Writing Apps

Not much documentation has been written yet (work in progress!) regarding the exact steps to follow to write apps. However, very good codebases are available for you to learn from.

  • The app-boilerplate is a thoroughly documented app that was specifically designed for developers to play around with and read the code.
  • The app-sia is also a thoroughly documented app written by the community. If you wish to study a fully-fledged app, this is the one for you!

Cloning and Making

Applications that support multiple BOLOS devices are typically contained within a single repository, so you can use the same repository to build an app for different Ledger devices. Just make sure that you’ve set BOLOS_SDK to the appropriate SDK for the device you’re using. The Makefiles used by our apps use the contents of the SDK to determine which device you’re using.

First, download the boilerplate app.

git clone https://github.com/LedgerHQ/ledger-app-boilerplate.git

Now you can let the Makefile do all the work. The load target will build the app if necessary and load it onto your device over USB.

cd ledger-app-boilerplate/
make load

And you’re done! After confirming the installation on your device, you should see an app named “Boilerplate”. The app can be deleted like so:

make delete

Display Management

The doc covered the art of displaying information on screen, go and check it out: Display Management