
directory. Different agents install skills to different paths. Construct the
script path dynamically:
# Auto-detect skill directory
SKILL_DIR="$(dirname "$(find ~ -path '*/yichen-mac-wechat-dual-open/SKILL.md' -maxdepth 4 2>/dev/null | head -1)")"
SCRIPT="$SKILL_DIR/scripts/wechat_dual_open.py"
Quick Commands
python3 "$SCRIPT" status # Check current state
python3 "$SCRIPT" create # Create the second WeChat
python3 "$SCRIPT" set-language --languages zh-Hans en # Set Chinese
python3 "$SCRIPT" recolor-icon --blue "#1296db" # Blue icon
python3 "$SCRIPT" launch # Start the second instance
python3 "$SCRIPT" repair # Fix bundle id, signing, language, caches
Default paths (override with --source-app, --target-app, --bundle-id):
- Source:
/Applications/WeChat.app
- Target:
~/Applications/WeChat-2.app
- Bundle ID:
com.tencent.xin2
Workflow
- Status first. Run
status to see what already exists.
- Create. If no second app exists, run
create. This copies the app,
changes the bundle ID, sets Chinese language, removes CFBundleIconName,
re-signs, and registers with Launch Services.
- Language. If the second instance opens in English, run
set-language,
then restart it.
- Icon. Run
recolor-icon to change the WeChat green to a user-chosen
blue. The script handles both the outer AppIcon.icns and the embedded
WeChatAppEx.app/.../app.icns, removes CFBundleIconName to avoid stale
Assets.car entries, and sets a Finder custom icon when the Carbon-era
tools (DeRez, Rez, SetFile) are available.
- Launch. Run
launch. The second WeChat should appear with its own login
window. Pin it to the Dock separately from the original.
Reliability & Tradeoffs
This is not an official method. Rate it roughly 6.5–7 / 10 for reliability:
- Works on many macOS + WeChat version combinations.
- No code injection or third-party tweaks — easy to inspect and undo.
- Breaks after WeChat updates. Re-run
create (or repair) after
updating the original WeChat.
- Push notifications may be unreliable (APNs tied to original identity).
- Login state and Keychain are isolated per bundle ID.
- Ad-hoc signing may fail if WeChat adds stricter signature checks.
See references/reliability-and-risks.md for the full analysis.
Icon Pitfalls
WeChat stores icons in multiple locations. The script handles all of them:
| Location |
What it affects |
Contents/Resources/AppIcon.icns |
Main app icon |
Contents/MacOS/WeChatAppEx.app/Contents/Resources/app.icns |
Embedded runtime icon |
Contents/Resources/Assets.car |
Asset catalog (handled via CFBundleIconName removal) |
Icon\r + Finder custom icon attr |
Finder "Applications" view |
If the user reports the icon is still green:
- They may be looking at
/Applications/WeChat.app (the original), not
~/Applications/WeChat-2.app. Verify with open -R ~/Applications/WeChat-2.app.
- Dock caches per-process icons. Quit and relaunch WeChat-2.
- The Finder custom icon step requires
DeRez/Rez/SetFile which may not
exist on macOS 13+. The script skips gracefully — icns replacement is usually
sufficient.
Safety
- Never modify
/Applications/WeChat.app — all changes are scoped to the copy.
- Ask before deleting an existing second app. Prefer
repair over delete/recreate.
- The
codesign step must run before adding a Finder custom icon, otherwise
macOS rejects the bundle with "resource fork, Finder information, or similar
detritus not allowed".
References & Attribution
- Original tutorial by @koffuxu
(2026-04, blog post: "Mac 微信双开最完美方案")
- Confirmed by @MinLiBuilds
(2026-04)
- Icon recoloring uses HSV/HLS hue rotation via Pillow.
- Finder custom icon technique uses classic Carbon resource tools (
DeRez/Rez).
