A reusable foundation for understandable tax rules
Fact Graph connects inputs with declarative rules so a calculation can resolve the values that depend on them. yTax builds on this framework, used by IRS Direct File, with its own tax dictionary and application.
Separating the rules from the application creates a useful foundation for examining tax logic and discussing how it should evolve.
Fact Graph and Direct File
IRS Direct File let eligible taxpayers prepare and electronically file federal returns at no charge. Fact Graph was its reusable calculation framework. IRS source repository
A brief history
2024 filing season — tax year 2023: Direct File launched as a pilot in 12 states. IRS pilot announcement
2025 filing season — tax year 2024: It expanded to 25 states and additional tax situations. IRS expansion announcement
2026 filing season — tax year 2025: The service was unavailable following its suspension in 2025. State revenue agency notice
Framework, rules and public code
Fact Graph evaluates connected facts and declarative rules, including when some inputs are still missing. The framework is reusable; a tax dictionary supplies the rules for a particular year and scope. Technical overview
The archived Direct File release includes application code and tax-year 2024 questions, logic and tests—not just the framework. Fact Graph also has its own repository. Direct File · Fact Graph
The upstream notices state public-domain treatment in the United States and a worldwide CC0 dedication. Third-party dependencies and yTax contributions have their own applicable terms. Direct File license · Fact Graph license