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".

                           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

!!! 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

MINIO_IDENTITY_LDAP_SERVER_STARTTLS         (on|off)    use StartTLS connection to AD/LDAP server, defaults to "off"
```

The server address variable is _required_. TLS is assumed to be on by default. The port in the server address is optional and defaults to 636 if not provided.

  /**
   * Returns the unsigned {@code int} value represented by a string with the given radix.
   *
   * <p><b>Java 8+ users:</b> use {@link Integer#parseUnsignedInt(String, int)} instead.
   *
   * @param string the string containing the unsigned integer representation to be parsed.
   * @param radix the radix to use while parsing {@code s}; must be between {@link
   *     Character#MIN_RADIX} and {@link Character#MAX_RADIX}.

                           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

                           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

!!! 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`