# 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`

First, you have to import it:

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


/// warning

            purposes.</description>
        </field>
        <field>
          <name>activation</name>
          <version>1.0.0</version>
          <description><![CDATA[The conditional logic which will automatically
            trigger the inclusion of this profile.]]></description>
          <association>
            <type>Activation</type>
          </association>
        </field>
        <field>
          <name>properties</name>

          <type>String</type>
          <required>true</required>
        </field>
        <field>
          <version>1.0.0</version>
          <name>configuration</name>
          <description>The place and syntax used to change the value of this expression.</description>
          <type>String</type>
        </field>
        <field>
          <version>1.0.0</version>
          <name>cliOptions</name>

                "Configure " + dispatcherMeta.displayName());
        context.addInHeader("");

        for (DispatcherMeta.Field field : dispatcherMeta.fields()) {
            String fieldKey = field.getKey();
            String fieldDescription = "Configure " + fieldKey + ": " + field.getDescription();
            if (field.getOptions().isPresent()) {
                // list options
                ListPromptBuilder listPromptBuilder =

                Field[] fields = FIELDS_BY_CLASS.computeIfAbsent(cls, k -> cls.getDeclaredFields());

                for (Field field : fields) {
                    Class<?> type = field.getType();
                    if (isQualifiedForInterpolation(field, type)) {
                        boolean isAccessible = field.isAccessible();
                        field.setAccessible(true);
                        try {

                    field.alias
                    if field.alias != field.name
                    else field.name.replace("_", "-")
                )
        value = _get_multidict_value(field, received_params, alias=alias)
        if value is not None:
            params_to_process[field.name] = value
        processed_keys.add(alias or field.alias)
        processed_keys.add(field.name)

          <field-name>source</field-name>
        </requirement>
        <requirement>
          <role>org.codehaus.plexus.PlexusContainer</role>
          <role-hint>default</role-hint>
          <field-name>container</field-name>
        </requirement>
        <requirement>
          <role>org.apache.maven.plugin.LegacySupport</role>
          <role-hint>default</role-hint>
          <field-name>legacySupport</field-name>

        builder.startObject();
        if (sessionId != null) {
            builder.field(SESSION_ID, sessionId);
        }
        if (ruleId != null) {
            builder.field(RULE_ID, ruleId);
        }
        if (url != null) {
            builder.field(URL, url);
        }
        if (parentUrl != null) {
            builder.field(PARENT_URL, parentUrl);
        }
        if (status != null) {

                    final Map<String, Object> fields = searchHit.getSourceAsMap();
                    target.setParentUrl(getFieldValue(fields.get("parentUrl"), String.class));
                    target.setMethod(getFieldValue(fields.get("method"), String.class));
                    target.setMimeType(getFieldValue(fields.get("mimeType"), String.class));
                    target.setSessionId(getFieldValue(fields.get("sessionId"), String.class));

            builder.field(SESSION_ID, sessionId);
        }
        if (method != null) {
            builder.field(METHOD, method);
        }
        if (url != null) {
            builder.field(URL, url);
        }
        if (parentUrl != null) {
            builder.field(PARENT_URL, parentUrl);
        }
        if (depth != null) {
            builder.field(DEPTH, depth);
        }