Google has released a Social Graph API so that developers can get social networkers using their applications when they join a new site.

Brad Fitzpatrick, a Google software engineer, said: "You've just built a totally sweet new social app and you can't wait for people to start using it. But there's a problem: when people join they don't have any friends on your site."

Fitzpatrick pointed out that users cannot use the app they have just signed up to with people they already know. At the moment the only option is for developers to get apps to ask users to search for and add all their friends.

"But you know that every other app is asking them to do the same thing and they're getting sick of it. Or they tried address book import, but that didn't totally work because they don't even have all their friends' email addresses," said Fitzpatrick.

Google's Social Graph API makes information about the public connections between people on the web easily available and useful. Developers can make it easy for users to bring their existing social connections into a new website.

"Here's how it works: we crawl the web to find publicly declared relationships between people's accounts, just like Google crawls the web for links between pages," said Fitzpatrick.

"But instead of returning links to HTML documents, the API returns JSON data structures representing the social relationships we discovered from all the XFN and FOAF.

"When a user signs up for your app, you can use the API to remind them who they've said they're friends with on other sites and ask them if they want to be friends on your new site."