/** Array of fields that can be highlighted in search results */
    protected String[] highlightedFields;

    /** Array of fields that can be searched against */
    protected String[] searchFields;

    /** Array of fields that can be used for faceted search */
    protected String[] facetFields;

    /** Array of fields that can be used for sorting search results */
    protected String[] sortFields;

{* ../../docs_src/query_params_str_validations/tutorial006_an_py39.py hl[9] *}

### Required, can be `None` { #required-can-be-none }

You can declare that a parameter can accept `None`, but that it's still required. This would force clients to send a value, even if the value is `None`.

# Response Model - Return Type { #response-model-return-type }

You can declare the type used for the response by annotating the *path operation function* **return type**.

You can use **type annotations** the same way you would for input data in function **parameters**, you can use Pydantic models, lists, dictionaries, scalar values like integers, booleans, etc.

{* ../../docs_src/response_model/tutorial001_01_py310.py hl[16,21] *}

For **TypeScript clients**, <a href="https://heyapi.dev/" class="external-link" target="_blank">Hey API</a> is a purpose-built solution, providing an optimized experience for the TypeScript ecosystem.

But you can configure the **application server** to trust the *forwarded* headers sent by the **proxy**. If you are using FastAPI CLI, you can use the *CLI Option* `--forwarded-allow-ips` to tell it from which IPs it should trust those *forwarded* headers.

{!../../docs_src/bigger_applications/app/routers/users.py!}
```

You can think of `APIRouter` as a "mini `FastAPI`" class.

All the same options are supported.

All the same `parameters`, `responses`, `dependencies`, `tags`, etc.

/// tip

In this example, the variable is called `router`, but you can name it however you want.

///

* Many PRs don't have tests, you can **remind** them to add tests, or you can even **suggest** some tests yourself. That's one of the things that consume most time and you can help a lot with that.

* Then also comment what you tried, that way I'll know that you checked it. 🤓

## Create a Pull Request { #create-a-pull-request }

You can help with everything on [Help FastAPI - Get Help](./help-fastapi.md){.internal-link target=_blank} the same ways as external contributors. But additionally, there are some tasks that only you (as part of the team) can perform.

Here are the general instructions for the tasks you can perform.

Thanks a lot for your help. 🙇

## Be Nice

First of all, be nice. 😊

If there is no discussion for that language, you can start by requesting the new language. For that, you can follow these steps:

* Create a new discussion following the template.
* Get a few native speakers to comment on the discussion and commit to help review translations for that language.

Once there are several people in the discussion, the FastAPI team can evaluate it and can make it an official translation.

Returns an HTTP redirect. Uses a 307 status code (Temporary Redirect) by default.

You can return a `RedirectResponse` directly:

{* ../../docs_src/custom_response/tutorial006.py hl[2,9] *}

---

Or you can use it in the `response_class` parameter:


{* ../../docs_src/custom_response/tutorial006b.py hl[2,7,9] *}

If you do that, then you can return the URL directly from your *path operation* function.