Brummer MCP Server

# MCP Activity Tracking Implementation ## Overview Updated the MCP diagnostics tab in brummer to show actual MCP activity instead of mock data. The implementation tracks all MCP connections and requests in real-time. ## Changes Made ### 1. Event System Updates (`pkg/events/events.go`) - Added new event types: - `MCPActivity`: Tracks MCP request/response activity - `MCPConnected`: Tracks new MCP client connections - `MCPDisconnected`: Tracks MCP client disconnections ### 2. MCP Server Activity Tracking (`internal/mcp/streamable_server.go`) - Modified `processMessage()` to track all MCP activity: - Records method, params, response, error, and duration - Publishes `MCPActivity` event for each request - Modified `handleStreamingConnection()` to track connections: - Publishes `MCPConnected` event when SSE connection established - Publishes `MCPDisconnected` event when connection closes - Includes session ID and client info (User-Agent) ### 3. TUI Model Updates (`internal/tui/model.go`) - Added fields to track MCP data: - `mcpConnections`: Map of session ID to connection info - `mcpActivities`: Map of session ID to activity history - `mcpActivityMu`: Mutex for thread-safe access - Added message types: - `mcpActivityMsg`: Carries MCP activity data - `mcpConnectionMsg`: Carries connection/disconnection events - Added event handlers: - `handleMCPConnection()`: Updates connection tracking - `handleMCPActivity()`: Records activity and updates stats - Updated view switching to refresh MCP data when entering MCP view ### 4. MCP Connections View (`internal/tui/mcp_connections.go`) - Updated `updateMCPConnectionsList()` to use real connection data - Updated `updateMCPActivityView()` to display real activity logs - Enhanced formatting: - Shows timestamp with milliseconds - Shows method names and duration - Shows params and responses (truncated if too long) - Uses arrows (→ ←) for better visual flow - Shows error messages in red ## How It Works 1. **Connection Tracking**: - When a client connects via SSE, a `MCPConnected` event is published - Connection info includes session ID, timestamp, and client User-Agent - Client name is extracted from User-Agent (e.g., "Claude Desktop", "VS Code MCP") 2. **Activity Tracking**: - Every MCP request/response is tracked via `MCPActivity` events - Activity includes method, parameters, response/error, and duration - Activities are stored per session (last 100 per session) 3. **TUI Display**: - Left panel shows active/inactive connections with stats - Right panel shows activity log for selected connection - Activity shown in reverse chronological order (newest first) - Real-time updates as new activity occurs ## Usage 1. Start brummer in debug mode to enable MCP diagnostics: ```bash brum --debug ``` 2. Navigate to the MCP view: - Press Tab or arrow keys to cycle through views - Or press 7 (if using number keys) 3. Select a connection to view its activity: - Use arrow keys to navigate connections - Press Enter to select and view activity ## Testing A test was added to verify activity tracking: - `internal/mcp/activity_test.go`: Tests that events are properly published The implementation has been tested with: - Multiple concurrent MCP requests - SSE streaming connections - Various MCP methods (initialize, tools/list, tools/call, etc.)