File

Defines a file parameter for a path operation, typically used to receive files uploaded via multipart/form-data. It configures metadata, validation rules, and OpenAPI schema representation for the uploaded file data.

def File(
    default: Any = Undefined,
    default_factory: Callable[[], Any] | None = _Unset,
    media_type: str = multipart/form-data,
    alias: str | None = null,
    alias_priority: int | None = _Unset,
    validation_alias: str | AliasPath | AliasChoices | None = null,
    serialization_alias: str | None = null,
    title: str | None = null,
    description: str | None = null,
    gt: float | None = null,
    ge: float | None = null,
    lt: float | None = null,
    le: float | None = null,
    min_length: int | None = null,
    max_length: int | None = null,
    pattern: str | None = null,
    regex: str | None = null,
    discriminator: str | None = null,
    strict: bool | None = _Unset,
    multiple_of: float | None = _Unset,
    allow_inf_nan: bool | None = _Unset,
    max_digits: int | None = _Unset,
    decimal_places: int | None = _Unset,
    examples: list[Any] | None = null,
    example: Any | None = _Unset,
    openapi_examples: dict[str, Example] | None = null,
    deprecated: deprecated | str | bool | None = null,
    include_in_schema: bool = true,
    json_schema_extra: dict[str, Any] | None = null,
    extra: Any = null
) - > Any

Defines a file parameter for a path operation, typically used to receive uploaded files via multipart/form-data.

Parameters

Name	Type	Description
default	Any = Undefined	Default value if the parameter field is not set.
default_factory	`Callable[[], Any]	None` = _Unset
media_type	str = multipart/form-data	The media type of this parameter field, affecting the generated OpenAPI documentation.
alias	`str	None` = null
alias_priority	`int	None` = _Unset
validation_alias	`str	AliasPath
serialization_alias	`str	None` = null
title	`str	None` = null
description	`str	None` = null
gt	`float	None` = null
ge	`float	None` = null
lt	`float	None` = null
le	`float	None` = null
min_length	`int	None` = null
max_length	`int	None` = null
pattern	`str	None` = null
regex	`str	None` = null
discriminator	`str	None` = null
strict	`bool	None` = _Unset
multiple_of	`float	None` = _Unset
allow_inf_nan	`bool	None` = _Unset
max_digits	`int	None` = _Unset
decimal_places	`int	None` = _Unset
examples	`list[Any]	None` = null
example	`Any	None` = _Unset
openapi_examples	`dict[str, Example]	None` = null
deprecated	`deprecated	str
include_in_schema	bool = true	Whether to include this parameter in the generated OpenAPI documentation.
json_schema_extra	`dict[str, Any]	None` = null
extra	Any = null	Deprecated keyword arguments for extra JSON Schema fields; use 'json_schema_extra' instead.

Returns

Type	Description
Any	A parameter metadata object that FastAPI uses to handle file uploads and generate OpenAPI schemas.