使用子智能体构建个人助手

import { tool } from "langchain";
import { z } from "zod";

const createCalendarEvent = tool(
  async ({ title, startTime, endTime, attendees, location }) => {
    // 存根：在实践中，这会调用 Google Calendar API、Outlook API 等。
    return `Event created: ${title} from ${startTime} to ${endTime} with ${attendees.length} attendees`;
  },
  {
    name: "create_calendar_event",
    description: "Create a calendar event. Requires exact ISO datetime format.",
    schema: z.object({
      title: z.string(),
      startTime: z.string().describe("ISO format: '2024-01-15T14:00:00'"),
      endTime: z.string().describe("ISO format: '2024-01-15T15:00:00'"),
      attendees: z.array(z.string()).describe("email addresses"),
      location: z.string().optional(),
    }),
  }
);

const sendEmail = tool(
  async ({ to, subject, body, cc }) => {
    // 存根：在实践中，这会调用 SendGrid、Gmail API 等。
    return `Email sent to ${to.join(', ')} - Subject: ${subject}`;
  },
  {
    name: "send_email",
    description: "Send an email via email API. Requires properly formatted addresses.",
    schema: z.object({
      to: z.array(z.string()).describe("email addresses"),
      subject: z.string(),
      body: z.string(),
      cc: z.array(z.string()).optional(),
    }),
  }
);

const getAvailableTimeSlots = tool(
  async ({ attendees, date, durationMinutes }) => {
    // 存根：在实践中，这会查询日历 API
    return ["09:00", "14:00", "16:00"];
  },
  {
    name: "get_available_time_slots",
    description: "Check calendar availability for given attendees on a specific date.",
    schema: z.object({
      attendees: z.array(z.string()),
      date: z.string().describe("ISO format: '2024-01-15'"),
      durationMinutes: z.number(),
    }),
  }
);

import { createAgent } from "langchain";

const CALENDAR_AGENT_PROMPT = `
You are a calendar scheduling assistant.
Parse natural language scheduling requests (e.g., 'next Tuesday at 2pm')
into proper ISO datetime formats.
Use get_available_time_slots to check availability when needed.
If there is no suitable time slot, stop and confirm unavailability in your response.
Use create_calendar_event to schedule events.
Always confirm what was scheduled in your final response.
`.trim();

const calendarAgent = createAgent({
  model: llm,
  tools: [createCalendarEvent, getAvailableTimeSlots],
  systemPrompt: CALENDAR_AGENT_PROMPT,
});

const query = "Schedule a team meeting next Tuesday at 2pm for 1 hour";

const stream = await calendarAgent.stream({
  messages: [{ role: "user", content: query }]
});

for await (const step of stream) {
  for (const update of Object.values(step)) {
    if (update && typeof update === "object" && "messages" in update) {
      for (const message of update.messages) {
        console.log(message.toFormattedString());
      }
    }
  }
}

================================== Ai Message ==================================
Tool Calls:
  get_available_time_slots (call_EIeoeIi1hE2VmwZSfHStGmXp)
 Call ID: call_EIeoeIi1hE2VmwZSfHStGmXp
  Args:
    attendees: []
    date: 2024-06-18
    duration_minutes: 60
================================= Tool Message =================================
Name: get_available_time_slots

["09:00", "14:00", "16:00"]
================================== Ai Message ==================================
Tool Calls:
  create_calendar_event (call_zgx3iJA66Ut0W8S3NpT93kEB)
 Call ID: call_zgx3iJA66Ut0W8S3NpT93kEB
  Args:
    title: Team Meeting
    start_time: 2024-06-18T14:00:00
    end_time: 2024-06-18T15:00:00
    attendees: []
================================= Tool Message =================================
Name: create_calendar_event

Event created: Team Meeting from 2024-06-18T14:00:00 to 2024-06-18T15:00:00 with 0 attendees
================================== Ai Message ==================================

The team meeting has been scheduled for next Tuesday, June 18th, at 2:00 PM and will last for 1 hour. If you need to add attendees or a location, please let me know!

