The rest code has been merged and is available as of version 2.0.0 of Roundup released in 2020-07-13.
From: https://sourceforge.net/p/roundup/mailman/message/34436352/
Date: Sun, 06 Sep 2015 14:36:39 +0300 From: Ezio Melotti <ezio.melotti> Subject: [Roundup-devel] REST interface -- GSoC Project Report Hi, Google Summer of Code is now over, and I'm glad to inform you that the project "Adding a REST API to Roundup" has been completed. The work has been done on the Roundup clone used for bugs.python.org, since we plan to integrate it and test it there first. The changes shouldn't affect any b.p.o-specific parts though, so you should be able to apply the changes on a regular Roundup clone too. I eventually plan to port this to upstream Roundup if it proves successful on b.p.o, but my resources are currently limited, so you are welcomed to beat me to it. You can find the code at https://bitbucket.org/kinggreedy1991/roundup-bpo , more information about the project at https://bpaste.net/show/7e2303d2aa7a , and the related core-workflow thread with more information (including another related project) at https://mail.python.org/pipermail/core-workflow/2015-September/000220.html .
The patch file from https://bitbucket.org/kinggreedy1991/roundup-bpo/downloads/ is attached here to have a second location where it is stored.