mac-app-dualizer

Clone a macOS app into a second copy that keeps its own data folder and its own login.
Written so two Claude accounts could run on one Mac at the same time. Works on any Electron app.

What it does · The rules it keeps · How far to trust it · How it works · Run it yourself · When something goes wrong

Why this exists

The Claude desktop app, which hosts Claude Code, runs many sessions at once but signs in to one account per install. A personal account and a work account cannot both be open. open -n -a "Claude" does not help: the second window shares the same data folder, so it shares the same login, and the two fight over lock files.

A real second instance needs four things. A bundle identifier and name of its own, so macOS treats it as another app. A data folder of its own, so it keeps its own cookies, session and login. Its Electron helper apps renamed to match, or it will not start. And a valid code signature after all of that, because macOS refuses a bundle whose signature no longer matches its contents.

That was worked out by hand for Claude, then turned into this tool so it works for any app. One command, or a small window you drag an app onto.

What it does

The rules it keeps

• Clone only apps you are licensed to use, within each app's terms of service. This is for two accounts or two profiles on your own Mac.
• Nothing leaves your Mac. The tool copies and re-signs a bundle on disk. It sends nothing anywhere and never asks for sudo.
• The CLI needs no npm install. The helpers use Node built-ins only. @electron/asar and pngjs are fetched on demand with npx. npm install is only for the GUI.
• Your login survives repair. Repair deletes and rebuilds the app bundle, never the data folder. Remove keeps the data folder unless you say --purge.
• productName is left alone. Only the bundle name changes, so the app's user agent and any "is this the desktop app?" check on a login page still pass.
• A clone that would crash is not written. After signing, the asar hash is checked once more. A mismatch aborts the clone instead of printing "Done".
• Not affiliated with Anthropic or with any app you clone.

How far to trust it

[!IMPORTANT]
It was built for Claude, and Claude is where it has been exercised. The screens above show a real Claude 2 clone on macOS 15, which dualize list reports healthy on 7 October 2026. Other Electron apps (Slack, Notion, VS Code, Discord, Figma) go through the same eight steps and should work, but each app is its own test. Try a low-stakes app first, and read the log.

What it cannot do yet:

• Native, non-Electron apps get a new identity only. Sandboxed apps get a fresh container from that; other apps may still share data with the original.
• Apps whose main script is an ES module are refused for data isolation. --no-isolate gives a separately named copy that shares the original's data.
• Auto-updates revert the clone. Run dualize repair afterwards.
• The signature is ad hoc. That is fine on the Mac that built the clone. A clone moved to another Mac needs its quarantine flag cleared (see below).
• No automated test clones an app. CI runs shellcheck, bash -n, node --check and a package.json parse, nothing more.

How it works

flowchart LR
  subgraph you ["What you give"]
    APP["/Applications/Claude.app"]
    NAME["A name: Claude 2"]
  end
  subgraph tool ["In this repository"]
    GUI["Electron window<br/>src/main.js"]
    DZ["dualize<br/>bin/dualize.js"]
    SH["clone-app.sh<br/>copy, rename, badge, sign, register"]
    AT["src/asar-tools.js<br/>inject snippet, repack, integrity hash"]
    REG["src/registry.js<br/>~/.config/mac-app-dualizer/clones.json"]
  end
  subgraph out ["What you get"]
    CLONE["/Applications/Claude 2.app<br/>own bundle id, re-signed"]
    DATA[("~/Library/Application Support/Claude 2<br/>cookies, session, login")]
  end
  APP --> SH
  NAME --> SH
  GUI --> SH
  DZ -->|clone, repair| SH
  SH --> AT --> CLONE
  SH --> REG
  DZ -->|list, remove| REG
  CLONE -->|first launch| DATA

clone-app.sh does the work in eight numbered steps and prints each one. dualize and the window both call it; neither does anything the script cannot do on its own.

