Old version

RzR.Web.Middleware.ResponseTime

A small ASP.NET Core library that measures how long requests take and exposes the result on the response.

There are two things you get out of the box:

• A middleware that records the total time spent serving a request.
• A filter that records the time spent inside a single action or minimal API endpoint.

Both write their result to the response so the client (or your browser dev tools) can read it without any extra plumbing.

Headers

Header	Source	Meaning
X-Response-Time	middleware	Total time the request spent in the pipeline, in milliseconds.
X-Action-Response-Time	[ResponseTime] attribute or .WithResponseTime() filter	Time spent inside the marked action / endpoint.
Server-Timing	both	Standard W3C header. Each contributor adds a metric (total, action). Browsers render this in the Network tab.

The X-* names are kept for backward compatibility. New consumers should prefer Server-Timing because it is a documented standard and shows up in dev tools without a custom extension.

Targets

netstandard2.0, net5.0, net6.0, net7.0, net8.0, net9.0. The minimal API endpoint filter is only compiled for net7.0 and above (it relies on IEndpointFilter).

Install

From NuGet:

Install-Package RzR.Web.Middleware.ResponseTime

Or pin a specific version:

Install-Package RzR.Web.Middleware.ResponseTime -Version x.x.x.x

Quick start

Register the services and add the middleware. That is enough to start emitting X-Response-Time and Server-Timing on every response.

services.AddResponseTime();

// ...

app.UseResponseTime();

For per-action timing on an MVC controller, decorate the action (or the controller) with [ResponseTime]:

[HttpGet]
[ResponseTime]
public IEnumerable<WeatherForecast> Get() => ...;

For minimal APIs, chain .WithResponseTime() on the endpoint or group:

app.MapGet("/weather", () => Results.Ok(forecast))
   .WithResponseTime();

var api = app.MapGroup("/api").WithResponseTime();
api.MapGet("/users", GetUsers);

Configuration

Pass a callback to AddResponseTime to override defaults:

services.AddResponseTime(o =>
{
    o.TotalHeaderName = "X-Total-Time"; // or null/empty to suppress
    o.ActionHeaderName = "X-Action-Time";
    o.EmitServerTiming = true;
    o.DurationFormat = "0.0"; // e.g. "12.3ms"
    o.Filter  = ctx => !ctx.Request.Path.StartsWithSegments("/health");
});

See ResponseTimeOptions for the full list of settings.

Documentation

1. USAGE
2. CHANGELOG
3. BRANCH GUIDE
4. MIGRATION