CICS and the Model Context Protocol
6.3 Applies to 6.3.
The Model Context Protocol (MCP) is an open protocol that standardizes how applications send and receive requests to LLMs and other tools and resources.
How does MCP work?
A Large Language Model (LLM) cannot know up to date information or perform actions against existing systems, which are constantly changing. To allow applications to perform functions, they must call tools to perform the specific function needed. MCP standardizes how agents and AI applications make requests to and receive responses from these various tools and understand the available capabilities.
While you might build some of these tools, for others you want to re-use from existing providers. Tools are aggregated into sets, known as toolboxes
A client, usually an AI application, makes a request to an MCP server, which in CICS is called the CICS MCP server. The request uses the MCP protocol as a standard for sending requests from the client and receiving responses from the MCP server.
MCP provides the ability to reference and use tools in a solution that you don’t control. Most solutions that use this functionality are agentic, allowing an AI to make decisions about which tools to use.
For more information about the protocol, see Model Context Protocol.
How does the CICS MCP server operate?
CICS already provides an interface, by means of CMCI, which fits the needs of MCP in CICS . The CICS MCP server runs in a CMCI JVM server called EYUCMCIJ.
The MCP server in CICS uses Server-Sent Events (SSE) within the CMCI JVM server environment.
Applications written to make use of the CICS MCP server call a toolbox end point, which identifies the available tools to the application by using the protocol. The application can then call a desired tool based on the MCP details for that tool.
The CICS MCP server supports tool calling. Applications written to make use of the CICS MCP server call a toolbox end point, which identifies the available tools to the application by using the protocol. The application can then call a desired tool based on the MCP details for that tool.
Security configuration for the CICS MCP server is covered in How the CMCI JVM server authenticates clients.