diff --git a/modules/authelia.nix b/modules/authelia.nix
new file mode 100644
index 0000000..1a7acab
--- /dev/null
+++ b/modules/authelia.nix
@@ -0,0 +1,373 @@
+{ config, pkgs, lib, ... }:
+
+with lib;
+
+let
+  cfg = config.services.authelia-auth;
+in
+{
+  options.services.authelia-auth = {
+    enable = mkEnableOption "Authelia authentication server with Traefik integration";
+    
+    domain = mkOption {
+      type = types.str;
+      default = "auth.example.com";
+      description = "Domain for Authelia web interface";
+    };
+    
+    secretsPath = mkOption {
+      type = types.str;
+      default = "/var/lib/authelia/secrets";
+      description = "Path to store Authelia secrets";
+    };
+    
+    dataPath = mkOption {
+      type = types.str;
+      default = "/var/lib/authelia";
+      description = "Path to store Authelia data (database, etc.)";
+    };
+    
+    logLevel = mkOption {
+      type = types.enum [ "debug" "info" "warn" "error" ];
+      default = "info";
+      description = "Logging level for Authelia";
+    };
+    
+    defaultRedirectionURL = mkOption {
+      type = types.str;
+      default = "https://www.example.com";
+      description = "Default URL to redirect after successful authentication";
+    };
+    
+    sessionDomain = mkOption {
+      type = types.str;
+      default = "example.com";
+      description = "Domain for session cookies";
+    };
+    
+    smtp = mkOption {
+      type = types.nullOr (types.submodule {
+        options = {
+          host = mkOption {
+            type = types.str;
+            description = "SMTP server host";
+          };
+          port = mkOption {
+            type = types.port;
+            default = 587;
+            description = "SMTP server port";
+          };
+          username = mkOption {
+            type = types.str;
+            description = "SMTP username";
+          };
+          passwordFile = mkOption {
+            type = types.str;
+            description = "Path to file containing SMTP password";
+          };
+          sender = mkOption {
+            type = types.str;
+            description = "Email sender address";
+          };
+        };
+      });
+      default = null;
+      description = "SMTP configuration for email notifications";
+    };
+    
+    users = mkOption {
+      type = types.attrsOf (types.submodule {
+        options = {
+          displayname = mkOption {
+            type = types.str;
+            description = "Display name for the user";
+          };
+          hashedPassword = mkOption {
+            type = types.str;
+            description = "Hashed password (use mkpasswd -m sha512 to generate)";
+          };
+          email = mkOption {
+            type = types.str;
+            description = "User email address";
+          };
+          groups = mkOption {
+            type = types.listOf types.str;
+            default = [];
+            description = "Groups the user belongs to";
+          };
+        };
+      });
+      default = {};
+      example = literalExpression ''
+        {
+          john = {
+            displayname = "John Doe";
+            hashedPassword = "$6$rounds=50000$...";
+            email = "john@example.com";
+            groups = [ "admins" "users" ];
+          };
+        }
+      '';
+      description = "User database for Authelia";
+    };
+    
+    accessControl = {
+      defaultPolicy = mkOption {
+        type = types.enum [ "bypass" "one_factor" "two_factor" "deny" ];
+        default = "deny";
+        description = "Default access control policy";
+      };
+      
+      rules = mkOption {
+        type = types.listOf (types.submodule {
+          options = {
+            domain = mkOption {
+              type = types.either types.str (types.listOf types.str);
+              description = "Domain(s) this rule applies to";
+            };
+            policy = mkOption {
+              type = types.enum [ "bypass" "one_factor" "two_factor" "deny" ];
+              description = "Policy to apply";
+            };
+            subject = mkOption {
+              type = types.nullOr (types.listOf types.str);
+              default = null;
+              description = "Subjects (users/groups) this rule applies to";
+            };
+            resources = mkOption {
+              type = types.nullOr (types.listOf types.str);
+              default = null;
+              description = "Resources (paths) this rule applies to";
+            };
+          };
+        });
+        default = [];
+        example = literalExpression ''
+          [
+            {
+              domain = "public.example.com";
+              policy = "bypass";
+            }
+            {
+              domain = "*.example.com";
+              policy = "two_factor";
+            }
+          ]
+        '';
+        description = "Access control rules";
+      };
+    };
+  };
+
+  config = mkIf cfg.enable {
+    # Create necessary directories
+    systemd.tmpfiles.rules = [
+      "d ${cfg.dataPath} 0750 authelia authelia - -"
+      "d ${cfg.secretsPath} 0750 authelia authelia - -"
+    ];
+    
+    # Create user for Authelia
+    users.users.authelia = {
+      isSystemUser = true;
+      group = "authelia";
+      home = cfg.dataPath;
+      description = "Authelia authentication server user";
+    };
+    
+    users.groups.authelia = {};
+    
+    # Generate secrets if they don't exist
+    systemd.services.authelia-secrets = {
+      description = "Generate Authelia secrets";
+      wantedBy = [ "authelia-main.service" ];
+      before = [ "authelia-main.service" ];
+      serviceConfig = {
+        Type = "oneshot";
+        RemainAfterExit = true;
