Inspiration
NAS owners frequently transfer data between operating systems, external drives, and storage environments. However, differences in filename restrictions, filesystem behavior, and path handling can cause unexpected failures.
These problems are often discovered only after a transfer has started.
I wanted to explore a simple question:
What if your NAS could identify compatibility problems before you moved your files?
That question led to Wetzly.
What it does
Wetzly is a pre-transfer compatibility assessment Skill for UGREEN AI NAS.
It examines authorized files against a specified destination environment and identifies potential issues, including:
- Incompatible filenames and paths.
- Case-insensitive naming collisions.
- File and directory conflicts.
- Unicode normalization risks.
- Filesystem limitations, including FAT32's 4 GiB individual file-size limit.
Wetzly produces a Portability Ledger linking each finding to its source path, relevant compatibility rule, and proposed correction.
It preserves original files, prioritizes minimal adjustments, and distinguishes verified findings from conditional risks and unknowns.
The goal is to identify preventable problems before they interrupt a transfer.
How we built it
I developed Wetzly using the official UGREEN Uliya Skill Development Kit 0.7.7.
The Skill uses Markdown-based orchestration and registered Uliya agents to inspect authorized NAS files, evaluate destination-specific compatibility rules, and generate traceable recommendations.
Development and local validation were performed on Windows using Python, PowerShell, Node.js, and the Uliya development tools, with assistance from Codex.
Challenges we ran into
One challenge was that filename compatibility is not always consistent across operating systems and APIs.
During testing, certain Windows device-like filenames behaved differently from conventional restrictions. I documented these discrepancies and refined the corresponding rules.
Another challenge was handling incomplete information without making unsupported compatibility guarantees.
Accomplishments that we're proud of
Wetzly now has a structured compatibility assessment workflow, source-linked findings, and non-destructive recommendations.
The official Uliya 0.7.7 static checker reports zero errors and warnings, and 119 offline policy tests passed, including adversarial scenarios.
What we learned
Directory structure, Unicode handling, destination conventions, and client behavior can all affect a transfer.
This project reinforced the importance of preserving original data, acknowledging uncertainty, and distinguishing verified behavior from assumptions.
What's next for Wetzly
The next step is to validate Wetzly in real NAS environments, improve its compatibility assessments, and expand support for additional filesystems, operating systems, and transfer scenarios.
Future development will focus on more precise diagnostics, safer migration planning, and better interoperability across storage platforms.
The objective is to make data portability more predictable, transparent, and reliable.
