I am building an MCP (Model Context Protocol) server using Ballerina and exposing tools for an AI agent. I need to fetch user-specific data from a JWT (passed in the Authorization header of the HTTP request) to authorize and customize the behavior of my tool calls.

Since Ballerina's MCP implementation abstracts the transport layer, my onCallTool method only gives me access to the mcp:CallToolRequest and mcp:Session objects.