1---2name: yichen-mac-wechat-dual-open3description: Create, inspect, repair, and polish a second WeChat app on macOS. Copy WeChat, change the bundle identifier, ad-hoc re-sign, launch the second instance, set Chinese language preferences, and recolor only the copied app icon from WeChat green to blue. Use when the user asks whether Mac WeChat dual-open methods are reliable, asks to double-open WeChat, fix WeChat-2 language/icon/cache issues, or make the second WeChat visually distinct without installing third-party injection tools.4---56# Mac WeChat Dual Open78Create a second WeChat instance on macOS for running two accounts simultaneously.910## Core Method1112The underlying mechanism is simple — macOS distinguishes apps by their bundle13identifier. By copying WeChat, changing the copy's bundle ID, and re-signing14it locally, macOS treats the copy as a separate app that can run alongside the15original:16171. Copy `/Applications/WeChat.app` to `~/Applications/WeChat-2.app`.182. Change the copy's `CFBundleIdentifier` (e.g., to `com.tencent.xin2`).193. Re-sign the copy with `codesign --force --deep --sign -`.204. Launch the copy via its executable directly.2122No third-party injection tools or modified binaries required.2324## Prerequisites2526- macOS 12+ with WeChat installed at `/Applications/WeChat.app`27- Python 3.10+ (system python works)28- Pillow (`pip3 install Pillow`) — required only for `recolor-icon`29- Xcode Command Line Tools (`xcode-select --install`) for `codesign`, `iconutil`, `sips`3031## Locating the Script3233The helper script lives at `scripts/wechat_dual_open.py` relative to this skill34directory. Different agents install skills to different paths. Construct the35script path dynamically:3637```bash38# Auto-detect skill directory39SKILL_DIR="$(dirname "$(find ~ -path '*/yichen-mac-wechat-dual-open/SKILL.md' -maxdepth 4 2>/dev/null | head -1)")"40SCRIPT="$SKILL_DIR/scripts/wechat_dual_open.py"41```4243## Quick Commands4445```bash46python3 "$SCRIPT" status # Check current state47python3 "$SCRIPT" create # Create the second WeChat48python3 "$SCRIPT" set-language --languages zh-Hans en # Set Chinese49python3 "$SCRIPT" recolor-icon --blue "#1296db" # Blue icon50python3 "$SCRIPT" launch # Start the second instance51python3 "$SCRIPT" repair # Fix bundle id, signing, language, caches52```5354Default paths (override with `--source-app`, `--target-app`, `--bundle-id`):5556- Source: `/Applications/WeChat.app`57- Target: `~/Applications/WeChat-2.app`58- Bundle ID: `com.tencent.xin2`5960## Workflow61621. **Status first.** Run `status` to see what already exists.632. **Create.** If no second app exists, run `create`. This copies the app,64 changes the bundle ID, sets Chinese language, removes `CFBundleIconName`,65 re-signs, and registers with Launch Services.663. **Language.** If the second instance opens in English, run `set-language`,67 then restart it.684. **Icon.** Run `recolor-icon` to change the WeChat green to a user-chosen69 blue. The script handles both the outer `AppIcon.icns` and the embedded70 `WeChatAppEx.app/.../app.icns`, removes `CFBundleIconName` to avoid stale71 `Assets.car` entries, and sets a Finder custom icon when the Carbon-era72 tools (`DeRez`, `Rez`, `SetFile`) are available.735. **Launch.** Run `launch`. The second WeChat should appear with its own login74 window. Pin it to the Dock separately from the original.7576## Reliability & Tradeoffs7778This is **not** an official method. Rate it roughly 6.5–7 / 10 for reliability:7980- Works on many macOS + WeChat version combinations.81- No code injection or third-party tweaks — easy to inspect and undo.82- **Breaks after WeChat updates.** Re-run `create` (or `repair`) after83 updating the original WeChat.84- Push notifications may be unreliable (APNs tied to original identity).85- Login state and Keychain are isolated per bundle ID.86- Ad-hoc signing may fail if WeChat adds stricter signature checks.8788See `references/reliability-and-risks.md` for the full analysis.8990## Icon Pitfalls9192WeChat stores icons in multiple locations. The script handles all of them:9394| Location | What it affects |95|----------|----------------|96| `Contents/Resources/AppIcon.icns` | Main app icon |97| `Contents/MacOS/WeChatAppEx.app/Contents/Resources/app.icns` | Embedded runtime icon |98| `Contents/Resources/Assets.car` | Asset catalog (handled via `CFBundleIconName` removal) |99| `Icon\r` + Finder custom icon attr | Finder "Applications" view |100101If the user reports the icon is still green:102- They may be looking at `/Applications/WeChat.app` (the original), not103 `~/Applications/WeChat-2.app`. Verify with `open -R ~/Applications/WeChat-2.app`.104- Dock caches per-process icons. Quit and relaunch WeChat-2.105- The Finder custom icon step requires `DeRez`/`Rez`/`SetFile` which may not106 exist on macOS 13+. The script skips gracefully — icns replacement is usually107 sufficient.108109## Safety110111- **Never modify `/Applications/WeChat.app`** — all changes are scoped to the copy.112- Ask before deleting an existing second app. Prefer `repair` over delete/recreate.113- The `codesign` step must run **before** adding a Finder custom icon, otherwise114 macOS rejects the bundle with "resource fork, Finder information, or similar115 detritus not allowed".116117## References & Attribution118119- Original tutorial by [@koffuxu](https://x.com/koffuxu/status/2043110831584690427)120 (2026-04, blog post: "Mac 微信双开最完美方案")121- Confirmed by [@MinLiBuilds](https://x.com/MinLiBuilds/status/2043121624971678083)122 (2026-04)123- Icon recoloring uses HSV/HLS hue rotation via Pillow.124- Finder custom icon technique uses classic Carbon resource tools (`DeRez`/`Rez`).
mcncarl