Paypal for a buy/sell website - e-commerce

So I'm working on this website where users post their items, other users add some items to their cart and purchase them online.
The flow i was thinking about goes like this:
A merchant posts an item along with their credit cart/ paypal information.
A buyer adds items (from different merchants) to his/her shopping cart and purchases.
The buyer pays by filling a form that includes the payment method fields within the website's layout (no redirection to paypal).
The website will work as a gateway, it will capture the payments from the buyers and pays the merchants accordingly and automatically.
Is this possible using PayPal? if so, what API should I use?
Any input/idea is appreciated...
Thanks,
/t

I have also investigated using PayPal in this way for a site with a similar concept. Unfortunately, PayPal does not allow this. This makes you something known as a Third Party Payment Aggregator which drastically increases the risk associated with providing you a Merchant Account (which is what PayPal is doing). You can read more here.
Though, you could probably do it for a while before PayPal caught on, they could cancel at anytime leaving you high and dry. I recommend investigating Third Party Payment Aggregator solutions (Braintree has something that helps with this).

I guess it is. Use Paypal API
https://cms.paypal.com/us/cgi-bin/?cmd=_render-content&content_ID=developer/howto_api_reference
https://developer.paypal.com/

Related

Which PayPal API and product shall be used for card payments with auth and capture

How shall I integrate custom shopping cart app with PayPal to accept indirect credit card payments without forcing buyers to register at PayPal?
There's a custom shopping cart web application and the task has been set to replace current credit/dept card payment with PayPal. The goal is to let the customers pay with their cards via PayPal. However, there are some constrains:
customers should enter their credit cards details (number, expiry date, secure code) not in shopping cart's page, but PayPal's page,
every payment must consists of authorization (blocking total sum) and subsequent capture if the ordered items are available and can be delivered,
customers aren't forced to create / login to PayPal account if they wish to pay via card.
The trouble is I'm really confused with the number of possible options at PayPal. The choice between REST API and Classic API isn't that problematic, but choosing the proper product from the whole list (like Classic API products or REST API products) isn't that obvious for PayPal newbie. Some other similar questions point to DoDirectPayment (but I don't know if it's the best choice) or suggest Website Payments Standard (I'm not sure if they're still available).
I was also considering Express Checkout, but the demo seems to force to create PayPal account.
ExpressCheckout is designed to be used in concert with a direct credit card acceptance method (such as PayPal's DoDirectPayment, or a non-PayPal credit card acceptance method), although it can be configured to also do guest payments. This is why the demos of the normal configuration handle only PayPal account creation; that's the normal usage.
One key question you need to ask yourself is whether you want to have access to the credit card information & be the "merchant of record" yourself or not.
YES: Doing this gives you the most flexibility, but will require you to go through some merchant vetting and carries some security obligations (PCI) even if you are using some solution which tries to distance you from the actual raw card numbers (e.g. collecting them via PayPal or Braintree code and immediatly encrypting & tokenizing them). In short: if you want full access to the card, then you have legal obligations re: handling that account access which technology can reduce but not eliminate.
NO: If you are content to always treat your customer's card information at arms length through PayPal, via the legal structure of a PayPal account (whether the user actually has a PayPal account or is just doing a "guest" payment on PayPal where they give PayPal their credit card for one-time use) then you can reduce your vetting & security constraints (no PCI requirements at all).
If you want (or need) access to the customer's card [YES above] then the "classic" API solutions are either DoDirectPayment (for when you collect the card info) or Hosted Sole Solution (for when PayPal collects the card info on their page). HSS meets all 3 of your requiremens above; DDP fails requirement #1.
If you can live with access to the customer & the payment but NOT the card account itself [NO above] then you can use Website Payments Standard, or EC with Guest Checkout option; both meet all three of your requirements.
All of the above solutions are not only still supported, but have tens or hundreds of thousands of integrated merchants and are the biggest/mainstream ways in which PayPal payments are handled.
If you prefer the newer products & are in the first category above (real card access, not guest payments) then you can also use Braintree or the RESTful APIs. These newer products don't yet have as much flexibility & coverage as the older products, but hey, less complexity can be a good thing as long as they have what you need. These products are generally designed around plugins for your web pages rather than entering card information on PayPal's site, however, so they don't meet your first requirement.
You can also do PayFlow (several variants) or Adaptive Payments or or or.... but in general I would advise picking either the most well-established or the new-and-growing options as being better supported & more future-proof.
Now that PayPal has acquired Braintree, the preferred integration method is v.zero. It is designed to be very easy to accept PayPal, Credit Cards and other options. (Venmo, Bitcoin, etc.)

