Url for a random article in JSON format from wikipedia

Wikipedia Random Article

http://en.wikipedia.org/w/api.php?action=query&generator=random&grnnamespace=0&prop=extracts&exchars=500&format=json

http://en.wikipedia.org/w/api.php?
  action=query &
  generator=random &
  grnnamespace=0 &
  prop=extracts &
  exchars=500 & // must be > 0
  format=json
  
response example:

{"query":{"pages":{"41571479":{"pageid":41571479,"ns":0,"title":"Babes in Toyland discography","extract":"<p><b>Babes in Toyland</b> was an American punk rock band formed in Minneapolis, Minnesota in 1987. The band was formed by Oregon native Kat Bjelland (lead vocals and guitar), with Lori Barbero (drums) and Michelle Leon (bass), who was later replaced by Maureen Herman in 1992. Courtney Love had a very brief stint in the band in 1987 as a bass player, before being kicked out and forming Hole in 1989.</p>\n<p>Between 1989 and 1995, Babes in Toyland released three studio albums; <i>Spanking Machine</i></p>..."}}}}
  
get pageid and req

http://en.wikipedia.org/wiki?curid=pageid

Having trouble finding the grnnamespace prop in the documentation. Any help?

How to get 10 pages from api?

if i am adding the grnlimit=10 with url as below it not giving the "extract" value in response please check below url

https://en.wikipedia.org/w/api.php?action=query&generator=random&grnnamespace=0&prop=extracts&exchars=500&format=json&grnlimit=10

can you help with this?