What is the best way to implement a point code system

[Zephren]

If you've played one of those many "free" MMO's with item malls or premium items, then you'll know what I'm talking about.

Here is what I have:

I have a system to generate a code which is associated with some number of "premium points", and that code gets stored it in a table.  This code needs to be presented to the user in some secure way.  Once the user has this code they can input it into a form.  Once the code is submitted and verified (only valid if it is in the table), it is removed from the table and the user is given the associated number of points, which can be spent in a premium shop.

Here is what I need:

I need a vendor or merchant service that a user can be sent to, so they can choose to buy one of a set of predefined number of premium points.  Here is where I would like some suggestions.  What is the best way for the merchant service to notify my game that a purchase has been made?  I think the ideal way would be for the service to accept a payment, and once it is verified, it would run a script on the game's web server, providing it an email address.  The script on the game web server would then generate a code, store it in the table, and send an email to the provided email address and or return it to the user via the merchant serivce.  Is there any way that this can be accomplished?  If not, what method might you suggest I use?

Thanks

[codestryke]

Each merchant system is different in how they communicate back to you.

We use two right now... PayPal which I believe is coded somewhere on this forum, if not PayPal gives some pretty good PHP code for you to use to communicate with there system for testing.

DaoPay which we use for mostly SMS overseas billing does something similar to PayPal.

If you want a specific way for a specific merchant post the merchant and I'll see how I can help

[Zephren]

I think I'd prefer to go with PayPal since I'm most familiar with it, and I am using PHP.  I just don't know what sort of functionality it has.

[Zeggy]

It's called Paypal Instant Payment Notification (IPN). You can find loads of code samples if you google it.

Basically, after a person makes a payment successfully, it will notify your server (a page) that the payment succeeded, and it will also send along all the payment details - name, amount, email, etc.

You can also set up the payment form to include hidden details, such as the player ID, which will also be sent back to your server so you can easily identify the player who paid for something.

[Zephren]

Thanks, thats exactly what I needed to know, and sounds like exactly what I need, I just couldn't find that information on their website.

[Barrikor]

This is where you download Paypal's SDK's from:

https://cms.paypal.com/us/cgi-bin/?cmd=_render-content&content_ID=developer/library_download_sdks#NVP

[JGadrow]

Just as a note... why bother with the security code? You can insert fields that would allow your system to identify the user account of the person making the transaction upon successful payment verification. Instead of having your system go through all the overhead of querying the database for the player, then creating a code, then stuffing that code into a table, and then e-mailing that code to the desired recipient. Who must then take the code, submit it back to your server, which must make another lookup in the database to validate the code and then, assuming it's valid, run another query to update the player's points.

Why don't you just update the points when you receive payment verification? Saves a TON of processing! lol Not to mention, makes for a smoother user experience.

[Scion]

aye and if you want players to be able to gift the points then just allow them to do point transfers....(assuming you dont give away free points in game, that would just ecourage point farming multi's)