API long description
PayPal offers online payment solutions and has more than 153 million customers worldwide. The PayPal API makes powerful functionality available to developers by exposing various features of the PayPal platform. Functionality includes but is not limited to invoice management, transaction processing and account management
PayPal is the most popular platform for receiving online payments today. The ease of opening a PayPal account and receiving payments compared to opening a merchant account with a traditional payment gateway is probably the number one reason for its popularity, with a close second being the comprehensive API that PayPal provides for its payment services. In this post, I will break down some of the techniques and approaches to working with the PayPal API, in order to make integration and troubleshooting simpler and easier.
The Different Payment Options
PayPal offers a variety of payment options, which might be confusing at first:
MAKING API REQUESTS
The premier PayPal service. Express Checkout allows you to receive payments without having a merchant account and without having to meet special requirements other than verifying your account (either via a bank account or a credit card). Previously, you could receive Express Checkout payments from PayPal users only, but PayPal has since added a credit-card option for non-PayPal users, making this service accessible to practically anyone with a major credit card. Note that the Express Checkout process occurs on PayPal’s platform and thus can never be fully integrated in your website’s experience.
- Direct Payment
The Direct Payment method allows you to receive credit-card payments directly through an API call. This enables you to host the payment process on your website in full, which might make for a more complete shopping experience for your customers. The Direct Payment method has several variations that enable you to authorize a payment and complete it at a later date: the appropriately named Authorization and Capture methods. These variations are a part of the Website Payments Pro API, which is available only to US, Canadian and UK accounts.
- Recurring Payments.
This allows you to set up a recurring transaction (i.e. a subscription payment)
- Mass Payments
This allows you to transfer money to multiple accounts at once.
- Adaptive Payments
Here is another API for sending funds to multiple recipients, with some differences from the Mass Payments API. (Did I mention that the PayPal API is confusing and a bit redundant?)
PayPal supports two main formats over HTTP: NVP and SOAP. NVP is short for Name-Value Pair, and SOAP stands for Simple Object Access Protocol. I will cover the NVP approach, which I prefer to SOAP’s relatively verbose and complex syntax.
Each of the API methods has different parameters, but they all share some basic parameters, which are used to identify the API account and sign the transaction. These include:
Your PayPal API user name.
Your PayPal API password.
The version number of the NVP API service, such as 74.0 (the most recent as of this writing).
Your PayPal API signature string. This parameter is optional if you use a certificate to authenticate.
More Details About PayPal API : http://coding.smashingmagazine.com/2011/09/05/getting-started-with-the-paypal-api/