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Calling in Mini Programs

WeChat Mini Programs can call the TCB Agent via wx.cloud.extend.AI, which supports streaming output.

Prerequisites​

  • Mini Program Basic Library 3.7.1+
  • TCB environment has been activated
  • Agent has been created

Initialization​

// app.js
App({
  onLaunch() {
    wx.cloud.init({
      env: 'your-env-id',
    });
  }
});

Basic Invocation​

function generateId() {
  const timestamp = Date.now().toString().slice(-4);
  const random = Math.floor(Math.random() * 10000).toString().padStart(4, '0');
  return timestamp + random;
}

async function sendMessage(message) {
  const res = await wx.cloud.extend.AI.bot.sendMessage({
    data: {
      // botId required, identifying the invoked Agent
      botId: 'your-agent-id',
      // Input parameter structure refers to the frontend-backend communication protocol:
      // https://docs.cloudbase.net/ai/agent/http-agent-protocol
      threadId: 'thread_id_' + generateId(),
      runId: 'run_id_' + generateId(),
      messages: [
        { id: String(Date.now()), role: 'user', content: message }
      ],
      tools: [],
      context: [],
      state: {},
      forwardedProps: {},
    }
  });

  // Receive streaming responses
  let response = '';
  for await (const event of res.eventStream) {
    // Need to manually parse event.data
    const data = JSON.parse(event.data);
    // Output based on event type; refer to the documentation for response events:
    // https://docs.cloudbase.net/ai/agent/http-agent-protocol#%E5%93%8D%E5%BA%94%E4%BA%8B%E4%BB%B6
    switch (data.type) {
      case 'TEXT_MESSAGE_CONTENT':
        response += data.delta;
        console.log(data.delta);  // Real-time output
        break;

      case 'RUN_ERROR':
        console.error('Runtime error:', data.message);
        break;

      case 'RUN_FINISHED':
        // Execution ended
        break;
    }
  }

  return response;
}

sendMessage('Hello');

Complete Example​

// pages/chat/chat.js

function generateId() {
  const timestamp = Date.now().toString().slice(-4);
  const random = Math.floor(Math.random() * 10000).toString().padStart(4, '0');
  return timestamp + random;
}

Page({
  data: {
    messages: [],
    inputValue: '',
    loading: false,
  },

  onInput(e) {
    this.setData({ inputValue: e.detail.value });
  },

  async sendMessage() {
    const { inputValue, messages } = this.data;
    if (!inputValue.trim() || this.data.loading) return;

    this.setData({
      messages: [...messages, { role: 'user', content: inputValue }],
      inputValue: '',
      loading: true,
    });

    try {
      const res = await wx.cloud.extend.AI.bot.sendMessage({
        data: {
          botId: 'your-agent-id',
          threadId: 'thread_id_' + generateId(),
          runId: 'run_id_' + generateId(),
          messages: [
            { id: String(Date.now()), role: 'user', content: inputValue }
          ],
          tools: [],
          context: [],
          state: {},
          forwardedProps: {},
        }
      });

      // Add an empty assistant message
      this.setData({
        messages: [...this.data.messages, { role: 'assistant', content: '' }],
      });

      // Receive streaming responses
      let fullText = '';
      for await (const event of res.eventStream) {
        const data = JSON.parse(event.data);
        if (data.type === 'TEXT_MESSAGE_CONTENT') {
          fullText += data.delta;
          const updatedMessages = [...this.data.messages];
          updatedMessages[updatedMessages.length - 1].content = fullText;
          this.setData({ messages: updatedMessages });
        }
      }
    } catch (error) {
      console.error('Failed to send message:', error);
      wx.showToast({ title: 'Send failed', icon: 'none' });
    } finally {
      this.setData({ loading: false });
    }
  },
});