Do I need to run my Azure function as an async method?

QUESTIONS - Why does my Azure function project (isolated process) not contain a namespace, class name or main method in the program.cs file? How come the Azure tools didn't generate this when I created the function project, but still runs? So do I need it?

Also the Microsoft examples (bottom example) all use async methods, should I make my program.cs file async, I thought with Azure functions that would defeat the purpose because each function gets run in its own process?

I created a net7.0 azure function project and noticed that my program.cs file has code like this below with no namespace, program class or main method:

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var host = new HostBuilder()
    .ConfigureFunctionsWorkerDefaults()
    .Build();
host.Run();

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And looking at examples that Microsoft has on Github they all have namespaces, program classes and main methods like below.

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namespace Function
{
    class Program
    {
        static async Task Main(string[] args)
        {
            string sqlConnectionString = Environment.GetEnvironmentVariable("SqlConnectionString");
            var host = new HostBuilder()
                .ConfigureFunctionsWorkerDefaults()
                .ConfigureServices(s => {
                    s.AddDbContext<BloggingContext>(
                        options => options.UseSqlServer(sqlConnectionString)
                    );
                })
                .Build();

            await host.RunAsync();
        }
    }
}

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This is a partial answer, hopefully it helps.

You are talking about 'top level statements' which were introduced in .NET 6. In a top level statement entrypoint, the namespace and main method are implicit, and it'll be generated as async if you use await anywhere within it.

Most of the examples from Microsoft were either written before this introduction, or had these elements added for clarity.

I don't know anyone that uses true top level statements in production (unless it's the IHostBuilder for web/service/di concerns), I've used them to extract the main method but included a bodyless namespace declaration at the top of the file to clarify that.

namespace Function;
var host = new HostBuilder()
    .ConfigureFunctionsWorkerDefaults()
    .Build();
await host.RunAsync();

Is functionally identical to:

namespace Function
{
    class Program
    {
        static async Task Main(string[] args)
        {
            var host = new HostBuilder()
                .ConfigureFunctionsWorkerDefaults()
                .Build();
            await host.RunAsync(); 
        }
    }
}