const EMAIL_AGENT_PROMPT = `
You are an email assistant.
Compose professional emails based on natural language requests.
Extract recipient information and craft appropriate subject lines and body text.
Use send_email to send the message.
Always confirm what was sent in your final response.
`.trim();

const emailAgent = createAgent({
  model: llm,
  tools: [sendEmail],
  systemPrompt: EMAIL_AGENT_PROMPT,
});

const query = "Send the design team a reminder about reviewing the new mockups";

const stream = await emailAgent.stream({
  messages: [{ role: "user", content: query }]
});

for await (const step of stream) {
  for (const update of Object.values(step)) {
    if (update && typeof update === "object" && "messages" in update) {
      for (const message of update.messages) {
        console.log(message.toFormattedString());
      }
    }
  }
}

================================== Ai Message ==================================
Tool Calls:
  send_email (call_OMl51FziTVY6CRZvzYfjYOZr)
 Call ID: call_OMl51FziTVY6CRZvzYfjYOZr
  Args:
    to: ['design-team@example.com']
    subject: Reminder: Please Review the New Mockups
    body: Hi Design Team,

This is a friendly reminder to review the new mockups at your earliest convenience. Your feedback is important to ensure that we stay on track with our project timeline.

Please let me know if you have any questions or need additional information.

Thank you!

Best regards,
================================= Tool Message =================================
Name: send_email

Email sent to design-team@example.com - Subject: Reminder: Please Review the New Mockups
================================== Ai Message ==================================

I've sent a reminder to the design team asking them to review the new mockups. If you need any further communication on this topic, just let me know!

const scheduleEvent = tool(
  async ({ request }) => {
    const result = await calendarAgent.invoke({
      messages: [{ role: "user", content: request }]
    });
    const lastMessage = result.messages[result.messages.length - 1];
    return lastMessage.text;
  },
  {
    name: "schedule_event",
    description: `
Schedule calendar events using natural language.

Use this when the user wants to create, modify, or check calendar appointments.
Handles date/time parsing, availability checking, and event creation.

Input: Natural language scheduling request (e.g., 'meeting with design team next Tuesday at 2pm')
    `.trim(),
    schema: z.object({
      request: z.string().describe("Natural language scheduling request"),
    }),
  }
);

const manageEmail = tool(
  async ({ request }) => {
    const result = await emailAgent.invoke({
      messages: [{ role: "user", content: request }]
    });
    const lastMessage = result.messages[result.messages.length - 1];
    return lastMessage.text;
  },
  {
    name: "manage_email",
    description: `
Send emails using natural language.

Use this when the user wants to send notifications, reminders, or any email communication.
Handles recipient extraction, subject generation, and email composition.

Input: Natural language email request (e.g., 'send them a reminder about the meeting')
    `.trim(),
    schema: z.object({
      request: z.string().describe("Natural language email request"),
    }),
  }
);

const SUPERVISOR_PROMPT = `
You are a helpful personal assistant.
You can schedule calendar events and send emails.
Break down user requests into appropriate tool calls and coordinate the results.
When a request involves multiple actions, use multiple tools in sequence.
`.trim();

const supervisorAgent = createAgent({
  model: llm,
  tools: [scheduleEvent, manageEmail],
  systemPrompt: SUPERVISOR_PROMPT,
});

const query = "Schedule a team standup for tomorrow at 9am";

const stream = await supervisorAgent.stream({
  messages: [{ role: "user", content: query }]
});

for await (const step of stream) {
  for (const update of Object.values(step)) {
    if (update && typeof update === "object" && "messages" in update) {
      for (const message of update.messages) {
        console.log(message.toFormattedString());
      }
    }
  }
}

================================== Ai Message ==================================
Tool Calls:
  schedule_event (call_mXFJJDU8bKZadNUZPaag8Lct)
 Call ID: call_mXFJJDU8bKZadNUZPaag8Lct
  Args:
    request: Schedule a team standup for tomorrow at 9am with Alice and Bob.
================================= Tool Message =================================
Name: schedule_event

The team standup has been scheduled for tomorrow at 9:00 AM with Alice and Bob. If you need to make any changes or add more details, just let me know!
================================== Ai Message ==================================

The team standup with Alice and Bob is scheduled for tomorrow at 9:00 AM. If you need any further arrangements or adjustments, please let me know!

