Etarn (ETAN) is a Web3 sustainability project addressing global sanitation and agricultural issues. Its "Toilet-to-Earn" model uses smart toilets that convert human waste into organic fertilizer. The technology also generates verified emission reductions for carbon credits.

The project creates utility through advertising revenue and anonymized data collection. A portion of revenues funds ETAN token buybacks and user rewards, linking the token to real-world economic activity. This model aims to improve public health and build a scalable, environmentally-focused token economy.