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Tag: openapi

10 posts

2026-08-09 csharp dotnet dotnet-11

How to serve OpenAPI documentation with Scalar instead of Swagger UI in ASP.NET Core 11

Replace UseSwaggerUI with MapScalarApiReference in ASP.NET Core 11: routing, multiple documents, pre-filled auth, production gating, offline assets, and the Scalar-only OpenAPI extensions that mark endpoints stable or hidden.

2026-07-24 migration swashbuckle openapi

Migrate Swashbuckle IOperationFilter and ISchemaFilter to OpenAPI transformers in .NET 11

A filter-by-filter porting reference for moving Swashbuckle IOperationFilter and ISchemaFilter code to the built-in operation and schema transformers in .NET 11, with the context-object field mapping and the Microsoft.OpenApi v2 changes that bite.

2026-07-14 csharp dotnet dotnet-11

How to return a typed Results<T1, T2> union from a minimal API endpoint in ASP.NET Core 11

Declare the handler's return type as Results<Ok<T>, NotFound> and return TypedResults.Ok / TypedResults.NotFound: the union gives compile-time checking that the handler only returns what it declares, and it self-describes to OpenAPI so you never write .Produces by hand. Covers async handlers, the six-type limit, and testing in ASP.NET Core 11.

2026-07-12 csharp dotnet dotnet-11

How to customize the OpenAPI document with AddOperationTransformer and AddSchemaTransformer in ASP.NET Core 11

A deep dive into the built-in OpenAPI transformer pipeline in .NET 11: operation vs schema transformers, the context objects, execution order, DI-activated transformers, and recipes for headers, responses, examples, and per-property tweaks.

2026-06-16 migration swashbuckle openapi

Migrate from Swashbuckle to the built-in OpenAPI generator in .NET 11

A step-by-step migration from Swashbuckle.AspNetCore to Microsoft.AspNetCore.OpenApi in .NET 11: swapping AddSwaggerGen for AddOpenApi, converting operation, schema, and document filters to transformers, keeping a UI, and the Microsoft.OpenApi v2 breaking changes that bite.

2026-06-08 csharp dotnet dotnet-11

How to expose OpenAPI without Swashbuckle in ASP.NET Core 11

Swashbuckle is gone from the ASP.NET Core templates. Here is how to generate and serve an OpenAPI document in .NET 11 with the built-in Microsoft.AspNetCore.OpenApi package: AddOpenApi, MapOpenApi, transformers, multiple documents, build-time generation, and a UI on top.

2026-05-24 dotnet-11 aspnetcore openapi

ASP.NET Core in .NET 11 Preview 4 Teaches OpenAPI About the HTTP QUERY Method

.NET 11 Preview 4 makes ASP.NET Core OpenAPI generation recognize HTTP QUERY as a first-class operation in OpenAPI 3.2, with a graceful fallback for 3.0 and 3.1 documents.

2026-04-28 dotnet-10 aspnetcore openapi

Asp.Versioning 10.0 finally plays nicely with built-in OpenAPI in .NET 10

Asp.Versioning 10.0 is the first release that targets .NET 10 and the new Microsoft.AspNetCore.OpenApi pipeline. Sander ten Brinke's April 23 walkthrough shows how to register one OpenAPI document per API version with WithDocumentPerVersion().

2026-04-28 aspnetcore openapi swagger

How to add OpenAPI authentication flows to Swagger UI in .NET 11

In .NET 11 the OpenAPI document is generated by Microsoft.AspNetCore.OpenApi and Swagger UI is no longer in the template. Here is how to wire Bearer, OAuth2 with PKCE, and OpenID Connect so the Authorize button actually works.

2026-04-24 dotnet dotnet-11 csharp

How to Generate Strongly Typed Client Code from an OpenAPI Spec in .NET 11

Use Kiota, Microsoft's official OpenAPI code generator, to produce a fluent, strongly typed C# client from any OpenAPI spec. Step-by-step: install, generate, wire into ASP.NET Core DI, and handle authentication.