Module Directory Structure

In this chapter, you'll learn about the files and directories you can create in a module's directory.

A module is a Go package, so MedusaGo doesn't require a fixed file layout: the compiler resolves your code through imports. The layout below is the one the chapters of this documentation use, and it mirrors the layout of a Medusa module.

src/modules/blog
├── models.go
├── service.go
├── index.go
├── loaders.go
├── options.go
└── migrations
    ├── .snapshot-blog.json
    ├── Migration20261114134517.go
    └── index.go

index.go#

The index.go file holds the module's definition: the call to Module with the module's data models, migrations, loaders, and the function that builds its service. It also exports the value you register in medusa-config.go.

// Module is the definition of the blog module.
var Module = utilsmodulessdk.Module(Name, utilsmodulessdk.ModuleDefinition{
	Models:     Models,
	Migrations: migrations.Migrations,
	Loaders:    []typesmodulessdk.Loader{SeedTags},
	Service: func(opts typesmodulessdk.ServiceOptions, base *utilsmodulessdk.MedusaService) (any, error) {
		options, err := ParseOptions(opts.Options)
		if err != nil {
			return nil, err
		}
		return &BlogModuleService{MedusaService: base, options: options}, nil
	},
})

Learn more in the Modules chapter.

service.go#

The service.go file holds the module's main service: the struct that embeds *MedusaService and the methods you add to it.

// BlogModuleService is the service of the blog module. Embedding
// *MedusaService gives it the generated methods (listPosts, createPosts, ...)
// and the internal service of each model.
type BlogModuleService struct {
	*utilsmodulessdk.MedusaService
	options Options
}

Learn more in the Service Factory chapter.

Other Files and Directories#

You can add the following to the module:

| File or directory | Description | | --- | --- | | models.go | The module's data models. A module with many models can group them in a models package, with one file per model. | | loaders.go | The module's loaders, the functions that run when the module is loaded. | | options.go | The type and the validation of the module's options. | | migrations | The module's migrations. db:generate writes it in the directory of the module, as a Go package named migrations, with an index.go file that lists the migrations and a .snapshot-<module>.json file with the schema snapshot. |