IDEs for Dart in Fuchsia

Dart SDK

A prebuilt Dart SDK is available for IDE consumption at: prebuilt/third_party/dart/{linux|mac|windows}-x64/bin/dart.

Visual Studio Code

  1. Download and install Visual Studio Code

  2. (Optional) Setup VS Code to launch from the command line

    • For macOS: To allow running VS Code from the terminal using the code command, see Launching from the command line.

    • For Linux and Windows: This should already be done as part of the installation

  3. Install the following extensions:

    • Dart Code: Support for programming in Dart. It should automatically find the dart-sdk in the Fuchsia tree.
    • FIDL language support: Syntax highlighting support for Fuchsia's FIDL files
    • GN: Syntax highlighting for GN build files
    • Optional but helpful git extensions:
  4. To improve your productivity for Dart in VS Code, you can set some useful settings.

    To add the settings:

    1. Open your user settings (Ctrl+,)
    2. Click the rotating page icon in the top left (or right for macOS) corner
    3. Add:

Note: This configuration file is a JSON file. Make sure that you properly use curly braces.

  • Auto-format your files when you save:
"editor.formatOnSave": true,
  • Check for new SDK updates for Fuchsia:
"dart.checkForSdkUpdates": false,
  • Configure VS Code to use the bundled Dart SDK
"dart.sdkPath": "/path/to/fuchsia/prebuilt/third_party/dart/linux-x64/bin/dart",

Note: For macOS, replace linux-x64 with mac-x64 in your supplied value for dart.sdkPath.

  • Don't run pub with fuchsia.
"dart.runPubGetOnPubspecChanges": false,
  • Configure an 80 character ruler and a tab size of two spaces
"[dart]": {
  "editor.rulers": [80],
  "editor.tabSize": 2


  • Add the Dart plugin by going to Settings > Plugins then searching for Dart language support.
  • Set the Dart path in Settings > Languages & Frameworks > Dart by
    • Check Enable Dart support for the project .
    • Enter the Dart SDK path “${FUCHSIA_SRC}/third_party/dart/tools/sdks/dart-sdk”


If you find that the IDE is unable to find imports (red squigglies) that are already correctly in your dependencies, this is usually a sign that Dart analysis is not working properly in your IDE.

When this happens, try the following:

Open only the project directory you are working on

E.g. only open /topaz/shell/ermine instead of /topaz. The analyzer can have issues with really large source trees.

Remove pub output

  1. Delete the .packages and pubspec.lock files in your project (if present).
  2. Ensure that "dart.runPubGetOnPubspecChanges": false, is present in your VS Code preferences to prevent the files from reappearing whenever a pubspec.yaml file is edited.
  3. Reload VS Code to restart the Dart analyzer.
    1. Press Ctrl+Shift+P to open the VS Code Command Palette
    2. Select “Reload Window”


Delete /out from your Fuchsia directory and rebuild. Dart FIDL bindings are build-generated and may be absent.

Ensure that your build contains all packages

Any Dart code from packages not included in your build will not be available to the analyzer, so ensure your build configuration (fx set) includes all the packages you need (the --with flag can be helpful.)

For example, to view the echo_client_async example Dart code in VS Code, add --with examples/fidl/dart/echo_client_async_dart to your fx set command. Then, rebuild with fx build examples/fidl/dart/echo_client_async_dart.

Reload the Dart Analyzer

Manually reloading the analyzer is often needed after modifying FIDLs.

VS Code

  1. Open the Command Palette (Ctrl+Shift+P)
  2. Enter and select “Reload Window”

This also restarts the Dart analyzer.


  1. Open Find Action (Ctrl+Shift+A)
  2. Enter and select “Restart Dart Analysis Server”

Check that the correct language has been detected for the current file type

  1. On VS Code use Ctrl+Shift+P then type “Change Language Mode” and ensure it is set to “Auto Detect”.
  2. If this doesn't fix the issue you can try to manually fix via Ctrl+Shift+P and “Configure file association for .dart”

Manually specifying the Dart sdk path

VS Code

See the recommended VS Code options above.


  1. Open Settings
  2. Under Languages & Frameworks > Dart, enter “[YOUR FUCHSIA DIR LOCATION]/prebuilt/third_party/dart/{mac,linux}-x64”