§08 从模板到真实项目：聊天 Agent 拆解

import { AIChatAgent } from "@cloudflare/ai-chat";
import { createWorkersAI } from "workers-ai-provider";
import { streamText, convertToModelMessages, tool, stepCountIs } from "ai";
import { z } from "zod";

export class ChatAgent extends AIChatAgent {
  async onChatMessage() {
    const workersai = createWorkersAI({ binding: this.env.AI });
    const result = streamText({
      model: workersai("@cf/moonshotai/kimi-k2.7-code"),
      messages: await convertToModelMessages(this.messages),
      tools: {
        getWeather: tool({
          description: "Get weather for a city",
          inputSchema: z.object({ city: z.string() }),
          execute: async ({ city }) => fetchWeather(city),
        }),
        processPayment: tool({
          description: "Process a payment",
          inputSchema: z.object({ amount: z.number(), recipient: z.string() }),
          needsApproval: async ({ amount }) => amount > 100, // 超 100 要批
          execute: async ({ amount, recipient }) => charge(amount, recipient),
        }),
      },
      stopWhen: stepCountIs(5),
    });
    return result.toUIMessageStreamResponse();
  }
}

{
  "ai": { "binding": "AI" },
  "durable_objects": {
    "bindings": [{ "name": "ChatAgent", "class_name": "ChatAgent" }]
  },
  "migrations": [{ "tag": "v1", "new_sqlite_classes": ["ChatAgent"] }]
}

import { useAgentChat } from "@cloudflare/ai-chat/react";

const { messages, sendMessage, addToolApprovalResponse } = useAgentChat({ agent: "ChatAgent" });