pages/Program.cs

using System.IO.Compression;
using Microsoft.AspNetCore.Authentication;
using Microsoft.Extensions.FileProviders;
using pages;

if (!Directory.Exists("pages"))
    Directory.CreateDirectory("pages");

WebApplicationBuilder builder = WebApplication.CreateBuilder(args);

builder.Services.AddAuthentication().AddScheme<AuthenticationSchemeOptions, FixedTokenAuthenticationHandler>("token", null);
builder.Services.AddAuthorization();

WebApplication app = builder.Build();

app.UseStatusCodePages();

app.UseDefaultFiles();
app.UseStaticFiles(new StaticFileOptions {
    FileProvider = new PhysicalFileProvider(Path.Combine(Directory.GetCurrentDirectory(), "pages"))
});

app.UseAuthentication();
app.UseAuthorization();

app.MapPost("/pages/{projectName}", async (string projectName, HttpRequest request) => {
    if (!request.HasFormContentType || request.Form.Files["zipfile"] is null)
        return Results.BadRequest();

    IFormFile zipFile = request.Form.Files["zipfile"]!;
    if (zipFile.Length == 0)
        return Results.BadRequest();

    var extractPath = Path.Combine("pages", projectName);

    if (Directory.Exists(extractPath))
        Directory.Delete(extractPath, true);

    Directory.CreateDirectory(extractPath);

    try {
        await using Stream stream = zipFile.OpenReadStream();
        using var zipArchive = new ZipArchive(stream);

        zipArchive.ExtractToDirectory(extractPath, true);
    } catch {
        return Results.BadRequest();
    }

    return Results.Ok();
}).RequireAuthorization();

app.Run();