• Create a composite bundle out of multiple MiniApps and start the react-native local packager to serve this bundle so that it can be loaded within the native host application


ern start


If you do not pass an argument to this command, you are prompted to select a native application version from the Cauldron. The command uses whatever MiniApp versions are curently declared in this native application version container to launch the command.


--descriptor/-d <descriptor>

  • Target a specific native application version, associated to the provided complete native application descriptor.

  • This option uses whatever MiniApp versions are currently declared in this native application version container to launch the command.

--miniapps/-m <miniapps>

  • Specify one or more MiniApps to launch this command

  • The command packages all the provided MiniApps in a composite bundle and starts the react-native packager.

  • You can use any valid Yarn package descriptor for the MiniApps provided to this command, including Git and other file system path schemes.


  • Specify one or more JS API Implementations to include

--watchNodeModules/-w <nodemodules>

  • A list of one or more directory name(s) from node_modules that should be watched for changes.

--extraJsDependencies/-e <jsdependencies>

  • Additional JavaScript dependencies to add to the composite JavaScript bundle.


  • Setting this option will bypass retrieval and installation of the binary from the Binary Store.

  • It can be useful in case you want to use ern start command in conjunction with your own mobile application native binary, build locally on your workstation or retrieved from a specific location.

Platform Specific Options


--packageName/-p <packagename>

  • Android application package name to avoid conflict with the names of classes or interfaces.

--activityName/-a <activity name>

  • Specify Android Activity to launch.

iOS --bundleId/-b

  • iOS Bundle Identifier unique to your app.


  • This command can be used to package multiple MiniApps inside a single composite bundle and automatically start the react-native local packager to serve this bundle.

  • Use this command when you need to launch and develop or debug your MiniApps from within a native host application which contains other MiniApps along with your MiniApp.

  • This command works with the ern link command. For additional information, see the documentation for the ern link command.

[ern link] | Link to a MiniApp directory

[ern link]: ./

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