Tower features a browseable API feature.
You can visit the API in a browser at: http://<Tower server name>/api
Clicking on various links in the API allows you to explore related resources.
Clicking on the next to the page name (toward the top of the screen) for an API endpoint gives you documentation on the access methods for that particular API endpoint and what data is returned when using those methods.
You can also PUT and POST on the specific API pages by formatting JSON in the various text fields.