Toward a Unified Data Access Layer: An Architectural Framework for Real-Time System Integration Using the Model Context Protocol

Organizations in the public and private sectors are fundamentally limited by systemic data fragmentation, where critical information is trapped in disparate silos of the legacyera. This paper proposes a novel architectural framework that uses the Model Context Protocol (MCP) to create a unified data abstraction layer. By deploying lightweight, domain-specific MCP servers as façades, complex backend infrastructure is exposed as standardized, callable "tools." We detail a governance model using an API Gateway to enforce security and manage costs through a tiered strategy, enabling secure data consumption for AI-enabled applications. We further investigate technical implementations within Azure and Google Cloud, protocol-level requirements (JSON-RPC 2.0), and performance optimizations for agentic streaming.