/// info

`Body` also has all the same extra validation and metadata parameters as `Query`, `Path` and others you will see later.

///

## Embed a single body parameter { #embed-a-single-body-parameter }

Let's say you only have a single `item` body parameter from a Pydantic model `Item`.

By default, **FastAPI** will then expect its body directly.

# =====================================================================================
# Without aliases


@app.post("/required-str", operation_id="required_str")
async def read_required_str(p: Annotated[str, Body(embed=True)]):
    return {"p": p}


class BodyModelRequiredStr(BaseModel):
    p: str


@app.post("/model-required-str", operation_id="model_required_str")
async def read_model_required_str(p: BodyModelRequiredStr):

```Python
item: Item = Body(embed=True)
```

so wie in:

{* ../../docs_src/body_multiple_params/tutorial005_an_py310.py hl[17] *}

In diesem Fall erwartet **FastAPI** einen Body wie:

```JSON hl_lines="2"
{

# Without aliases


@app.post("/optional-list-str", operation_id="optional_list_str")
async def read_optional_list_str(
    p: Annotated[Optional[list[str]], Body(embed=True)] = None,
):
    return {"p": p}


class BodyModelOptionalListStr(BaseModel):
    p: Optional[list[str]] = None


@app.post("/model-optional-list-str", operation_id="model_optional_list_str")

```Python
item: Item = Body(embed=True)
```

como en:

{* ../../docs_src/body_multiple_params/tutorial005_an_py310.py hl[17] *}

En este caso, **FastAPI** esperará un cuerpo como:

```JSON hl_lines="2"
{
    "item": {
        "name": "Foo",

```Python
item: Item = Body(embed=True)
```

como em:

{* ../../docs_src/body_multiple_params/tutorial005_an_py310.py hl[17] *}

Neste caso o **FastAPI** esperará um corpo como:

```JSON hl_lines="2"
{
    "item": {

```Python
item: Item = Body(embed=True)
```

так же, как в этом примере:

{* ../../docs_src/body_multiple_params/tutorial005_an_py310.py hl[17] *}

В этом случае **FastAPI** будет ожидать тело запроса в формате:

```JSON hl_lines="2"
{

# Without aliases


@app.post("/required-list-str", operation_id="required_list_str")
async def read_required_list_str(p: Annotated[list[str], Body(embed=True)]):
    return {"p": p}


class BodyModelRequiredListStr(BaseModel):
    p: list[str]


@app.post("/model-required-list-str", operation_id="model_required_list_str")

# =====================================================================================
# Without aliases


@app.post("/optional-str", operation_id="optional_str")
async def read_optional_str(p: Annotated[Optional[str], Body(embed=True)] = None):
    return {"p": p}


class BodyModelOptionalStr(BaseModel):
    p: Optional[str] = None


@app.post("/model-optional-str", operation_id="model_optional_str")

        // Replace YouTube references by embedded videos, ?si= attribute is a must
        // E.g. @youtube(Summary,UN0AFCLASZA?si=9aG5tDzj6nL1_IKT&start=371)@ => https://www.youtube.com/embed/UN0AFCLASZA?si=9aG5tDzj6nL1_IKT&start=371"
        // "&rel=0" is also force-injected to prevent video recommendations from other channels
        rewritten = rewritten.replaceAll("\\@youtube\\(([a-zA-Z\\-_]+)\\,([^\\s<]+)\\)\\@",