Build high-quality flutter widgets faster.

Monarch is a tool for developing widgets in isolation. It makes building beautiful widgets a more pleasant and faster experience. It is inspired by Storybook.

Monarch allows you to browse a widget library, view the different states of each widget, and interactively develop widgets.


First, you write stories for the widgets you want to test. A story is a function that returns a widget in a specific state. For example, if you have a widget called MyFancyCard that takes in a title, then you could write these two stories:

Widget shortTitle() => MyFancyCard(title: 'A');

Widget standardTitle() => MyFancyCard(title: 'A standard title');

Widget longTitle() => MyFancyCard(title: 'Some long title lorem ipsum dolor sit amet, consectetur adipiscing elit');

Then, you will run Monarch which will generate the code needed to display your stories in the Monarch desktop app. You can now see your stories in isolation, without all of your app's dependencies.

You can see your stories in the Monarch macOS or Windows desktop apps.

This is the beta release of Monarch. We support flutter development on macOS and Windows.


  1. Add monarch and build_runner to your project dev_dependencies:
  monarch: ^0.0.32
  build_runner: ^1.10.3
  1. Run flutter pub get on your project.

  2. Create a build.yaml file at the top level of your project and add the following:

      - $package$
      - lib/**
      - stories/**
  1. Download the Monarch binaries, which include the Monarch CLI and desktop app. Download them into your directory of choice using curl, for example:
In macOS:
$ cd ~/development
$ curl -O
$ unzip

In Windows:
cd development
curl -O
tar -x -f
  1. Add the monarch binaries to your path:
In macOS:
$ export PATH="$PATH:`pwd`/monarch/bin"

In Windows:
set PATH=%PATH%;C:\path\to\monarch\bin

This command sets your PATH variable for the current terminal window only. To permanently add Monarch to your path, see Update your path.

Update your path

Follow these instructions to update your path variable permanently, which will let you run monarch from any terminal window.

In macOS:

  1. Open your rc file, which may be ~/.bash_profile, ~/.bashrc or ~/.zshrc.
  2. Add the following line and change PATH_TO_MONARCH to be the path where you unzipped Monarch:
export PATH="$PATH:[PATH_TO_MONARCH]/monarch/bin"
  1. Run source ~/.<rc file> to refresh the current window, or open a new terminal window to automatically source the file.
  2. Verify that the monarch/bin directory is now in your PATH by running:
$ echo $PATH
  1. Verify that the monarch command is available by running:
$ monarch --version

In Windows:

  1. From the Start search bar, enter ‘env’ and select Edit environment variables for your account.
  2. Under User variables, look for an entry called Path, then append the full path of monarch\bin using ; as a separator from existing values.


Write stories

To write stories just create a stories directory at the top level of your project. Then start adding files that end in *_stories.dart.

You could also add stories inside your lib directory. The only requirement is that story files should end in *_stories.dart.

Stories are functions that return a Widget. Therefore, your stories code doesn't require a dependency to Monarch. Also, since stories are plain functions, they can be re-used from your widget tests.

Run monarch run to see your stories

The monarch run command will prepare your stories so you can use them in the Monarch desktop app. Make sure you run it from inside your project directory.

$ monarch run

You should see Monarch working and eventually opening the Monarch app.

Once the app opens, you should see your stories listed on screen. You can select each story to see how it would render. You can also select different device resolutions, themes and locales.

You can now add more stories. As you add more stories, Monarch will automatically detect the changes and reload the stories in the app.

Monarch will generate a .monarch directory in your project. You can gitignore that directory.

# in .gitignore


Your stories can render using your app's themes. If you want to see themes in Monarch then you need to add the package:monarch_annotations to your dependencies:

  monarch_annotations: ^0.0.12

Then, you can annotate your themes:

import 'package:monarch_annotations/monarch_annotations.dart';

@MonarchTheme('Fancy Theme')
final fancyTheme = ThemeData(...);

When you run the Monarch app, you should be able to select your theme in the Theme dropdown.

Internationalization (or Localizations)

If your application is internationalized (or localized), you can render your stories using the locales you have declared in code.

First, make sure to add the package:monarch_annotations to your dependencies:

  monarch_annotations: ^0.0.12

Then, you can annotate your app-specific localizations delegate:

import 'package:monarch_annotations/monarch_annotations.dart';

class MyLocalizationsDelegate extends LocalizationsDelegate<MyLocalizations> {...}

@MonarchLocalizations([MonarchLocale('en', 'US'), MonarchLocale('es')])
const myLocalizationsDelegate = MyLocalizationsDelegate();

In the example above, the locales en-US and es will display in the Monarch app.

When you run the Monarch app, you should be able to select the locales you want to use from the Locale dropdown.


If you experience any issues while running monarch, you can run it in verbose mode.

$ monarch run -v

If you are running Monarch on Windows, you may experience some stability issues. Flutter desktop on Windows is still in alpha.

Monarch CLI Commands

You can run monarch -h to see usage information.

Upgrade Monarch

To upgrade to the latest version of Monarch just run this command:

$ monarch upgrade