Run it on your machine

You need macOS (Apple Silicon or Intel), the Xcode Command Line Tools for codesign, and Node.js 18 or newer.

xcode-select --install

git clone https://github.com/vishalmeena2211/mac-app-dualizer.git && cd mac-app-dualizer

chmod +x clone-app.sh

./clone-app.sh --source "/Applications/Claude.app" --name "Claude 2"

open -a "Claude 2"

You now have Claude and Claude 2, each with its own data folder, so each can sign in to a different account and both can run at once, with separate Claude Code sessions. The clone's data lives in ~/Library/Application Support/Claude 2. The same command works for other Electron apps:

./clone-app.sh --source "/Applications/Slack.app" --name "Slack Work"

Every option

Managing clones

node bin/dualize.js list

node bin/dualize.js repair "Claude 2"

node bin/dualize.js repair --all

node bin/dualize.js remove "Claude 2"

list shows each clone's status: ok, missing, needs repair (code signature) or needs repair (asar integrity hash). repair rebuilds the clone from the current app with the same options and keeps the login. repair --all skips healthy clones. remove keeps the data folder; add --purge to delete it too. node bin/dualize.js clone --source ... --name ... is the same as running the script.

The window

npm install

npm start

Drag an app onto the window, or click Browse. Its icon, bundle id and an Electron or Native badge appear. Give the clone a name, choose whether it gets its own data folder and whether to drop URL schemes, click Clone app, watch the log, then Launch clone. The window does not yet expose --tint or --dest-dir.

Signing the clone into a second account

A magic link signs in the app that opens it, and macOS routes claude:// links to the original app. So either start the Continue with email flow inside the Claude 2 window, which makes that instance the one that completes it, or hand the link to the clone by name:

open -a "Claude 2" "claude://magic-link#<token-from-your-login-email>"

Keep the clone's productName unchanged. The tool does this for you. Renaming it makes the web login flow treat the app as a browser and show the marketing site instead of the sign-in.

When something goes wrong

The clone crashes the instant it opens. The crash report says EXC_BREAKPOINT (SIGTRAP) in Electron Framework, and Console shows Integrity check failed for asar archive. The app checks app.asar against the ElectronAsarIntegrity hash in Info.plist, and the clone's hash is stale. Versions of this tool before September 2026 could leave it stale when run from a bare git clone: the hash step needed @electron/asar to be require()-able and silently skipped when it was not (#1). Pull the latest version and rebuild the clone. Its data folder, and your login, are kept:

node bin/dualize.js repair "Claude 2"

If the clone predates the registry and dualize list does not know it, delete the .app and run clone-app.sh again with the same name.

"could not inject the data-isolation snippet". The app's main script is not a CommonJS file the tool knows how to patch, such as an ES-module entry. Clone with --no-isolate to get a separately named copy that shares the original's data, and please open an issue naming the app.

The Dock still shows the old icon. Run killall Dock.

A clone copied from another Mac will not open. The ad-hoc signature is fine where it was made. Elsewhere, clear quarantine:

xattr -dr com.apple.quarantine "/Applications/Claude 2.app"

Removing a clone by hand, without dualize:

rm -rf "/Applications/Claude 2.app" "$HOME/Library/Application Support/Claude 2"

Repository layout

Roadmap

• A CLI that clones, isolates data, re-signs and registers
• An Electron window: drag, name, clone, launch
• Correct asar integrity hash from a bare git clone (#1)
• Registry, list, repair and remove
• Distinct icon badges
• CI: shellcheck and syntax checks
• Apps whose main script is an ES module
• --tint and --dest-dir in the window
• A packaged .app of the window, built with electron-builder
• Better data isolation for native, non-Electron apps
• A CI job that clones a real Electron app

Contributing

Read CONTRIBUTING.md first. Test against a low-stakes Electron app before a critical one. Before a pull request, bash -n clone-app.sh, shellcheck --severity=warning clone-app.sh and node --check on each script must pass; that is what CI runs. Keep the script Bash 3.2 compatible and keep src/asar-tools.js free of third-party packages, so the CLI keeps working from a bare git clone. Say which app, macOS version and chip you tested on.

Please do not propose features aimed at circumventing licensing, DRM or an app's terms of service.

Credits

• Electron for the asar format and @electron/asar, which extracts and repacks the archive.
• pngjs for reading and writing the icon PNGs.
• Apple's codesign, PlistBuddy, ditto, iconutil and lsregister, which do the parts that need macOS.

Licence

MIT. Use it, change it and share it, keeping the copyright notice. The apps you clone keep their own licences and terms; this tool does not change them.

Words used here