Just use any kind of model, any kind of class, any kind of database that you need for your application. **FastAPI** has you covered with the dependency injection system.

## Code size { #code-size }

This example might seem verbose. Keep in mind that we are mixing security, data models, utility functions and *path operations* in the same file.

Just remember, the most important point is: try to be kind. People come with their frustrations and in many cases don't ask in the best way, but try as best as you can to be kind. 🤗

The idea is for the **FastAPI** community to be kind and welcoming. At the same time, don't accept bullying or disrespectful behavior towards others. We have to take care of each other.

---

But when checking benchmarks and comparisons you should keep the following in mind.

## Benchmarks and speed { #benchmarks-and-speed }

When you check the benchmarks, it is common to see several tools of different types compared as equivalent.

* You can then further modify the `response` before returning it.

{* ../../docs_src/middleware/tutorial001.py hl[8:9,11,14] *}

/// tip

Keep in mind that custom proprietary headers can be added <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers" class="external-link" target="_blank">using the 'X-' prefix</a>.

 * [Coil](https://github.com/coil-kt/coil): An image loading library for Android backed by Kotlin Coroutines.
 * [Communicator](https://github.com/Taig/Communicator): An OkHttp wrapper for Scala built with Android in mind.
 * [Cronet Transport for OkHttp](https://github.com/google/cronet-transport-for-okhttp): A HTTP3 ready transport layer for OkHttp on Android, based on Chromium network stack.

* data validation
* data serialization
* data documentation, etc.

This works the same way as with Pydantic models. And it is actually achieved in the same way underneath, using Pydantic.

/// info

Keep in mind that dataclasses can't do everything Pydantic models can do.

So, you might still need to use Pydantic models.

 * newHasher().putBytes(new byte[] { b1, b2, b3 }).hash()
 * }
 *
 * <p>If you wish to avoid this, you should either prepend or append the size of each chunk. Keep in
 * mind that when dealing with char sequences, the encoded form of two concatenated char sequences
 * is not equivalent to the concatenation of their encoded form. Therefore, {@link

Passing the `root_path` to `FastAPI` would be the equivalent of passing the `--root-path` command line option to Uvicorn or Hypercorn.

### About `root_path` { #about-root-path }

Keep in mind that the server (Uvicorn) won't use that `root_path` for anything else than passing it to the app.

///

The files will be uploaded as "form data".

If you declare the type of your *path operation function* parameter as `bytes`, **FastAPI** will read the file for you and you will receive the contents as `bytes`.

Keep in mind that this means that the whole contents will be stored in memory. This will work well for small files.

But there are several cases in which you might benefit from using `UploadFile`.

```
Client #1596980209979 left the chat
```

/// tip

The app above is a minimal and simple example to demonstrate how to handle and broadcast messages to several WebSocket connections.

But keep in mind that, as everything is handled in memory, in a single list, it will only work while the process is running, and will only work with a single process.