How to Seamlessly Link Multiple Merchant Mini‑Programs with Unified Identity in WeChat

Platform mini‑programs integrate multiple merchant modules into a single application, allowing users to access services from different merchants without switching apps, improving convenience and exposure.

Why link multiple merchant mini‑program identities?

Each merchant mini‑program has its own OpenID, making seamless switching difficult. The platform mini‑program cannot directly obtain merchant OpenIDs, so a unified solution is required.

Weimob Live, a live‑streaming platform built on WeChat mini‑programs, needs to unify merchant identities to provide marketing tools, product display, and sales functions.

Implementation Methods

2.1 Authorized Login

Merchants provide an authorization entry; users log in to obtain identity information, which the platform mini‑program retrieves via merchant APIs to achieve identity linking.

2.2 Unified Identity Authentication

Both platform and merchant mini‑programs use a common authentication center; logging in once grants automatic login across all mini‑programs.

2.3 Pros and Cons Comparison

Weimob Live Unified Identity Practice

3.1 Business Background

The platform product embeds merchant business modules, such as coupon distribution.

User identity in merchant modules depends on the live platform.

3.2 Solution Confirmation

Weimob Live adopts the unified authentication approach for a seamless user experience.

3.2.1 Live‑Based Identity Linking

The live mini‑program uses its OpenID and associates it with merchant OpenIDs via the Weimob Live public account.

3.2.2 Merchant‑Based Identity Linking

Merchant OpenID serves as the identity marker, minimizing impact on existing transaction logic.

3.2.3 Overall Design

Live public account creates the association between live and merchant mini‑program OpenIDs, enabling backend OpenID replacement in the Node.js middleware.

3.2.4 Design Advantages

Accurate Identity Association

Ensures all linked accounts originate from the same WeChat ID.

User‑Free Experience

Silent authorization via WebView requires no user actions.

Low‑Cost Merchant Capability Reuse

Node.js middleware swaps OpenIDs, allowing merchant code to run unchanged.

Considerations

Protect user privacy and comply with regulations.

Optimize user experience by minimizing steps.

Ensure reliability and stability of the technical solution.

Design for adaptability across different merchant mini‑programs.

Summary

The article outlines the need for identity linking in platform mini‑programs, presents authorized login and unified authentication methods, details Weimob Live’s implementation, and highlights privacy, user experience, reliability, and adaptability as key considerations.