Shopify / Paypal Express: Shipping cost not showing until after payment

Ok so I got the following problem with my Shopify shop: Because my shipping varies based on weight paypal does not show the shipping rate until after the customer has logged in and paid for it. It then gets send back to Shopify where it receives the message that it will be billed an additional $10 for shipping, which already got me some complaints.
So what I want is that it will already shows the shipping cost before the customer logs in and pays for it. I imagined that more people had this problem and perhaps found a solution to fix this?
Thank you
There are a number of ways to handle this with the PayPal system, but I'm not sure if Shopify is open enough for you to make any changes. You'll probably need to ask them how it's configured and see if you have any option to adjust it.
The standard flow for Express Checkout is that you would show the user their cart and any fees you've gathered at that point so you can generate the subtotal. Then you send them over to PayPal where they login and agree, and are then sent back to your site. Back at your site you would obtain the shipping address from PayPal and you could then display a final review page that breaks down any additional shipping, tax, etc. that might be applied now that you know their shipping address. No money would actually be charged until they approve this final review page.
In order to skip the additional review page on your own site, PayPal introduced the Instant Update API a few years ago. This gives you the ability to generate a web service that PayPal's review page will call and send the shipping address so that the service can calculate shipping and tax and return it back to PayPal. The PayPal review would then update accordingly so the buyer can choose their shipping option and see the grand total on the PayPal review page. That way they can finalize and would still be returned to your site, but you wouldn't need to show another review. You could simply show the thank you / receipt page.
I'm not sure if that first method I outlined is in fact what you're getting..?? It sounds like you're saying that Shopify is skipping the extra review, finalizing the payment, and then simply notifying the user that more money was charged than they agreed to. If that's the case, I would say that's very sloppy checkout design.
Again, though, as Shopify is a hosted solution, you probably won't have the ability to adjust this on your own. It's possible they have the Instant Update API available, though, and maybe you just need to enable it..??
You'll need to check with them for more details about your options.

eCommerce website - taking payments and Stripe

I'm considering setting up a eCommerce website and was wondering about the payment side of things.
After some searching I came across Stripe, which seems very similar to PayPal and Google Checkout.
I have a few questions about Stripe and eCommerce in general.
What do I need to take payments on my website? Presume that I have the shop set up, and the buy button in place. Do I need an SSL certificate, I've read something about being PCI complaint? What is and why would I need a merchant account.
Stripe appears to handle a number of things for me, and it stores the users card details. How would this work with things such as logging in to a website. Would I store the users email and password and then when they wanted to buy something Stripe would just handle the credit card side of things or would the entire user details be stored on Stripe.
Can you build and style your own payment form that then connects to Stripe or do you have to use their form on your page?
Do you have to upload all of your products to Stripe or can you store these in your own database and just pass the value of goods purchased to Stripe for payment?
What are the advantages/disadvantages of Stripe and is there any competitors that I should know about?
Thanks
Stripe requests that you should serve up payments pages over SSL. Anyone involved in payment processing must comply with PCI, if you use something like Stripe you will need to serve the payments page on SSL, but Strip will handle the payment info. Check out https://support.stripe.com/questions/do-i-need-to-be-pci-compliant-what-do-i-have-to-do for more details on what you'd need to do.
Not entirely sure on this front, perhaps someone else can comment?
You'll be able to style your page and use Stripe for the payment piece.
You can use Stripe's checkout or build your own (sounds like this is what you want to do) via Stripe.js.
Stripe is generally recognized as one of the most developer-friendly ways to accept payments online. They've worked hard to build a simple service that a developer can get up and running a matter of hours. Braintree is a competitor that may offer some valued added services and you might want to take a look at Balanced as well. I work at LevelUp, which has been used in conjunction with Stripe (as another payment method, similar to PayPal) and as a stand alone solution for apps processing online or mobile payments.