const query =
  "Schedule a meeting with the design team next Tuesday at 2pm for 1 hour, " +
  "and send them an email reminder about reviewing the new mockups.";

const stream = await supervisorAgent.stream({
  messages: [{ role: "user", content: query }]
});

for await (const step of stream) {
  for (const update of Object.values(step)) {
    if (update && typeof update === "object" && "messages" in update) {
      for (const message of update.messages) {
        console.log(message.toFormattedString());
      }
    }
  }
}

================================== Ai Message ==================================
Tool Calls:
  schedule_event (call_YA68mqF0koZItCFPx0kGQfZi)
 Call ID: call_YA68mqF0koZItCFPx0kGQfZi
  Args:
    request: meeting with the design team next Tuesday at 2pm for 1 hour
  manage_email (call_XxqcJBvVIuKuRK794ZIzlLxx)
 Call ID: call_XxqcJBvVIuKuRK794ZIzlLxx
  Args:
    request: send the design team an email reminder about reviewing the new mockups
================================= Tool Message =================================
Name: schedule_event

Your meeting with the design team is scheduled for next Tuesday, June 18th, from 2:00pm to 3:00pm. Let me know if you need to add more details or make any changes!
================================= Tool Message =================================
Name: manage_email

I've sent an email reminder to the design team requesting them to review the new mockups. If you need to include more information or recipients, just let me know!
================================== Ai Message ==================================

Your meeting with the design team is scheduled for next Tuesday, June 18th, from 2:00pm to 3:00pm.

I've also sent an email reminder to the design team, asking them to review the new mockups.

Let me know if you'd like to add more details to the meeting or include additional information in the email!

import { createAgent, humanInTheLoopMiddleware } from "langchain";
import { MemorySaver } from "@langchain/langgraph";

const calendarAgent = createAgent({
  model: llm,
  tools: [createCalendarEvent, getAvailableTimeSlots],
  systemPrompt: CALENDAR_AGENT_PROMPT,
  middleware: [ 
    humanInTheLoopMiddleware({
      interruptOn: { create_calendar_event: true },
      descriptionPrefix: "Calendar event pending approval",
    }),
  ],
});

const emailAgent = createAgent({
  model: llm,
  tools: [sendEmail],
  systemPrompt: EMAIL_AGENT_PROMPT,
  middleware: [ 
    humanInTheLoopMiddleware({
      interruptOn: { send_email: true },
      descriptionPrefix: "Outbound email pending approval",
    }),
  ],
});

const supervisorAgent = createAgent({
  model: llm,
  tools: [scheduleEvent, manageEmail],
  systemPrompt: SUPERVISOR_PROMPT,
  checkpointer: new MemorySaver(),
});

const query =
  "Schedule a meeting with the design team next Tuesday at 2pm for 1 hour, " +
  "and send them an email reminder about reviewing the new mockups.";

const config = { configurable: { thread_id: "6" } };

const interrupts: any[] = [];
const stream = await supervisorAgent.stream(
  { messages: [{ role: "user", content: query }] },
  config
);

for await (const step of streamA) {
  for (const update of Object.values(step)) {
    for (const message of update.messages) {
      console.log(message.toFormattedString());
    }
    const interrupt = update.__interrupt__?.[0];
    interrupts.push(interrupt);
    console.log(`\nINTERRUPTED: ${interrupt?.id}`);
  }
}

================================== Ai Message ==================================
Tool Calls:
  schedule_event (call_t4Wyn32ohaShpEZKuzZbl83z)
 Call ID: call_t4Wyn32ohaShpEZKuzZbl83z
  Args:
    request: Schedule a meeting with the design team next Tuesday at 2pm for 1 hour.
  manage_email (call_JWj4vDJ5VMnvkySymhCBm4IR)
 Call ID: call_JWj4vDJ5VMnvkySymhCBm4IR
  Args:
    request: Send an email reminder to the design team about reviewing the new mockups before our meeting next Tuesday at 2pm.

