Mock sample for your project: Qualpay Payment Gateway API

Note: This is a (Limited Release) API available only to select developers approved by business units. Enables a seller adding an ad or item on a Partner's site to automatically create an eBay listing draft using the item details from the Partner's site.

A product library is a representation of all the items that can be
displayed, put in a shopping cart and sold to a customer. Items may be
either producs or discounts.
A product is a synthetic construct, wrapping one or more variants (which is
the actual item being sold) Variants expresses different variations of
properties such as for example price, size or color. A discount will reduce
the total amount charged in a shopping cart. It can be used per item line,
or on the whole cart. It may reduce the affected amount by a percentage, or
by a fixed amount.
Together, the above types of entities makes up a complete library. The
library can be fetched as a whole through the library endpoint, where each
consecutive change applied to the library is available. Once the full
library is retrieved, only later events needs to be fetched to keep the
client up to date with the server
All path patterns "/organizations/{organizationUuid}/" can be replaced
with "/organizations/self/" for convenience as all endpoints are for
authorized users.

Service for providing information to sellers about their listings being non-compliant, or at risk for becoming non-compliant, against eBay listing policies.

Documentation of the Billbee REST API to connect a Billbee account to external aplications.
Endpoint
The Billbee API endpoint base url is https://app.billbee.io/api/v1
Activation
You have to enable the API in the settings of your Billbee account. In addition you need a Billbee API Key identifying the application you develop. To get an API key, send a mail to [email protected] and send us a short note about what you are building.
Authorization & security
Because you can access private data with the Billbee API, every request has to be sent over https and must
Contain a valid API Key identifying the application/developer. It has to be sent as the HTTP header X-Billbee-Api-Key
Contain a valid user login with billbee username and api password in form of a basic auth HTTP header
Throttling
Each endpoint has a throttle of max 2 requests per second per combination of API Key and Billbee user.
When you exceed these 2 calls, the API will return a HTTP 429 status code

The DocuSign REST API provides you with a powerful, convenient, and simple Web services API for interacting with DocuSign.

https://www.beanstream.com/api/v1

The Feed API lets sellers upload input files, download reports and files including their status, filter reports using URI parameters, and retrieve customer service metrics task details.

Note: This is a (Limited Release) API available only to select developers approved by business units. The Feed API provides the ability to download TSV_GZIP feed files containing eBay items and an hourly snapshot file of the items that have changed within an hour for a specific category, date and marketplace. In addition to the API, there is an open source Feed SDK written in Java that downloads, combines files into a single file when needed, and unzips the entire feed file. It also lets you specify field filters to curate the items in the file.

The Analytics API provides data and information about a seller and their eBay business. The resources and methods in this API let sellers review information on their listing performance, metrics on their customer service performance, and details on their eBay seller performance rating. The three resources in the Analytics API provide the following data and information: Customer Service Metric – Returns data on a seller's customer service performance as compared to other seller's in the same peer group. Traffic Report – Returns data that shows how buyers are engaging with a seller's listings. Seller Standards Profile – Returns data pertaining to a seller's performance rating. Sellers can use the data and information returned by the various Analytics API methods to determine where they can make improvements to increase sales and how they might improve their seller status as viewed by eBay buyers. For details on using this API, see Analyzing seller performance.

Note: This is a (Limited Release) API available only to select developers approved by business units. Retrieves the authenticated user's account profile information. It can be used to let users log into your app or site using eBay, which frees you from needing to store and protect user's PII (Personal Identifiable Information) data.

The Charity API allows third-party developers to search for and access details on supported charitable organizations.

The Account API gives sellers the ability to configure their eBay seller accounts, including the seller's policies (the Fulfillment Policy, Payment Policy, and Return Policy), opt in and out of eBay seller programs, configure sales tax tables, and get account information. For details on the availability of the methods in this API, see Account API requirements and restrictions.