Framework Package Format

The Framework Package Format (FPF) is the specification that all tsx packages follow. An FPF package is a versioned, self-describing bundle of code generators, templates, and metadata that can be installed into any compatible project with a single command.

What is a framework package?

Think of an FPF package as a smart scaffold. Unlike a plain code snippet or a library dependency, a framework package:

Knows about your project structure and writes files into the right places.
Declares capabilities it provides (e.g. auth, crud) so other packages can integrate with it.
Integrates automatically with other installed packages via the integrates_with slot system.
Is versioned and pinnable, so teams get reproducible scaffolding.

Directory layout

After installation, a package lives under .tsx/packages/<name>/:

.tsx/
└── packages/
    └── with-auth/
        ├── manifest.json       # Package manifest (pinned version)
        ├── generators/         # Rhai or shell generator scripts
        │   ├── setup.rhai      # Scaffolds the full auth integration
        │   └── add-route.rhai  # Adds a new protected route
        └── templates/          # Handlebars templates
            ├── auth.server.ts.hbs
            ├── auth.client.ts.hbs
            └── middleware.ts.hbs

The manifest

Every package must have a manifest.json at its root. It declares the package identity, capabilities, generators, and integration slots. See manifest.json reference for the full field specification.

Generators

Generators are scripts that receive a JSON input schema and write files to the project. They are defined in the generators[] array of the manifest and invoked via:

tsx run <package>:<generator> [--input '{"key":"value"}']

The slot system

The integrates_with map in the manifest describes how this package modifies other packages' output. For example, the with-auth package can inject a session check into routes generated by tanstack-crud:

"integrates_with": {
  "tanstack-crud": {
    "slot": "route.beforeLoad",
    "inject": "templates/auth-guard-slot.hbs"
  }
}