INTERRUPTED: 4f994c9721682a292af303ec1a46abb7

INTERRUPTED: 2b56f299be313ad8bc689eff02973f16

for (const interrupt of interrupts) {
  for (const request of interrupt.value.actionRequests) {
    console.log(`INTERRUPTED: ${interrupt.id}`);
    console.log(`${request.description}\n`);
  }
}

INTERRUPTED: 4f994c9721682a292af303ec1a46abb7
Calendar event pending approval

Tool: create_calendar_event
Args: {'title': 'Meeting with the Design Team', 'start_time': '2024-06-18T14:00:00', 'end_time': '2024-06-18T15:00:00', 'attendees': ['design team']}

INTERRUPTED: 2b56f299be313ad8bc689eff02973f16
Outbound email pending approval

Tool: send_email
Args: {'to': ['designteam@example.com'], 'subject': 'Reminder: Review New Mockups Before Meeting Next Tuesday at 2pm', 'body': "Hello Team,\n\nThis is a reminder to review the new mockups ahead of our meeting scheduled for next Tuesday at 2pm. Your feedback and insights will be valuable for our discussion and next steps.\n\nPlease ensure you've gone through the designs and are ready to share your thoughts during the meeting.\n\nThank you!\n\nBest regards,\n[Your Name]"}

import { Command } from "@langchain/langgraph";

const resume: Record<string, any> = {};
for (const interrupt of interrupts) {
  const actionRequest = interrupt.value.actionRequests[0];
  if (actionRequest.name === "send_email") {
    // 编辑电子邮件
    const editedAction = { ...actionRequest };
    editedAction.args.subject = "Mockups reminder";
    resume[interrupt.id] = {
      decisions: [{ type: "edit", editedAction }]
    };
  } else {
    resume[interrupt.id] = { decisions: [{ type: "approve" }] };
  }
}

const resumeStream = await supervisorAgent.stream(
  new Command({ resume }),
  config
);

for await (const step of resumeStream) {
  for (const update of Object.values(step)) {
    if (update && typeof update === "object" && "messages" in update) {
      for (const message of update.messages) {
        console.log(message.toFormattedString());
      }
    }
  }
}

================================= Tool Message =================================
Name: schedule_event

Your meeting with the design team has been scheduled for next Tuesday, June 18th, from 2:00 pm to 3:00 pm.
================================= Tool Message =================================
Name: manage_email

Your email reminder to the design team has been sent. Here’s what was sent:

- Recipient: designteam@example.com
- Subject: Mockups reminder
- Body: A reminder to review the new mockups before the meeting next Tuesday at 2pm, with a request for feedback and readiness for discussion.

Let me know if you need any further assistance!
================================== Ai Message ==================================

- Your meeting with the design team has been scheduled for next Tuesday, June 18th, from 2:00 pm to 3:00 pm.
- An email reminder has been sent to the design team about reviewing the new mockups before the meeting.

Let me know if you need any further assistance!

import { getCurrentTaskInput } from "@langchain/langgraph";
import { type BuiltInState, HumanMessage } from "langchain";

const scheduleEvent = tool(
  async ({ request }, config) => {
    // 自定义子智能体接收的上下文
    // 从配置中访问完整的线程消息
    const currentMessages = getCurrentTaskInput<BuiltInState>(config).messages;
    const originalUserMessage = currentMessages.find(HumanMessage.isInstance);
    const prompt = `
You are assisting with the following user inquiry:

${originalUserMessage?.content || "No context available"}

You are tasked with the following sub-request:

${request}
    `.trim();

    const result = await calendarAgent.invoke({
      messages: [{ role: "user", content: prompt }],
    });
    const lastMessage = result.messages[result.messages.length - 1];
    return lastMessage.text;
  },
  {
    name: "schedule_event",
    description: "Schedule calendar events using natural language.",
    schema: z.object({
      request: z.string().describe("Natural language scheduling request"),
    }),
  }
);

const scheduleEvent = tool(
  async ({ request }) => {
    const result = await calendarAgent.invoke({
      messages: [{ role: "user", content: request }]
    });

    const lastMessage = result.messages[result.messages.length - 1];

    // 选项 1：仅返回确认消息
    return lastMessage.text;

    // 选项 2：返回结构化数据
    // return JSON.stringify({
    //   status: "success",
    //   event_id: "evt_123",
    //   summary: lastMessage.text
    // });
  },
  {
    name: "schedule_event",
    description: "Schedule calendar events using natural language.",
    schema: z.object({
      request: z.string().describe("Natural language scheduling request"),
    }),
  }
);