diff --git a/src/vocalinux/app_identity.py b/src/vocalinux/app_identity.py
new file mode 100644
index 0000000..444e6fe
--- /dev/null
+++ b/src/vocalinux/app_identity.py
@@ -0,0 +1,78 @@
+"""Central user-visible application identity for Vocalinux.
+
+Ticket #17 prefactor: every user-visible identity string that is hardcoded in
+more than one place is driven from this single module. No value changes here;
+the rename ticket (#18) flips them in one place instead of a scavenger hunt.
+
+Retained internal names (the ``vocalinux`` Python package, upstream URLs, and
+changelog history) are recorded in :data:`RETAINED_SURFACES`, not renamed.
+"""
+
+APP_NAME: str = "Vocalinux"
+APP_ID: str = "vocalinux"
+APP_DIR_NAME: str = "vocalinux"
+CLI_PROG: str = "vocalinux"
+
+BUS_NAME: str = "com.vocalinux.Vocalinux"
+OBJECT_PATH: str = "/com/vocalinux/Vocalinux"
+INTERFACE_NAME: str = "com.vocalinux.Vocalinux"
+
+DESKTOP_FILENAME: str = "vocalinux.desktop"
+DESKTOP_ICON_NAME: str = "vocalinux"
+
+TRAY_TITLE: str = APP_NAME
+ICON_DEFAULT: str = "vocalinux-microphone-off"
+ICON_ACTIVE: str = "vocalinux-microphone"
+ICON_PROCESSING: str = "vocalinux-microphone-process"
+ICON_BASE_NAMES: tuple[str, ...] = (
+    "vocalinux",
+    ICON_ACTIVE,
+    ICON_DEFAULT,
+    ICON_PROCESSING,
+)
+
+ENGINE_NAME: str = "vocalinux"
+ENGINE_LONGNAME: str = "Vocalinux"
+ENGINE_DESCRIPTION: str = "Vocalinux voice dictation (use as default input method)"
+COMPONENT_NAME: str = "org.freedesktop.IBus.Vocalinux"
+IBUS_DIR_NAME: str = "vocalinux-ibus"
+IBUS_TEXTDOMAIN: str = "vocalinux"
+
+UPDATE_CHECKER_USER_AGENT: str = "Vocalinux-UpdateChecker"
+
+RESOURCE_DIR_NAME: str = "vocalinux"
+
+VERIFICATION_STAMP_NAME: str = ".vocalinux_verified"
+LOG_FILE_PREFIX: str = "vocalinux_logs_"
+PORTAL_TOKEN_PREFIX: str = "vocalinux_"
+
+ENV_FORCE_BACKEND: str = "VOCALINUX_FORCE_BACKEND"
+ENV_INJECT_MODIFIER_WAIT: str = "VOCALINUX_INJECT_MODIFIER_WAIT"
+ENV_YDOTOOL_KEY_DELAY: str = "VOCALINUX_YDOTOOL_KEY_DELAY"
+
+SITE_URL: str = "https://vocalinux.com"
+
+#: Files the rename ticket (#18) must flip. Checked by
+#: ``tests/test_app_identity.py`` so the list cannot drift silently.
+RENAME_SURFACES: tuple[str, ...] = (
+    "pyproject.toml",
+    "vocalinux.desktop",
+    "snap/gui/vocalinux.desktop",
+    "snap/snapcraft.yaml",
+    "packaging/flatpak/com.vocalinux.Vocalinux.desktop",
+    "packaging/flatpak/com.vocalinux.Vocalinux.metainfo.xml",
+    "packaging/flatpak/com.vocalinux.Vocalinux.yml",
+    "packaging/aur/vocalinux-bin/vocalinux.desktop",
+    "web/src/app/page.tsx",
+    "web/package.json",
+    "README.md",
+    "docs/INSTALL.md",
+)
+
+#: Surfaces deliberately never renamed (internal module name, upstream URLs,
+#: history). Recorded here so the rename ticket does not touch them.
+RETAINED_SURFACES: tuple[str, ...] = (
+    "src/vocalinux (Python import package name)",
+    "https://github.com/VocaHQ/vocalinux (upstream URLs and provenance)",
+    "CHANGELOG.md (historical changelog entries)",
+)
diff --git a/src/vocalinux/dbus_service.py b/src/vocalinux/dbus_service.py
index e68b706..0632340 100644
--- a/src/vocalinux/dbus_service.py
+++ b/src/vocalinux/dbus_service.py
@@ -14,11 +14,9 @@ from typing import Callable, Optional
 
