# Debug API reference

> API reference of the Debug extension (yii\debug), generated from its PHPDoc.

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

Classes, interfaces, traits and enums of `yii\debug`, generated from the PHPDoc of [yii2-extensions/debug](https://github.com/yii2-extensions/debug) at `main`. Machine-readable catalog: [debug.json](https://yii2-framework.github.io/docs/reference/debug.json).

## Namespaces

| Namespace | Types |
| --- | --- |
| [`yii\debug\actions`](/docs/extensions/debug/reference/actions/index.md) | 12 |
| [`yii\debug\collectors`](/docs/extensions/debug/reference/collectors/index.md) | 13 |
| [`yii\debug\db`](/docs/extensions/debug/reference/db/index.md) | 1 |
| [`yii\debug\exception`](/docs/extensions/debug/reference/exception/index.md) | 1 |
| [`yii\debug\models`](/docs/extensions/debug/reference/models/index.md) | 12 |
| [`yii\debug\panels`](/docs/extensions/debug/reference/panels/index.md) | 17 |
| [`yii\debug\routing`](/docs/extensions/debug/reference/routing/index.md) | 1 |
| [`yii\debug\service`](/docs/extensions/debug/reference/service/index.md) | 12 |
| [`yii\debug\storage`](/docs/extensions/debug/reference/storage/index.md) | 2 |
| [`yii\debug\view`](/docs/extensions/debug/reference/view/index.md) | 1 |
| [`yii\debug\widgets`](/docs/extensions/debug/reference/widgets/index.md) | 7 |

## Classes

| Class | Summary |
| --- | --- |
| [`ComponentResolver`](/docs/extensions/debug/reference/componentresolver/index.md) final | Normalizes Yii component configuration values into a resolvable type and its remaining properties. |
| [`DebugAsset`](/docs/extensions/debug/reference/debugasset/index.md) | Asset bundle for the debugger pages: the main CSS theme, the panel interactivity, the dark/light theme toggle, and the history-page cursor handling. |
| [`DebugResponseHeaders`](/docs/extensions/debug/reference/debugresponseheaders/index.md) final | Applies defense-in-depth headers to debugger responses without preventing the same-origin toolbar iframe. |
| [`GridViewConfig`](/docs/extensions/debug/reference/gridviewconfig/index.md) final | Shared default configuration for GridView widgets rendered inside the debug panel UI. |
| [`IpAllowlist`](/docs/extensions/debug/reference/ipallowlist/index.md) final readonly | Matches a requesting IP against the debugger's allowed IP filters and host allowlist. |
| [`LogTarget`](/docs/extensions/debug/reference/logtarget/index.md) | Per-request JSON snapshot collector consumed by the debug toolbar. |
| [`Module`](/docs/extensions/debug/reference/module/index.md) | Bootstraps the debug toolbar and the full-page debugger over the active application. |
| [`Panel`](/docs/extensions/debug/reference/panel/index.md) | Base class for debug toolbar panels. |
| [`ToolbarAsset`](/docs/extensions/debug/reference/toolbarasset/index.md) final | Defines the Yii2 asset bundle for the shared toolbar runtime. |
| [`ToolbarDataMapper`](/docs/extensions/debug/reference/toolbardatamapper/index.md) final readonly | Maps Yii2 panel envelopes to the shared typed toolbar contract. |
| [`ToolbarRenderer`](/docs/extensions/debug/reference/toolbarrenderer/index.md) final readonly | Renders shared toolbar views and resolves their assets through Yii2. |
| [`VersionResolver`](/docs/extensions/debug/reference/versionresolver/index.md) final | Resolves human-readable Composer package versions for the debug UI. |