# OpenAPI Webhooks { #openapi-webhooks }

There are cases where you want to tell your API **users** that your app could call *their* app (sending a request) with some data, normally to **notify** of some type of **event**.

This means that instead of the normal process of your users sending requests to your API, it's **your API** (or your app) that could **send requests to their system** (to their API, their app).

This is normally called a **webhook**.

        just a feature that seems like a sensible addition to Guava?


        Before new features get added to Guava, we really want to be sure that it's for a use case
        that actually comes up in the real world. We want to hear the real-world use case so the
        community can discuss and debate whether this feature is actually the *best* way to address

				VersionID:   "",
				IsLatest:    true,
				NumVersions: 1,
			},
			want: 0,
			lc:   lc,
		},
	}
	for i, tc := range tests {
		t.Run(fmt.Sprintf("test-%d", i+1), func(t *testing.T) {
			if got := tc.lc.FilterRules(tc.opts); len(got) != tc.want {
				t.Fatalf("Expected %d rules to match but got %d", tc.want, len(got))
			}
			w := httptest.NewRecorder()
			tc.lc.SetPredictionHeaders(w, tc.opts)

 * is only meant as a utility for developers that want to employ the settings builder outside of the Maven build system,
 * Maven plugins should always acquire settings builder instances via dependency injection. Developers might want to
 * subclass this factory to provide custom implementations for some of the components used by the settings builder.
 *

                is not available, instead of erroring out, the dependency result will
                be `None`.

                This is useful when you want to have optional authentication.

                It is also useful when you want to have authentication that can be
                provided in one of multiple optional ways (for example, with OpenID
                Connect or in a cookie).
                """

    "version" that omits the class to avoid conflicts with the copy in Guava
    itself. The idea is:

    - If users want only ListenableFuture, they depend on listenablefuture-1.0.

    - If users want all of Guava, they depend on guava, which, as of Guava
    27.0, depends on
    listenablefuture-9999.0-empty-to-avoid-conflict-with-guava. The 9999.0-...

		Ciphertext: key.Ciphertext,
	})
	if err != nil {
		t.Fatalf("Failed to decrypt key: %v", err)
	}
	if !bytes.Equal(key.Plaintext, plaintext) {
		t.Fatalf("Decrypted key does not match generated one: got %x - want %x", key.Plaintext, plaintext)
	}
}

func TestDecryptKey(t *testing.T) {
	KMS, err := ParseSecretKey("my-key:eEm+JI9/q4JhH8QwKvf3LKo4DEBl6QbfvAl1CAbMIv8=")
	if err != nil {

<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.

You can use Pydantic's model configuration to `forbid` any `extra` fields:

{* ../../docs_src/query_param_models/tutorial002_an_py310.py hl[10] *}

///

/// note

This is supported since FastAPI version `0.113.0`. 🤓

///

## Pydantic Models for Forms { #pydantic-models-for-forms }

You just need to declare a **Pydantic model** with the fields you want to receive as **form fields**, and then declare the parameter as `Form`:

{* ../../docs_src/request_form_models/tutorial001_an_py39.py hl[9:11,15] *}

For example, let's say that you want to use <a href="https://github.com/ijl/orjson" class="external-link" target="_blank">`orjson`</a>, but with some custom settings not used in the included `ORJSONResponse` class.

Let's say you want it to return indented and formatted JSON, so you want to use the orjson option `orjson.OPT_INDENT_2`.