Membership systems have evolved significantly, with modern public-facing applications using digital membership cards instead of traditional physical cards. Today’s systems must support real-time member validation, identity management, multi-platform access, and backend architectures that can scale and evolve over time. ASP.NET Core is well suited for these systems due to its high performance, modular architecture, and built-in support for modern authentication protocols.
This article explains how to architect a digital membership card system using ASP.NET Core, inspired by the real world requirements solved by Membership Anywhere, while focusing on scalability, security, and seamless integrations. A membership card system should provide the following capabilities:
- Secure member authentication
- A uniquely assigned digital card for each member
- Real-time validation at entry points (gyms, spas, etc.)
- Scalability across platforms and high concurrent usage
- Integration with external services (notifications, CRM, analytics)
To achieve this, we adopt an API-first design that decouples membership logic from presentation layers.
Architectural Overview (API-First)
ASP.NET Core is designed for API-first development with lightweight routing, dependency injection, and middleware-based pipelines.
Separation of Concerns
Authentication, card issuance, and validation logic are isolated into dedicated services.
Minimal APIs
Each endpoint has a single responsibility.
Service Abstractions
Interfaces define contracts for core services such as card generation and validation.
Example API Endpoint
Third-party systems can use this endpoint to fetch a digital membership card.
Building Structure of the System
1. Managing Member Identity
After authentication, a member receives a JWT (JSON Web Token) used for subsequent requests. No server-side session storage is required.
JWT claims include:
- Member ID
- Member role (Standard, Premium, Admin)
- Expiration timestamp
This enables easier horizontal scaling.
2. Digital Card Representation
A digital membership card is a structured object representing access rights.
The QrData field stores a secure token.
Securing Digital Membership Card Data
Digital membership systems contain sensitive information such as identity, privileges, and validity periods. Security must be enforced at both API and data layers.
1. Generating Secure Card Tokens
This token can be embedded in a QR code.
2. Secure Card Validation Endpoint
Tokens expire automatically, cards can be revoked instantly, and validation logic remains server-controlled.
3. Encrypt Sensitive Data at Rest
Encryption protects data even if the database is compromised.
Integrating Native Wallet Tickets
To support Apple Wallet or Google Wallet, the backend must generate wallet-compatible passes containing secure membership tokens. ASP.NET Core handles pass issuance and validation, while the wallet serves as secure client-side storage.
Example: Shopify to Digital Membership Card Integration
Step 1: Shopify Webhook Models
Step 2: Secure Webhook Endpoint
Step 3: Issue Digital Membership Card
Step 4: Sync Membership Status Back to Shopify
Step 5: CRM Integration Service
Step 6: Register HTTP Client for CRM
