FacTool, developed by GAIR-NLP, is a tool designed to detect factuality in generative artificial intelligence. The tool is hosted on GitHub, allowing users to contribute to its development through the open-source platform. FacTool is primarily used in the realm of Natural Language Processing to determine the factuality of content produced by generative models. It represents a significant contribution to the field of AI by automating and enhancing the process of fact-checking, adding an additional layer of reliability to generated content. FacTool operates under an Apache-2.0 license which allows for free use, modification, and distribution of the tool under certain conditions. The FacTool repository offers multiple features and resources including datasets, example work files, as well as security and insights sections to assist users in effectively utilizing the tool. The tool's progressive updates and potential enhancements are managed through branches, pull requests and commits, ensuring iterative improvement and development. Note that continuous updates may occur as it is maintained on a regular basis by the user community on GitHub.