Athena: Intermediate Representations for Iterative Scaffolded App Generation with an LLM

It is challenging to generate the code for a complete user interface using a Large Language Model (LLM). User interfaces are complex and their implementations often consist of multiple, inter-related files that together specify the contents of each screen, the navigation flows between the screens, and the data model used throughout the application. It is challenging to craft a single prompt for an LLM that contains enough detail to generate a complete user interface, and even then the result is frequently a single large and intricate file that contains all of the generated screens. In this paper, we introduce Athena, a prototype application generation environment that demonstrates how the use of shared intermediate representations, including an app storyboard, data model, and GUI skeletons, can help a developer work with an LLM in an iterative fashion to craft a complete user interface. These intermediate representations also scaffold the LLM’s code generation process, producing organized and structured code in multiple files while limiting errors. We evaluated Athena with a user study with 12 developers. Participants appreciated Athena’s support for prototyping multi-screen iOS apps, acknowledged that the intermediate representations improved their control and understanding of generated code, and discussed the limitations of the system and potential directions for improvement.