Prompt Joy is a tool to help understand and debug LLM (Large Language Model) prompts. Its main features include logging and A/B testing. Logging can record the LLM's requests and responses, making it easy to check the output results. Split testing allows for easy A/B testing to find the best-performing prompts. It is decoupled from specific LLMs and can be used with OpenAI, Anthropic, and other LLMs. It provides APIs for logging and split testing. Built with Node.js + PostgreSQL.