ts
复制代码
import { createAgent, summarizationMiddleware, tool, trimMessages } from "langchain"
import { MemorySaver, InMemoryStore } from "@langchain/langgraph"
import readline from 'readline';
import { getModel } from "../model/index.js";
import z from "zod";
const mainModel = getModel("gpt-4o");
const summaryModel = getModel();
// 下一个订单ID
let nextOrderId = 1;
// 记忆功能
const checkpointer = new MemorySaver();
// 创建内存存储
const store = new InMemoryStore();
const userId = "user123";
const createOrder = tool(
async ({ customerName, items, totalPrice }, config) => {
const orderId = `ORD-${String(nextOrderId).padStart(3, "0")}`;
nextOrderId++;
const orderData = {
id: orderId,
customer: customerName,
status: "pending",
total: totalPrice,
items,
createdAt: new Date().toISOString(),
};
await config.store.put(
['orders', userId],
orderId,
orderData,
)
// 这里必须写return
return `订单已创建，客户 ${customerName} 订单商品为 ${items.join("，")}，当前商品状态为 ${orderData.status}，订单总价为 ${totalPrice} 元。订单编号：${orderId}`
}, {
name: 'create_order',
defaultConfig: '创建订单',
schema: z.object({
customerName: z.string().describe("Customer name"),
items: z.array(z.string()).describe("List of items in the order"),
totalPrice: z.number().describe("Total order price"),
})
}
)
const getOrderList = tool(
async ({ }, config) => {
try {
const allOrders = await config.store.search(
["orders", userId]
);
if (!allOrders || allOrders.length === 0) {
return "还没有订单";
}
const orderSummary = allOrders.map(item => {
const order = item.value;
return `客户${order.customer} - ${order.items.join("、")} - ${order.total}元`;
}).join("\n");
return `订单列表(共${allOrders.length}个):\n${orderSummary}`;
} catch (error) {
return `查询订单列表出错：${error.message}`;
}
}, {
name: 'get_order_list',
description: "查询所有订单",
schema: z.object({})
}
)
const getOrderByName = tool(
async ({ customerName }, config) => {
try {
const allOrders = await config.store.search(
["orders", userId]
);
const orderItem = allOrders.find(item =>
item.value.customer === customerName
);
if (orderItem) {
const order = orderItem.value;
return `客户 ${customerName} 的订单详情：\n订单ID: ${order.id}\n商品: ${order.items.join("、")}\n总价: ${order.total}元\n状态: ${order.status}`;
} else {
return `客户 ${customerName} 没有找到订单`;
}
} catch (error) {
// 错误时也要返回字符串，不要返回 undefined
return `查询订单出错：${error.message}`;
}
}, {
name: 'get_order_by_name',
description: "根据客户姓名查询订单详情",
schema: z.object({
customerName: z.string().describe("Customer name"),
})
}
)
const updateOrderStatus = tool(
async ({ orderId, newStatus }, config) => {
try {
const result = await config.store.get(
["orders", userId],
orderId
);
if (!result || !result.value) { // ✅ 检查 result.value
return `订单 ${orderId} 不存在`;
}
const order = result.value; // ✅ 从 .value 获取数据
order.status = newStatus;
// 更新订单
await config.store.put(
["orders", userId],
orderId,
order
);
return `订单 ${orderId} 状态已更新为 ${newStatus}`;
} catch (error) {
return `更新订单状态出错：${error.message}`;
}
}, {
name: 'update_order_status',
description: "更新订单状态",
schema: z.object({
orderId: z.string().describe("Order ID"),
newStatus: z.string().describe("New order status"),
})
}
)
const agent = createAgent({
model: mainModel,
tools: [createOrder, getOrderList, getOrderByName, updateOrderStatus],
systemPrompt: `
你是一个专业的订单助手，负责处理客户订单事务。
你能够：
1. 创建新订单
2. 查询订单详情
3. 根据订单中的用户名称查询订单
4. 列出特定客户的所有订单
5. 更新订单状态(其中pending为待处理，shipped为已发货，delivered为已交付)，在返回状态的时候应该返回对应的中文状态
请根据客户的需求调用相应的工具，并提供清晰准确的回复,在返回的时候不要忘记包含订单ID。
`,
// 如果不希望处理其他消息在提示中添加，请不要回答其他问题，只回答与订单相关的问题
// 那么ai不会处理除订单之外任何问题
checkpointer,
store,
middleware: [
// 先对消息进行总结
summarizationMiddleware({
model: summaryModel,
trigger: { tokens: 1000 },
keep: { messages: 25 },
})
],
preModelHook: async (state) => {
return {
// 对消息进行裁剪，保留最后2000个token
messages: await trimMessages(state.messages, {
strategy: "last",
maxTokens: 2000,
startOn: "human",
endOn: ["human", "tool"],
tokenCounter: (msgs) => msgs.length,
}),
};
},
})
const rl = readline.createInterface({
input: process.stdin,
output: process.stdout
});
function askQuestion(query) {
return new Promise((resolve) => {
rl.question(query, resolve);
});
}
async function runChat() {
console.log("订单助手已启动。输入 'exit' 退出。\n");
while (true) {
const userInput = await askQuestion("客户: ");
if (userInput.toLowerCase() === "exit") {
console.log("再见！");
rl.close();
break;
}
const result = await agent.invoke(
{ messages: [{ role: "user", content: userInput }] },
{ configurable: { thread_id: userId } }
);
const lastMessage = result.messages[result.messages.length - 1];
console.log(`助手: ${lastMessage.content}\n`);
}
}
runChat();