Parsing the JIRA openapi description and generating a Perl client from it is part of the test suite for my module OpenAPI::PerlGenerator. I'm happy to be no current user of JIRA, so I can't test the generated code.

If that code works for you, I'm happy to release it as a stand-alone (generated) distribution. If there are changes you need to make to the OpenAPI specification, the openapi.json in the parent directory contains the specification for the generated code.

I fear you will have to restructure your current program though, because my code simply translates the JIRA openapi spec and has no thoughts about making JIRA easy to use.