Yammer, a microblogging-for-business site and winner of the top prize at the recent TechCrunch50 conference, has released an API to allow developers to build their own applications around the service (Yammer API profile). Created by the people behind genealogy site Geni, Yammer has taken the tried and tested Twitter model, which asks users to answer the question "What are you doing?" in 140 characters or less, and adapted it for businesses, turning the question into "What are you working on?" Users sign in with their work email addresses and their posts are visible only within their company.
Their new API is RESTful and provides responses in XML or JSON format. For developers not using fully REST-compliant libraries the API provides a _method parameter for PUT and DELETE requests. Its documentation describes method for retrieving messages, tags, users, and subscriptions (followers and followees, in Twitter parlance), and for sending and deleting messages. HTTP basic authentication is used to verify the identities of users of applications built on Yammer's API, and no further authentication is required for developers. Applications are limited to five requests per minute per user.
Though the company says its iPhone, Blackberry, and Adobe Air-based desktop apps are built on the public API, their source code is not available, and no code samples or sample applications have been provided so far. However, support may be found at the user forum, which seems light on API discussion so far but well-staffed by Yammer employees.