* As connecting to an email server and sending an email tends to be "slow" (several seconds), you can return the response right away and send the email notification in the background.
* Processing data:
    * For example, let's say you receive a file that must go through a slow process, you can return a response of "Accepted" (HTTP 202) and process the file in the background.

## Using `BackgroundTasks`

	...
</pre>

<p>
This is the list of instructions and their spellings as known to the assembler and linker for that architecture.
Each instruction begins with an initial capital <code>A</code> in this list, so <code>AAND</code>
represents the bitwise and instruction,
<code>AND</code> (without the leading <code>A</code>),
and is written in assembly source as <code>AND</code>.
The enumeration is mostly in alphabetical order.

  // the associated expression.
  // Name must be a qualified name consisting of alphanumeric characters, '-', '_' or '.', and
  // must start and end with an alphanumeric character (e.g. 'MyName',  or 'my.name',  or
  // '123-abc', regex used for validation is '([A-Za-z0-9][-A-Za-z0-9_.]*)?[A-Za-z0-9]') with an
  // optional DNS subdomain prefix and '/' (e.g. 'example.com/MyName')
  //
  // Required.
  optional string name = 1;

And then you can set headers in that *temporal* response object.

```Python hl_lines="1  7-8"
{!../../docs_src/response_headers/tutorial002.py!}
```

And then you can return any object you need, as you normally would (a `dict`, a database model, etc).

And if you declared a `response_model`, it will still be used to filter and convert the object you returned.

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