diff --git a/Makefile b/Makefile
index 91091cfd2b..5472c9b2a4 100644
--- a/Makefile
+++ b/Makefile
@@ -557,6 +557,9 @@ export STATUSKEYCARD_QT_LIB := $(STATUSKEYCARD_QT_LIBDIR)/$(STATUSKEYCARD_QT_LIB
 STATUSKEYCARD_QT_DYLIB_NAME := $(notdir $(STATUSKEYCARD_QT_LIB))
 STATUSKEYCARD_QT_LINKNAME := $(patsubst lib%,%,$(basename $(STATUSKEYCARD_QT_DYLIB_NAME)))
 
+KEYCARD_SIM_SRC_DIR := $(STATUS_KEYCARD_QT_SOURCE_DIR)/test/keycard-simulator
+KEYCARD_SIM_RUNTIME_BITS := run.sh libs versions out
+
 status-keycard-qt: $(STATUSKEYCARD_QT_LIB)
 $(STATUSKEYCARD_QT_LIB): | deps check-qt-dir
 	echo -e $(BUILD_MSG) "status-keycard-qt"
@@ -893,6 +896,15 @@ $(STATUS_CLIENT_DMG): nim_status_client
 	cp status-macos.svg $(MACOS_OUTER_BUNDLE)/Contents/
 	cp -R resources.rcc $(MACOS_OUTER_BUNDLE)/Contents/
 
+# Precompile (JDK from nix) + bundle the keycard simulator into the app, before macdeployqt/signing
+ifeq ($(USE_SIMULATED_KEYCARD),true)
+	echo -e $(BUILD_MSG) "keycard-simulator (precompile + bundle)"
+	nix shell .#jdk -c bash -c 'cd $(KEYCARD_SIM_SRC_DIR) && ./build.sh'
+	mkdir -p $(MACOS_OUTER_BUNDLE)/Contents/Resources/keycard-simulator
+	cp -R $(addprefix $(KEYCARD_SIM_SRC_DIR)/,$(KEYCARD_SIM_RUNTIME_BITS)) \
+		$(MACOS_OUTER_BUNDLE)/Contents/Resources/keycard-simulator/
+endif
+
 	echo -e $(BUILD_MSG) "app"
 	MAC_QTQMLDIR=$(shell $(QMAKE) -query QT_INSTALL_QML) && \
 	macdeployqt \
diff --git a/flake.nix b/flake.nix
index 0b8039254a..5f505ddfe5 100644
--- a/flake.nix
+++ b/flake.nix
@@ -21,6 +21,9 @@
               hash = "sha256-Z2sXrNRIiZ9tSoOyGE4GV0gEROy2rJxJIoie+tnl2/s=";
             };
           });
+
+          # JDK to precompile the keycard simulator when packaging a USE_SIMULATED_KEYCARD build
+          jdk = pkgs.jdk;
         }
       );
     };
diff --git a/scripts/init_app_dir.sh b/scripts/init_app_dir.sh
index 289a1924b9..844532f68e 100755
--- a/scripts/init_app_dir.sh
+++ b/scripts/init_app_dir.sh
@@ -25,6 +25,19 @@ copy_system_libs() {
   cp -P /usr/local/lib/x86_64-linux-gnu/libpcsclite*.so* "$dest/"
 }
 
+bundle_keycard_simulator() {
+  local dest="$1"
+  local src="vendor/status-keycard-qt/test/keycard-simulator"
+  if ! command -v javac >/dev/null 2>&1; then
+    echo "WARNING: javac not found; skipping keycard simulator bundle." >&2
+    return 0
+  fi
+  echo "Bundling keycard simulator (precompile + copy)..."
+  ( cd "$src" && ./build.sh )
+  mkdir -p "$dest"
+  cp -R "$src"/run.sh "$src"/libs "$src"/versions "$src"/out "$dest/"
+}
+
 DEST="${APP_DIR:?APP_DIR must be set}/usr"
 rm -rf "${APP_DIR}"
 
@@ -48,6 +61,11 @@ cp status.png "${DEST}/"
 copy_native_libs "${DEST}/lib"
 cp "${FCITX5_QT}" "${DEST}/plugins/platforminputcontexts/"
 
