<div class="screenshot">
<img src="/img/tutorial/request-form-models/image01.png">
</div>

## Forbid Extra Form Fields { #forbid-extra-form-fields }

In some special use cases (probably not very common), you might want to **restrict** the form fields to only those declared in the Pydantic model. And **forbid** any **extra** fields.

/// note

This is supported since FastAPI version `0.114.0`. 🤓

///

 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.common.graph;

import static com.google.common.truth.Truth.assertThat;

import org.jspecify.annotations.NullUnmarked;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.JUnit4;

/**

 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.common.graph;

import static java.util.Objects.requireNonNull;

import com.google.common.collect.Maps;
import java.util.Map;
import java.util.Set;
import org.jspecify.annotations.Nullable;

/**

 * limitations under the License.
 */

package com.google.common.xml;

import static java.lang.annotation.ElementType.FIELD;
import static java.lang.annotation.ElementType.METHOD;
import static java.lang.annotation.ElementType.PARAMETER;
import static java.lang.annotation.RetentionPolicy.CLASS;

import com.google.common.annotations.GwtCompatible;
import java.lang.annotation.Retention;

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.common.collect;

import com.google.common.annotations.GwtCompatible;
import java.io.Serializable;

/**
 * An abstract base class for implementing the <a
 * href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>. The {@link

{* ../../docs_src/header_params/tutorial001_an_py310.py hl[9] *}

/// note | Technical Details

`Header` is a "sister" class of `Path`, `Query` and `Cookie`. It also inherits from the same common `Param` class.

But remember that when you import `Query`, `Path`, `Header`, and others from `fastapi`, those are actually functions that return special classes.

///

/// info

@com.google.errorprone.annotations.CheckReturnValue

@com.google.errorprone.annotations.CheckReturnValue

@com.google.errorprone.annotations.CheckReturnValue

 * or implied. See the License for the specific language governing permissions and limitations under
 * the License.
 */

package com.google.common.hash;

import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkNotNull;

import com.google.errorprone.annotations.Immutable;
import java.security.Key;
import java.util.ArrayList;
import java.util.Arrays;