Version 4 of the API is legacy at this point. There are still many existing integrations that use v4 and so we continue to make the documentation available.
Version 5 of the API is our current version and should be used when creating a new integration.
The v5 Templated Jobs API is also a current API, but is solely devoted to the creation of new jobs from existing templates. This is the best option if you need to create jobs in vWork and requires the least coding.