}
```

## Recap { #recap }

You can add multiple body parameters to your *path operation function*, even though a request can only have a single body.

But **FastAPI** will handle it, give you the correct data in your function, and validate and document the correct schema in the *path operation*.

You can also declare singular values to be received as part of the body.

      - name: Build on ${{ matrix.os }}
        if: matrix.os == 'ubuntu-latest'
        env:
          CGO_ENABLED: 0
          GO111MODULE: on
        run: |
          sudo sysctl net.ipv6.conf.all.disable_ipv6=0
          sudo sysctl net.ipv6.conf.default.disable_ipv6=0

      - name: Build on ${{ matrix.os }}
        if: matrix.os == 'ubuntu-latest'
        env:
          CGO_ENABLED: 0
          GO111MODULE: on
        run: |
          sudo sysctl net.ipv6.conf.all.disable_ipv6=0
          sudo sysctl net.ipv6.conf.default.disable_ipv6=0

Additional classes for handling WebSockets.

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

```python
from fastapi.websockets import WebSocketDisconnect, WebSocketState
```

::: fastapi.websockets.WebSocketDisconnect

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

Here is the reference for it and its parameters.

You can import it directly from `fastapi`:

```python
from fastapi import Depends
```

::: fastapi.Depends

## `Security()`

For many scenarios, you can handle security (authorization, authentication, etc.) with dependencies, using `Depends()`.

But when you want to also declare OAuth2 scopes, you can use `Security()` instead of `Depends()`.

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*.

Read more about it in the [FastAPI docs about returning a custom Response](https://fastapi.tiangolo.com/advanced/response-directly/#returning-a-custom-response)

<%@page pageEncoding="UTF-8" contentType="text/html; charset=UTF-8"%>
<h2>Query Syntax</h2>
<dl>
	<dt>Field</dt>
	<dd>
		You can search any field by typing the field name followed by a colon
		":" and then the term you are looking for. If you want to find
		documents which has "Fess" as the document title, you can enter:
		<pre>title:Fess</pre>
		The available fields are "url", "host", "site", "title", "content",

### No Return Type { #no-return-type }

You can also omit the return type. FastAPI will use the [`jsonable_encoder`](./encoder.md) to convert the data and send it.

{* ../../docs_src/server_sent_events/tutorial001_py310.py ln[34:37] hl[35] *}

## `ServerSentEvent` { #serversentevent }

If you need to set SSE fields like `event`, `id`, `retry`, or `comment`, you can yield `ServerSentEvent` objects instead of plain data.

But normally you won't have to worry about it, it's done automatically, continue reading. 🤓

///

## Use Cases { #use-cases }

You could use this to stream data from an **AI LLM** service, from **logs** or **telemetry**, or from other types of data that can be structured in **JSON** items.

/// tip

CxC,IACED,EAAIxL,GAAO0L,CAQb,CAPE,MAAAC,GACA3D,OAAO4D,eAAeJ,EAAKxL,EAAK,CAC9B6L,cAAc,EACdzL,IAAGA,IACMsL,GAGb,CAGF,OAAOF,CACT,CCnTA,SAASM,EAAcJ,GACrB,GAAc,SAAVA,EACF,OAAO,EAGT,GAAc,UAAVA,EACF,OAAO,EAGT,GAAIA,IAAUhG,OAAOgG,GAAOK,WAC1B,OAAOrG,OAAOgG,GAGhB,GAAc,KAAVA,GAA0B,SAAVA,EAClB,OAAO,KAGT,GAAqB,iBAAVA,EACT,OAAOA,EAGT,IACE,OAAOM,KAAKC,MAAMC,mBAAmBR,GAGvC,CAFE,MAAAC,GACA,OAAOD,CACT,CACF,CAEA,SAASS,EAAiBnM,GACxB,OAAOA,EAAImB,QAAQ,UAAUiL,GAAQ,IAAGA,EAAIC,iBAC9C,CAEA,MAAMC,EAAc,CAClBC,iBAAiBxM,EAA...