FastAPI will use the `response_model` parameter (that includes dataclasses) to convert the response.

You can combine `dataclasses` with other type annotations in many different combinations to form complex data structures.

Check the in-code annotation tips above to see more specific details.

## Learn More

You can also combine `dataclasses` with other Pydantic models, inherit from them, include them in your own models, etc.

```

`app.add_middleware()` receives a middleware class as the first argument and any additional arguments to be passed to the middleware.

## Integrated middlewares

**FastAPI** includes several middlewares for common use cases, we'll see next how to use them.

!!! note "Technical Details"
    For the next examples, you could also use `from starlette.middleware.something import SomethingMiddleware`.

Different versions of **FastAPI** will use a specific newer version of Starlette.

So, you can just let **FastAPI** use the correct Starlette version.

## About Pydantic

Pydantic includes the tests for **FastAPI** with its own tests, so new versions of Pydantic (above `1.0.0`) are always compatible with FastAPI.

You can pin Pydantic to any version above `1.0.0` that works for you and below `2.0.0`.

For example:

This schema definition includes your API paths, the possible parameters they take, etc.

#### Data "schema"

The term "schema" might also refer to the shape of some data, like a JSON content.

In that case, it would mean the JSON attributes, and data types they have, etc.

#### OpenAPI and JSON Schema

So, they will be included in the JSON response.

!!! tip
    Notice that the default values can be anything, not only `None`.

    They can be a list (`[]`), a `float` of `10.5`, etc.

### `response_model_include` and `response_model_exclude`

You can also use the *path operation decorator* parameters `response_model_include` and `response_model_exclude`.

distribution = true

[tool.pdm.build]
source-includes = [
    "tests/",
    "docs_src/",
    "requirements*.txt",
    "scripts/",
    # For a test
    "docs/en/docs/img/favicon.png",
    ]

[tool.tiangolo._internal-slim-build.packages.fastapi-slim.project]
name = "fastapi-slim"

[tool.tiangolo._internal-slim-build.packages.fastapi]
include-optional-dependencies = ["standard"]

You can use this template to get started, as it includes a lot of the initial set up, security, database and some API endpoints already done for you.

  "email": "******@****.***",
  "full_name": "John Doe",
  "disabled": false
}
```

<img src="/img/tutorial/security/image09.png">

If you open the developer tools, you could see how the data sent only includes the token, the password is only sent in the first request to authenticate the user and get that access token, but not afterwards:

<img src="/img/tutorial/security/image10.png">

!!! note

    callbacks=callback_router3.routes,
)

router2_override.include_router(router4_override)

router2_override.include_router(router4_default)

router2_default.include_router(
    router4_override,
    prefix="/level3",
    tags=["level3a", "level3b"],
    dependencies=[Depends(dep3)],
    responses={
        403: {"description": "Client error level 3"},

Here's the reference information for the request parameters.

These are the special functions that you can put in *path operation function* parameters or dependency functions with `Annotated` to get data from the request.

It includes:

* `Query()`
* `Path()`
* `Body()`
* `Cookie()`
* `Header()`
* `Form()`
* `File()`

You can import them all directly from `fastapi`:

```python