We present the XMM CLuster Archive Super Survey (X-CLASS)
our ongoing effort to build a cosmologically useful
catalog of purely X-ray selected galaxy clusters by analizying the whole
XMM-Newton archive.

We have reprocessed about 4000 XMM observations up to August 2015
with our dedicated pipeline which allowed us to build a high purity
sample, including the about 2700 observations (up to May 2010) in
Clerc et al 2012; human screening of the recovered clusters
is under way and an updated catalog is expected this year.

An ongoing campaign with the 7-Band GROND instrument of the 2.2m
ESO-MPG telescope is under way to provide photo-z for the XCLASS
clusters visible with it
 
A correlation with the redMaPPer catalog shows that all high richness
redMaPPer clusters are recovered in X-CLASS