In my Umb12 instance when I wanted to add a custom class to use in my razor pages I added it in the startup.cs file using

services.AddScoped<>();

then the

@inject

command in the razor page. In my new Umb13 there is no startup.cs, checking with ChatGPT it says I now need to make a custom "Composer" class and inject in there. Is this the correct way now? Here is the code it generated:

using Umbraco.Cms.Core.Composing;
using Umbraco.Cms.Core.DependencyInjection;

public class CustomComposer : IComposer
{
    public void Compose(IUmbracoBuilder builder)
    {
        builder.Services.AddScoped<IMyCustomService, MyCustomService>();
    }
}

A composer is a good place to do this. Can definitely recommend. Alternatively, you register your services inside program.cs now.

Do I need to do anything special or just make the compioser using the template ChatGPT gave and then I am golden? I suck at DI and the only way I have ever done it was in the startup.cs usign the addcsoped call

That's pretty much it. Umbraco automatically picks up the composers, so simply making the class is enough

Thanks, I had seen that but was confused on it. I will make the composer and if I run into any issues I will post up here.