is there an official api to request suggestions to show them as autocomplete for the search box at the own website?

I found different solution, but no one of these uses an offical api:

• Request XML from the report of the most used keywords of the month (statistics) (URL)
  
• Use the interface, which uses the official google result page or some toolbars to request the suggestions (URL1, URL2, ) 
  
• Use the deprecated Google Web Search API (URL) to attach an autocomplete to search box (the newer Google Custom Search API doesn't support autocomplete)