configuration.nix

@@ -1,7 +1,15 @@
-{ pkgs, radiantwave, upgradeFlakeRef, radiantwavePlymouth, ... }:
+{ config, pkgs, radiantwave, upgradeFlakeRef, radiantwavePlymouth, ... }:
 
 let
   radiantApp = radiantwave.packages.${pkgs.system}.default;
+  # When the live-updater module is enabled (currently dev variants only),
+  # RadiantWave launches through the mutable /var/lib/radiantwave/current
+  # pointer so it can be swapped without a full nixos-rebuild. Otherwise it
+  # launches straight from the immutable system closure as before.
+  launchBin =
+    if config.services.radiantwaveUpdater.enable or false
+    then "/var/lib/radiantwave/current/bin/radiantwave"
+    else "/run/current-system/sw/bin/radiantwave";
   myKey = [ "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIL4qWNZnYU5JaqR9c2qh6oFZktzVNBOx42PfDaGofCL6 cnclack@pm.me macbook" ];
 in
 {
@@ -159,7 +167,7 @@ in
       # Release the splash screen right before the compositor takes over the display
       sudo -n plymouth quit --wait || true
 
-      exec dbus-run-session cage -- /run/current-system/sw/bin/radiantwave -d -s > /tmp/kiosk.log 2>&1
+      exec dbus-run-session cage -- ${launchBin} -d -s > /tmp/kiosk.log 2>&1
     fi
   '';
 

flake.nix

@@ -55,6 +55,18 @@
 
       revision = self.rev or self.dirtyRev or null;
 
+      # Live app-update side channel, dev-only for now. The manifest is
+      # served by the fileserver; closures are fetched (never built) from the
+      # dev Attic cache. Promotes to prod once validated.
+      radiantwaveDevUpdaterModule = { baseline }: {
+        services.radiantwaveUpdater = {
+          enable = true;
+          manifestUrl = "https://files.radiantwavetech.com/radiantwave-dev/manifest.json";
+          atticUrl = "https://attic.radiantwavetech.com/radiantwave-dev";
+          baselinePackage = baseline;
+        };
+      };
+
       mkKioskSystem = {
         system,
         radiantwave,
@@ -79,6 +91,7 @@
               system.configurationRevision = revision;
             }
             ./configuration.nix
+            ./radiantwave-updater.nix
             disko.nixosModules.disko
             diskModule
             nixos-facter-modules.nixosModules.facter
@@ -116,6 +129,7 @@
               ];
             })
             ./configuration.nix
+            ./radiantwave-updater.nix
             radiantwave.nixosModules.default
             {
               networking.hostName = hostName;
@@ -194,6 +208,9 @@
           hostName = "radiantwavekiosk-dev";
           diskModule = ./disk-config.nix;
           upgradeFlakeRef = "git+https://gitea.radiantwavetech.com/RadiantWaveTech/KioskConfig.git?ref=dev#radiantwavekiosk-dev";
+          extraModules = [
+            (radiantwaveDevUpdaterModule { baseline = radiantwave-dev.packages.x86_64-linux.default; })
+          ];
         };
         radiantwavekiosk-commercial = mkKioskSystem {
           system = "x86_64-linux";
@@ -208,6 +225,9 @@
           hostName = "radiantwavekiosk-commercial-dev";
           diskModule = ./commercial-disk-config.nix;
           upgradeFlakeRef = "git+https://gitea.radiantwavetech.com/RadiantWaveTech/KioskConfig.git?ref=dev#radiantwavekiosk-commercial-dev";
+          extraModules = [
+            (radiantwaveDevUpdaterModule { baseline = radiantwave-dev.packages.x86_64-linux.default; })
+          ];
         };
         # Rotated screen for android-style displays.
         radiantwavekiosk-android = mkKioskSystem {
@@ -228,6 +248,7 @@
           upgradeFlakeRef = "git+https://gitea.radiantwavetech.com/RadiantWaveTech/KioskConfig.git?ref=dev#radiantwavekiosk-android-dev";
           extraModules = [
             ./rotated_display.nix
+            (radiantwaveDevUpdaterModule { baseline = radiantwave-dev.packages.x86_64-linux.default; })
           ];
         };
         # Raspberry Pi 5.
@@ -240,6 +261,9 @@
           radiantwave = radiantwave-dev;
           hostName = "radiantwavekiosk-rpi-dev";
           upgradeFlakeRef = "git+https://gitea.radiantwavetech.com/RadiantWaveTech/KioskConfig.git?ref=dev#radiantwavekiosk-rpi-dev";
+          extraModules = [
+            (radiantwaveDevUpdaterModule { baseline = radiantwave-dev.packages.aarch64-linux.default; })
+          ];
         };
 
