☁️ Private Cloud Drives: Mounting & Sync Guide

ZZ Music connects directly to private cloud drives and local network storage with an advanced Dry-Run delta synchronization engine.

🔌 1. Supported Storage Protocols

Go to Settings -> Cloud Storage -> Add Connection:

Supported: AList, Synology WebDAV Server, Nextcloud, Nutstore.
Enter server URL, credentials, and mount directory. Tap "Test Connection" for standard HTTP PROPFIND validation.

Direct scan-to-authenticate QR code. Automatic token rotation with zero re-login hassle.

Tap-to-Play Streaming: once mounted, every audio file in the cloud drive is presented as a directory tree — tap any track and it is streamed in chunks for instant playback.
Metadata & Lyrics Matched in Seconds: while playing a cloud track, the app automatically extracts the ID3 tags and matches accurate rolling lyrics online.
Local Lossless Cache: cloud tracks you have already played are automatically cached into local private sandbox storage, so they can be played back later at full fidelity even when offline.

Sync Mode	Logic	Best Use Case
Two-way Sync	Uploads new local tracks, downloads new cloud tracks. Keeps both mirrored.	Multi-device collaboration between phone and PC/NAS.
Local First	Unidirectional push to cloud. Overwrites remote outdated files.	Phone as primary library; backup to cloud.
Cloud First	Unidirectional pull to local device. Overwrites local files.	NAS as master repository; phone downloads latest albums.
Mirror Delete	Deletions on one end mirror to the other end.	Strict two-way folder mirroring.

To avoid losing precious lossless music through a careless operation, ZZ Music ships a Dry-Run difference preview engine:

Pre-flight comparison: before you tap "Start Sync", the engine first compares file paths, sizes, and modification timestamps in memory (allowing a small tolerance of a few seconds) — no hashing is performed;
Difference listing: a dialog itemizes exactly what will happen:
- 🟢 To Download: 3 tracks (120MB)
- 🔵 To Upload: 1 track (45MB)
- 🔴 To Delete: 0 tracks (or the specific files pending deletion)
Execution after confirmation: the underlying task writes to the filesystem only after you have reviewed the list and tapped "Confirm & Execute".

Physical synchronization starts only after your explicit confirmation.

Transfer music between two devices at high speed — no data cable required:

Face-to-Face QR Transfer: the sender picks tracks and generates a dedicated QR code; the receiver opens the app and scans it. Both devices then connect directly over the WiFi LAN, at whatever speed your local network allows.
10-Minute Burn-After-Reading Relay: if the two devices are on different networks (across the public internet), the sender can upload to a cloud relay in one tap and receives a 6-digit pickup code. The receiver enters the code to download the track, and the file is physically shredded and destroyed server-side 10 minutes later, or as soon as the download completes. Note that during this window the file is temporarily stored on the relay server — it is never retained there permanently. This protects both copyright and privacy.