Some of you may not know that NAV has an API, but it has!
The reason for adding an API to NAV was to enable local developers to use the considerable knowledge NAV has about your network to make useful tools - first of all for local use, but also for sharing.
As with everything NAV related we are dependent on feedback and patches from our users to make things better. The API is no exception, and we have already gotten pointers about things that can be improved. Take a look at the community channels for how to contact us and contribute.