The callback server URL is how our servers notify your servers of offer completions. Your callback URL must be outside social network platforms and should not require any authentication process in order to reach your server.

NOTE: The callback url is REQUIRED in order to go live, however is not necessary during testing.

Format: The callback URL format you will receive from our servers is displayed below:

Example: http://www.yourserver.com/anypath/reward.php?snuid=[user id]&currency=[currency credit to user]&id=[transaction id]&verifier=[signature]&affl=[additional user data]

Where the URL parameters are defined as follows (these are values that Offerpal will append to your callback url):

Parameter	Use of Value	Type of Values
snuid	the user ID (see: What is a SNUID?)	This is the snuid that Offerpal recieves.
currency	the amount that the user should be credited	This is a number value
id	transaction ID or the Offerpal ID shown on the offer status page - this is unique to every action for each user	This can be up to 18 characters long (alpha-numeric)
verifier	security hash signature used to verify callback authenticity (see: OfferpalSECURE for more info)	This is a MD5 hash
affl	use of this parameter is optional - it allows you to pass in an affl parameter in the URL to track additional information (e.g., the application's traffic source). If the box is checked, our servers will return the affl parameter in the callback URL for tracking purposes. (see: How to pass additional user data?)	This can be up to 32 characters long

NOTE: We highly recommend to add an extra check on your callback server to prevent duplicate transaction ids. Should we receive a response that your server is having issues we will retry automatically in hopes of crediting the user.

Customer Service Callbacks:

At times, our customer service department will need to assist your users in receiving their currency. Should this occur - we will add the value-pair &error=1 to the callback (Example below).
These are transactions for one reason or another did not automatically credit. Should this occur, the user typically contacts our customer support where an agent will verify their information and process the request. To help identify these transactions for your benefit we append a &error=1 to the callback. They are not really errors however that is the parameter that is used to communicate the issue to you.

You should honor these callbacks as the users are expecting to get their credits after Customer Service told them that they would receive them.

Example: http://www.yourserver.com/anypath/reward.php?snuid=[user id]&currency=[currency credit to user]&id=[transaction id]&verifier=[signature]&affl=[additional user data]&error=1

Need an example to get you started?
Download the file below: callback_url.php This is a great way to get started!