source: TFP-WebServer/WebServer/src/WebAPI/APIs/OpenAPI.cs@ 459

using System.Net;
using JetBrains.Annotations;
using Webserver.Permissions;

namespace Webserver.WebAPI.APIs {
        [UsedImplicitly]
        public class OpenAPI : AbsRestApi {
                public OpenAPI (Web _parentWeb) : base (_parentWeb) {
                }

                protected override void HandleRestGet (RequestContext _context) {
                        string path = _context.RequestPath;
                        
                        if (!ParentWeb.OpenApiHelpers.TryGetOpenApiSpec (path, out string specText)) {
                                WebUtils.WriteText (_context.Response, $"Spec for {path} not found", HttpStatusCode.NotFound);
                                return;
                        }

                        WebUtils.WriteText (_context.Response, specText, _mimeType: "text/x-yaml");
                }

                public override int DefaultPermissionLevel () => AdminWebModules.PermissionLevelGuest;
        }
}