The Zoho Books API is accounting software for small businesses. It is RESTful, HTTP and JSON formatted, and allows access to all the typical Zoho Books functionalities, while also offering a platform for customization. Through Zoho Books, users can send invoices, accept payments, and manage and categorize cash flow. Access to documentation requires a Zoho username and password. However, Zoho does offer free trials. With a paid membership users are limited to 2500 API requests per day per business.