(I am reposting this question here because I tried on the google news group and got no responses.)
I need to build a shop for my client, and the client already has a domain and a web site. I need to integrate e-commerce functionality in to the site. This is going to be done by sending AJAX requests to the API.
my question is whether I need to get a partner account for this? I am not yet going to write an app that people would install, I am just building a store for my client. how is it done?
You do not need a Shopify Partner account for this. You can instead create a “Private application” within the normal shopify admin, which will give you the api credentials you need to make stuff happen.
This article on the shopify wiki gives a good overview of the process for getting started (the first sections are most relevant in your case):
http://wiki.shopify.com/Using_the_shopify_api_gem_with_the_credentials_of_a_private_app