Fix dependency issue in history - export types for users to import so that they do not silently fail to append the message in history

Author: pietrozullo

index.ts

@@ -19,10 +19,10 @@ export * from './src/managers/tools/index.js'
 // Export telemetry utilities
 export { setTelemetrySource, Telemetry } from './src/telemetry/index.js'
 
+// Re-export message classes to ensure a single constructor instance is shared by consumers
+export { AIMessage, BaseMessage, HumanMessage, SystemMessage, ToolMessage } from '@langchain/core/messages'
+
 // Re-export StreamEvent type from LangChain for convenience
 export type { StreamEvent } from '@langchain/core/tracers/log_stream'
 
-// Re-export message classes to ensure a single constructor instance is shared by consumers
-export { BaseMessage, HumanMessage, AIMessage, SystemMessage, ToolMessage } from '@langchain/core/messages'
-
 export { BaseConnector, HttpConnector, loadConfigFile, Logger, logger, MCPAgent, MCPClient, MCPSession, StdioConnector, WebSocketConnector }

src/agents/mcp_agent.ts

@@ -694,6 +694,9 @@ export class MCPAgent {
         if (msg instanceof HumanMessage || msg instanceof AIMessage || msg instanceof ToolMessage) {
           langchainHistory.push(msg)
         }
+        else {
+          logger.info(`⚠️ Skipped message of type: ${msg.constructor.name}`)
+        }
       }
 
       // Prepare inputs