Add Response Headers to ASP.NET Core Middleware

Question

I want to add a processing time middleware to my ASP.NET Core WebApi like this

public class ProcessingTimeMiddleware  
{
    private readonly RequestDelegate         


        

Answer 1

On a related note, without answering your question as such, there is now a Server-Timing specification, a standard header to provide durations, amongst other metrics. This should allow you to use

Server-Timing: processingTime;dur=12ms

You can find the specification at https://www.w3.org/TR/server-timing/