Scalar

Core Principles

1. Scalar replaces Swagger UI — Scalar is the recommended API documentation UI for .NET 10. Faster rendering, built-in dark mode, code generation for dozens of languages, and full OpenAPI 3.1 support.
2. Development only by default — Wrap MapScalarApiReference() in an IsDevelopment() check. API documentation exposes internal structure. If needed in production, add authorization.
3. Disable the proxy for sensitive APIs — Scalar's "Try It" feature routes through proxy.scalar.com by default. Disable it with .WithProxy(null) to keep auth headers local.
4. Security schemes come from OpenAPI — Scalar reads security schemes from the OpenAPI document. Configure them via document transformers, not in Scalar directly.

Patterns

Basic Setup

using Scalar.AspNetCore;

var builder = WebApplication.CreateBuilder(args);
builder.Services.AddOpenApi();