I’ve been using phpGSB GSB client for a while for pretty large volumes (~100k pages/hour). Looks like it finally croaked. Hasn’t been updated since March. So here is a brief survey of what else is out there:

• gglsbl in Python on github looks like supports 3.0
• Net::Google::SafeBrowsing3 in Perl on CPAN says 3.0 by default
• In Go (of all languages) on Github
• The aforementioned phpGSB – having a hard time with it

I’m currently leaning towards the first option, may also try Go. I know, lazy, should have just implemented my own, but there is too much other stuff to do.