# RootModel

RootModel class and type definitions.

## RootModel

**Bases:** [`BaseModel`](/guides/pydantic-base-model#basemodel), `Generic[RootModelRootType]`

:::callout{intent="note" title="Usage Documentation"}
[`RootModel` and Custom Root Types](/guides/concepts-models#rootmodel-and-custom-root-types)
:::

A Pydantic `BaseModel` for the root object of the model.

### Attributes

#### root

The root object of the model.

**Type:** `RootModelRootType`

#### \_\_pydantic\_root\_model\_\_

Whether the model is a RootModel.

#### \_\_pydantic\_private\_\_

Private fields in the model.

#### \_\_pydantic\_extra\_\_

Extra fields in the model.

### Methods

#### model\_construct

`@classmethod`

```python
def model_construct(
    cls,
    root: RootModelRootType,
    _fields_set: set[str] | None = None,
) -> Self
```

Create a new model using the provided root object and update fields set.

##### Returns

[`Self`](https://docs.python.org/3/library/typing.html#typing.Self) — The new model.

##### Parameters

**`root`** : `RootModelRootType`

The root object of the model.

**`_fields_set`** : [`set`](https://docs.python.org/3/reference/expressions.html#set)\[[`str`](https://docs.python.org/3/builtins/stdtypes.html#str)] | [`None`](https://docs.python.org/3/builtins/constants.html#None) _Default:_ `None`

The set of fields to be updated.

##### Raises

- `NotImplemented` — If the model is not a subclass of `RootModel`.

#### model\_dump

```python
def model_dump(
    *,
    mode: Literal['json', 'python'] | str = 'python',
    include: Any = None,
    exclude: Any = None,
    context: dict[str, Any] | None = None,
    by_alias: bool | None = None,
    exclude_unset: bool = False,
    exclude_defaults: bool = False,
    exclude_none: bool = False,
    exclude_computed_fields: bool = False,
    round_trip: bool = False,
    warnings: bool | Literal['none', 'warn', 'error'] = True,
    serialize_as_any: bool = False,
) -> Any
```

This method is included just to get a more accurate return type for type checkers. It is included in this `if TYPE_CHECKING:` block since no override is actually necessary.

See the documentation of `BaseModel.model_dump` for more details about the arguments.

Generally, this method will have a return type of `RootModelRootType`, assuming that `RootModelRootType` is not a `BaseModel` subclass. If `RootModelRootType` is a `BaseModel` subclass, then the return type will likely be `dict[str, Any]`, as `model_dump` calls are recursive. The return type could even be something different, in the case of a custom serializer. Thus, `Any` is used here to catch all of these cases.

##### Returns

[`Any`](https://docs.python.org/3/library/typing.html#typing.Any)

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## Related pages

- [API Documentation](./api-documentation-index.md)
- [Concepts](./concepts-index.md)
- [Dev Tools](./dev-tools-index.md)
- [Error Messages](./error-messages-index.md)
- [Examples](./examples-index.md)
- [Integrations](./integrations-index.md)
- [Internals](./internals-index.md)
- [Production Tools](./production-tools-index.md)
- [Pydantic](./pydantic-index.md)
- [Pydantic Core](./pydantic-core-index.md)

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