Mock sample for your project: Magento B2B 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.

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.

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

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

Just Eat API
Just Eat offers services for our various business partners and our consumer applications.
How you interact with the API depends on the services you wish to interact with.
Security
HTTPS
All api calls and callbacks require HTTPS. Your service will need a valid SSL certificate and be accessible via the standard SSL port (port 443).
Making an API request
Some API calls require an API key, to authenticate the partner calling the API.

reverb

The Browse API has the following resources: itemsummary: Lets shoppers search for specific items by keyword, GTIN, category, charity, product, or item aspects and refine the results by using filters, such as aspects, compatibility, and fields values. (Experimental) searchbyimage: Lets shoppers search for specific items by image. You can refine the results by using URI parameters and filters. item: Lets you retrieve the details of a specific item or all the items in an item group, which is an item with variations such as color and size and check if a product is compatible with the specified item, such as if a specific car is compatible with a specific part. Provides a bridge between the eBay legacy APIs, such as Finding, and the RESTful APIs, which use different formats for the item IDs. (Experimental) shoppingcart: Provides the ability for eBay members to see the contents of their eBay cart, and add, remove, and change the quantity of items in their eBay cart. Note: This resource is not available in the eBay API Explorer. The itemsummary, searchbyimage, and item resource calls require an Application access token. The shoppingcart resource calls require a User access token.

This API allows 3rd party developers to translate item title, description, search query.

Polls is a simple API allowing consumers to view polls and vote in them.

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.