# yii

> 1 class of the yii namespace.

[API reference](/docs/api/index.md) › yii

## Namespaces

| Namespace | Types |
| --- | --- |
| [`yii\base`](/docs/api/yii/base/index.md) | 48 |
| [`yii\behaviors`](/docs/api/yii/behaviors/index.md) | 8 |
| [`yii\caching`](/docs/api/yii/caching/index.md) | 18 |
| [`yii\captcha`](/docs/api/yii/captcha/index.md) | 4 |
| [`yii\console`](/docs/api/yii/console/index.md) | 18 |
| [`yii\data`](/docs/api/yii/data/index.md) | 9 |
| [`yii\db`](/docs/api/yii/db/index.md) | 110 |
| [`yii\di`](/docs/api/yii/di/index.md) | 4 |
| [`yii\filters`](/docs/api/yii/filters/index.md) | 18 |
| [`yii\grid`](/docs/api/yii/grid/index.md) | 8 |
| [`yii\helpers`](/docs/api/yii/helpers/index.md) | 28 |
| [`yii\i18n`](/docs/api/yii/i18n/index.md) | 12 |
| [`yii\log`](/docs/api/yii/log/index.md) | 11 |
| [`yii\mail`](/docs/api/yii/mail/index.md) | 5 |
| [`yii\mutex`](/docs/api/yii/mutex/index.md) | 7 |
| [`yii\rbac`](/docs/api/yii/rbac/index.md) | 10 |
| [`yii\rest`](/docs/api/yii/rest/index.md) | 11 |
| [`yii\test`](/docs/api/yii/test/index.md) | 8 |
| [`yii\validators`](/docs/api/yii/validators/index.md) | 25 |
| [`yii\web`](/docs/api/yii/web/index.md) | 62 |
| [`yii\widgets`](/docs/api/yii/widgets/index.md) | 19 |

## Classes

| Class | Summary |
| --- | --- |
| [`BaseYii`](/docs/api/yii/baseyii/index.md) | BaseYii is the core helper class for the Yii framework. |