GMS-UTML-Patcher

GMS-UTML-Patcher is a command-line utility designed to modify data.win files created with GameMaker Studio. It uses UndertaleModLib to patch game assets, including graphics, fonts, audio, and GML code.

Note

Work in Progress

• Documentation is being improved
• Some advanced features may change

Contributions are welcome! Please see Issues and Pull Requests.

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Features

• Loads and modifies data.win files
• Applies patches based on JSON configuration
• Supports all major asset types (code, graphics, fonts, audio)
• Configurable patching behavior for each asset type
• Checksum verification for data integrity (--make-checks)

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Requirements

• .NET 8 SDK
• UndertaleModLib

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Building

dotnet build

or on Windows:

./build.ps1

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Usage

GMS-UTML-Patcher --data-path path/to/data.win --patcher-file path/to/patch.json [options]

Command-line options

Option	Description
--data-path	Path to the original data.win file (required)
--patcher-file	Path to the JSON patch configuration (required)
--output	Output path (default: original.patched.win)
--skip-hash-check	Skip SHA256 hash validation
--skip-timecheck	Skip build timestamp checks
--make-checks	Generate checksums without patching

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Configuration

Basic configuration structure (all sections except checks are optional):

{
  "checks": {
    ...
  },
  "gml": {
    "directory": "code/"
  },
  "fonts": {
    "directory": "fonts/"
  },
  "graphics": {
    "directory": "graphics/"
  },
  "audio": {
    "directory": "audio/"
  }
}

For detailed configuration options and advanced features, see Configuration.md.

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Exit codes

This app has fully documented exit codes, see ExitCodes.md

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License

MIT License. See LICENSE for details.

⚠️ Uses UndertaleModLib (GPLv3).

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Support

Report issues at:
https://github.com/ZAZiOs/GMS-UTML-Patcher/issues