Requests with v2 API are not working anymore

Has the v2 API been modified/retired? All requests I make through /rest/v2/query are now failing, but I’ve used that code for years now, without recent changes. It broke our online ELATE app integration with MaterialsProject…

Trivial request showing the issue:

Yes, we are in the process of replacing our legacy API at /rest/v2/ with our next-generation API and website. Our legacy services will stay available for a little while at and you could set it as your URL to connect to it explicitly. I just tested your code example and it appears to be working fine that way. HTH.

Thanks. I do not think this “legacy” URL is documented: Materials Project - API
Will there be an announcement of the retirement date, before it is retired?

Hi @fxcoudert,

Thanks, we’ll add a note. We do have a redirect in place so the hope was that people would continue to use the route without issue but we think some information is getting stripped somewhere by our proxy.

Currently, we are thinking the legacy route will be available for about a year. There will be an announcement. The important thing to note is that the legacy API will not have data updates.

However, for ELATE, there would be benefit to switching to the new API; the new API will incorporate future version updates including, importantly, updates to the elastic constant dataset (including new elastic tensors + fixes for some issues that have been discovered in existing elastic tensors).

There’s also a route whereby we could embed some ELATE visualizations directly on Materials Project if there was interest from your side (with an appropriate citation of course) but this might require some code modifications. We now drive all our plots via plotly which makes this somewhat easier.



Hi @mkhorton

I have started migrating ELATE to the new API and I have a couple of questions. I have opened a new topic at Migrating from old "v2" API to new: a few questions, and any help there would be appreciated.