feat: Basic trip planner agent

agent/agent.tsx

@@ -4,18 +4,22 @@ import { z } from "zod";
 import { GenerativeUIAnnotation, GenerativeUIState } from "./types";
 import { stockbrokerGraph } from "./stockbroker";
 import { ChatOpenAI } from "@langchain/openai";
+import { tripPlannerGraph } from "./trip-planner";
+
+const allToolDescriptions = `- stockbroker: can fetch the price of a ticker, purchase/sell a ticker, or get the user's portfolio
+- tripPlanner: helps the user plan their trip. it can suggest restaurants, and places to stay in any given location.`;
 
 async function router(
   state: GenerativeUIState,
 ): Promise<Partial<GenerativeUIState>> {
   const routerDescription = `The route to take based on the user's input.
 - stockbroker: can fetch the price of a ticker, purchase/sell a ticker, or get the user's portfolio
-- weather: can fetch the current weather conditions for a location
+- tripPlanner: helps the user plan their trip. it can suggest restaurants, and places to stay in any given location.
 - generalInput: handles all other cases where the above tools don't apply
 `;
   const routerSchema = z.object({
     route: z
-      .enum(["stockbroker", "weather", "generalInput"])
+      .enum(["stockbroker", "tripPlanner", "generalInput"])
       .describe(routerDescription),
   });
   const routerTool = {
@@ -61,13 +65,19 @@ You should analyze the user's input, and choose the appropriate tool to use.`;
 
 function handleRoute(
   state: GenerativeUIState,
-): "stockbroker" | "weather" | "generalInput" {
+): "stockbroker" | "tripPlanner" | "generalInput" {
   return state.next;
 }
 
 async function handleGeneralInput(state: GenerativeUIState) {
   const llm = new ChatOpenAI({ model: "gpt-4o-mini", temperature: 0 });
-  const response = await llm.invoke(state.messages);
+  const response = await llm.invoke([
+    {
+      role: "system",
+      content: `You are an AI assistant.\nIf the user asks what you can do, describe these tools. Otherwise, just answer as normal.\n\n${allToolDescriptions}`,
+    },
+    ...state.messages,
+  ]);
 
   return {
     messages: [response],
@@ -77,19 +87,17 @@ async function handleGeneralInput(state: GenerativeUIState) {
 const builder = new StateGraph(GenerativeUIAnnotation)
   .addNode("router", router)
   .addNode("stockbroker", stockbrokerGraph)
-  .addNode("weather", () => {
-    throw new Error("Weather not implemented");
-  })
+  .addNode("tripPlanner", tripPlannerGraph)
   .addNode("generalInput", handleGeneralInput)
 
   .addConditionalEdges("router", handleRoute, [
     "stockbroker",
-    "weather",
+    "tripPlanner",
     "generalInput",
   ])
   .addEdge(START, "router")
   .addEdge("stockbroker", END)
-  .addEdge("weather", END)
+  .addEdge("tripPlanner", END)
   .addEdge("generalInput", END);
 
 export const graph = builder.compile();