How to Secure a Spring AI MCP Server with an API Key via Spring Security

Instead of building custom integrations for a variety of AI assistants or Large Language Models (LLMs) you interact with — e.g., ChatGPT, Claude, or any custom LLM — you can now, thanks to the Model Context Protocol (MCP), develop a server once and use it everywhere. 

This is exactly as we used to say about Java applications; that thanks to the Java Virtual Machine (JVM), they’re WORA (Write Once Run Anywhere). They’re built on one system and expected to run on any other Java-enabled system without further adjustments.