# 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

          </association>
        </field>
      </fields>
    </class>
    <class>
      <name>Profile</name>
      <version>1.0.0</version>
      <description><![CDATA[
        Modifications to the build process which is keyed on some
        sort of environmental parameter.
      ]]></description>
      <fields>
        <field>
          <name>id</name>
          <required>true</required>

      <description>A plugin parameter expression supported by Maven</description>
      <fields>
        <field>
          <version>1.0.0</version>
          <name>syntax</name>
          <description>The syntax of the expression</description>
          <type>String</type>
          <required>true</required>
        </field>
        <field>
          <version>1.0.0</version>
          <name>description</name>

    # fields but it's the same one, so count them by name
    body_param_names_set = {field.name for field in fields}
    # A top level field has to be a single field, not multiple
    if len(body_param_names_set) > 1:
        return True
    first_field = fields[0]
    # If it explicitly specifies it is embedded, it has to be embedded

            fields will be ignored at serialization time.
            """
        ),
    ] = None,
    convert_underscores: Annotated[
        bool,
        Doc(
            """
            Automatically convert underscores to hyphens in the parameter field name.

            Read more about it in the

                "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 {

	trustDomain string
	SecretMeta
}

// Name sets the name field on a secretItemBuilder
func (s *secretItemBuilder) Name(name string) SecretItemBuilder {
	s.name = name
	return s
}

// Data sets the data field on a secretItemBuilder
func (s *secretItemBuilder) Data(data string) SecretItemBuilder {
	s.data = data
	return s
}

// Source sets the source field on a secretItemBuilder

    fields `username` and `password`.

    All the initialization parameters are extracted from the request.

    The only difference between `OAuth2PasswordRequestFormStrict` and
    `OAuth2PasswordRequestForm` is that `OAuth2PasswordRequestFormStrict` requires the
    client to send the form field `grant_type` with the value `"password"`, which

    extends AggregateFuture<V, C> {
  /*
   * We access this field racily but safely. For discussion of a similar situation, see the comments
   * on the fields of TimeoutFuture. This field is slightly different from the fields discussed
   * there: cancel() never reads this field, only writes to it. That makes the race here completely
   * harmless, rather than just 99.99% harmless.
   */