PolyDroid
Your Android phone mounted natively in Mac Finder.

Connect your Android smartphone or tablet to your Mac over USB and it mounts instantly in Finder under Locations as a real local folder. Browse, search, transfer, and stream photos, 4K videos, documents, and music at wire speed — with zero spinning beachballs and zero crashes.

Key architectural innovations

• Native Apple File Provider integration: Powered by Apple’s modern NSFileProviderReplicatedExtension framework. Your phone appears directly in the Finder sidebar (~/Library/CloudStorage/PolyDroid/), supporting Mac drag-and-drop, Quick Look previews, Spotlight search, and direct file access from any Mac application or CLI script.
• Zero spinning beachball latency: Engineered specifically for USB MTP simplex serial buses. Disables aggressive cloud-style recursive directory crawling; strictly requests items on-demand with an 8-second silent freshness cache to eliminate the notorious 3–5 second Finder beachball.
• Ultra-lightweight footprint (<10 MB): Free of heavy Electron frameworks or cloud bloat. Built on a tailored, universal Rust MTP runtime (libopendal_ffi.dylib), keeping the entire application bundle under 10 MB.
• High-speed transfers & streaming (>4GB): Pure Rust nusb USB bulk endpoint protocol stack delivering sequential transfer speeds up to 38+ MB/s. Full 64-bit MTP streaming enables seamless transfers of massive video files (>4GB).
• Memory safety with disk spooling: Uploads use a 1MB chunked disk spool pipeline with memory strictly capped under 30MB, completely preventing macOS jetsam memory terminations during large file transfers.
• Instant media Quick Look: Uses MTP 4MB chunk slicing (GetPartialObject) with adaptive read-ahead windows, allowing instant scrubbing and streaming preview of high-res video and audio directly from your phone.
• Three-tier cache & instant sync: Fast SQLite3 metadata caching with 8-second silent TTL for instantaneous folder opening, synchronous cache invalidation on file create/rename/delete, and a menu bar broadcast trigger for instant full refresh.
• Hot-plug & auto-recovery: Unplugging the USB cable gracefully preserves directory metadata instead of crashing Finder. Reconnecting your phone and unlocking the screen automatically awakens the heartbeat daemon and restores browsing within seconds.
• Dual-channel hybrid transport: Directly claims USB interfaces via nusb, while automatically falling back to Apple ImageCaptureCore pass-through (requestSendPTPCommand) when system daemons (such as ptpcamerad) claim the device.
• 100% private & offline: Pure local communication over USB. Zero network access permissions, zero cloud servers, zero analytics, zero telemetry, and zero user accounts.

Technical specifications

Why PolyDroid vs. Legacy Android Transfer Tools

System requirements

PolyDroid is built for modern macOS releases. It runs natively on:

• Mac computers with Apple silicon (M1, M2, M3, M4 or later) or Intel processors.
• macOS 13 or later (macOS Ventura, Sonoma, Sequoia, or later).
• Any Android smartphone or tablet running Android 5.0 Lollipop or newer with USB MTP file transfer support.

How it works

1. Connect your device: Connect your Android phone to your Mac using a USB-C or USB-A cable.
2. Authorize on phone: Unlock your phone screen, swipe down the notification shade, and set USB preferences to “File Transfer” (MTP).
3. Browse in Finder: PolyDroid automatically detects your phone and mounts it under Locations in the Finder sidebar. Open, edit, copy, and organize files just like a local drive.

Frequently asked questions

How is PolyDroid different from traditional Android file transfer tools?

Unlike outdated standalone utilities or electron apps, PolyDroid integrates directly into macOS Finder using Apple's modern File Provider framework. Your Android device mounts under Locations in the Finder sidebar just like a native flash drive, allowing you to use native Mac drag-and-drop, Quick Look, and Spotlight search.

Why do other Android MTP tools cause the spinning beachball on Mac?

USB MTP operates on a simplex serial bus. Most legacy tools attempt aggressive recursive crawling when a folder is opened, saturating the USB pipe and freezing macOS Finder for 3-5 seconds. PolyDroid eliminates contention by requesting items strictly on-demand, caching directory trees with an 8-second freshness TTL, and pausing background polling when transfers occur.

Can PolyDroid transfer files larger than 4GB?

Yes. PolyDroid implements 64-bit MTP streaming with an intelligent 1MB disk spooling pipeline. It easily transfers huge 4K videos and large archive files while keeping host memory usage under 30MB, completely avoiding macOS jetsam memory kills.

What happens if I unplug my phone while Finder is open?

PolyDroid protects Finder stability. When the USB cable is disconnected, PolyDroid reports a transient network state to retain cached directory metadata, preventing Finder crashes or blank window freezes. Once you plug the device back in and unlock it, the session restores automatically in seconds.

Does PolyDroid collect any personal data or require an account?

No. PolyDroid operates 100% locally and offline. It has zero network communication, sends no telemetry or analytics, and requires no user account or login.