JSS is available as of Sitecore 9.0. It is not supported by Sitecore for 8.2
If you are looking to do headless on 8.2, you do have the SXA with JSON Device option to get full personalized layout information, and you can do traditional Sitecore Services Client (SSC) which is a content-only API.
I recently responded to a similar StackOverflow question with some suggestions for 8.2 and React: stackoverflow.com/.../57056525
You may want to also take a look in the JSS forum: community.sitecore.net/.../40
There are several folks who have done headless on 8.2, JSS is not the only way. However, if you can upgrade and start using JSS you'll find a lot more support for front-end frameworks.