Need advice on where to start with an addon

I am in the process of developing an external Age verification check with Veratad's IDResponse system for a client. The vendor has supplied me with an API reference on what to expect on sending/receiving.

The two options available on passing/receiving information is in the form of XML or via a cURL interface.

I need a couple of pointers if someone doesn't mind.

For making the call to the external site, this will have to be somewhere in the account creation process. I would think that once the data for the customer has been collected and saved, it can then be passed to the external API and, pending the return code, continue through the checkout process or display a failure message.

I want to make this a contribution and need some direction.

Your most urgent reply is appreciated.

Thanks

I think there are likely some suitable notifier hooks to link to during the account-creation process, which might help prevent you from having to touch any core files. Check the /includes/modules/pages/create_account/header_php.php and /includes/modules/create_account.php for the existing logic and find the notifier points in there.
THere is documentation on the notifier/observer system in the wiki.

Mart -

I don't suppose you got any farther along with this, did you? I'm just beginning to read the idresponse information for integration, and our particular problem is reprompting the user for the last four, id calc, etc, when they aren't found on the initial address search.

Chris
https://www.customblends.com