Integration of jira with nodejs

I try to use the rest api of JIRA with nodejs. I want to login, list issues, get issues, resolve issues. But I have problems. I stuck at the beginning.

Firstly, I checked my JIRA version. It says;

Bug tracking and project tracking for software development powered by Atlassian JIRA (v4.2.1) 

Then to be able to see the documentation of this version's rest api, I navigate to; https://docs.atlassian.com/jira/REST/4.2.1/

When I try to go to the link; https://MYHOSTNAME/jira/rest/api/2.0.alpha1/version

it throws an error as;

HTTP Status 404 - /jira/rest/api/2.0.alpha1/version

I don't understand, does my JIRA version is not supported? What am I missing?

via mmu36478