storybook/docs/api/main-config-core.md

title
core

Parent: main.js|ts configuration

Type:

{
  builder?: string | { name: string; options?: BuilderOptions };
  channelOptions?: ChannelOptions;
  crossOriginIsolated?: boolean;
  disableProjectJson?: boolean;
  disableTelemetry?: boolean;
  disableWebpackDefaults?: boolean;
  disableWhatsNewNotifications?: boolean;
  enableCrashReports?: boolean;
  renderer?: RendererName;
}

Configures Storybook's internal features.

builder

Type:

| '@storybook/builder-vite' | '@storybook/builder-webpack5'
| {
    name: '@storybook/builder-vite' | '@storybook/builder-webpack5';
    options?: BuilderOptions;
  }

Configures Storybook's builder, Vite or Webpack.

💡 With the new Framework API, framework.options.builder is now the preferred way to configure the builder.

You should only use core.builder.options if you need to configure a builder that is not part of a framework.

<CodeSnippets paths={[ 'common/main-config-core-builder.js.mdx', 'common/main-config-core-builder.ts.mdx', ]} />

channelOptions

Type: ChannelOptions

{
  allowClass: boolean;
  allowDate: boolean;
  allowFunction: boolean;
  allowRegExp: boolean;
  allowSymbol: boolean;
  allowUndefined: boolean;
  lazyEval: boolean;
  maxDepth: number;
  space: number | undefined;
}

Configures the channel used by Storybook to communicate between the manager and preview.

Only two properties are likely to be used:

channelOptions.allowFunction

Type: boolean

Default: false

Enables serializing functions across the channel, which can be a security risk.

channelOptions.maxDepth

Type: number

Default: 3

The maximum depth of nested objects to serialize across the channel. Larger values will be slower.

crossOriginIsolated

Type: boolean

Enable CORS headings to run document in a "secure context". See SharedArrayBuffer security requirements

This enables these headers in development-mode:

• Cross-Origin-Opener-Policy: same-origin
• Cross-Origin-Embedder-Policy: require-corp

<CodeSnippets paths={[ 'common/main-config-core-cross-origin-isolated.js.mdx', 'common/main-config-core-cross-origin-isolated.ts.mdx', ]} />

disableProjectJson

Type: boolean

Disables the generation of project.json, a file containing Storybook metadata

<CodeSnippets paths={[ 'common/main-config-core-disable-project-json.js.mdx', 'common/main-config-core-disable-project-json.ts.mdx', ]} />

disableTelemetry

Type: boolean

Disables Storybook's telemetry collection.

<CodeSnippets paths={[ 'common/main-config-core-disable-telemetry.js.mdx', 'common/main-config-core-disable-telemetry.ts.mdx', ]} />

disableWebpackDefaults

Type: boolean

Disables Storybook's default Webpack configuration.

<CodeSnippets paths={[ 'common/main-config-core-disable-webpack-defaults.js.mdx', 'common/main-config-core-disable-webpack-defaults.ts.mdx', ]} />

disableWhatsNewNotifications

Type: boolean

Disables the "What's New" notifications in the UI for new Storybook versions and ecosystem updates (e.g., addons, content, etc.).

<CodeSnippets paths={[ 'common/main-config-core-disable-update-notifications.js.mdx', 'common/main-config-core-disable-update-notifications.ts.mdx', ]} />

enableCrashReports

Type: boolean

Enable crash reports to be sent to Storybook telemetry.

<CodeSnippets paths={[ 'common/main-config-core-enable-crash-reports.js.mdx', 'common/main-config-core-enable-crash-reports.ts.mdx', ]} />

renderer

Type: RendererName