US IRS free online tax filing open source repo

The IRS has released Direct File, an open-source free tax filing service that allows U.S. taxpayers to electronically file federal tax returns directly with the IRS through an interview-based platform available on multiple devices and in English and Spanish. The service converts plain-language answers into standard tax forms and uses a knowledge graph system to handle incomplete information, with additional features enabling integration with state tax filing tools. The open-source repository includes the tax logic, test cases, and technical infrastructure that may be useful for other organizations developing tax software or business rules engines.