Highwire offers 2 APIs that you can leverage to build custom apps and build stunning custom themes:
HTML API
The Highwire Flexibile HTML API allows you to fully customize your store using a simple templating engine.
Changing your theme’s code requires a decent understanding of HTML, CSS, and JavaScript.
REST API
Perfect for allowing developers to connect your Highwire store to
write custom plug-ins or larger third-party application.
Coming Soon!