+if [[ "${USE_SIMULATED_KEYCARD:-}" == "true" ]]; then
+  # Bundled at usr/share/keycard-simulator; the app finds it at ../share relative to usr/bin.
+  bundle_keycard_simulator "${DEST}/share/keycard-simulator"
+fi
+
 # Qt WebEngine only (process + resources + locales)
 copy_qt_webengine() {
   local dest="$1"
diff --git a/src/app_service/service/keycardV2/test_controller.nim b/src/app_service/service/keycardV2/test_controller.nim
index 8b4dc815fb..9d8cadac8a 100644
--- a/src/app_service/service/keycardV2/test_controller.nim
+++ b/src/app_service/service/keycardV2/test_controller.nim
@@ -14,13 +14,28 @@ when defined(useSimulatedKeycard):
   const
     KEYCARD_SIMULATOR_DEFAULT_VERSION = "3.2"
     KEYCARD_SIMULATOR_DEFAULT_SIMULATOR_ADDRESS = "127.0.0.1:9025"
-    KEYCARD_SIMULATOR_DEFAULT_SIMULATOR_DIR = "vendor/status-keycard-qt/test/keycard-simulator"
+    # Subdirs (relative to the app executable) where packaging bundles the precompiled simulator:
+    #   macOS  Status.app/Contents/MacOS/nim_status_client -> ../Resources/keycard-simulator
+    #   Linux  AppDir/usr/bin/nim_status_client            -> ../share/keycard-simulator
+    KEYCARD_SIMULATOR_BUNDLED_SUBDIRS = ["../Resources/keycard-simulator", "../share/keycard-simulator"]
+    KEYCARD_SIMULATOR_DEV_DIR = "vendor/status-keycard-qt/test/keycard-simulator"
 
   var ignoreKeycardLibSignals = false # used to avoid triggering of any keycard actions while setting up the test keycard
 
   proc shouldIgnoreKeycardLibSignals*(): bool =
     return ignoreKeycardLibSignals
 
+  proc resolveSimDir(): string =
+    let envDir = getEnv("STATUS_KEYCARD_SIM_DIR")
+    if envDir.len > 0:
+      return absolutePath(envDir)
+    let appDir = getAppDir()
+    for sub in KEYCARD_SIMULATOR_BUNDLED_SUBDIRS:
+      let candidate = normalizedPath(appDir / sub)
+      if dirExists(candidate):
+        return candidate
+    return absolutePath(KEYCARD_SIMULATOR_DEV_DIR)
+
   type
     LoadCardArg = ref object of QObjectTaskArg
       params: JsonNode
@@ -56,6 +71,21 @@ when defined(useSimulatedKeycard):
       self.QObject.delete
 
     proc startSimulator*(self: KeycardTestController, version: string) {.slot.} =
+      var safeVersion = ""
+      for c in version:
+        if c in {'0'..'9', '.'}: safeVersion.add(c)
+      if safeVersion.len == 0:
+        safeVersion = KEYCARD_SIMULATOR_DEFAULT_VERSION
+      let simDir = resolveSimDir()
+      if not dirExists(simDir):
+        error "keycard simulator directory not found; set STATUS_KEYCARD_SIM_DIR to " &
+          "'<status-desktop checkout>/vendor/status-keycard-qt/test/keycard-simulator'", dir = simDir
+        return
+      let port = getEnv("STATUS_KEYCARD_SIM_ENDPOINT", KEYCARD_SIMULATOR_DEFAULT_SIMULATOR_ADDRESS).rsplit(":", 1)[^1]
+      let launch =
+        if dirExists(simDir / "out"): "exec ./run.sh " & port & " " & safeVersion
+        else: "./build.sh && exec ./run.sh " & port & " " & safeVersion
+
       if not self.simProcess.isNil and self.simProcess.running:
         self.simProcess.terminate()
         self.simProcess.close()
@@ -64,16 +94,9 @@ when defined(useSimulatedKeycard):
       discard keycard_go.keycardTestRemoveCard()
       discard keycard_go.keycardTestUnplugReader()
 
-      var safeVersion = ""
-      for c in version:
-        if c in {'0'..'9', '.'}: safeVersion.add(c)
-      if safeVersion.len == 0:
-        safeVersion = KEYCARD_SIMULATOR_DEFAULT_VERSION
-      let simDir = getEnv("STATUS_KEYCARD_SIM_DIR", KEYCARD_SIMULATOR_DEFAULT_SIMULATOR_DIR)
-      let port = getEnv("STATUS_KEYCARD_SIM_ENDPOINT", KEYCARD_SIMULATOR_DEFAULT_SIMULATOR_ADDRESS).rsplit(":", 1)[^1]
       try:
         self.simProcess = startProcess("/bin/bash",
-          args = @["-c", "cd '" & simDir & "' && ./build.sh && exec ./run.sh " & port & " " & safeVersion],
+          args = @["-c", "cd '" & simDir & "' && " & launch],
           options = {poParentStreams})
         info "starting keycard simulator", dir = simDir, port = port, version = safeVersion
       except CatchableError as e:
diff --git a/vendor/status-keycard-qt b/vendor/status-keycard-qt
index 95ba7ba6d0..81b16c5449 160000
--- a/vendor/status-keycard-qt
+++ b/vendor/status-keycard-qt
@@ -1 +1 @@
-Subproject commit 95ba7ba6d0a44fc25a41d031d7dbf9ef327894fd
+Subproject commit 81b16c544984a652e32a95f0b24188d2f492aaf9