# Flutter pubspec options > Describes the Flutter-only fields in the pubspec file. Every project written in the Dart language, including all Flutter apps and libraries, includes a `pubspec.yaml` file, referred to as _the pubspec_. Creating a new project generates a basic pubspec at the top of the project tree that contains metadata and lists project dependencies. **Fields common to both Dart and Flutter projects are described in [The pubspec file][pubspec] on dart.dev.** This page lists fields that are only valid for a Flutter project. [Package dependency management]: /packages-and-plugins/dependency-management [pubspec]: https://dart.dev/tools/pub/pubspec ## Example When you create a new project with the `flutter create` command (or by using the equivalent button in your IDE), it creates a pubspec for a basic Flutter app. The first time you build your project, it also creates a `pubspec.lock` file that contains specific versions of the included packages. This ensures that you get the same version the next time the project is built. To learn more about how Flutter and Dart resolve package dependencies, check out [Package dependency management][]. The following example of a pubspec file highlights fields used only in a Flutter app. Learn more about the non-highlighted fields on [dart.dev][pubspec]. ```yaml title="pubspec.yaml" name: description: A new Flutter project. publish_to: 'none' # Remove this line if you wish to publish to pub.dev version: 1.0.0+1 environment: sdk: ^3.13.0 dependencies: [!flutter:!] # Required for every Flutter project [!sdk: flutter!] # Required for every Flutter project [!flutter_localizations:!] # Required to enable localization [!sdk: flutter!] # Required to enable localization [!material_ui!] # Required for projects that use the Material components pkg [!cupertino_ui!] # Required for projects that use the Cupertino components pkg [!cupertino_icons: ^1.0.8!] # Only required if you use Cupertino (iOS style) icons dev_dependencies: [!flutter_test:!] [!sdk: flutter!] # Required for a Flutter project that includes tests [!integration_test:!] [!sdk: flutter!] # Required for integration tests [!flutter_lints: ^6.0.0!] # Contains a set of recommended lints for Flutter code [!flutter:!] [!uses-material-design: true!] # Required if you use the Material icon font [!generate: true!] # Enables generation of localized strings from arb files [!config:!] # App-specific configuration flags that mirror `flutter config` [!enable-swift-package-manager: true!] [!assets:!] # Lists assets, such as image files [!- images/a_dot_burr.jpeg!] [!- images/a_dot_ham.jpeg!] [!licenses:!] # Lists additional license files to be bundled with the app [!- assets/my_license.txt!] [!fonts:!] # Required if your app uses custom fonts [!- family: Schyler!] [!fonts:!] [!- asset: fonts/Schyler-Regular.ttf!] [!- asset: fonts/Schyler-Italic.ttf!] [!style: italic!] [!- family: Trajan Pro!] [!fonts:!] [!- asset: fonts/TrajanPro.ttf!] [!- asset: fonts/TrajanPro_Bold.ttf!] [!weight: 700!] ``` ## Fields This page discusses Flutter-only pubspec fields. Learn more about general Dart fields in [Dart's pubspec supported fields][]. :::note The pubspec can have additional auto-generated Flutter fields that aren't listed here. ::: [Dart's pubspec supported fields]: https://dart.dev/tools/pub/pubspec#supported-fields ### assets field {: #assets } A list of asset paths that your app uses. These assets are bundled with your application. Common types of assets include static data (for example, `JSON`), configuration files, icons, and images (`JPEG`, `WebP`, `GIF`, animated `WebP/GIF`, `PNG`, `BMP`, and `WBMP`). Besides listing the images that are included in the app package, an image asset can also refer to one or more resolution-specific "variants". For more information, visit the [resolution aware][] section of the [Assets and images][] page. For information on adding assets from package dependencies, visit the [asset images in package dependencies][] section in the same page. The `assets` field has the following structure: ```yaml title="pubspec.yaml" flutter: assets: - [ path_to_file | path_to_directory ] [ flavor_path_field | platform_path_field | transformer_path_field ] [...] ``` ```yaml # path_to_file structure - path/to/directory/file ``` ```yaml # path_to_directory structure - path/to/directory/ ``` ```yaml # flavor_path_field structure - path: path/to/directory flavors: - flavor_name ``` ```yaml # platform_path_field structure - path: path/to/file platforms: - platform_name ``` ```yaml # transformer_path_field structure - path: path/to/file transformers: - package: transformer_package_name args: ['arg1', 'arg2'] # Optional ``` Subfields of `assets`: * `path_to_file`: A string that represents the path to a file. * `path_to_directory`: A string that represents the path to a directory. * `flavor_path_field`: A path field and its flavor subfields. * `platform_path_field`: A path field and its platform subfields. * `transformer_path_field`: A path field and its transformer subfields. * `path`: The path to an asset