Mock sample for your project: Zettle Product Library API

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

Use this api to fetch information to Amazon products and more.

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.

Terms and Definitions
Throughout this document and the Velo platform the following terms are used:
Payor. An entity (typically a corporation) which wishes to pay funds to one or more payees via a payout.
Payee. The recipient of funds paid out by a payor.
Payment. A single transfer of funds from a payor to a payee.
Payout. A batch of Payments, typically used by a payor to logically group payments (e.g. by business day). Technically there need be no relationship between the payments in a payout - a single payout can contain payments to multiple payees and/or multiple payments to a single payee.
Sandbox. An integration environment provided by Velo Payments which offers a similar API experience to the production environment, but all funding and payment events are simulated, along with many other services such as OFAC sanctions list checking.
Overview
The Velo Payments API allows a payor to perform a number of operations. The following is a list of the main capabilities in a natural order of execution:
Authenticate with the Velo platform
Maintain a collection of payees
Query the payor’s current balance of funds within the platform and perform additional funding
Issue payments to payees
Query the platform for a history of those payments
This document describes the main concepts and APIs required to get up and running with the Velo Payments platform. It is not an exhaustive API reference. For that, please see the separate Velo Payments API Reference.
API Considerations
The Velo Payments API is REST based and uses the JSON format for requests and responses.
Most calls are secured using OAuth 2 security and require a valid authentication access token for successful operation. See the Authentication section for details.
Where a dynamic value is required in the examples below, the {token} format is used, suggesting that the caller needs to supply the appropriate value of the token in question (without including the { or } characters).
Where curl examples are given, the –d @filename.json approach is used, indicating that the request body should be placed into a file named filename.json in the current directory. Each of the curl examples in this document should be considered a single line on the command-line, regardless of how they appear in print.
Authenticating with the Velo Platform
Once Velo backoffice staff have added your organization as a payor within the Velo platform sandbox, they will create you a payor Id, an API key and an API secret and share these with you in a secure manner.
You will need to use these values to authenticate with the Velo platform in order to gain access to the APIs. The steps to take are explained in the following:
create a string comprising the API key (e.g. 44a9537d-d55d-4b47-8082-14061c2bcdd8) and API secret (e.g. c396b26b-137a-44fd-87f5-34631f8fd529) with a colon between them. E.g. 44a9537d-d55d-4b47-8082-14061c2bcdd8:c396b26b-137a-44fd-87f5-34631f8fd529
base64 encode this string. E.g.: NDRhOTUzN2QtZDU1ZC00YjQ3LTgwODItMTQwNjFjMmJjZGQ4OmMzOTZiMjZiLTEzN2EtNDRmZC04N2Y1LTM0NjMxZjhmZDUyOQ==
create an HTTP Authorization header with the value set to e.g. Basic NDRhOTUzN2QtZDU1ZC00YjQ3LTgwODItMTQwNjFjMmJjZGQ4OmMzOTZiMjZiLTEzN2EtNDRmZC04N2Y1LTM0NjMxZjhmZDUyOQ==
perform the Velo authentication REST call using the HTTP header created above e.g. via curl:
If you make other Velo API calls which require authorization but the Authorization header is missing or invalid then you will get a 401 HTTP status response.

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.

Note: This is a (Limited Release) API available only to select developers approved by business units. The Logistics API resources offer the following capabilities: shipping_quote – Consolidates into a list a set of live shipping rates, or quotes, from which you can select a rate to ship a package. shipment – Creates a "shipment" for the selected shipping rate. Call createShippingQuote to get a list of live shipping rates. The rates returned are all valid for a specific time window and all quoted prices are at eBay-negotiated rates. Select one of the live rates and using its associated rateId, create a "shipment" for the package by calling createFromShippingQuote. Creating a shipment completes an agreement, and the cost of the base service and any added shipping options are summed into the returned totalShippingCost value. This action also generates a shipping label that you can use to ship the package. The total cost of the shipment is incurred when the package is shipped using the supplied shipping label. Important! Sellers must set up a payment method via their eBay account before they can use the methods in this API to create a shipment and the associated shipping label.

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

Import your orders, retrieve your orders and generate labels.

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.

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.