One Claude subscription, many windows, many APIs — at the same time

What it does It spawns extra Claude Desktop windows on Windows, each with its own data directory, its own recoloured icon (desktop, taskbar, tray), and its own API. Your official window keeps the subscription login; the others talk to whatever third-party provider you point them at via cc-switch — either a fixed provider or one that follows cc-switch’s current selection. It’s glue code in the best sense: PowerShell orchestrating per-window LOCALAPPDATA isolation, junctioned session folders, and tinted icons generated locally from your installed app.

The interesting bit The README documents the reverse-engineering that made it possible: --user-data-dir and CLAUDE_USER_DATA_DIR are stripped or overridden in the production build, so the trick is giving each window a private LOCALAPPDATA, from which the 3P data dir is derived. Session sync is equally pragmatic — Claude Desktop has no file watcher, so idle background windows silently restart (minimised, no focus steal) to pick up new sessions, pins, and MCP config.

Key highlights

• Official subscription window plus N third-party windows, each on its own API, simultaneously
• Per-window icons in preset palettes (Gemini, GPT, Perplexity, DeepSeek) or any #RRGGBB
• Multi-official-account support with per-account proxy (-Proxy) and injected timezone (-Timezone) for egress alignment
• check command audits each instance’s egress IP, residential status, risk score, and timezone
• Update-proof on Windows: nothing patched or copied; install path resolved from the Store package at every launch

Caveats

• macOS port is experimental and was written without access to a Mac — never run on real hardware; pin/MCP sync, claude:// routing, and tray icons aren’t ported yet
• Pin syncing is best-effort: a running window keeps its own pins until restart, and the app trims the list it reads (17 written pins came back as 12 in testing)
• The same session open in two windows interleaves transcripts; you get a warning notification, not a fix

Verdict Worth a look if you juggle a Claude subscription plus third-party or multiple official accounts and want them all live at once with clear visual separation. If one window and one API is your life, this is solving a problem you don’t have.