I do not pay for any services or software from ESRI,
I use a non-ESRI API to access those images (i.e. Leaflet or OpenLayers),
I do not "scrape" the service or cache tiles for offline use, and
I properly attribute the map with the "Copyright Text" exposed by the ESRI data service?
If such use is in violation of the TOS, would wrapping ESRI JavaScript API calls under other APIs also violate TOS? In that case the data access would be through an ESRI API, but the visualization would utilize another API.
I'm looking into it, but it may take a while before I hear back anything definitive -- today's the end of the user conference, and many folks are traveling or otherwise unavailable at the moment.
I'm still getting confused, conflicting answers from multiple sources. From the FAQ you just linked:
Can I access the basemaps and services from my own API or a different API?Yes you can access our APIs from any other API if you have a paid plan or while you are testing or developing an application with the Free Development and Testing plan
... so that sounds like the answer is no. I am not allowed to use ESRI base layers in an OpenLayers or Leaflet application without a paid subscription to ArcGIS Online. In this case it would be a good idea to prominently display a disclaimer here: https://github.com/Esri/esri-leaflet that informs us that using this tool is only legal if we pay for a subscription to ArcGIS Online.
However in the Github thread I linked above, this comment suggests that it is okay for me to do this, as long as I am not monetizing my application and I am properly attributing ESRI.
