///

## Declare metadata { #declare-metadata }

You can declare all the same parameters as for `Query`.

For example, to declare a `title` metadata value for the path parameter `item_id` you can type:

{* ../../docs_src/path_params_numeric_validations/tutorial001_an_py310.py hl[10] *}

/// note

	}
	defer xioutil.SafeClose(out)
	var objsReturned int

	objReturned := func(metadata []byte) {
		if opts.Limit <= 0 {
			return
		}
		if m, _, _ := isIndexedMetaV2(metadata); m != nil && !m.AllHidden(true) {
			objsReturned++
		}
	}
	send := func(entry metaCacheEntry) error {
		objReturned(entry.metadata)
		select {
		case <-ctx.Done():
			return ctx.Err()
		case out <- entry:
		}

// from the metadata using the SSE-Copy client key of the HTTP headers
// and returns the decrypted object key.
func (sse ssecCopy) UnsealObjectKey(h http.Header, metadata map[string]string, bucket, object string) (key ObjectKey, err error) {
	clientKey, err := sse.ParseHTTP(h)
	if err != nil {
		return key, err
	}
	return unsealObjectKey(clientKey[:], metadata, bucket, object)
}

import org.apache.maven.artifact.repository.ArtifactRepository;
import org.apache.maven.artifact.repository.RepositoryRequest;
import org.apache.maven.artifact.repository.metadata.RepositoryMetadataResolutionException;
import org.apache.maven.artifact.repository.metadata.Versioning;
import org.apache.maven.artifact.resolver.ArtifactNotFoundException;
import org.apache.maven.artifact.resolver.ArtifactResolutionException;

/**

	return extractMetadata(ctx, textproto.MIMEHeader(r.Form), textproto.MIMEHeader(r.Header))
}

func extractMetadata(ctx context.Context, mimesHeader ...textproto.MIMEHeader) (metadata map[string]string, err error) {
	metadata = make(map[string]string)

	for _, hdr := range mimesHeader {
		// Extract all query values.
		err = extractMetadataFromMime(ctx, hdr, metadata)
		if err != nil {

 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.maven.artifact.metadata;

import javax.inject.Inject;
import javax.inject.Named;
import javax.inject.Singleton;

import java.util.HashSet;
import java.util.List;
import java.util.Set;

import org.apache.maven.artifact.Artifact;

# Body - Fields { #body-fields }

The same way you can declare additional validation and metadata in *path operation function* parameters with `Query`, `Path` and `Body`, you can declare validation and metadata inside of Pydantic models using Pydantic's `Field`.

## Import `Field` { #import-field }

First, you have to import it:

{* ../../docs_src/body_fields/tutorial001_an_py310.py hl[4] *}


/// warning

## OpenAPI-Metadaten – Dokumentation { #openapi-metadata-docs }

Um Metadaten zu Ihrem OpenAPI-Schema hinzuzufügen, einschließlich einer Lizenz, Version, Kontakt, usw., lesen Sie die Dokumentation unter [Tutorial – Metadaten und URLs der Dokumentation](../tutorial/metadata.md){.internal-link target=_blank}.

## Benutzerdefinierte OpenAPI-URL { #openapi-custom-url }

package org.apache.maven.artifact.repository.metadata;

import org.apache.maven.artifact.Artifact;
import org.apache.maven.artifact.ArtifactUtils;
import org.apache.maven.artifact.repository.ArtifactRepository;
import org.apache.maven.artifact.versioning.ArtifactVersion;
import org.apache.maven.artifact.versioning.Restriction;
import org.apache.maven.artifact.versioning.VersionRange;

/**
 * Metadata for the artifact directory of the repository.

 * This enum is used to differentiate between various SSO operations,
 * such as metadata requests and logout actions.
 */
public enum SsoResponseType {
    /**
     * Indicates a request for SSO metadata, which is typically used for
     * configuration and discovery in protocols like SAML.
     */
    METADATA,

    /**
     * Indicates a request to perform a logout operation, terminating the