Designing a REST API for a payment gateway requires more than just functionality. It requires a carefully structured and consistent approach to ensure that developers can understand, use, and integrate with your API efficiently. Here, we’ll cover REST API best practices specifically tailored for a payment gateway API, emphasizing clarity, usability, and security. Use Nouns for Resources A well-named API uses nouns to represent resources rather than actions. In a payment gateway API, endpoints should focus on entities such as payments , transactions , customers , and invoices . For example: Do : POST /transactions to initiate a transaction. Avoid : POST /makePayment since it implies an action rather than a resource. Using nouns clarifies the intent of each endpoint and aligns with RESTful principles. Use Consistent Pluralization for Collections Consistency in naming conventions improves the intuitiveness of your API. For collections, use pl...