## Technical Details { #technical-details }

The class `BackgroundTasks` comes directly from <a href="https://www.starlette.io/background/" class="external-link" target="_blank">`starlette.background`</a>.

/// warning

Notice that these parameters are passed directly to the *path operation decorator*, not to your *path operation function*.

///

## Response Status Code { #response-status-code }

You can define the (HTTP) `status_code` to be used in the response of your *path operation*.

You can pass directly the `int` code, like `404`.

     * The method analyzes the User-Agent header to categorize the browser type
     * and caches the result in the request attribute for subsequent calls.
     *
     * @return the detected user agent type, or OTHER if no specific type is detected
     */
    public UserAgentType getUserAgentType() {
        return LaRequestUtil.getOptionalRequest().map(request -> {

///

## Run your code with your debugger { #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"

/**
 * RDMA capability flags indicating what operations are supported
 * by an RDMA provider implementation.
 */
public enum RdmaCapability {
    /**
     * Remote direct read operations
     */
    RDMA_READ,

    /**
     * Remote direct write operations
     */
    RDMA_WRITE,

    /**
     * Traditional send/receive with RDMA
     */
    RDMA_SEND_RECEIVE,

    /**

You can use:

* `HTTPException`
* `WebSocketException`

These exceptions can be imported directly from `fastapi`:

```python
from fastapi import HTTPException, WebSocketException
```

::: fastapi.HTTPException

import static org.junit.jupiter.api.Assertions.assertTrue;

/**
 * Verifies scope inheritance of direct and transitive dependencies.
 *
 * Should show three behaviors:
 *
 * 1. dependencyManagement should override the scope of transitive dependencies.
 * 2. Direct dependencies should override the scope of dependencyManagement.
 * 3. Direct dependencies should inherit scope from dependencyManagement when
 *    they do not explicitly state a scope.

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

In short:

* `100 - 199` are for "Information". You rarely use them directly.  Responses with these status codes cannot have a body.
* **`200 - 299`** are for "Successful" responses. These are the ones you would use the most.
    * `200` is the default status code, which means everything was "OK".

/// note | Technical Details

You could also use `from starlette.websockets import WebSocket`.

**FastAPI** provides the same `WebSocket` directly just as a convenience for you, the developer. But it comes directly from Starlette.

///

## Await for messages and send messages { #await-for-messages-and-send-messages }

In your WebSocket route you can `await` for messages and send messages.

# Middleware

There are several middlewares available provided by Starlette directly.

Read more about them in the [FastAPI docs for Middleware](https://fastapi.tiangolo.com/advanced/middleware/).

::: fastapi.middleware.cors.CORSMiddleware

It can be imported from `fastapi`:

```python
from fastapi.middleware.cors import CORSMiddleware
```

::: fastapi.middleware.gzip.GZipMiddleware

It can be imported from `fastapi`: