API Gateway

Design Specification

1. Introduction

This document specifies the requirements for an API Gateway that will serve as a central point for managing all external API calls to a concrete backend system. The gateway will integrate with an identity service for authorization and implement various best practices and techniques for backend management.

2. System Overview

The API Gateway is envisioned as a crucial middleware that intercepts all external requests to various backend services. It will handle aspects such as routing, authentication, authorization, monitoring, and security.

3. Functional Requirements

3.1 Request Routing

• Endpoint Management: Configurable endpoints for routing requests to the appropriate backend services.

• Load Balancing: Efficient load distribution among different backend instances.

3.2 Authentication and Authorization

• Identity Service Integration: Integration with an identity service for user authentication.

• Token Validation: Validate access tokens to ensure secure access.

• Role-Based Access Control: Implement RBAC to manage user permissions based on roles.[Not Necessary till we introduced multiple actors in the system]

3.3 API Management

• Rate Limiting: Implement rate limiting to prevent abuse and maintain service quality.

• Request and Response Transformation: Ability to modify requests and responses as per backend requirements.

3.4 Security

• Data Encryption: Encrypt data in transit and, optionally, at rest.

• DDoS Protection: Implement measures to safeguard against Distributed Denial-of-Service attacks.

• API Security Standards: Adhere to standards like OAuth 2.0, OpenID Connect, etc.

4. Non-Functional Requirements

4.1 Performance and Scalability

• High Performance: Optimize for low-latency API responses.

• Scalability: Ability to handle increasing loads and spikes in traffic.

4.2 Reliability and Availability

• High Availability: Design for minimal downtime with redundancy and failover mechanisms.

4.3 Maintainability and Extensibility

• Modular Design: Easy to update and maintain without affecting existing functionalities.

• Extensibility: Support for adding new features and integrations.

5. Conclusion

The API Gateway is designed to be a robust, secure, and efficient middleware that manages all external API interactions with the concrete backend system. It will ensure high performance, security, and compliance while providing a centralized platform for managing API calls, authentication, and authorization. This gateway is integral for maintaining a streamlined, scalable, and secure backend infrastructure.