Frontend: React + .NET API

The most common real-world full-stack .NET pairing. This section focuses on the integration boundary — auth flows, real-time, API design — not on React itself.

Topics (canonical order)

React SPA + ASP.NET Core Integration

Project layout, dev proxy, build pipeline, deploying SPA + API
Auth Flows — React + API

OIDC + PKCE in SPA, BFF pattern, token storage trade-offs, silent refresh
SignalR from React

@microsoft/signalr JS client, reconnection, auth, type-safe hubs
API Design for SPA Clients

Pagination, errors as ProblemDetails, idempotency, OpenAPI-driven types
Astro with .NET API

Islands architecture, content collections, SSG + SSR + .NET API, when to pick over React

Why this order

Project setup → auth → real-time → API design walks from "stand it up" to "operate it well". Auth is second because token strategy dictates everything downstream (where SignalR auth comes from, how API errors flow back).

Cross-references

Auth flows reference OAuth2 & OIDC Flows, JWT Validation Pitfalls.
SignalR client connects to SignalR.
API design references API Versioning & REST Contracts, ProblemDetails & Error Handling, OpenAPI & Swagger.