         # === USB Images ===

radiantwave-updater.nix

@@ -0,0 +1,85 @@
+{ config, lib, pkgs, ... }:
+
+let
+  cfg = config.services.radiantwaveUpdater;
+in
+{
+  options.services.radiantwaveUpdater = {
+    enable = lib.mkEnableOption "live RadiantWave app updates via a polled manifest";
+
+    manifestUrl = lib.mkOption {
+      type = lib.types.str;
+      description = "HTTP(S) URL of the JSON manifest announcing the current app store path.";
+    };
+
+    atticUrl = lib.mkOption {
+      type = lib.types.str;
+      description = "Attic cache URL to fetch the app closure from (fetch-only, never builds).";
+    };
+
+    baselinePackage = lib.mkOption {
+      type = lib.types.package;
+      description = "Copy of RadiantWave baked into the system closure, used to seed the runtime pointer before the first update.";
+    };
+  };
+
+  config = lib.mkIf cfg.enable {
+    # Runtime pointer the login shell launches RadiantWave from. Seeded on
+    # first boot to the baseline copy already baked into the system closure
+    # (so the ISO carries it with no duplication); the updater service later
+    # re-points it atomically to newer closures fetched from Attic.
+    systemd.tmpfiles.rules = [
+      "L /var/lib/radiantwave/current - - - - ${cfg.baselinePackage.outPath}"
+    ];
+
+    systemd.services.radiantwave-updater = {
+      description = "Poll the RadiantWave manifest and swap the live app pointer";
+      after = [ "network-online.target" ];
+      wants = [ "network-online.target" ];
+      serviceConfig = {
+        Type = "oneshot";
+        RemainAfterExit = true;
+      };
+      script = ''
+        set -u
+
+        NEW_PATH=$(${pkgs.curl}/bin/curl -fsSL "${cfg.manifestUrl}" \
+          | ${pkgs.jq}/bin/jq -er .storePath) || {
+          echo "radiantwave-updater: failed to fetch/parse manifest from ${cfg.manifestUrl}"
+          exit 0
+        }
+
+        CURRENT=$(${pkgs.coreutils}/bin/readlink /var/lib/radiantwave/current 2>/dev/null || true)
+
+        if [ -z "$NEW_PATH" ] || [ "$NEW_PATH" = "$CURRENT" ]; then
+          echo "radiantwave-updater: already current (''${CURRENT})"
+          exit 0
+        fi
+
+        # Fetch the closure from the signed Attic cache only. This never
+        # builds from source; it fails outright if the path isn't there.
+        echo "radiantwave-updater: acquiring ''${NEW_PATH}"
+        ${pkgs.nix}/bin/nix copy --from "${cfg.atticUrl}" "$NEW_PATH" || {
+          echo "radiantwave-updater: nix copy failed for ''${NEW_PATH}"
+          exit 1
+        }
+
+        # Atomic swap: the app never observes a half-updated pointer.
+        ${pkgs.coreutils}/bin/ln -sfn "$NEW_PATH" /var/lib/radiantwave/current.tmp
+        ${pkgs.coreutils}/bin/mv -T /var/lib/radiantwave/current.tmp /var/lib/radiantwave/current
+        echo "radiantwave-updater: swapped ''${CURRENT} -> ''${NEW_PATH}"
+      '';
+    };
+
+    systemd.timers.radiantwave-updater = {
+      description = "Check for RadiantWave app updates";
+      wantedBy = [ "timers.target" ];
+      timerConfig = {
+        OnBootSec = "2min";
+        OnUnitActiveSec = "2min";
+        Persistent = true;
+        Unit = "radiantwave-updater.service";
+      };
+    };
+  };
+}