}
```

Again, doing just that declaration, with **FastAPI** you get:

* Editor support (completion, etc.), even for nested models
* Data conversion
* Data validation
* Automatic documentation

## Special types and validation { #special-types-and-validation }

Apart from normal singular types like `str`, `int`, `float`, etc. you can use more complex singular types that inherit from `str`.

-type")||"image";if(!f)throw new Error("Google reCaptcha site key is required.");var j=grecaptcha.render(e,{sitekey:f,theme:g,size:h,type:i,callback:function(a){b.find('[data-validation~="recaptcha"]').trigger("validation",a&&""!==a)},"expired-callback":function(){b.find('[data-validation~="recaptcha"]').trigger("validation",!1)}});d.valAttr("recaptcha-widget-id",j).hide().on("beforeValidation",function(a){a.stopImmediatePropagation()}).parent().append(e)})})},a(b).on("validatorsLoaded formValid...

 * governing permissions and limitations under the License.
 */
package org.codelibs.fess.app.web.admin.dataconfig;

import org.lastaflute.web.validation.Required;
import org.lastaflute.web.validation.theme.conversion.ValidateTypeFailure;

import jakarta.validation.constraints.Size;

/**
 * Form class for editing data crawling configurations in the admin interface.

 * governing permissions and limitations under the License.
 */
package org.codelibs.fess.app.web.admin.group;

import org.lastaflute.web.validation.Required;
import org.lastaflute.web.validation.theme.conversion.ValidateTypeFailure;

import jakarta.validation.constraints.Size;

/**
 * Form class for editing user groups in the admin interface.

 * governing permissions and limitations under the License.
 */
package org.codelibs.fess.app.web.admin.pathmap;

import org.lastaflute.web.validation.Required;
import org.lastaflute.web.validation.theme.conversion.ValidateTypeFailure;

import jakarta.validation.constraints.Size;

/**
 * Form class for editing path mapping configurations in the admin interface.

 * governing permissions and limitations under the License.
 */
package org.codelibs.fess.app.web.admin.relatedcontent;

import org.lastaflute.web.validation.Required;
import org.lastaflute.web.validation.theme.conversion.ValidateTypeFailure;

import jakarta.validation.constraints.Size;

/**
 * Form class for editing related content configurations in the admin interface.

 * governing permissions and limitations under the License.
 */
package org.codelibs.fess.app.web.admin.webauth;

import org.lastaflute.web.validation.Required;
import org.lastaflute.web.validation.theme.conversion.ValidateTypeFailure;

import jakarta.validation.constraints.Size;

/**
 * Form class for editing web authentication configurations in the admin interface.

import org.lastaflute.web.validation.ActionValidator;
import org.lastaflute.web.validation.LaValidatable;
import org.lastaflute.web.validation.VaMessenger;

import jakarta.annotation.Resource;

/**
 * The base action class for Fess web application.
 * This abstract class provides common functionality for all Fess web actions,
 * including user authentication, validation, message handling, and access context management.

# 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

## Rajouter plus de validation

Vous pouvez aussi rajouter un second paramètre `min_length` :

{* ../../docs_src/query_params_str_validations/tutorial003.py hl[9] *}

## Ajouter des validations par expressions régulières