A Guide to Suffering Through WeChat Mini Program Development

Wed, 23 Apr 2025 14:02:30 +0800

The auth interaction flow between a WeChat Mini Program and the backend

The core flow of WeChat Mini Program login: the mini program gets a temporary credential code → the backend exchanges the code for an openid → the backend issues its own JWT to the mini program. Below is the overall flow diagram.

sequenceDiagram
    participant MP as WeChat Mini Program
    participant WX as WeChat server
    participant GW as gateway
    participant Auth as auth module
    participant User as user-service
    participant DB as lia_user database

    MP->>WX: wx.login() to get code
    WX-->>MP: returns temporary code
    MP->>GW: POST /auth/wx-login {code}
    GW->>Auth: forward the request
    Auth->>WX: code2session(code)
    WX-->>Auth: returns openid + session_key
    Auth->>User: OpenFeign to query/create the user
    User->>DB: query by openid
    DB-->>User: user record (or empty)
    User-->>Auth: return userId
    Auth->>Auth: generate JWT
    Auth-->>MP: return token + user info
    MP->>MP: store into Storage

Breaking down the key points

1. The mini program gets the code (frontend)

Frontend Development on LOCRIAN_V Blog

A Guide to Suffering Through WeChat Mini Program Development

The auth interaction flow between a WeChat Mini Program and the backend

Breaking down the key points