A product-based JavaScript API client should enable seamless interaction between a front-end application and back-end servers or services, while providing easy access to the full range of features in the application it serves. Additionally, an API client should offer valuable additional functionality, such as customizable parameters and improved logging capabilities, allowing developers to create more robust applications. A product-based API client can also be used by companies to sell their software platform as a product, with the client available in multiple programming languages and frameworks. By using a JavaScript API client, SaaS companies can simplify front-end code and improve response times, while managing challenges related to client-side application development and the specificities of the JavaScript language. Recent improvements have enhanced the flexibility and customizability of the API client, including tree shakeable methods, non-opinionated requests, and improved logging capabilities.