variable monthly charges to users

I have a situation where I am to bill the site users monthly. But the invoice amount that is raised depends on the the leads that our site generates for his business. For example if the user gets 5 leads from my site and I charge him $10 per lead, at the end of month he will be charged $50. similarly leads might vary each month so will the amount.
Now I cant store his cc/ paypal credentials on my site for security reasons nor can I pre bill him or ask him to take credits and then use it. Please let me know the way to handle this situation. How can I handle this using paypal?
There are a few different ways to handle this, but I would recommend Preapproved Payments, which are part of the Adaptive Payments API.
With this method your users would create a profile with you (using the Preapproval API) when they first create their account on your site. That will give you a preapproval key that you can store with your user account. Then in the future when you need to bill them you can use the Pay API with the preapproval key to process funds immediately without further approval.
If you're working with PHP my class library for PayPal will make these calls very simple for you. You would just use the Preapproval.php template to setup the profiles for people, and then use PayWithOptions.php to process payments using the preapproval key(s) accordingly.
If you end up using it and need more help you can contact me directly for support.

Does this simple paypal solution allow credit card transactions and Negative Testing?

I am so confused about the services and over here the paypal website also seems to be serving up 400's and 404s.
This is how the webpage looks for customers on my site when they are ready to pay:
As far as I know, I don't have Express Checkout, but I'm not sure if I have Website Payments Pro (my company created this account).
Now I have two questions:
1- This is just the sandbox. But on the real site, does this solution that give users the opportunity to pay by credit card? I've actually successfully done a credit card transaction in the sandbox, I'm just worried because I've heard that customers can only do direct credit card transactions in PayPal Website Payments Pro. The PayPal website is overloaded with information and I can't find my way around it to answer simple questions like this.
2- Is it possible to do negative testing for transactions on this page? Such as simulating the events that the user's credit card or Paypal account doesn't have enough balance? If it is possible, and I am using the ButtonManagerAPI, then is the technique below the correct way to go about it?
I put an error code in the amount variable that is passed on to IPN via via an NVP api call, like this (lots of value pairs in the middle excluded as irrelevant):
$nvpReq = "BUTTONCODE=HOSTED&..............&L_BUTTONVAR1=amount=".$err_code
EDIT
So it appears I have PayPal Website Payments Standard, which means I cannot incorporate cannot have credit card payment forms directly on my website, but customers have to be directed to PayPal. I'm fine with that, as long as customers have the option to pay with credit cards.
The screenshot looks like PayPal Standard, which is an HTML-only (non-API) integration.
Any regular business account that can receive money can make use of the Express Checkout API.. typically by authenticating with an API USER/PWD/SIGNATURE. For businesses with programming/development resources, EC is by far the recommended way to accept PayPal payments.
If you pass SOLUTIONTYPE=Sole in the initial SetExpressCheckout call, it will accept credit cards from "guest" customers who don't have a PayPal account, similar to the Standard screenshot you're displaying above.
The main reason to choose EC over Standard is that it's a much tighter handshake between your checkout software and PayPal's servers. With Standard's HTML-only, the customer is redirected away from your site and might not return to your site after a successful transaction is committed (they may stay on paypal.com and not click to return or their browser might crash before return --- whereas with EC the return to your site is built-in before anything touches the financial system)
With the recent beta of developer.paypal.com, all new sandbox Business accounts are full Pro accounts by default. Signing up for a live Pro account would be useful if, in addition to accepting PayPal payments, you wished to create a credit card entry form directly on your own site.
Here are some EC links for programmers:
https://tryit.paypal.com/guide/ec
https://paypal-labs.com/integrationwizard/ecpaypal/main.php
The button manager API is unlikely to be useful to you. And there are ways to do negative testing with the sandbox, but it's really not an important concern when you're still deciding on a product/API.