
Savvy merchants know in order to stay relevant and successful as sellers, they need to keep up with the ongoing digital transformation in the retail and selling sectors. Innovations in merchandising, discovery, payments, distribution, sales & customer service are all things merchants need to consider for running a profitable enterprise. Luckily, there is plenty of technological assistance for all of those tasks, in the form of APIs.
What is a Merchants API?
A Merchants API is an Application Programming Interface in which developers can utilize for adding functions and services to applications for merchants.
Developers looking to find suitable APIs for creating their Merchants applications should head to the Merchants category of the ProgrammableWeb API directory.
In this article, we provide details of ten of the most popular APIs in that category, based on reader interest and web page visits.
1. Shopify Admin API
Shopify's ecommerce APIs provide a way to create apps for merchants, and detailed SDKs, tutorials that includes access to dedicated API and developer support. The Shopify Admin API allows you to build applications and integrations for Shopify Admin with methods to manage access, analytics, billing, customers, discounts, events, inventory, marketing event, online store, orders, products, sales channels, shipping and fulfillment, Shopify Payments and more.
2. Credit Reporting Services
Credit Reporting Services (CRS) is a credit reporting agency certified as a re-seller for Experian, TransUnion, and Equifax. The company offers services for industries requiring credit data. The company's XML Credit Report API is available for providing credit report data.

Screenshot: Credit Reporting Services
3. Delivery.com API
Delivery.com offers laundry, food, alcohol, and grocery delivery in over 38 cities of the United States and abroad. The Delivery.com API overviews how to make requests and how to receive HTTP response codes. Users can sign up for an API Key to implement laundry delivery services into mobile apps.
4. Amazon Selling Partner API
The Amazon Selling Partner API (SP-API) provides all the legacy functionality offered to developers via Amazon Market Web Services Track this API with improvements including REST-based format and JSON outputs. The API offers methods to build applications for use with your own Amazon seller account, build applications for sellers to authorize and use to help manage their Amazon business, and to publish applications to the Amazon Marketplace Appstore.
5. Mastercard Payment Gateway Services API
Mastercard Payment Gateway Services enables customers to accept and process transactions across eCommerce, mobile commerce, and cardholder present channels such as mail order, call center, or SMS, on any device. The API features JSON responses for managing browser payments, merchants, orders including currency and refunds, and transactions.
6. Payfort API
The Payfort REST API integrates payments into merchant applications in the Middle East. JSON formats are available to perform callbacks that display amount, customer, language, payment and signature in return. Payfort is an Amazon company.
7. Bypass API
Bypass is a commerce service and solution for sports and event venues. Bypass offers commerce solutions for concessionaires and merchants that work in sports and event venues.The Bypass API allows developers to access and integrate the functionality of Bypass with other applications.

Screenshot Bypass
8. Cashfree API
Cashfree offers payments solutions for fintech companies and marketplaces. The Cashfree REST API allows developers to access and integrate the functionality of Cashfree with other applications. Some example API methods include integration with payment gateways and processing payments.
Also of Interest: 11 Popular Marketplace APIs
9. Square API
Square helps consumers to pay with card in a mobile environment. The Square Connect API offers functions for point of sale transactions with cards using iPad, iPhone, and Android. Retrieve reports for users' payments, refunds, and settlements, as well as manage merchant's items with this API.
10. Verifone Open API
Verifone's Platform allows applications to be added to Point of Sale terminals. The platform is accessible via interaction with the Commerce Applications SDK. Verifone is a global technology provider for electronic payment and point-of-sale services. The company provides services to the financial, retail, hospitality, government, petroleum and other industries.
Find more APIs, plus SDKs and other developer resources in the Merchants category.