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Project File

Master Packager Dev uses a single JSON file as its project format. This file — commonly named with the .json extension — is the only input needed to define, configure, and build an MSI or MSIX installer.

File Format​

The project file is a standard JSON (JavaScript Object Notation) document. It is human-readable, easy to diff, and works natively with version control systems like Git.

A minimal project file looks like this:

{
  "$schema": "https://www.masterpackager.com/support-master-packager-dev/mpdev-schema.json",
  "name": "My Application",
  "version": "1.0.0",
  "manufacturer": "My Company"
}

How It Works​

  1. Write — Define your package content (files, registry entries, shortcuts, services, etc.) in the JSON project file.
  2. Validate — Master Packager Dev validates the project against its JSON schema, catching errors before build time.
  3. Build — Run mpdev build pointing to your project file. MPDEV reads the JSON, resolves all paths and references, and produces the final MSI and/or MSIX installer.

Because the project file is plain text, it integrates naturally into CI/CD pipelines, code reviews, and automated workflows.

Key Characteristics​

  • Single source of truth — One file describes the entire installer configuration.
  • Schema-validated — IDE auto-complete and real-time error detection via the JSON schema.
  • Portable — No binary dependencies; the JSON file and your source files are all you need.
  • Dual output — The same project file can produce both MSI and MSIX installers, with format-specific sections for properties that differ between the two.