feat: add parent-to-subagent communication in agentMessage tool

Author: bhouston

packages/agent/src/core/toolAgent/toolAgentCore.ts

@@ -61,6 +61,34 @@ export const toolAgent = async (
 
     interactions++;
 
+    // Check for messages from parent agent
+    // This assumes the context has an agentTracker and the current agent's ID
+    if (context.agentTracker && context.currentAgentId) {
+      const agentState = context.agentTracker.getAgentState(
+        context.currentAgentId,
+      );
+
+      // Process any new parent messages
+      if (
+        agentState &&
+        agentState.parentMessages &&
+        agentState.parentMessages.length > 0
+      ) {
+        // Get all parent messages and clear the queue
+        const parentMessages = [...agentState.parentMessages];
+        agentState.parentMessages = [];
+
+        // Add each message to the conversation
+        for (const message of parentMessages) {
+          logger.info(`Message from parent agent: ${message}`);
+          messages.push({
+            role: 'user',
+            content: `[Message from parent agent]: ${message}`,
+          });
+        }
+      }
+    }
+
     // Convert tools to function definitions
     const functionDefinitions = tools.map((tool) => ({
       name: tool.name,

packages/agent/src/core/types.ts

@@ -26,6 +26,7 @@ export type ToolContext = {
   userPrompt?: boolean;
   agentId?: string; // Unique identifier for the agent, used for background tool tracking
   agentName?: string; // Name of the agent, used for browser tracker
+  currentAgentId?: string; // ID of the current agent, used for parent-to-subagent communication
   provider: ModelProvider;
   model?: string;
   baseUrl?: string;

packages/agent/src/tools/agent/AgentTracker.ts

@@ -33,6 +33,7 @@ export interface AgentState {
   workingDirectory: string;
   tools: unknown[];
   aborted: boolean;
+  parentMessages: string[]; // Messages from parent agent
 }
 
 export class AgentTracker {

packages/agent/src/tools/agent/agentMessage.ts

@@ -33,6 +33,14 @@ const returnSchema = z.object({
     .boolean()
     .optional()
     .describe('Whether the sub-agent was terminated by this message'),
+  messageSent: z
+    .boolean()
+    .optional()
+    .describe('Whether a message was sent to the sub-agent'),
+  messageCount: z
+    .number()
+    .optional()
+    .describe("The number of messages in the sub-agent's queue"),
 });
 
 type Parameters = z.infer<typeof parameterSchema>;
@@ -68,6 +76,8 @@ export const agentMessageTool: Tool<Parameters, ReturnType> = {
           output: agentState.output || 'Sub-agent was previously terminated',
           completed: true,
           terminated: true,
+          messageSent: false,
+          messageCount: 0,
         };
       }
 
@@ -80,19 +90,24 @@ export const agentMessageTool: Tool<Parameters, ReturnType> = {
           output: agentState.output || 'Sub-agent terminated before completion',
           completed: true,
           terminated: true,
+          messageSent: false,
+          messageCount: 0,
         };
       }
 
-      // Add guidance to the agent state for future implementation
-      // In a more advanced implementation, this could inject the guidance
-      // into the agent's execution context
+      // Add guidance to the agent state's parentMessages array
+      // The sub-agent will check for these messages on each iteration
       if (guidance) {
         logger.info(
           `Guidance provided to sub-agent ${instanceId}: ${guidance}`,
         );
-        // This is a placeholder for future implementation
-        // In a real implementation, we would need to interrupt the agent's
-        // execution and inject this guidance
+
+        // Add the guidance to the parentMessages array
+        agentState.parentMessages.push(guidance);
+
+        logger.verbose(
+          `Added message to sub-agent ${instanceId}'s parentMessages queue. Total messages: ${agentState.parentMessages.length}`,
+        );
       }
 
       // Get the current output
@@ -103,6 +118,8 @@ export const agentMessageTool: Tool<Parameters, ReturnType> = {
         output,
         completed: agentState.completed,
         ...(agentState.error && { error: agentState.error }),
+        messageSent: guidance ? true : false,
+        messageCount: agentState.parentMessages.length,
       };
     } catch (error) {
       if (error instanceof Error) {
@@ -112,6 +129,8 @@ export const agentMessageTool: Tool<Parameters, ReturnType> = {
           output: '',
           completed: false,
           error: error.message,
+          messageSent: false,
+          messageCount: 0,
         };
       }
 
@@ -123,6 +142,8 @@ export const agentMessageTool: Tool<Parameters, ReturnType> = {
         output: '',
         completed: false,
         error: `Unknown error occurred: ${errorMessage}`,
+        messageSent: false,
+        messageCount: 0,
       };
     }
   },
@@ -142,5 +163,11 @@ export const agentMessageTool: Tool<Parameters, ReturnType> = {
     } else {
       logger.info('Sub-agent is still running');
     }
+
+    if (output.messageSent) {
+      logger.info(
+        `Message sent to sub-agent. Queue now has ${output.messageCount || 0} message(s).`,
+      );
+    }
   },
 };

packages/agent/src/tools/agent/agentStart.ts

@@ -116,6 +116,7 @@ export const agentStartTool: Tool<Parameters, ReturnType> = {
       workingDirectory: workingDirectory ?? context.workingDirectory,
       tools,
       aborted: false,
+      parentMessages: [], // Initialize empty array for parent messages
     };
 
     // Register agent state with the tracker
@@ -131,6 +132,7 @@ export const agentStartTool: Tool<Parameters, ReturnType> = {
         const result = await toolAgent(prompt, tools, agentConfig, {
           ...context,
           workingDirectory: workingDirectory ?? context.workingDirectory,
+          currentAgentId: instanceId, // Pass the agent's ID to the context
         });
 
         // Update agent state with the result