# Request Parameters

Here's the reference information for the request parameters.

These are the special functions that you can put in *path operation function* parameters or dependency functions with `Annotated` to get data from the request.

It includes:

* `Query()`
* `Path()`
* `Body()`
* `Cookie()`
* `Header()`
* `Form()`
* `File()`

You can import them all directly from `fastapi`:

```python

# Request-Parameter

Hier die Referenzinformationen für die Request-Parameter.

Dies sind die Sonderfunktionen, die Sie mittels `Annotated` in *Pfadoperation-Funktion*-Parameter oder Abhängigkeitsfunktionen einfügen können, um Daten aus dem Request abzurufen.

Dies beinhaltet:

* `Query()`
* `Path()`
* `Body()`
* `Cookie()`
* `Header()`
* `Form()`
* `File()`

Sie können diese alle direkt von `fastapi` importieren:

```python

    {!> ../../../docs_src/query_params/tutorial002.py!}
    ```

In this case, the function parameter `q` will be optional, and will be `None` by default.

!!! check
    Also notice that **FastAPI** is smart enough to notice that the path parameter `item_id` is a path parameter and `q` is not, so, it's a query parameter.

## Query parameter type conversion

You can also declare `bool` types, and they will be converted:

    @Suppress("UNCHECKED_CAST")
    fun generate(parameters: Map<String, Any>) {
        generateKotlinDslApiExtensionsSourceTo(
            parameters["asmLevel"] as Int,
            parameters["platformClassLoader"] as ClassLoader,
            parameters["incubatingAnnotationTypeDescriptor"] as String,
            parameters["outputDirectory"] as File,
            parameters["packageName"] as String,

  fun emptyCache(parameters: Pair<FileSystem, Boolean>) {
    setUp(parameters.first, parameters.second)
    cache.close()
    assertJournalEquals()
  }

  @ParameterizedTest
  @ArgumentsSource(FileSystemParamProvider::class)
  fun recoverFromInitializationFailure(parameters: Pair<FileSystem, Boolean>) {
    setUp(parameters.first, parameters.second)

* Calling your dependency ("dependable") function with the correct parameters.
* Get the result from your function.
* Assign that result to the parameter in your *path operation function*.

```mermaid
graph TB

common_parameters(["common_parameters"])
read_items["/items/"]
read_users["/users/"]

common_parameters --> read_items
common_parameters --> read_users
```

# Body - Multiple Parameters

Now that we have seen how to use `Path` and `Query`, let's see more advanced uses of request body declarations.

## Mix `Path`, `Query` and body parameters

First, of course, you can mix `Path`, `Query` and request body parameter declarations freely and **FastAPI** will know what to do.

And you can also declare body parameters as optional, by setting the default to `None`:

=== "Python 3.10+"

    {!> ../../../docs_src/body/tutorial004.py!}
    ```

The function parameters will be recognized as follows:

* If the parameter is also declared in the **path**, it will be used as a path parameter.
* If the parameter is of a **singular type** (like `int`, `float`, `str`, `bool`, etc) it will be interpreted as a **query** parameter.

    private
    val taskPathReports: Map<String, List<File>>
        get() = parameters.taskPathToReports.get()

    private
    val rootBuildDir: File
        get() = parameters.rootBuildDir.get().asFile

    private
    val testPathToBinaryResultsDirs: Map<String, File>
        get() = parameters.testPathToBinaryResultsDirs.get()

    override fun onFinish(event: FinishEvent) {

      if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
        val parameters = sslSocket.sslParameters
        Log.d("CustomSSLSocketFactory", "old applicationProtocols: $parameters.applicationProtocols")
        parameters.applicationProtocols = arrayOf("x-amzn-http-ca")
        sslSocket.sslParameters = parameters
      }

      return sslSocket
    }
  }

  var client = OkHttpClient()

  @Test