URLs of the index files used by the software update client on OS X

osx-software-update-urls.txt

10.3 (Panther):
https://swscan.apple.com/scanningpoints/scanningpointX.xml

10.4 (Tiger):
https://swscan.apple.com/content/catalogs/index.sucatalog
https://swscan.apple.com/content/catalogs/index-1.sucatalog

10.5 (Leopard):
https://swscan.apple.com/content/catalogs/others/index-leopard.merged-1.sucatalog

10.6 (Snow Leopard):
https://swscan.apple.com/content/catalogs/others/index-leopard-snowleopard.merged-1.sucatalog

10.7 (Lion):
https://swscan.apple.com/content/catalogs/others/index-lion-snowleopard-leopard.merged-1.sucatalog

10.8 (Mountain Lion):
https://swscan.apple.com/content/catalogs/others/index-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog
10.8 (Mountain Lion incl. seeds):
https://swscan.apple.com/content/catalogs/others/index-mountainlionseed-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog

10.9 (Mavericks):
https://swscan.apple.com/content/catalogs/others/index-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog
10.9 (Mavericks incl. seeds):
https://swscan.apple.com/content/catalogs/others/index-10.9seed-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog

10.10 (Yosemite):
https://swscan.apple.com/content/catalogs/others/index-10.10-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog
10.10 (Yosemite incl. seeds):
https://swscan.apple.com/content/catalogs/others/index-10.10seed-10.10-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog
10.10 (Yosemite Beta Program):
https://swscan.apple.com/content/catalogs/others/index-10.10beta-10.10-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog

10.11 (El Capitan):
https://swscan.apple.com/content/catalogs/others/index-10.11-10.10-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog
10.10 (El Capitan incl. seeds):
https://swscan.apple.com/content/catalogs/others/index-10.11seed-10.11-10.10-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog
10.11 (El Capitan Beta Program):
https://swscan.apple.com/content/catalogs/others/index-10.11beta-10.11-10.10-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog


-------------------------------------
For Reposado (edit reposadocommon.py)
-------------------------------------

# ('http://swscan.apple.com/scanningpoints/scanningpointX.xml'), # 10.3
  ('https://swscan.apple.com/content/catalogs/index.sucatalog'), # 10.4
  ('https://swscan.apple.com/content/catalogs/index-1.sucatalog'), # 10.4
  ('https://swscan.apple.com/content/catalogs/others/index-leopard.merged-1.sucatalog'), # 10.5
  ('https://swscan.apple.com/content/catalogs/others/index-leopard-snowleopard.merged-1.sucatalog'), # 10.6
  ('https://swscan.apple.com/content/catalogs/others/index-lion-snowleopard-leopard.merged-1.sucatalog'), # 10.7
  ('https://swscan.apple.com/content/catalogs/others/index-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog'), # 10.8
  ('https://swscan.apple.com/content/catalogs/others/index-mountainlionseed-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog'), # 10.8
  ('https://swscan.apple.com/content/catalogs/others/index-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog'), # 10.9
  ('https://swscan.apple.com/content/catalogs/others/index-10.9seed-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog'), # 10.9
  ('https://swscan.apple.com/content/catalogs/others/index-10.10-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog'), # 10.10
  ('https://swscan.apple.com/content/catalogs/others/index-10.10beta-10.10-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog'), # 10.10
  ('https://swscan.apple.com/content/catalogs/others/index-10.10seed-10.10-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog'), # 10.10
  ('https://swscan.apple.com/content/catalogs/others/index-10.11-10.10-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog'), # 10.11
  ('https://swscan.apple.com/content/catalogs/others/index-10.11beta-10.11-10.10-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog'), # 10.11
  ('https://swscan.apple.com/content/catalogs/others/index-10.11seed-10.11-10.10-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog'), # 10.11

What about 10.14

Mojave: https://swscan.apple.com/content/catalogs/others/index-10.14seed-10.14-10.13-10.12-10.11-10.10-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog.gz

Catalina: https://swscan.apple.com/content/catalogs/others/index-10.15seed-10.15-10.14-10.13-10.12-10.11-10.10-10.9-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog.gz