Web Service API Callbacks

You can specify an API callback URL for your game (on the game edit form) that can be used to have your server notified when specific events happen in the Kongregate back-end. Notifications will be sent via HTTP using the POST method.

It is good practice to have your web server handle these requests quickly, as Kongregate reserves the right to terminate connections which are taking too long to complete. Ideally, one should close the connection nearly immediately, and then do any other processing elsewhere (in a queue, different thread, etc)


To specify the callback URL, use the edit game page on Kongregate, and specify your API Callback URL, then save. To access the edit game URL, either click the edit link on your game page, or add /edit onto the end of your game URL:



The request sent to the HTTP endpoint will always contain the following parameters:

  • event: The name of the event that triggered the callback.
  • api_key: Your game's API key. You can use this to verify which game the request is referring to, and also as protection against spoofing. If a request does not have a valid API key, you should ignore it.
  • time: The time (on our server) at which the action was performed.


Inventory Invalidation: invalidate_user_inventory

This callback (invalidate_user_inventory) is fired when a user's inventory is changed. This can happen when they complete a purchase. When you receive this event, you should request an updated list of the player's item instances so you can update the information on your end.


  • user_id: The user_id of the player who had their inventory changed.
  • username: The username of the player who had their inventory changed.
  • game_auth_token: The game_auth_token of the player who had their inventory changed.