Shipping Tool aims to develop a modular shipping rate checker integrating FedEx, UPS, and USPS APIs. It will accept shipment details from various sources, query the carriers for rates, normalize services, and return results. The system will compare discounted and retail rates, highlighting the best options. It includes a REST API for input, a report generation feature, and a modular design for scalability. Key functionalities involve carrier API integrations, rate normalization, input processing, and output generation. Non-functional requirements focus on performance, security, scalability, reliability, and usability. The project includes a timeline for development, testing, and deployment.