Container Provider

The Container Provider is a special provider that you should not initialize. It is automatically registered with each container, so you can resolve the container itself directly.

Injecting the Container Itself

You can inject the container into your dependencies in two ways:

Automatic Injection (Type-Based)

If your creator function has a parameter annotated with Container, it will be automatically resolved:

from modern_di import Container, Group, Scope, providers

def my_creator(di_container: Container) -> str:
    # Access the container's scope or other properties
    return f"Container scope: {di_container.scope}"

class Dependencies(Group):
    my_factory = providers.Factory(scope=Scope.APP, creator=my_creator)

container = Container(groups=[Dependencies])
result = container.resolve(str)
# result: "Container scope: Scope.APP"

Explicit Injection

You can also explicitly inject the container using providers.container_provider:

from modern_di import Container, Group, Scope, providers

def another_creator(di_container: Container) -> str:
    # Use the container to manually resolve dependencies
    return "some value"

class Dependencies(Group):
    another_factory = providers.Factory(
        scope=Scope.APP,
        creator=another_creator,
        kwargs={"di_container": providers.container_provider}
    )

Context Propagation

ContextRegistry is per-container. Calling set_context on a parent container does not propagate to child containers that were already built — each container keeps its own context map.

!!! warning "set_context only affects this container" The following does not work as written:

```python
app_container = Container()
request_container = app_container.build_child_container(scope=Scope.REQUEST)
app_container.set_context(MyContext, value)  # invisible to request_container
```

Either set context **before** building the child, or pass it via `build_child_container`:

```python
# Option A: set on the parent first
app_container = Container()
app_container.set_context(MyContext, value)
request_container = app_container.build_child_container(scope=Scope.REQUEST)

# Option B: pass context directly to the child
request_container = app_container.build_child_container(
    scope=Scope.REQUEST, context={MyContext: value}
)
```