file or directory. * `flavors`: A list of flutter flavors to use with assets at a specific path. To learn more about flavors, consult the guides on setting up flavors for [Android][], [iOS and macOS][], [Linux][], and [Windows][]. * `platforms`: A list of platforms to use with assets at a specific path. Valid values are `android`, `ios`, `web`, `linux`, `macos`, and `windows`. * `transformers`: A list of transformer packages to run on the asset at build time. To learn more, see [Transforming assets at build time][]. You can pass in a path to a file: ```yaml title="pubspec.yaml" flutter: assets: - assets/images/my_image_a.png - assets/images/my_image_b.png ``` You can pass in a path to a directory: ```yaml title="pubspec.yaml" flutter: assets: - assets/images/ - assets/icons/ ``` You can pass in a path to a directory for specific flavors: ```yaml title="pubspec.yaml" flutter: assets: - path: assets/flavor_a_and_b/images flavors: - flavor_a - flavor_b - path: assets/flavor_c/images flavors: - flavor_c ``` You can pass in a path to a file for specific platforms: ```yaml title="pubspec.yaml" flutter: assets: - path: assets/web_worker.js platforms: - web - path: assets/desktop_icon.png platforms: - windows - linux - macos ``` You can configure build-time asset transformers: ```yaml title="pubspec.yaml" flutter: assets: - path: assets/logo.svg transformers: - package: vector_graphics_compiler args: ['--tessellate'] ``` [Android]: /deployment/flavors [iOS and macOS]: /deployment/flavors-ios [Linux]: /deployment/flavors-linux [Windows]: /deployment/flavors-windows [Transforming assets at build time]: /ui/assets/asset-transformation [Assets and images]: /ui/assets/assets-and-images [asset images in package dependencies]: /ui/assets/assets-and-images#from-packages [resolution aware]: /ui/assets/assets-and-images#resolution-aware ### config field {: #config } A map of keys to flags (`true` or `false`) that influences how the `flutter` CLI is executed. The available keys mirror those available in `flutter config --list`. ```yaml title="pubspec.yaml" flutter: config: cli-animations: false ``` Use `flutter config --help` for a description of each flag. Flags are only read from the current _application_ package, and have no effect in the context of a package or dependency. #### enable-swift-package-manager field {: #enable-swift-package-manager } Control whether Flutter uses Swift Package Manager to manage native iOS and macOS dependencies for this project. To disable it for this project, set the field to `false`. ```yaml title="pubspec.yaml" flutter: config: enable-swift-package-manager: false ``` :::version-note In Flutter versions earlier than 3.44, Swift Package Manager isn't enabled by default. Support for disabling Swift Package Manager will be removed in a future Flutter release. To get started with Swift Package Manager, check out [Swift Package Manager for app developers][] or [Swift Package Manager for plugin authors][]. ::: [Swift Package Manager for app developers]: /packages-and-plugins/swift-package-manager/for-app-developers [Swift Package Manager for plugin authors]: /packages-and-plugins/swift-package-manager/for-plugin-authors ### default-flavor field {: #default-flavor } Assign a default Flutter flavor for an app. When used, you don't need to include the name of this flavor in the Flutter launch command. ```yaml title="pubspec.yaml" flutter: default-flavor: flavor_name ``` In the following example, an Android Flutter app has a flavor called `staging` and `production`. The `production` flavor is the default flavor. When that flavor is run, you don't need to include it in the launch command. ```yaml title="pubspec.yaml" flutter: default-flavor: production ``` ```console title="console" # Use this command to run the default flavor (production). $ flutter run # Use this command to run non-default flavors (staging). $ flutter run --flavor staging ``` To learn how to create Flutter flavors, consult the guides on setting up flavors for [Android][], [iOS and macOS][], [Linux][], and [Windows][]. ### deferred-components field {: #deferred-components } Defer downloading components to reduce the initial download size of an Android app. Most often used with large applications, modularized applications, and applications with on-demand features. The `deferred-components` field has the following structure: ```yaml title="pubspec.yaml" flutter: deferred-components: - name: component_name libraries: - string_expression [...] assets: - string_expression [...] [...] ``` Deferred component subfields: * `name`: The unique identifier for a specific deferred component. * `libraries`: A list of Dart libraries that are part of the deferred component. * `assets`: A list of asset paths that are associated with the deferred component. Example: ```yaml title="pubspec.yaml" flutter: deferred-components: - name: box_component libraries: - package:testdeferredcomponents/box.dart - name: gallery_feature libraries: - package:testdeferredcomponents/gallery_feature.dart assets: - assets/gallery_images/gallery_feature.png ``` To learn more about how you can use deferred components with a Flutter Android app, see [Deferred components for Android]. [Deferred components for Android]: /perf/deferred-components ### flutter field {: #flutter } A field that contains Flutter-specific settings for your app. ```yaml title="pubspec.yaml" flutter: [flutter_field] [...] ``` ### fonts field {: #fonts } Configure and include custom fonts in your Flutter application. For examples of using fonts visit the [Use a custom font][] and [Export fonts from a package][] recipes in the Flutter cookbook. The `fonts` field has the following structure: ```yaml title="pubspec.yaml" flutter: fonts: - { font_family_field | font_asset_field } [...] ``` ```yaml # font_family_field structure - family: font_name fonts: - font_asset_field [...] ``` ```yaml # font_asset_field structure - asset: path/to/directory/font_name weight: int_expression # Optional style: string_expression # Optional ``` Subfields of `fonts`: + `family`: Optional. The font family name. Can have multiple font assets. + `asset`: The font to use. + `weight`: Optional. The weight of the font. This can be `100`, `200`, `300`, `400`, `500`, `600`, `700`, `800` or `900`. + `style`: Optional. The style of the font. This can be `italic`. Use a font that is not part of a font family: ```yaml title="pubspec.yaml" flutter: fonts: - asset: fonts/Roboto-Regular.ttf weight: 900 # Optional style: italic # Optional ``` Use a font family: ```yaml title="pubspec.yaml" flutter: fonts: - family: Roboto # Optional fonts: - asset: fonts/Roboto-Regular.ttf - asset: fonts/Roboto-Bold.ttf weight: 700 # Optional style: italic # Optional ``` Alternatively, if you have a font that requires no family, weight or style requirements, you can declare it as a simple asset: ```yaml title="pubspec.yaml" flutter: assets: - fonts/Roboto-Regular.ttf ``` [Export fonts from a package]: /cookbook/design/package-fonts [Use a custom font]: /cookbook/design/fonts ### generate field {: #generate } Enables generation of Dart files with localized strings from `.arb` files. Enable general localization: ```yaml title="pubspec.yaml" flutter: generate: true ``` To learn more, visit [Internationalizing Flutter apps][]. [Internationalizing Flutter apps]: /ui/accessibility-and-internationalization/internationalization ### licenses field {: #licenses } A list of additional license file paths that should be bundled with your application. These files are typically found within your project's `assets` directory. The `licenses` field has the following structure: ```yaml title="pubspec.yaml" flutter: licenses: - [path_to_file] ``` ### module field {: #module } Configure settings for a Flutter module project when adding Flutter to an existing host Android or iOS application (Add-to-App). The `module` field has the following structure: ```yaml title="pubspec.yaml" flutter: module: androidPackage: com.example.my_module # Optional iosBundleIdentifier: com.example.myModule # Optional ``` Subfields of `module`: * `androidX`: Optional. Specifies whether the module uses AndroidX. * `androidPackage`: Optional. The package name used for generated Android code. * `iosBundleIdentifier`: Optional. The bundle identifier used for generated iOS code. To learn more, visit [Add Flutter to existing apps][]. [Add Flutter to existing apps]: /add-to-app ### plugin field {: #plugin } Configure settings specifically for Flutter plugins. The `plugin` field has the following structure: ```yaml title="pubspec.yaml" flutter: plugin: platforms: android: # Optional package: com.example.my_plugin pluginClass: MyPlugin dartPluginClass: MyPluginClassName ffiPlugin: true default_package: my_plugin_name fileName: my_file.dart ios: # Optional pluginClass: MyPlugin dartPluginClass: MyPluginClassName ffiPlugin: true default_package: my_plugin_name fileName: my_file.dart sharedDarwinSource: true macos: # Optional pluginClass: MyPlugin dartPluginClass: MyPluginClassName ffiPlugin: true default_package: my_plugin_name fileName: my_file.dart sharedDarwinSource: true windows: # Optional pluginClass: MyPlugin dartPluginClass: MyPluginClassName ffiPlugin: true default_package: my_plugin_name fileName: my_file.dart linux: # Optional pluginClass: MyPlugin dartPluginClass: MyPluginClassName ffiPlugin: true default_package: my_plugin_name fileName: my_file.dart web: # Optional ffiPlugin: true default_package: my_plugin_name fileName: my_file.dart implements: # Optional - example_platform_interface ``` Subfields of `plugin`: * `platforms`: A list of platforms that will have configuration settings. * `package`: The Android package name of the plugin. This can be used with the Android platform and is required. * `pluginClass`: The name of the plugin class. Optional if `dartPluginClass` is used for the same platform. This can be used with the Android, iOS, Linux macOS, and Windows platforms. * `default_package`: Optional. The package that should be used as the default implementation of a platform interface. Only applicable to federated plugins, where the plugin's implementation is