The Kongregate API allows you to initiate a variety of messages to players to help increase engagement and social awareness of the game and a player's accomplishments within it. These fall within a few major categories: user-to-feed (self-posts and announcements), user-to-user (invites and gifting), and game-to-user (game updates, re-engagement). All of these messages will be subject to rate limiting, and the exact rates are still being tweaked by Kongregate based on game and user activity levels.
These types of posts enable users to put accomplishments on their own feed. You can initiate a feed posting with
showFeedPostBox to allow user-to-self messages. The
showShoutBox function will enable a self-post to the player's "Shouts", which is similar to Facebook's wall posts, and can be used for bragging about accomplishments. The primary difference between these functions is that a "shout" will appear as being posted by the player, while a "feed post" will be posted by the game and can have embedded images.
To help raise awareness of your game, you can have players send an invite to other players for the game with
showInvitationBox. The same function can be used for gifting or other click-to-action messages by simply including a URL link with whatever parameters are appropriate. Remember that to be passed into an iframe, parameters need to be prefixed with kv_, such as ?kv_foo=bar.
Your game can initiate a private message to the player with the client-side
privateMessage method. Additionally, to let players know about updates, turn information, etc., you can initiate an offline private message server-side with the
private_message REST method.