But by using `Security` instead of `Depends`, **FastAPI** will know that it can declare security scopes, use them internally, and document the API with OpenAPI.

But when you import `Query`, `Path`, `Depends`, `Security` and others from `fastapi`, those are actually functions that return special classes.

///

## Use `SecurityScopes` { #use-securityscopes }

Now update the dependency `get_current_user`.

If you declare a [Response Model](../tutorial/response-model.md) FastAPI will use it to serialize the data to JSON, using Pydantic.

If you don't declare a response model, FastAPI will use the `jsonable_encoder` explained in [JSON Compatible Encoder](../tutorial/encoder.md) and put it in a `JSONResponse`.

You could also create a `JSONResponse` directly and return it.

## Explore Further

- [Use `mc` with MinIO Server](https://docs.min.io/community/minio-object-store/reference/minio-mc.html)
- [Use `aws-cli` with MinIO Server](https://docs.min.io/community/minio-object-store/integrations/aws-cli-with-minio.html)
- [Use `minio-go` SDK with MinIO Server](https://docs.min.io/community/minio-object-store/developers/go/minio-go.html)

In this case, you can override the dependency that calls that provider, and use a custom dependency that returns a mock user, only for your tests.

### Use the `app.dependency_overrides` attribute { #use-the-app-dependency-overrides-attribute }

For these cases, your **FastAPI** application has an attribute `app.dependency_overrides`, it is a simple `dict`.

    val response1Body =
      client.newCall(request).execute().use {
        if (!it.isSuccessful) throw IOException("Unexpected code $it")

        println("Response 1 response:          $it")
        println("Response 1 cache response:    ${it.cacheResponse}")
        println("Response 1 network response:  ${it.networkResponse}")
        return@use it.body.string()
      }

    val response2Body =

        that it's for a use case that actually comes up in the real world. We want to hear the
        real-world use case so the community can discuss and debate whether this feature is actually
        the *best* way to address the real use case, or whether or not a different approach might be
        more appropriate.


        It's okay if you can't provide complete context on a use case. We understand if you are not

It is based on [HTTPX](https://www.python-httpx.org), which in turn is designed based on Requests, so it's very familiar and intuitive.

With it, you can use [pytest](https://docs.pytest.org/) directly with **FastAPI**.

## Using `TestClient` { #using-testclient }

/// info

To use `TestClient`, first install [`httpx`](https://www.python-httpx.org).

So, for everything to work correctly, it's better to specify explicitly the allowed origins.

## Use `CORSMiddleware` { #use-corsmiddleware }

You can configure it in your **FastAPI** application using the `CORSMiddleware`.

* Import `CORSMiddleware`.
* Create a list of allowed origins (as strings).

/*
 * Copyright 2012-2025 CodeLibs Project and the Others.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,

# Form Models { #form-models }

You can use **Pydantic models** to declare **form fields** in FastAPI.

/// info

To use forms, first install [`python-multipart`](https://github.com/Kludex/python-multipart).

Make sure you create a [virtual environment](../virtual-environments.md), activate it, and then install it, for example:

```console
$ pip install python-multipart
```

///

/// note