CMZ Stats SAV Decompiler

A standalone browser-based CastleMiner Z stats.sav decompiler for inspecting player stat saves locally.

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About

CMZ Stats SAV Decompiler is a simple single-file HTML tool for reading CastleMiner Z stats.sav files. It runs entirely in your browser and does not upload your save file anywhere.

The tool is intended for save inspection, debugging, and modding research. It can decode CastleMiner Z SaveDevice-wrapped stats.sav files, parse the DNA PlayerStats header, and display the known CastleMiner Z stats payload in a readable format.

Features

• Opens stats.sav directly in the browser.
• Detects CastleMiner Z SaveDevice wrapper files.
• Supports RTSD SaveDevice metadata parsing.
• Supports encrypted/compressed stats files when a valid key source is provided.
• Parses known CastleMiner Z stat fields such as blocks dug, item stats, ban list entries, settings, and input bindings.
• Detects optional MA_EXTRA_V1 MoreAchievements trailer data when present.
• Shows parse warnings and trailing bytes to help with reverse engineering unknown fields.
• Does not require a server, install, or backend.

Usage

1. Open the HTML page in a browser.
2. Click Choose File and select your CastleMiner Z stats.sav.
3. If the file is encrypted, enter one of the following key sources:
   • SteamID64 folder name, usually found in %LocalAppData%\CastleMinerZ\<SteamID64>\stats.sav
   • Old gamertag, only for older pre-migration saves
   • Raw 16-byte key hex, if you already know the exact key
4. Click Parse / Re-parse.
5. Review the decoded sections and warnings.

Privacy

This tool is designed to run completely client-side. Your stats.sav is read by the browser using the local File API. The file is not uploaded, submitted, or sent to a remote server by the tool.

Limitations

This is a decompiler/parser, not a full save editor. It only displays fields that are currently understood.

Some CastleMiner Z achievement/stat values may be managed through Steam or game runtime state and may not exist directly in stats.sav. Unknown or version-specific bytes may appear as warnings or trailing data until the format is mapped further.

Supported file notes

CastleMiner Z stats.sav files may be stored inside the game's SaveDevice format. SaveDevice files can be compressed, encrypted, or both. Encrypted files require the correct key source before the payload can be parsed.

Known key source options supported by the page:

• SteamID64 + CastleMiner Z key suffix
• legacy gamertag source for older saves
• raw 16-byte key hex

License

SPDX-License-Identifier: GPL-3.0-or-later

Copyright (c) 2025 RussDev7

This project is licensed under the GNU General Public License v3.0 or later. See LICENSE for details.