Mock sample for your project: Zalando Shop API

The Metadata API has operations that retrieve configuration details pertaining to the different eBay marketplaces. In addition to marketplace information, the API also has operations that get information that helps sellers list items on eBay.

API2Cart

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

The Marketing API retrieves eBay products based on a metric, such as Best Selling, as well as products that were also bought and also viewed.

One API serving data spanned across multiple verticals

Use the Taxonomy API to discover the most appropriate eBay categories under which sellers can offer inventory items for sale, and the most likely categories under which buyers can browse or search for items to purchase. In addition, the Taxonomy API provides metadata about the required and recommended category aspects to include in listings, and also has two operations to retrieve parts compatibility information.

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 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.

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.

dropX.io API provides programmatic access to the e-commerce intelligence data.

Allows sellers to: 1) Load products definitions to the BrandLovers marktplace. 2) Receive and update orders status. 3) Receive and update shipping information. 4) Receive and update customer tickets. All requests consume and return application/json content. All request must be authenticated and use HTTPS.