PromptLayer is a tool for tracking and managing GPT prompt engineering. It functions as an intermediary between code and the OpenAI Python library, recording all API requests made to OpenAI and allowing users to search and review their request history on the PromptLayer dashboard. To utilize PromptLayer, users need to sign up and generate an API key. The platform can be installed via pip and used with OpenAI APIs by including an additional pl_tags argument, enabling users to track and categorize requests on the dashboard.