Contemporary software architectures struggle to support autonomous agents whose reasoning is adaptive, probabilistic, and context-dependent, while system integration remains dominated by static interfaces and deterministic contracts. This paper introduces Liquid Interfaces, a coordination paradigm in which interfaces are not persistent technical artifacts, but ephemeral relational events that emerge through intention articulation and semantic negotiation at runtime.We formalize this model and present the Liquid Interface Protocol (LIP),which governs intention-driven interaction, negotiated execution, and enforce ephemerality under semantic uncertainty. We further discuss the governance implications of this approach and describe a reference architecture that demonstrates practical feasibility. Liquid Interfaces provide a principled foundation for adaptive coordination in agent-based systems

翻译：当代软件架构难以支撑具有适应性、概率性及上下文依赖性的自主智能体推理，而系统集成领域仍被静态接口与确定性契约所主导。本文提出液态接口这一协调范式，其中接口并非持久性技术构件，而是通过运行时意图表达与语义协商涌现的瞬时关系事件。我们形式化该模型并提出液态接口协议，该协议在语义不确定性条件下规范意图驱动交互、协商式执行并强制瞬时性。我们进一步探讨该方法的治理意义，并描述论证其实际可行性的参考架构。液态接口为基于智能体的系统提供了自适应协调的理论基础。