Fibers extracted from the indigenous banana plants in Kerala, have long been utilized by local craftspeople to create a diverse array of craft products, situating banana fiber craft within the robust craft heritage of India. While it is essential for craft products to adhere to a certain language to maintain a shared identity, innovation is imperative to keep up with the ever-changing market requirements. Our field research revealed that the banana fiber craftspeople often encounter challenges in fulfilling customer requests for customized products, as unfamiliar patterns and forms demand an extremely high degree of skill and attention to detail. In this study, the design researchers collaborate with the craftspeople by first grasping the nuances of the craft practice through apprenticeship. Later, the insights gained through the field research were utilized to develop a computational design tool such as shape grammar. The banana fiber craft shape grammar has diverse applications, including ease of transmission of crafting knowledge. The principles of the shape grammar were further utilized to develop a physical tool that works as a modular template for new pattern development. This demonstrates the possibilities in the application of shape grammars for design exploration in Indian crafts.