* **FastAPI** adds a reference here to the global JSON Schemas in another place in your OpenAPI instead of including it directly. This way, other applications and clients can use those JSON Schemas directly, provide better code generation tools, etc.

The generated responses in the OpenAPI for this *path operation* will be:

```JSON hl_lines="3-12"
{
    "responses": {

When a client disconnects, a `WebSocketDisconnect` exception is raised, you can catch it.

You can import it directly form `fastapi`:

```python
from fastapi import WebSocketDisconnect
```

::: fastapi.WebSocketDisconnect

## WebSockets - additional classes

Additional classes for handling WebSockets.

Provided directly by Starlette, but you can import it from `fastapi`:

```python

# and also repacks libtensorflow-src.jar into a standardized format.

# Helper function to copy a srcjar after moving any source files
# directly under the root to the "maven-style" src/main/java layout
#
# Source files generated by annotation processors appear directly
# under the root of srcjars jars created by bazel, rather than under
# the maven-style src/main/java subdirectory.
#

     * for finalName directly in the plugin configuration section. It is also useful to ensure that - for example - a
     * List-typed parameter which expects items of type Artifact doesn't get a List full of Strings.
     *
     * @return <code>true</code> if the user should not be allowed to configure the parameter directly
     */
    boolean readonly() default false;

You can declare a parameter in a *path operation function* or dependency to be of type `Response` and then you can set data for the response like headers or cookies.

You can also use it directly to create an instance of it and return it from your *path operations*.

You can import it directly from `fastapi`:

```python
from fastapi import Response
```

# `Request` class

You can declare a parameter in a *path operation function* or dependency to be of type `Request` and then you can access the raw request object directly, without any validation, etc.

You can import it directly from `fastapi`:

```python
from fastapi import Request
```

!!! tip

You can use the `TestClient` class to test FastAPI applications without creating an actual HTTP and socket connection, just communicating directly with the FastAPI code.

Read more about it in the [FastAPI docs for Testing](https://fastapi.tiangolo.com/tutorial/testing/).

You can import it directly from `fastapi.testclient`:

```python
from fastapi.testclient import TestClient
```

## `Depends()`

Dependencies are handled mainly with the special function `Depends()` that takes a callable.

Here is the reference for it and its parameters.

You can import it directly from `fastapi`:

```python
from fastapi import Depends
```

::: fastapi.Depends

## `Security()`

## Run your code with your debugger

Because you are running the Uvicorn server directly from your code, you can call your Python program (your FastAPI application) directly from the debugger.

---

For example, in Visual Studio Code, you can:

* Go to the "Debug" panel.
* "Add configuration...".
* Select "Python"

These status codes have a name associated to recognize them, but the important part is the number.

In short:

* `100` and above are for "Information". You rarely use them directly.  Responses with these status codes cannot have a body.
* **`200`** and above are for "Successful" responses. These are the ones you would use the most.
    * `200` is the default status code, which means everything was "OK".