There is a `#contributing` channel on the community Slack which you can use
to ask any questions.

## Setting up your development environment

In order to make changes to Gradle, you'll need:

* A [Java Development Kit](http://jdk.java.net/) (JDK) **version 11**. Fixed version is required to use [remote cache](#remote-build-cache). 

!!! tip
    For new code and whenever possible, use `Annotated` as explained above. There are multiple advantages (explained below) and no disadvantages. 🍰

        str,
        Doc(
            """
            The URL to use to load the Swagger UI JavaScript.

            It is normally set to a CDN URL.
            """
        ),
    ] = "https://cdn.jsdelivr.net/npm/swagger-ui-dist@5.9.0/swagger-ui-bundle.js",
    swagger_css_url: Annotated[
        str,
        Doc(
            """
            The URL to use to load the Swagger UI CSS.

            It is normally set to a CDN URL.

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:

Kotlin, Groovy, Java, and other JVM-based languages should be able to use the Gradle API without relying on another language's standard library.

Historically, Gradle has shipped with some Groovy types in very prominent APIs.
This required the Kotlin DSL to add special integration to work with Groovy closures.
This has also forced plugins written in languages other than Groovy to use Groovy types for some APIs.

            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