# Flutter pubspec options > Describes the Flutter-only fields in the pubspec file. This page is primarily aimed at folks who write Flutter apps. If you write packages or plugins, (perhaps you want to create a federated plugin), you should check out the [Developing packages and plugins][] page. ## Overview Every Flutter project includes a `pubspec.yaml` file, often referred to as _the pubspec_. A basic pubspec is generated when you create a new Flutter project. It's located at the top of the project tree and contains metadata about the project that the Dart and Flutter tooling needs to know. The pubspec is written in [YAML][], which is human readable, but be aware that _white space (tabs v spaces) matters_. The pubspec specifies dependencies that the project requires, such as: + Particular packages and their versions + Fonts + Images + Developer packages (like testing or mocking packages) + Particular constraints on the version of the Flutter SDK Fields common to both Dart and Flutter projects are described in [the pubspec file][] on [dart.dev][]. This page lists _Flutter-specific_ fields and packages that are only valid for a Flutter project. [YAML]: https://yaml.org/ [the pubspec file]: https://dart.dev/tools/pub/pubspec [dart.dev]: https://dart.dev ## 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. Here is an example of a Flutter project pubspec file. The Flutter-only fields and packages are highlighted. ```yaml title="pubspec.yaml" name: description: A new Flutter project. publish_to: none version: 1.0.0+1 environment: sdk: ^3.12.0 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 [!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 [!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.png!] [!- images/a_dot_ham.png!] [!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 Flutter-specific and Dart-specific fields can be added to the Flutter pubspec. To learn more about Flutter-specific fields, see the following sections. To learn more about Dart-specific fields, see [Dart's pubspec supported fields][]. :::note The pubspec can have additional auto-generated Flutter fields that are not 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, see the [resolution aware][] section of the [Assets and images][] page. For information on adding assets from package dependencies, see the [asset images in package dependencies][] section in the same page. The `asset` field has this structure: ```yaml title="pubspec.yaml" flutter: assets: - [ path_to_file | path_to_directory ] [ flavor_path_field | platform_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 ``` 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. * `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, see [Set up flavors for iOS and macOS] and [Set up flavors for Android]. * `platforms`: A list of platforms to use with assets at a specific path. Valid values are `android`, `ios`, `web`, `linux`, `macos`, and `windows`. 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 ``` [Set up flavors for iOS and macOS]: /deployment/flavors-ios [Set up flavors for Android]: /deployment/flavors [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 Assign a default Flutter flavor for an app. When used, you don't need to include the name of this flavor in 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, see [Set up Flutter flavors for Android][] and [Set up Flutter flavors for iOS and macOS][]. [Set up Flutter flavors for Android]: /deployment/flavors [Set up Flutter flavors for iOS and macOS]: /deployment/flavors-ios ### deferred-components field Defer initial the 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 this 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 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 see the [Use a custom font][] and [Export fonts from a package][] recipes in the Flutter cookbook. The `fonts` field has this 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 Handles localization tasks. This field can appear as a subfield of `flutter` and `material`. Enable general localization: ```yaml title="pubspec.yaml" flutter: generate: true ``` ### 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 this structure: ```yaml title="pubspec.yaml" flutter: licenses: - [path_to_file] ``` ### plugin field Configure settings specifically for Flutter plugins. The `plugin` field has this 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 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 has this structure: ```yaml title="pubspec.yaml" flutter: shaders: - { path_to_file | path_to_directory } [...] ``` ```yaml # path_to_file structure - assets/shaders/file ``` ```yaml # path_to_directory structure - assets/shaders/ ``` Add specific shaders: ```yaml title="pubspec.yaml" flutter: shaders: - assets/shaders/shader_a.frag - assets/shaders/shader_b.frag ``` Add a directory of shaders: ```yaml title="pubspec.yaml" flutter: shaders: - assets/shaders/ ``` Alternatively, you can add your shader directory to the `assets` field: ```yaml title="pubspec.yaml" flutter: assets: - assets/shaders/my_shader.frag ``` ### uses-material-design field Use Material Design components 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 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 A package that represents the Flutter SDK itself and can be added to the `dependencies` field. Use this to enable the localization of `ARB` files. Often used with the `intl` package. ```yaml title="pubspec.yaml" dependencies: flutter_localizations: sdk: flutter intl: any ``` ### flutter_test package A package that represents the Flutter SDK itself and can be added to the `dependencies` field. Use this if you have unit, widget, or integration tests for your Flutter app. ```yaml title="pubspec.yaml" dependencies: flutter_test: sdk: flutter ``` ### flutter_lints package A package that that provides a set of recommended lints for Flutter projects. This package can be added to the `dev_dependency` field in the pubspec. ```yaml title="pubspec.yaml" dev_dependencies: flutter_lints: ^6.0.0 ``` ### 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 `dependency` field in the pubspec. ```yaml title="pubspec.yaml" dependencies: cupertino_icons: ^1.0.0 ``` ## More information For more information on packages, plugins, and pubspec files, see the following: * [Creating packages][] on dart.dev * [Glossary of package terms][] on dart.dev * [Package dependencies][] on dart.dev * [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