Utilizing the ChatGPT API(and also Azure OpenAI Service) presents challenges: it's hard to discern its accuracy and value without creating a product, yet building it can be time-consuming and costly. We specializes in contracted development of products utilizing generative AI. By consolidating frequently developed features and screens into this product as a common platform, we offer prototype development for value verification in just a few hours to days. This allows for efficient validation without significant time or cost, ensuring confident investment for full-scale development. With the release of LangCore, we believe more companies and developers will be able to efficiently harness the power of the ChatGPT API.