feat: agent make constructScratchPad async

Author: jacobrosenthal

langchain/src/agents/agent.ts

@@ -262,7 +262,9 @@ export abstract class Agent extends BaseSingleActionAgent {
   /**
    * Construct a scratchpad to let the agent continue its thought process
    */
-  constructScratchPad(steps: AgentStep[]): string | BaseChatMessage[] {
+  async constructScratchPad(
+    steps: AgentStep[]
+  ): Promise<string | BaseChatMessage[]> {
     return steps.reduce(
       (thoughts, { action, observation }) =>
         thoughts +

langchain/src/agents/chat/index.ts

@@ -65,8 +65,8 @@ export class ChatAgent extends Agent {
     return new ChatAgentOutputParser();
   }
 
-  constructScratchPad(steps: AgentStep[]): string {
-    const agentScratchpad = super.constructScratchPad(steps);
+  async constructScratchPad(steps: AgentStep[]): Promise<string> {
+    const agentScratchpad = await super.constructScratchPad(steps);
     if (agentScratchpad) {
       return `This was your previous work (but I haven't seen any of it! I only see what you return as final answer):\n${agentScratchpad}`;
     }

langchain/src/agents/chat_convo/index.ts

@@ -75,7 +75,7 @@ export class ChatConversationalAgent extends Agent {
     }
   }
 
-  constructScratchPad(steps: AgentStep[]): BaseChatMessage[] {
+  async constructScratchPad(steps: AgentStep[]): Promise<BaseChatMessage[]> {
     const thoughts: BaseChatMessage[] = [];
     for (const step of steps) {
       thoughts.push(new AIChatMessage(step.action.log));