So, you could add additional data to the automatically generated schema.

For example, you could decide to read and validate the request with your own code, without using the automatic features of FastAPI with Pydantic, but you could still want to define the request in the OpenAPI schema.

You could do that with `openapi_extra`:

  @CanIgnoreReturnValue
  @VisibleForTesting
  @ParametricNullness
  static <V extends @Nullable Object, X extends Exception> V getChecked(
      GetCheckedTypeValidator validator, Future<V> future, Class<X> exceptionClass) throws X {
    validator.validateClass(exceptionClass);
    try {
      return future.get();
    } catch (InterruptedException e) {
      currentThread().interrupt();
      throw newWithCause(exceptionClass, e);

 */
package jcifs.internal.smb2.ioctl;

import jcifs.Encodable;
import jcifs.internal.util.SMBUtil;

/**
 * SMB2 Validate Negotiate Info request data structure. This structure is used to validate
 * that the negotiated SMB2 dialect matches what was originally negotiated.
 *
 * @author mbechler
 *
 */
public class ValidateNegotiateInfoRequest implements Encodable {

/** File generated by Grunt -- do not modify
 *  JQUERY-FORM-VALIDATOR
 *
 *  @version 2.3.77
 *  @website http://formvalidator.net/
 *  @author Victor Jonsson, http://victorjonsson.se
 *  @license MIT
 */

@Named
@Singleton
public class DefaultModelValidator implements ModelValidator {

    @Inject
    private org.apache.maven.model.validation.ModelValidator modelValidator;

    @Override
    public ModelValidationResult validate(Model model) {
        ModelValidationResult result = new ModelValidationResult();

        ModelBuildingRequest request =

            assertEquals(0, flag & (flag - 1), "Flag should be power of 2: " + Integer.toHexString(flag));
        }

        @Test
        @DisplayName("Should validate all constants are unique")
        void shouldHaveUniqueConstants() {
            int[] accessConstants = { ACE.FILE_READ_DATA, ACE.FILE_WRITE_DATA, ACE.FILE_APPEND_DATA, ACE.FILE_READ_EA, ACE.FILE_WRITE_EA,

     * @return HTML response for the edit form
     */
    @Execute
    @Secured({ ROLE })
    public HtmlResponse edit(final EditForm form) {
        validate(form, messages -> {}, this::asListHtml);
        final String id = form.id;
        relatedContentService.getRelatedContent(id).ifPresent(entity -> {
            copyBeanToBean(entity, form, op -> {});

errors.header = <ul class="has-error">
errors.footer = </ul>
errors.prefix = <li><i class="fa fa-exclamation-circle"></i>
errors.suffix = </li>
# ----------------------------------------------------------
# Javax Validator
# ---------------
constraints.AssertFalse.message = {item} musi być fałszywe.
constraints.AssertTrue.message = {item} musi być prawdziwe.
constraints.DecimalMax.message = {item} musi być mniejsze niż {value}.

  verbose " - Running Downloader.java ..."
  "$(native_path "$JAVACMD")" -cp "$(native_path "$TMP_DOWNLOAD_DIR")" Downloader "$distributionUrl" "$(native_path "$targetZip")"
fi

# If specified, validate the SHA-256 sum of the Maven distribution zip file
if [ -n "${distributionSha256Sum-}" ]; then
  distributionSha256Result=false
  if [ "$MVN_CMD" = mvnd.sh ]; then

Extra keys passed to `Field` will also be present in the resulting OpenAPI schema for your application.
As these keys may not necessarily be part of the OpenAPI specification, some OpenAPI tools, for example [the OpenAPI validator](https://validator.swagger.io/), may not work with your generated schema.

///

## Recap { #recap }

You can use Pydantic's `Field` to declare extra validations and metadata for model attributes.