I am currently working on a project which needs some offline mapping. I am using Leaflet.js as my base library. I have also seen that leaflet can be used with the following tile providers:
https://leaflet-extras.github.io/leaflet-providers/preview/
The idea would be to download a minimal set of tiles from one of the sources given in the previous link in order to use them in "offline mode" (no internet connection).
I was initially planning on using cartodb because their base tiles are "clutter-free" and a good starting point to add my own annotations.
Depending on the zoom level, I would need between 1000-10000 tiles that, I will have to update every 6 months.
I am trying to figure out if I am not breaking any terms of services by accessing their public REST API (http://{s}.basemaps.cartocdn.com/light_nolabels/{z}/{x}/{y}.png
) in order to download tiles for offline viewing.
There are no API keys or any other form of identification in order to access the afore-mentioned service. Can assume that this is therefore public data (ie free)?
The cartodb terms of service are given here: https://carto.com/terms/#acceptable-use
I am not lawyer myself, but from my understanding it seems to me that it is OK to use their public REST API in order to cache tiles offline as long as I provide attribution.
Can anyone advise on this or tell how they solved a similar issue?
Edit: OK answering my own question (I can't add a separate answer because my question has been put on hold). Using the carto "base maps/tiles" is free as long as you are not building any commercial apps.
If you are building a commercial app which embeds the base maps, or if you are using the maps in order to track assets (my case), you need a commercial API key. All clearly explained here: