ReactJS.NET VS FluentValidation

but it doesn't. What am I missing? I checked there was a similar issue here but with no solution

One potential option would have been to use ReactJS.NET - a platform almost specifically built to do what we were trying to do. But the coupling of Razor and React required by this tool just felt "wrong", and would have left us inseparably tied to React (a view also expressed by the Optimizely team themselves). Given our "proof of concept" stage, maintaining the ability to swap out one framework for another one in the (unlikely-but-you-just-never-know) event of reaching an insurmountable road block was important.

ASP.NET Core. Or React, which can be done on .NET.

ReactJs.net can do SSR on aspnet.core https://reactjs.net/

Have you looked into this?

Here is an example of Command handler with built-in Fluent Validation and fire and forget style:

There is an RFC called Problem Details (RFC7807) that standardizes how an error in an API should be responded to for the client. If you use Fluent validation, you may have noticed that the response is within this pattern.

here we're defining the input validation requirements using fluent validation rules. let's see what happens when the user input doesn't meet the above criteria. execute the same request in swagger with the following incorrect json content:

I remember FluentValidation being a nice library for this type of stuff.

Literally the code example in the front page: https://fluentvalidation.net/

https://www.nuget.org/packages/Newtonsoft.Json/ https://www.nuget.org/packages/AutoMapper/ https://www.nuget.org/packages/Dapper/ https://www.nuget.org/packages/FluentValidation/ https://www.nuget.org/packages/FluentAssertions/ https://www.nuget.org/packages/NUnit/ https://www.nuget.org/packages/xunit/ https://www.nuget.org/packages/YamlDotNet/ https://www.nuget.org/packages/Moq/ That is simply not true. Mature c# projects purposely maintain no downstream dependencies and is they do, it's to a major reputable lib. See for yourself - these are staple third party packages commonly used. Anything dependency starting with System or NETStandard is Microsoft maintained.

FluentValidator for validating and authorising certain fields.

Now that we know the importance of providing users with enough information about their requests and how it was processed, let’s focus on how we can configure our API to help us do that.One aspect of such meaningful experience is Request Validation (400 Error Range). For that purpose I am using a library called Fluent Validation.