It is designed to be very simple to use, and to make it very easy for any developer to integrate other components with **FastAPI**.

## What is "Dependency Injection"

**"Dependency Injection"** means, in programming, that there is a way for your code (in this case, your *path operation functions*) to declare things that it requires to work and use: "dependencies".

# Form Data

When you need to receive form fields instead of JSON, you can use `Form`.

!!! info
    To use forms, first install <a href="https://github.com/Kludex/python-multipart" class="external-link" target="_blank">`python-multipart`</a>.

    E.g. `pip install python-multipart`.

## Import `Form`

Import `Form` from `fastapi`:

=== "Python 3.9+"

    ```Python hl_lines="3"

!!! tip
    You could use the same technique to extend the JSON Schema and add your own custom extra info.

    For example you could use it to add metadata for a frontend user interface, etc.

!!! info
    OpenAPI 3.1.0 (used since FastAPI 0.99.0) added support for `examples`, which is part of the **JSON Schema** standard.

    ```

=== "Python 3.8+ non-Annotated"

    !!! tip
        Prefer to use the `Annotated` version if possible.

    ```Python hl_lines="12"
    {!> ../../../docs_src/request_files/tutorial001.py!}
    ```

Using `UploadFile` has several advantages over `bytes`:

* You don't have to use `File()` in the default value of the parameter.
* It uses a "spooled" file:

            desc: "use istio.io/istio/pkg/slices"
          - pkg: k8s.io/utils/pointer
            desc: "use istio.io/istio/pkg/ptr"
          - pkg: go.opencensus.io
            desc: "do not use OpenCensus; use OpenTelemetry instead"
          - pkg: golang.org/x/exp/maps
            desc: "do not use golang.org/x/exp/maps; use istio.io/istio/pkg/maps instead"
          - pkg: maps

    return executorService.submit<Handshake> {
      serverSocket!!.accept().use { rawSocket ->
        val sslSocket =
          server.sslSocketFactory().createSocket(
            rawSocket,
            rawSocket.inetAddress.hostAddress,
            rawSocket.port,
            true,
          ) as SSLSocket
        sslSocket.use {
          sslSocket.useClientMode = false
          sslSocket.wantClientAuth = true

!!! note
    If you use a response class with no media type, FastAPI will expect your response to have no content, so it will not document the response format in its generated OpenAPI docs.

## Use `ORJSONResponse`

   *
   * @throws UnsupportedOperationException always
   * @deprecated Use {@link ImmutableSortedSet#toImmutableSortedSet}.
   * @since 21.0
   */
  @DoNotCall("Use toImmutableSortedSet")
  @Deprecated
  public static <E> Collector<E, ?, ImmutableSet<E>> toImmutableSet() {
    throw new UnsupportedOperationException();
  }

  /**
   * Not supported. Use {@link #naturalOrder}, which offers better type-safety, instead. This method

                           Version 2.0, January 2004
                        http://www.apache.org/licenses/

   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION

   1. Definitions.

      "License" shall mean the terms and conditions for use, reproduction,
      and distribution as defined by Sections 1 through 9 of this document.

      "Licensor" shall mean the copyright owner or entity authorized by

    traceSampling: 1.0
    # Resources for a small pilot install
    resources:
      requests:
        cpu: 500m
        memory: 2048Mi
    # Set to `type: RuntimeDefault` to use the default profile if available.
    seccompProfile: {}
    # Whether to use an existing CNI installation
    cni:
      enabled: false
      provider: default
    # Additional container arguments
    extraContainerArgs: []
    env: {}