+        User = "authelia";
+        Group = "authelia";
+      };
+      script = ''
+        # Generate JWT secret if it doesn't exist
+        if [ ! -f "${cfg.secretsPath}/jwt_secret" ]; then
+          ${pkgs.openssl}/bin/openssl rand -hex 32 > "${cfg.secretsPath}/jwt_secret"
+          chmod 600 "${cfg.secretsPath}/jwt_secret"
+        fi
+        
+        # Generate storage encryption key if it doesn't exist
+        if [ ! -f "${cfg.secretsPath}/storage_encryption_key" ]; then
+          ${pkgs.openssl}/bin/openssl rand -hex 32 > "${cfg.secretsPath}/storage_encryption_key"
+          chmod 600 "${cfg.secretsPath}/storage_encryption_key"
+        fi
+        
+        # Generate session secret if it doesn't exist
+        if [ ! -f "${cfg.secretsPath}/session_secret" ]; then
+          ${pkgs.openssl}/bin/openssl rand -hex 32 > "${cfg.secretsPath}/session_secret"
+          chmod 600 "${cfg.secretsPath}/session_secret"
+        fi
+      '';
+    };
+    
+    # Generate users database file
+    systemd.services.authelia-users = {
+      description = "Generate Authelia users database";
+      wantedBy = [ "authelia-main.service" ];
+      before = [ "authelia-main.service" ];
+      serviceConfig = {
+        Type = "oneshot";
+        RemainAfterExit = true;
+        User = "authelia";
+        Group = "authelia";
+      };
+      script = ''
+        cat > "${cfg.dataPath}/users.yml" << 'EOF'
+        users:
+        ${concatStringsSep "\n" (mapAttrsToList (name: user: ''
+          ${name}:
+            displayname: "${user.displayname}"
+            password: "${user.hashedPassword}"
+            email: "${user.email}"
+            groups:
+            ${concatMapStringsSep "\n" (group: "      - ${group}") user.groups}
+        '') cfg.users)}
+        EOF
+        chmod 600 "${cfg.dataPath}/users.yml"
+      '';
+    };
+    
+    # Configure Authelia instance
+    services.authelia.instances.main = {
+      enable = true;
+      
+      secrets = {
+        jwtSecretFile = "${cfg.secretsPath}/jwt_secret";
+        storageEncryptionKeyFile = "${cfg.secretsPath}/storage_encryption_key";
+      };
+      
+      settings = {
+        theme = "light";
+        default_2fa_method = "totp";
+        
+        log = {
+          level = cfg.logLevel;
+        };
+        
+        server = {
+          host = "0.0.0.0";
+          port = 9091;
+        };
+        
+        session = {
+          name = "authelia_session";
+          domain = cfg.sessionDomain;
+          same_site = "lax";
+          secret = { file = "${cfg.secretsPath}/session_secret"; };
+          expiration = "1h";
+          inactivity = "5m";
+        };
+        
+        regulation = {
+          max_retries = 5;
+          find_time = "2m";
+          ban_time = "5m";
+        };
+        
+        storage = {
+          local = {
+            path = "${cfg.dataPath}/db.sqlite3";
+          };
+        };
+        
+        notifier = if cfg.smtp != null then {
+          smtp = {
+            host = cfg.smtp.host;
+            port = cfg.smtp.port;
+            username = cfg.smtp.username;
+            password = { file = cfg.smtp.passwordFile; };
+            sender = cfg.smtp.sender;
+            disable_require_tls = false;
+          };
+        } else {
+          filesystem = {
+            filename = "${cfg.dataPath}/notifications.txt";
+          };
+        };
+        
+        authentication_backend = {
+          file = {
+            path = "${cfg.dataPath}/users.yml";
+            watch = true;
+            password = {
+              algorithm = "argon2";
+              argon2 = {
+                variant = "argon2id";
+                iterations = 3;
+                memory = 65536;
+                parallelism = 4;
+                key_length = 32;
+                salt_length = 16;
+              };
+            };
+          };
+        };
+        
+        access_control = {
+          default_policy = cfg.accessControl.defaultPolicy;
+          rules = map (rule: {
+            domain = if isList rule.domain then rule.domain else [ rule.domain ];
+            policy = rule.policy;
+          } // optionalAttrs (rule.subject != null) {
+            subject = rule.subject;
+          } // optionalAttrs (rule.resources != null) {
+            resources = rule.resources;
+          }) cfg.accessControl.rules;
+        };
+        
+        default_redirection_url = cfg.defaultRedirectionURL;
+      };
+    };
+    
+    # Add Traefik middleware configuration
+    services.traefik.dynamicConfigOptions = mkIf (config.services.traefik.enable or false) {
+      http.middlewares.authelia = {
+        forwardAuth = {
+          address = "http://localhost:9091/api/authz/forward-auth";
+          trustForwardHeader = true;
+          authResponseHeaders = [
+            "Remote-User"
+            "Remote-Groups"
+            "Remote-Name"
+            "Remote-Email"
+          ];
+        };
+      };
+      
+      # Add router for Authelia itself
+      http.routers.authelia = {
+        rule = "Host(`${cfg.domain}`)";
+        entrypoints = [ "websecure" ];
+        service = "authelia";
+        tls = {
+          certResolver = "cloudflare";
+          domains = [{
+            main = "*.${cfg.sessionDomain}";
+          }];
+        };
+      };
+      
+      http.services.authelia = {
+        loadBalancer = {
+          servers = [{
+            url = "http://localhost:9091";
+          }];
+        };
+      };
+    };
+    
+    # Ensure Authelia starts after network
+    systemd.services.authelia-main = {
+      after = [ "network-online.target" ];
+      wants = [ "network-online.target" ];
+    };
+  };
+}
\ No newline at end of file