* Even dependencies can have dependencies, creating a hierarchy or **"graph" of dependencies**.
* All **automatically handled** by the framework.
* All the dependencies can require data from requests and **augment the path operation** constraints and automatic documentation.

```JSON
{
  "detail": "Item not found"
}
```

/// tip

When raising an `HTTPException`, you can pass any value that can be converted to JSON as the parameter `detail`, not only `str`.

You could pass a `dict`, a `list`, etc.

They are handled automatically by **FastAPI** and converted to JSON.

///

///

## Advanced usage with `scopes` { #advanced-usage-with-scopes }

OAuth2 has the notion of "scopes".

You can use them to add a specific set of permissions to a JWT token.

Then you can give this token to a user directly or a third party, to interact with your API with a set of restrictions.

You can learn how to use them and how they are integrated into **FastAPI** later in the **Advanced User Guide**.

## Recap { #recap }

FastAPI is open source and based on standards. You can deploy FastAPI apps to any cloud provider you choose.

Follow your cloud provider's guides to deploy FastAPI apps with them. 🤓

## Deploy your own server { #deploy-your-own-server }

# `Response` class

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
```

### Concurrency + Parallelism: Web + Machine Learning { #concurrency-parallelism-web-machine-learning }

With **FastAPI** you can take advantage of concurrency that is very common for web development (the same main attraction of NodeJS).

But you can also exploit the benefits of parallelism and multiprocessing (having multiple processes running in parallel) for **CPU bound** workloads like those in Machine Learning systems.

- we need to deal with plugins as core application logic which can also interact with plugins

* Along with this comes the testing strategies that make this work
* The repository model where plugins can be stored and cataloged
* Bridging this into an OSGi system: if this could be done then we can basically take over p2

TODO

	)

	ErrInvalidBrowserValue = newErrFn(
		"Invalid console value",
		"Please check the passed value",
		"Environment can only accept `on` and `off` values. To disable Console access, set this value to `off`",
	)

	ErrInvalidFSOSyncValue = newErrFn(
		"Invalid O_SYNC value",
		"Please check the passed value",
		"Can only accept `on` and `off` values. To enable O_SYNC for fs backend, set this value to `on`",
	)

from MinIO before returning it to an application. You can register a Lambda Function target on MinIO, once successfully registered it can be used to transform the data for application GET requests on demand.

This document focuses on showing a working example on how to use Object Lambda with MinIO, you must have [MinIO deployed in your environment](https://docs.min.io/community/minio-object-store/operations/installation.html) before you can start using external lambda functions. You also must...

## 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).
* Add it as a "middleware" to your **FastAPI** application.

You can also specify whether your backend allows:

* Credentials (Authorization headers, Cookies, etc).