CalTopo has always made its map layers available to other apps and websites, but we’ve decided it’s time to phase that out.  Our slope angle shading layer will no longer be available outside of CalTopo on Oct 1, with all other layers no longer available in other apps and sites in January 2021.  We know that this will inconvenience some of our customers who also use other apps, so we wanted to take a minute to explain our decision.

What does that mean for users come October 1 or January 2021? If you’re used to using the CalTopo slope angle shading, topographic maps, or other layers outside of the CalTopo website and app, you will no longer be able to do so as of these dates. The only way to access CalTopo layers and maps will be in the CalTopo app and on the CalTopo website.

There are three major reasons we’re doing this:

* Improve our ability to develop new layers.  As we look to expand internationally, we will increasingly be incorporating proprietary datasets that we need to license.  There is no way we can seamlessly incorporate proprietary data into our existing tilesets, while continuing to license those tilesets to other users.  Maintaining a stable API also hinders our ability to make technical improvements such as switching to 512 pixel tiles.

* Cost control.  While layer licensing generates some revenue, maintaining a public endpoint is also costly – CalTopo spends thousands of dollars a month on bandwidth alone.  We recently discovered that a much larger company was driving those costs up by using our tileset without permission, and had to go multiple rounds with an attorney to get them to stop.  It will be easier for us to implement technical measures to block unauthorized use if we do not also need to support licensed use.

* Control of our brand.  Only a portion of CalTopo’s layer set is available for licensing, and over time many of the pre-rendered, licensed layers have diverged from what is available on CalTopo.  For example, the slope angle shading on CalTopo has greatly improved in both coverage and accuracy compared to the version that we license out, and because we render it on the fly, there’s no scalable way to give other apps access.  This has been an ongoing source of confusion, and it’s been difficult to explain clearly how XYZ app “has some CalTopo layers, but not all, and the ones they do have don’t fully match ours”.

In order to make for a smooth transition, we’ve given apps that license our layers significant advanced notice, so that they have time to find or create alternate tilesets.  CalTopo has always had a generous free use policy, and we intend to continue allowing free noncommercial use of our tilesets going forward – with the caveat that such use is a secondary consideration, so there may be short-notice changes that free users will need to adapt to.