# Story parameter reference

Control capture for an individual story, component, or preview.

## Where parameters go
Set defaults in `.storybook/preview.ts`, component-level parameters on the story file's default export, and specific overrides on an exported story. Storybook's parameter inheritance applies.

```ts
export const Loading = {
  parameters: {
    framecheck: {
      viewport: { width: 390, height: 844 },
      delay: 300,
      region: 'viewport',
    },
  },
};
```

## Supported Framecheck parameters
| Parameter | Value | Purpose |
| --- | --- | --- |
| `skip` | Boolean | Exclude the story from capture. |
| `delay` | Integer, 0–30000 | Additional wait in milliseconds. |
| `viewport` | `{ width, height }` | Explicit capture viewport. |
| `globals` | Object | Storybook globals to apply. |
| `region` | `fullPage`, `viewport`, or `{ selector }` | What area to capture. |
| `modes` | Named objects | Variants with globals, viewport, or `disable`. |
| `ignoreSelectors` | Array of CSS selectors | Mask changing regions. |
| `dom` | Boolean | Whether to record page structure for this story. |

## Capture one element
```ts
export const Card = {
  parameters: {
    framecheck: { region: { selector: '[data-testid="profile-card"]' } },
  },
};
```

The element must exist when capture runs. Use a stable selector and read diagnostics if it cannot be found. Changing the region changes the image being approved.

## Skip a story
```ts
export const NativeOnly = {
  parameters: { framecheck: { skip: true } },
};
```

Excluded stories are not counted as captured snapshots. Use exclusion intentionally: it removes visual coverage for that story.

## Accessibility parameters
`parameters.a11y.disable: true` or `parameters.a11y.test: 'off'` skips that story's accessibility scan. It is reported as skipped, not passed. Other Storybook a11y settings are not automatically applied; use the project's accessibility settings for supported rule configuration.

## Chromatic compatibility
Framecheck recognises `chromatic.disableSnapshot`, `chromatic.delay`, `chromatic.modes`, and `chromatic.ignoreSelectors`. Corresponding explicit Framecheck settings take precedence. Unsupported parameters produce warnings; do not assume all provider-specific configuration is portable.

See [migration from Chromatic](/migrate-chromatic/) before relying on existing configuration.