features:
  - content.code.annotate
  - content.code.copy
  - content.footnote.tooltips
  - content.tabs.link
  - content.tooltips
  - navigation.footer
  - navigation.indexes
  - navigation.instant
  - navigation.instant.prefetch
  - navigation.instant.progress
  - navigation.path
  - navigation.tabs
  - navigation.tabs.sticky
  - navigation.top
  - navigation.tracking
  - search.highlight
  - search.share

{* ../../docs_src/websockets/tutorial003_py39.py hl[79:81] *}

To try it out:

* Open the app with several browser tabs.
* Write messages from them.
* Then close one of the tabs.

That will raise the `WebSocketDisconnect` exception, and all the other clients will receive a message like:

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

/// tip

    }

    /**
     * Escapes special characters in a value string for safe logging.
     *
     * @param action the string value to escape
     * @return the escaped string with tabs replaced by spaces
     */
    protected String escapeValue(final String action) {
        return action.replace('\t', ' ');
    }

    /**
     * Outputs a log message using the statistics logger.
     *

     * Go to <i>Computer Management</i>
     * &gt; <i>System Tools</i> &gt; <i>Shared Folders</i> &gt; <i>Shares</i> and
     * look at the <i>Properties</i> for a share. You will see two tabs - one
     * for "Share Permissions" and another for "Security". These correspond to
     * the ACLs returned by <code>getShareSecurity</code> and <code>getSecurity</code>
     * respectively.
     *

     * Go to <i>Computer Management</i>
     * &gt; <i>System Tools</i> &gt; <i>Shared Folders</i> &gt; <i>Shares</i> and
     * look at the <i>Properties</i> for a share. You will see two tabs - one
     * for "Share Permissions" and another for "Security". These correspond to
     * the ACLs returned by {@code getShareSecurity} and {@code getSecurity}
     * respectively.

### Add some custom `tags`, `responses`, and `dependencies` { #add-some-custom-tags-responses-and-dependencies }

We are not adding the prefix `/items` nor the `tags=["items"]` to each *path operation* because we added them to the `APIRouter`.

<img src="/img/tutorial/generate-clients/image05.png">

## FastAPI App with Tags { #fastapi-app-with-tags }

In many cases, your FastAPI app will be bigger, and you will probably use tags to separate different groups of *path operations*.

For example, you could have a section for **items** and another section for **users**, and they could be separated by tags:

{* ../../docs_src/generate_clients/tutorial002_py39.py hl[21,26,34] *}

* ✨ Add support for tags with Enums. PR [#4468](https://github.com/tiangolo/fastapi/pull/4468) by [@tiangolo](https://github.com/tiangolo). New docs: [Path Operation Configuration - Tags with Enums](https://fastapi.tiangolo.com/tutorial/path-operation-configuration/#tags-with-enums).

        List<String> fields = new ArrayList<>();
        fields.add("field1");
        List<String> tags = new ArrayList<>();
        tags.add("tag1");
        List<String> roles = new ArrayList<>();
        roles.add("role1");

        elevateWord = new ElevateWord(word, boost, readings, fields, tags, roles);

        // Check that we get the same references
        assertTrue(readings == elevateWord.getReadings());

/// tip

You don't have to add metadata for all the tags that you use.

///

### Use your tags { #use-your-tags }

Use the `tags` parameter with your *path operations* (and `APIRouter`s) to assign them to different tags:

{* ../../docs_src/metadata/tutorial004.py hl[21,26] *}

/// info

Read more about tags in [Path Operation Configuration](path-operation-configuration.md#tags){.internal-link target=_blank}.

///