mbta-mpc-server

// ABOUTME: This file implements logging middleware for the MCP server. // ABOUTME: It provides request/response logging and timing functionality. package server import ( "context" "log" "time" "github.com/mark3labs/mcp-go/mcp" mcpserver "github.com/mark3labs/mcp-go/server" ) // loggingMiddleware creates a middleware that logs request and response information. // It wraps the original handler and provides timing and debug information. func loggingMiddleware(debug bool) mcpserver.ToolHandlerMiddleware { return func(next mcpserver.ToolHandlerFunc) mcpserver.ToolHandlerFunc { return func(ctx context.Context, req mcp.CallToolRequest) (*mcp.CallToolResult, error) { // Log basic request information log.Printf("[INFO] Request received: tool=%s", req.Params.Name) // Log parameters if in debug mode if debug { log.Printf("[DEBUG] Request arguments: %v", req.Params.Arguments) } // Record start time for duration calculation startTime := time.Now() // Call the actual handler resp, err := next(ctx, req) // Calculate request duration duration := time.Since(startTime) // Log response information if err != nil { log.Printf("[ERROR] Request error: tool=%s error=%v duration=%v", req.Params.Name, err, duration) return nil, err } // Log success information log.Printf("[INFO] Request completed: tool=%s duration=%v", req.Params.Name, duration) // Log more detailed response information in debug mode if debug && resp != nil { // Log error details if present if resp.IsError { log.Printf("[DEBUG] Response marked as error") } else { log.Printf("[DEBUG] Response content length: %d", len(resp.Content)) } } return resp, nil } } } // ApplyMiddleware applies the middleware to the server. // This applies the logging middleware to all handlers. func (s *Server) ApplyMiddleware() { log.Println("Applying logging middleware to MCP server") // We can't apply middleware globally with the current mcp-go API, // so we'll need to manually wrap each tool handler when it's registered. // This would be done in the registerTransitInfoTools function. // For now, we just log that middleware would be applied. if s.config.Debug { log.Printf("[DEBUG] Applied logging middleware to MCP server") } } // wrapWithMiddleware wraps a tool handler with middleware. // This is a helper function that can be used when registering tools. func (s *Server) wrapWithMiddleware(handler mcpserver.ToolHandlerFunc) mcpserver.ToolHandlerFunc { // Apply logging middleware return loggingMiddleware(s.config.Debug)(handler) }