Getting started

Install by runtime

Web

pnpm add @chinafast/web-wechat-pay

Expo

pnpm add @chinafast/expo-wechat-pay

Server

pnpm add @chinafast/server-wechat-pay

Payment flow

1. The web or Expo package selects the appropriate one-time payment channel.
2. The core client asks your backend to create an order.
3. The server package signs a WeChat Pay API v3 request with merchant credentials.
4. The client launches WeChat, redirects to H5, invokes JSAPI, or renders a Native Pay QR code.
5. Your backend verifies the signed webhook or queries the order before fulfilment.

Requirements

• Node.js 20 or newer for the backend.
• A WeChat Pay merchant account for live mode.
• A WeChat Open Platform mobile app for Expo App Pay.
• Registered H5 and JSAPI domains for those browser channels.
• An Official Account openId flow for JSAPI.
• An Expo development build or standalone app for native App Pay.

Amounts and products

Amounts are integer fen. For known products, configure the price on the server and send only a product ID from the client. Never trust a client-supplied price.

Mock mode needs no merchant credentials and is the right first integration target.