DemoGPT, in collaboration with LangChain, aims to simplify the creation of applications powered by Large Language Models (LLMs) by utilizing a structured approach to code generation and leveraging the capabilities of Foundation Models. Built on LangChain and Streamlit, DemoGPT facilitates the auto-generation of applications through a series of stages including planning, task creation, code snippet generation, and combining code snippets. This process, which incorporates self-refining techniques to minimize hallucinations and optimize functionality, allows for the efficient development of applications using lighter models like GPT-3.5. The collaboration introduces the DemoGPT Marketplace, a platform where developers and AI enthusiasts can showcase, exchange, and monetize their applications, fostering a dynamic and user-centric ecosystem. This partnership not only enhances the interactivity and user experience of applications but also promotes a continuous cycle of creation, feedback, and refinement, bridging the gap between creators and consumers in the LLM landscape.