OpenClaw WeChat Mini Program API development

Building a WeChat Mini Program that talks to an AI backend sounds like a weekend project — until you hit the reality of API design, authentication, rate limiting, and the WeChat platform's own quirks. Let's cut through the noise and build a clean API layer between your Mini Program and OpenClaw.

The Architecture

Your WeChat Mini Program doesn't talk to OpenClaw directly. Instead, it goes through a lightweight API gateway running on your Tencent Cloud Lighthouse instance:

Mini Program → HTTPS → Lighthouse API Gateway → OpenClaw → Model API → Response

This separation gives you control over authentication, rate limiting, and response formatting — things the Mini Program framework expects but OpenClaw doesn't natively provide for WeChat's specific requirements.

Setting Up the API Endpoint

On your Tencent Cloud Lighthouse instance, create an API layer that the Mini Program can call:

// /opt/clawdbot/api/miniprogram-gateway.js
const express = require('express');
const crypto = require('crypto');
const app = express();

app.use(express.json());

// WeChat session validation middleware
const validateSession = (req, res, next) => {
  const sessionKey = req.headers['x-wx-session'];
  if (!sessionKey || !isValidSession(sessionKey)) {
    return res.status(401).json({ error: 'Invalid session' });
  }
  next();
};

// Main chat endpoint
app.post('/api/chat', validateSession, async (req, res) => {
  const { message, conversation_id } = req.body;
  
  if (!message || message.length > 2000) {
    return res.status(400).json({ error: 'Invalid message' });
  }

  try {
    const response = await forwardToOpenClaw({
      message,
      conversation_id,
      user_id: req.wxUserId
    });
    
    res.json({
      reply: response.text,
      conversation_id: response.conversation_id,
      tokens_used: response.tokens
    });
  } catch (err) {
    console.error('OpenClaw error:', err.message);
    res.status(500).json({ error: 'Service temporarily unavailable' });
  }
});

// Health check
app.get('/api/health', (req, res) => {
  res.json({ status: 'ok', timestamp: Date.now() });
});

app.listen(3000, () => console.log('Mini Program API running on :3000'));

Mini Program Client Code

On the Mini Program side, call your API:

// pages/chat/chat.js
Page({
  data: {
    messages: [],
    inputText: '',
    conversationId: null,
    loading: false
  },

  async sendMessage() {
    const message = this.data.inputText.trim();
    if (!message) return;

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

    try {
      const res = await wx.request({
        url: 'https://YOUR_LIGHTHOUSE_IP/api/chat',
        method: 'POST',
        header: {
          'Content-Type': 'application/json',
          'x-wx-session': wx.getStorageSync('sessionKey')
        },
        data: {
          message: message,
          conversation_id: this.data.conversationId
        }
      });

      if (res.statusCode === 200) {
        this.setData({
          messages: [...this.data.messages, { role: 'assistant', content: res.data.reply }],
          conversationId: res.data.conversation_id
        });
      }
    } catch (err) {
      wx.showToast({ title: 'Network error', icon: 'none' });
    } finally {
      this.setData({ loading: false });
    }
  }
});

Authentication Flow

WeChat Mini Programs use a specific auth flow. Here's how to integrate it:

// Login flow on Mini Program side
wx.login({
  success: async (loginRes) => {
    // Exchange code for session on your server
    const result = await wx.request({
      url: 'https://YOUR_LIGHTHOUSE_IP/api/auth/wx-login',
      method: 'POST',
      data: { code: loginRes.code }
    });
    
    wx.setStorageSync('sessionKey', result.data.sessionKey);
  }
});

Server-side session exchange:

// /opt/clawdbot/api/auth.js
app.post('/api/auth/wx-login', async (req, res) => {
  const { code } = req.body;
  
  const wxRes = await fetch(
    `https://api.weixin.qq.com/sns/jscode2session?appid=${APPID}&secret=${SECRET}&js_code=${code}&grant_type=authorization_code`
  );
  const wxData = await wxRes.json();
  
  // Generate a session key for your API
  const sessionKey = crypto.randomBytes(32).toString('hex');
  
  // Store session mapping
  sessions.set(sessionKey, {
    openid: wxData.openid,
    created: Date.now()
  });
  
  res.json({ sessionKey });
});

Rate Limiting

Protect your API from abuse:

const rateLimit = require('express-rate-limit');

const limiter = rateLimit({
  windowMs: 60 * 1000, // 1 minute
  max: 20, // 20 requests per minute per user
  keyGenerator: (req) => req.wxUserId || req.ip,
  message: { error: 'Too many requests. Please slow down.' }
});

app.use('/api/chat', limiter);

Deploy on Lighthouse

Get your API gateway running on proper infrastructure:

1. Visit the Tencent Cloud Lighthouse OpenClaw page to provision your instance.
2. Select the "OpenClaw (Clawdbot)" application template under "AI Agents".
3. Deploy by clicking "Buy Now" — your API backend is ready to serve your Mini Program.

API Documentation for Your Team

Keep a simple API doc alongside your code:

POST /api/chat
  Headers: x-wx-session (required)
  Body: { "message": string, "conversation_id": string|null }
  Response: { "reply": string, "conversation_id": string, "tokens_used": number }

POST /api/auth/wx-login
  Body: { "code": string }
  Response: { "sessionKey": string }

GET /api/health
  Response: { "status": "ok", "timestamp": number }

Next Steps

A clean API layer is the foundation for everything else — streaming responses, conversation history, user preferences, and analytics. Get the basics right first, then iterate.

1. Visit https://www.tencentcloud.com/act/pro/intl-openclaw to start building.
2. Select the "OpenClaw (Clawdbot)" template under "AI Agents".
3. Deploy and give your Mini Program users an AI experience that feels native.

Build the API. Ship the Mini Program. Iterate fast.