中断

import {
  Command,
  MemorySaver,
  START,
  END,
  StateGraph,
  StateSchema,
  interrupt,
} from "@langchain/langgraph";
import * as z from "zod";

const State = new StateSchema({
  actionDetails: z.string(),
  status: z.enum(["pending", "approved", "rejected"]).nullable(),
});

const graphBuilder = new StateGraph(State)
  .addNode("approval", async (state) => {
    // 暴露详细信息，以便调用者可以在 UI 中渲染它们
    const decision = interrupt({
      question: "Approve this action?",
      details: state.actionDetails,
    });
    return new Command({ goto: decision ? "proceed" : "cancel" });
  }, { ends: ['proceed', 'cancel'] })
  .addNode("proceed", () => ({ status: "approved" }))
  .addNode("cancel", () => ({ status: "rejected" }))
  .addEdge(START, "approval")
  .addEdge("proceed", END)
  .addEdge("cancel", END);

// 在生产环境中使用更持久的检查点保存器
const checkpointer = new MemorySaver();
const graph = graphBuilder.compile({ checkpointer });

const config = { configurable: { thread_id: "approval-123" } };
const initial = await graph.invoke(
  { actionDetails: "Transfer $500", status: "pending" },
  config,
);
console.log(initial.__interrupt__);
// [{ value: { question: ..., details: ... } }]

// 使用决策恢复；true 路由到 proceed，false 路由到 cancel
const resumed = await graph.invoke(new Command({ resume: true }), config);
console.log(resumed.status); // -> "approved"

import {
  Command,
  MemorySaver,
  START,
  END,
  StateGraph,
  StateSchema,
  interrupt,
} from "@langchain/langgraph";
import * as z from "zod";

const State = new StateSchema({
  generatedText: z.string(),
});

const builder = new StateGraph(State)
  .addNode("review", async (state) => {
    // 要求审查者编辑生成的内容
    const updated = interrupt({
      instruction: "Review and edit this content",
      content: state.generatedText,
    });
    return { generatedText: updated };
  })
  .addEdge(START, "review")
  .addEdge("review", END);

const checkpointer = new MemorySaver();
const graph = builder.compile({ checkpointer });

const config = { configurable: { thread_id: "review-42" } };
const initial = await graph.invoke({ generatedText: "Initial draft" }, config);
console.log(initial.__interrupt__);
// [{ value: { instruction: ..., content: ... } }]

// 使用审查者编辑后的文本恢复
const finalState = await graph.invoke(
  new Command({ resume: "Improved draft after review" }),
  config,
);
console.log(finalState.generatedText); // -> "Improved draft after review"

import { tool } from "@langchain/core/tools";
import { ChatAnthropic } from "@langchain/anthropic";
import {
  Command,
  MemorySaver,
  START,
  END,
  StateGraph,
  StateSchema,
  MessagesValue,
  GraphNode,
  interrupt,
} from "@langchain/langgraph";
import * as z from "zod";

const sendEmailTool = tool(
  async ({ to, subject, body }) => {
    // 发送前暂停；负载在 result.__interrupt__ 中呈现
    const response = interrupt({
      action: "send_email",
      to,
      subject,
      body,
      message: "Approve sending this email?",
    });

    if (response?.action === "approve") {
      const finalTo = response.to ?? to;
      const finalSubject = response.subject ?? subject;
      const finalBody = response.body ?? body;
      console.log("[sendEmailTool]", finalTo, finalSubject, finalBody);
      return `Email sent to ${finalTo}`;
    }
    return "Email cancelled by user";
  },
  {
    name: "send_email",
    description: "Send an email to a recipient",
    schema: z.object({
      to: z.string(),
      subject: z.string(),
      body: z.string(),
    }),
  },
);

const model = new ChatAnthropic({ model: "claude-sonnet-4-6" }).bindTools([sendEmailTool]);

const State = new StateSchema({
  messages: MessagesValue,
});

const agent: typeof State.Node = async (state) => {
  // LLM 可能决定调用该工具；中断在发送前暂停
  const response = await model.invoke(state.messages);
  return { messages: [response] };
};

const graphBuilder = new StateGraph(State)
  .addNode("agent", agent)
  .addEdge(START, "agent")
  .addEdge("agent", END);

const checkpointer = new MemorySaver();
const graph = graphBuilder.compile({ checkpointer });

const config = { configurable: { thread_id: "email-workflow" } };
const initial = await graph.invoke(
  {
    messages: [
      { role: "user", content: "Send an email to alice@example.com about the meeting" },
    ],
  },
  config,
);
console.log(initial.__interrupt__); // -> [{ value: { action: 'send_email', ... } }]

// 使用批准和可选的编辑参数恢复
const resumed = await graph.invoke(
  new Command({
    resume: { action: "approve", subject: "Updated subject" },
  }),
  config,
);
console.log(resumed.messages.at(-1)); // -> send_email 返回的工具结果

import {
  Command,
  MemorySaver,
  START,
  END,
  StateGraph,
  StateSchema,
  interrupt,
} from "@langchain/langgraph";
import * as z from "zod";

const State = new StateSchema({
  age: z.number().nullable(),
});

const builder = new StateGraph(State)
  .addNode("collectAge", (state) => {
    let prompt = "What is your age?";

    while (true) {
      const answer = interrupt(prompt); // 负载在 result.__interrupt__ 中呈现

      if (typeof answer === "number" && answer > 0) {
        return { age: answer };
      }

      prompt = `'${answer}' is not a valid age. Please enter a positive number.`;
    }
  })
  .addEdge(START, "collectAge")
  .addEdge("collectAge", END);

const checkpointer = new MemorySaver();
const graph = builder.compile({ checkpointer });

const config = { configurable: { thread_id: "form-1" } };
const first = await graph.invoke({ age: null }, config);
console.log(first.__interrupt__); // -> [{ value: "What is your age?", ... }]

// 提供无效数据；节点重新提示
const retry = await graph.invoke(new Command({ resume: "thirty" }), config);
console.log(retry.__interrupt__); // -> [{ value: "'thirty' is not a valid age...", ... }]

// 提供有效数据；循环退出并更新状态
const final = await graph.invoke(new Command({ resume: 30 }), config);
console.log(final.age); // -> 30