Methods of adding products to cart, from outside cs-cart

I would like the know the best method of adding products directly to the cart from outside cs-cart, like an email or another website.

Can it be done via a URL, or does it need to be a form post. What info is required, product_id, quantity?

Example of how I might use this is, to send an email with product info and buy button, that would add a product directly to the cart.

Is there a way to add more than one product at a time, with a single button.

I’m sure someone has done this, right?

Adding a product directly to cart with a URL? Or a from a form?

I have the product_id, and quantity, Isn’t that enough to add a product(s) to the cart?

I’m quite interested in this too, has anyone done it? I guess I’m just going to downoad the trial and poke around to see if it’s possible?

I just wrote a php page that handles the reformatting or the URL for cs-cart.

So I use it like /mypage.php?pid=1234_1,1266_2

where pid=[product_id][quantity],[product_id][quantity]

the mypage.php then formats a URL for adding the product(s) to the cart.

It seems to be working fine and is currently in testing with the client I wrote it for.