description=description,
            gt=gt,
            ge=ge,
            lt=lt,
            le=le,
            min_length=min_length,
            max_length=max_length,
            discriminator=discriminator,
            multiple_of=multiple_of,
            allow_inf_nan=allow_inf_nan,
            max_digits=max_digits,
            decimal_places=decimal_places,
            **extra,
        )

    class OtherItem(BaseModel):
        value: Literal["other"]
        price: float

    Item = Annotated[
        Union[Annotated[FirstItem, Tag("first")], Annotated[OtherItem, Tag("other")]],
        Field(discriminator="value"),
    ]

    @app.post("/items/")
    def save_union_body_discriminator(
        item: Item, q: Annotated[str, Field(description="Query string")]
    ) -> dict[str, Any]:
        return {"item": item}

        gt=gt,
        ge=ge,
        lt=lt,
        le=le,
        min_length=min_length,
        max_length=max_length,
        pattern=pattern,
        regex=regex,
        discriminator=discriminator,
        strict=strict,
        multiple_of=multiple_of,
        allow_inf_nan=allow_inf_nan,
        max_digits=max_digits,
        decimal_places=decimal_places,
        example=example,

    examples: Optional[list[Any]] = None
    # Ref: OpenAPI 3.1.0: https://github.com/OAI/OpenAPI-Specification/blob/main/versions/3.1.0.md#schema-object
    # Schema Object
    discriminator: Optional[Discriminator] = None
    xml: Optional[XML] = None
    externalDocs: Optional[ExternalDocumentation] = None
    example: Annotated[
        Optional[Any],
        typing_deprecated(

    "serialization_alias": None,
    "title": None,
    "field_title_generator": None,
    "description": None,
    "examples": None,
    "exclude": None,
    "exclude_if": None,
    "discriminator": None,
    "deprecated": None,
    "json_schema_extra": None,
    "frozen": None,
    "validate_default": None,
    "repr": True,
    "init": None,
    "init_var": None,
    "kw_only": None,
}

* 🐛 Fix parameter aliases. PR [#14371](https://github.com/fastapi/fastapi/pull/14371) by [@YuriiMotov](https://github.com/YuriiMotov).

## 0.124.3

### Fixes

* 🐛 Fix support for tagged union with discriminator inside of `Annotated` with `Body()`. PR [#14512](https://github.com/fastapi/fastapi/pull/14512) by [@tiangolo](https://github.com/tiangolo).

### Refactors