The code for a tex.se answer. (http://tex.stackexchange.com/questions/316606/placing-your-live-reputation-in-a-document)

fetch.lua

UPDATING = true
USER = 'digitalis'
USERID = 5477562
cache = {}

cache_name = function (user, site)
   return ('cache/' .. user .. '_' .. site)
end

curl_user = function (user, site)
   os.execute('mkdir -p cache')
   print('\nGetting ' .. user .. ' from ' .. site .. '...\n')
   os.execute('curl "http://api.stackexchange.com/2.2/users?inname='
      .. user .. '&site=' .. site
      .. '" > ' .. cache_name(user, site) .. '.gz')
   os.execute('gunzip -f ' .. cache_name(user, site) .. '.gz')
end

extract_user = function (user, userid, site)
   if UPDATING then
      curl_user(user, site)
   end

   io.input(cache_name(user, site))
   raw = io.read('*all')
   me = string.match(raw, userid .. '.*')
   io.input():close()
   return me
end

get_user = function (user, userid, site)
   if cache[user] == nil then
      cache[user] = {}
   end

   if cache[user][site] == nil then
      cache[user][site] = {}
      cache[user][site]['_raw'] = extract_user(user, userid, site)
   end
   
   return cache[user][site]['_raw']
end

get_field = function (field, user, userid, site)
   if not (cache[user]
	      and cache[user][site]
	      and cache[user][site][field]) then
      me = get_user(user, userid, site)
      pure = string.match(me, '"' .. field .. '":[^,}]+')
      cache[user][site][field] = string.match(pure, '[^:]+$')
   end
   return cache[user][site][field]
end

get_rep = function (site)
   return get_field('reputation', USER, USERID, site)
end