Stop Hand-Rolling AI Glue: Claude 4 MCP + Spring AI is the New Enterprise Standard In 2026, if you are still building proprietary wrappers to connect LLMs to your microservices, you are creating technical debt that will haunt your team for years. The industry has consolidated around Claude 4 and the Model Context Protocol (MCP) because it finally brings the type safety and standardized discovery we’ve lacked in the "prompt engineering" era. Why Most Developers Get This Wrong Schema Drift: Treating LLM tools as loosely typed REST calls, leading to Claude 4 hallucinating parameter types and crashing your downstream services. Over-Orchestration: Building complex "Agent Frameworks" from scratch instead of using Spring AI’s native MCP client to handle the JSON-RPC over SSE handshake. Security Blindness: Exposing raw database access to the model instead of defining granular McpResource boundaries via the Java SDK.…