This paper introduces JANUS, a Stablecoin 3.0 protocol designed to address the stablecoin trilemma--simultaneously improving decentralization (D), capital efficiency (E), and safety-stability (S). Building upon insights from previous stablecoin generations, JANUS leverages a dual-token system (Alpha and Omega), integrates crypto-assets and real-world assets (RWAs), employs a soft-peg mechanism, and utilizes AI-driven stabilization. We provide a comprehensive theoretical framework, including formal definitions of D, E, and S, along with equilibrium existence proofs and analogies drawn from international trade and open-economy macroeconomics. By introducing a second token backed by external yield, JANUS breaks from ponzinomic dynamics and creates a more robust foundation. Multi-collateralization and a soft peg enable controlled price oscillations, while AI-driven parameter adjustments maintain equilibrium. Through these innovations, JANUS aims to approach the center of the stablecoin trilemma, offering a globally resilient, inflation-adjusted, and decentralized stablecoin ecosystem bridging DeFi and TradFi. The main body presents a high-level overview of the trilemma and JANUS's key features, while the Appendix provides more formal mathematical treatments, including rigorous metrics for decentralization, capital efficiency, and stability, as well as the optimization challenges inherent in the trilemma.

翻译：本文提出JANUS——一种旨在解决稳定币三难困境（即同时提升去中心化程度（D）、资本效率（E）与安全稳定性（S））的Stablecoin 3.0协议。基于对前几代稳定币的深入分析，JANUS采用双代币系统（Alpha与Omega），整合加密资产与现实世界资产（RWA），运用软挂钩机制，并引入人工智能驱动的稳定策略。我们提供了一个完整的理论框架，包括对D、E、S的形式化定义、均衡存在性证明，以及从国际贸易与开放经济宏观经济学中汲取的类比。通过引入由外部收益支持的第二代币，JANUS摆脱了庞氏经济模式，建立了更稳健的基础。多重抵押与软挂钩机制允许可控的价格波动，而人工智能驱动的参数调整则维持系统均衡。借助这些创新，JANUS力求逼近稳定币三难困境的核心解，构建一个连接DeFi与传统金融（TradFi）、具备全球韧性、通胀调整且去中心化的稳定币生态系统。正文部分对三难困境及JANUS的关键特性进行了高层概述，附录则提供了更形式化的数学处理，包括去中心化、资本效率与稳定性的严格度量指标，以及三难困境中固有的优化挑战。