I just checked out the ESI website and I don’t see any mention of corporation assets? Is that going to be added and if so when, I have some tools that utilize the ability to pull corp asset data.
It’s not done, yet. But, everything in the XML API and CREST is planned to be added to ESI at some point. They are working on corp endpoints, but, corp assets may be one of the later corp endpoints to be completed (as it’s a complex endpoint). You can use the following link to se what is done:
I saw that the old APIs are being decommissioned next May, so looking forward to the single API being fully online.
Thanks for sharing that link, I’ll bookmark it and use that for reference moving forward to see what is going to be done vs. what is complete 
Thanks!
They won’t remove the old APIs until it’s all in ESI, but, they have said they may remove the old APIs early, if usage falls very low. So, do everything you can in ESI and try migrate when new ESI endpoints are released, so, you don’t have to do it all in one go, when they close the old APIs.
That said some of the newly released endpoints may be a little buggy when first released (in my experience).
http://eveonline-third-party-documentation.readthedocs.io/en/latest/index.html
CREST and XML API are going to be shut down by May 8th, 2018, or earlier if metrics signal a trivial level of usage.
So I read that is it is going to shut down in May, earlier if metrics signal lower usage of the old API systems.
That is correct, I just meant that at that point everything you could do with the old APIs will be available in ESI.
Well almost everything . I know they’re removing some functionality, like see all characters linked with an account, as well as whether a character is Omega or not, among some other odds and ends.