On Thu, Mar 29, 2018 at 12:54 AM, Zainan Zhou (a.k.a Victor) <zzn@google.com> wrote:

… monitor the list of all the current available wikipedia's sites and the number of articles for each language, …
https://en.wikipedia.org/wiki/List_of_Wikipedias. has the information we need, but the list is manually edited, not automatic
https://stats.wikimedia.org/EN/Sitemap.htm, has the full list, but the information seems pretty out of date(last updated almost a month ago)
StatsV2 UI: https://stats.wikimedia.org/v2/#/all-projects, I can't find the full list nor the number of articles
API https://wikimedia.org/api/rest_v1/ suggested by elukey on #wikimedia-analytics channel, it doesn't seem to have # of article information

I don't think this has yet been mentioned: Wikistats has an automatically-updated CSV file listing all the Wikipedias (and Wiktionaries, etc.) as well as how many total articles they have, how many "good" articles, how many stubs, etc., each language has, from English to Kanuri:

https://wikistats.wmflabs.org/ -> "csv" link -> https://wikistats.wmflabs.org/api.php?action=dump&table=wikipedias&format=csv

I use this enough that I made a little JavaScript library to fetch this data, parse it, and programmatically yield a nice JSON representation:

https://github.com/fasiha/wikipedia-languages/

Sorry if I overlooked one of your requirements and am suggesting something that won't work for you.