A web API is an HTTP-accessible application interface that exposes operations or data to clients. ASP.NET Core web APIs support RESTful or HTTP-based applications, including mobile apps, browser single-page applications, and other backend services. section 1.2 section 1.6
Web APIs add more structure and features than minimal APIs. Both use ASP.NET Core’s shared foundations, while the appropriate choice depends on application requirements, existing systems, clients, scalability, and uptime. section 1.2 section 2.3
Figure 2.5 ASP.NET Core can act as the server-side application for a variety of clients: it can serve HTML pages for traditional web applications, act as a REST API for client-side SPA applications, or act as an ad hoc RPC service for client applications.
Shows how one ASP.NET Core server can serve HTML pages, expose a REST API for a client-side SPA, or provide an RPC service to client applications. section 2.3
Apply the concept across common API situations:
- Serve data and operations to a mobile application or browser-based single-page application. section 1.2
- Provide an interface for other backend services, where browser protections cannot be assumed. section 28.4.3
- Use HTTPS-only listening for API applications so clients cannot accidentally send requests over HTTP. section 28.4.3
A single server, several clients
An ASP.NET Core application can render HTML for a traditional website while also exposing a REST API consumed by a browser SPA or mobile application. A separate backend service can call the same API over HTTPS. section 2.3 section 28.4.3
