The current revamped PRISMA API v2 will be available for you to connect and test by end of Q1/2019. As of then you can start the migration on your side.

Do I have to upgrade to version 2?

Not right away. You are free to use version 1 of the API at least until end of this year. We will contact you in due time, in case we have to discontinue support of version 1.