Awesome

Prometheus.Client.Owin

Extension for Prometheus.Client

Installation:

 dotnet add package Prometheus.Client.Owin

Use

There are Examples

public void Configuration(IAppBuilder app)
{  
    app.UsePrometheusServer();         
}

or

public void Configuration(IAppBuilder app)
{ 
    app.UsePrometheusServer(q =>
    {
        q.MapPath = "/api/metrics";
    });
}