split into multiple platform-specific packages. * `dartPluginClass`: Optional. The Dart class that serves as the entry point for a Flutter plugin. This can be used with the Android, iOS, Linux macOS, and Windows platforms. * `sharedDarwinSource`: Optional. Indicates that the plugin shares native code between iOS and macOS. This can be used with the iOS and macOS platforms. * `fileName`: Optional. The file that contains the plugin class. * `ffiPlugin`: Optional. True if the plugin uses a Foreign Function Interface (FFI). * `implements`: Optional. The platform interfaces that a Flutter plugin implements. To learn more about plugins, see [Developing packages & plugins][]. [Developing packages & plugins]: /packages-and-plugins/developing-packages ### shaders field {: #shaders } GLSL shaders with the `.frag` extension must be declared in the `shaders` section of your project's `pubspec.yaml` file. The Flutter command-line tool compiles the shader to its appropriate backend format and generates its necessary runtime metadata. The compiled shader is then included in the application just like an asset. The `shaders` field accepts a list of individual file paths; directory paths aren't supported. The field has the following structure: ```yaml title="pubspec.yaml" flutter: shaders: - [path_to_file] [...] ``` For example, to add specific shaders to your project: ```yaml title="pubspec.yaml" flutter: shaders: - assets/shaders/shader_a.frag - assets/shaders/shader_b.frag ``` Don't list shader files under the `assets` field, either directly or through a directory that contains them. The Flutter tool reports an error if a shader is declared in both places. Like other assets, shaders also support `flavors`, `platforms`, and `transformers`. To learn more about using shaders in Flutter, check out [Writing and using fragment shaders][]. [Writing and using fragment shaders]: /ui/design/graphics/fragment-shaders ### uses-material-design field {: #uses-material-design } Use Material Design components and icon font in your Flutter app. ```yaml title="pubspec.yaml" flutter: uses-material-design: true ``` ## Packages The following Flutter-specific packages can be added to the pubspec. If you add a package, run `flutter pub get` in your terminal to install the package. ### flutter package {: #flutter-package } A package that represents the Flutter SDK itself and can be added to the `dependencies` field. Use this if your project relies on the Flutter SDK, not a regular package from pub.dev. ```yaml title="pubspec.yaml" dependencies: flutter: sdk: flutter ``` ### flutter_localizations package {: #flutter-localizations } A package provided by the Flutter SDK that enables localization of `ARB` files. Often used with the `intl` package. ```yaml title="pubspec.yaml" dependencies: flutter_localizations: sdk: flutter intl: any ``` ### flutter_test package {: #flutter_test } A package provided by the Flutter SDK that contains testing utilities for unit and widget tests for your Flutter app. ```yaml title="pubspec.yaml" dev_dependencies: flutter_test: sdk: flutter ``` ### integration_test package {: #integration_test } A package provided by the Flutter SDK for running integration tests on target devices or emulators. ```yaml title="pubspec.yaml" dev_dependencies: integration_test: sdk: flutter ``` To learn more, visit [Integration testing][]. [Integration testing]: /testing/integration-tests ### flutter_lints package {: #flutter_lints } A package that provides a set of recommended lints for Flutter projects. This package can be added to the `dev_dependencies` field in the pubspec. ```yaml title="pubspec.yaml" dev_dependencies: flutter_lints: ^6.0.0 ``` ### cupertino_icons package {: #cupertino_icons } A package that provides a set of Apple's Cupertino icons for use in Flutter applications. This package can be added to the `dependencies` field in the pubspec. ```yaml title="pubspec.yaml" dependencies: cupertino_icons: ^1.0.8 ``` ## More information For more information on packages, plugins, and pubspec files, visit the following: * [Add Flutter to existing apps][] * [Creating packages][] on dart.dev * [Glossary of package terms][] on dart.dev * [Integration testing][] * [Package dependency management][] * [Package dependencies][] on dart.dev * [Set up Flutter flavors for Android][Android] * [Set up Flutter flavors for iOS and macOS][iOS and macOS] * [Set up Flutter flavors for Linux][Linux] * [Set up Flutter flavors for Windows][Windows] * [Transforming assets at build time][] * [Using packages][] * [What not to commit][] on dart.dev [Creating packages]: https://dart.dev/guides/libraries/create-library-packages [Developing packages and plugins]: /packages-and-plugins/developing-packages [Federated plugins]: /packages-and-plugins/developing-packages#federated-plugins [Glossary of package terms]: https://dart.dev/tools/pub/glossary [Package dependencies]: https://dart.dev/tools/pub/dependencies [Using packages]: /packages-and-plugins/using-packages [What not to commit]: https://dart.dev/guides/libraries/private-files#pubspeclock