A versatile option is the [OpenAPI Generator](https://openapi-generator.tech/), which supports **many programming languages** and can generate SDKs from your OpenAPI specification.

For **TypeScript clients**, [Hey API](https://heyapi.dev/) is a purpose-built solution, providing an optimized experience for the TypeScript ecosystem.

You can discover more SDK generators on [OpenAPI.Tools](https://openapi.tools/#sdk).

/// tip

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.

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.

///

require approval from native speakers for translation PRs generated automatically by our translation workflow. However, you can still review them and suggest improvements to the LLM prompt for that language to make the future translations better.

You can check the currently [existing pull requests](https://github.com/fastapi/fastapi/pulls) for your language. You can filter the pull requests by the ones with the label for your language. For example, for Spanish, the label is [`lang-es`](...

If you use any other tool to manage your installations, like `uv`, Poetry, Pipenv, or others, they all have a way that you can use to define specific versions for your packages.

## Available versions { #available-versions }

You can see the available versions (e.g. to check what is the current latest) in the [Release Notes](../release-notes.md).

## About versions { #about-versions }

* You can get metadata from the uploaded file.
* It has a [file-like](https://docs.python.org/3/glossary.html#term-file-like-object) `async` interface.
* It exposes an actual Python [`SpooledTemporaryFile`](https://docs.python.org/3/library/tempfile.html#tempfile.SpooledTemporaryFile) object that you can pass directly to other libraries that expect a file-like object.

You can configure the two documentation user interfaces included:

* **Swagger UI**: served at `/docs`.
    * You can set its URL with the parameter `docs_url`.
    * You can disable it by setting `docs_url=None`.
* **ReDoc**: served at `/redoc`.
    * You can set its URL with the parameter `redoc_url`.
    * You can disable it by setting `redoc_url=None`.

/// info

Keep in mind that dataclasses can't do everything Pydantic models can do.

So, you might still need to use Pydantic models.

But if you have a bunch of dataclasses laying around, this is a nice trick to use them to power a web API using FastAPI. 🤓

///

## Dataclasses in `response_model` { #dataclasses-in-response-model }

You can also use `dataclasses` in the `response_model` parameter:

   * occur when using {@link CacheBuilder#weakKeys}, {@link CacheBuilder#weakValues}, or {@link
   * CacheBuilder#softValues}.
   */
  COLLECTED {
    @Override
    boolean wasEvicted() {
      return true;
    }
  },

  /**
   * The entry's expiration timestamp has passed. This can occur when using {@link

## Check the Docs { #check-the-docs }

You can see the query parameters in the docs UI at `/docs`:

<div class="screenshot">
<img src="/img/tutorial/query-param-models/image01.png">
</div>

## Forbid Extra Query Parameters { #forbid-extra-query-parameters }

In some special use cases (probably not very common), you might want to **restrict** the query parameters that you want to receive.