Enterprise operations rely heavily on multiple heterogeneous business systems and information applications, resulting in severe data silos and process fragmentation. Conventional enterprise application integration approaches, including Enterprise Service Bus (ESB), API gateway infrastructures, and Robotic Process Automation (RPA), suffer from limitations such as high architectural coupling, escalating operation and maintenance costs, and limited intelligence capabilities. This paper proposes Agentic Nesting, a multi-agent collaboration framework where existing enterprise applications are encapsulated as autonomous AI agents within a hierarchically nested structure. Agents are organized into layered stewardship topologies, and a digital agent proxy is extracted from each legacy application to enable natural-language interaction and autonomous manipulation. The framework coordinates multiple agents through a central orchestrator for task decomposition and dynamic dispatching, and exposes a unified conversational interface for cross-application querying and process orchestration. The main contributions of this paper are the proposition of the "Application-as-Agent" integration paradigm and the "Conversation-as-Integration" interaction philosophy, along with an exploration of the generalization potential of this methodology in scenarios encompassing heterogeneous system coordination and large-scale data applications. Blogger's Review: Agentic Nesting provides a new perspective on enterprise application integration by encapsulating applications as autonomous agents, achieving a more flexible and intelligent integration approach, which may be the future direction of enterprise application integration.