Providers¶

Providers describe how to create an instance of a type. Each variant is a separate class — the type checker enforces correct usage.

from spryx_di import ClassProvider, FactoryProvider, ValueProvider, ExistingProvider

ClassProvider¶

Map an interface to a concrete class. The container auto-wires the class's __init__.

ClassProvider(provide=TeamReader, use_class=PgTeamReader)

FactoryProvider¶

Provide a callable that receives the container. Use for conditional logic or complex setup.

FactoryProvider(
    provide=BillingGateway,
    use_factory=lambda c: StripeBillingGateway(c.resolve(Config)),
)

ValueProvider¶

Register a pre-built instance.

ValueProvider(provide=Database, use_value=my_db_instance)

ExistingProvider¶

Alias one type to another. When provide is requested, the container resolves use_existing instead.

ExistingProvider(provide=AssetService, use_existing=AssetServiceImpl)

Eliminates boilerplate factory functions for port → implementation mappings.

Scope¶

ClassProvider and FactoryProvider accept a scope parameter. Default is Scope.SINGLETON.

from spryx_di import Scope

ClassProvider(provide=Handler, use_class=Handler, scope=Scope.TRANSIENT)

Union Type¶

All four are unified under Provider:

Provider = ClassProvider | FactoryProvider | ValueProvider | ExistingProvider

Bare Type Shorthand¶

Pass a class directly in providers as shorthand for ClassProvider(provide=T, use_class=T):

Module(
    name="identity",
    providers=[PgTeamReader, PgUserReader],  # singleton, self-bound
)

In NestJS, this is equivalent to listing a class in providers: [TeamService].