 from gi.repository import Gio, GLib
 
-logger = logging.getLogger(__name__)
+from .app_identity import BUS_NAME, INTERFACE_NAME, OBJECT_PATH
 
-BUS_NAME = "com.vocalinux.Vocalinux"
-OBJECT_PATH = "/com/vocalinux/Vocalinux"
-INTERFACE_NAME = "com.vocalinux.Vocalinux"
+logger = logging.getLogger(__name__)
 
 # Maps CLI trigger names to the D-Bus method names exposed below.
 COMMAND_METHODS = {
@@ -27,9 +25,9 @@ COMMAND_METHODS = {
     "stop": "Stop",
 }
 
-_INTROSPECTION_XML = """
+_INTROSPECTION_XML = f"""
 <node>
-  <interface name="com.vocalinux.Vocalinux">
+  <interface name="{INTERFACE_NAME}">
     <method name="Toggle"/>
     <method name="Start"/>
     <method name="Stop"/>
diff --git a/src/vocalinux/main.py b/src/vocalinux/main.py
index f7b6040..85a4bbf 100644
--- a/src/vocalinux/main.py
+++ b/src/vocalinux/main.py
@@ -13,6 +13,7 @@ import time
 from concurrent.futures import Future, ThreadPoolExecutor
 from typing import Any, Dict, Optional
 
+from .app_identity import APP_ID, APP_NAME, CLI_PROG
 from .utils.host_process import running_from_appimage
 from .utils.vosk_model_info import SUPPORTED_LANGUAGES
 from .version import __version__
@@ -58,12 +59,12 @@ def _should_append_trailing_space() -> bool:
 
 def parse_arguments():
     """Parse command line arguments."""
-    parser = argparse.ArgumentParser(prog="vocalinux", description="Vocalinux")
+    parser = argparse.ArgumentParser(prog=CLI_PROG, description=APP_NAME)
     parser.add_argument(
         "--version",
         action="version",
         version=f"%(prog)s {__version__}",
-        help="Show the installed Vocalinux version and exit",
+        help=f"Show the installed {APP_NAME} version and exit",
     )
     parser.add_argument("--debug", action="store_true", help="Enable debug logging")
     # default model, language and engine are loaded from default config
@@ -174,13 +175,13 @@ def _run_file_transcription(path: str) -> int:
         blocks = transcribe_audio_file(path)
     except (OSError, ValueError, RuntimeError) as error:
         print(
-            f"vocalinux: could not transcribe {path}: {type(error).__name__}: {error}",
+            f"{CLI_PROG}: could not transcribe {path}: {type(error).__name__}: {error}",
             file=sys.stderr,
         )
         return 1
 
     transcript = format_transcript(blocks)
-    print(transcript if transcript else "vocalinux: no speech detected")
+    print(transcript if transcript else f"{CLI_PROG}: no speech detected")
     return 0
 
 
@@ -376,9 +377,9 @@ def main():
         try:
             from gi.repository import Notify
 
-            Notify.init("Vocalinux")
+            Notify.init(APP_NAME)
             notification = Notify.Notification.new(
-                "Vocalinux",
+                APP_NAME,
                 "Another instance is already running. Only one instance is allowed at a time.",
                 "dialog-error",
             )
@@ -404,13 +405,13 @@ def main():
     gi.require_version("GLib", "2.0")
     from gi.repository import GLib
 
-    GLib.set_prgname("vocalinux")
-    GLib.set_application_name("Vocalinux")
+    GLib.set_prgname(APP_ID)
+    GLib.set_application_name(APP_NAME)
     try:
         gi.require_version("Gdk", "3.0")
         from gi.repository import Gdk
 
-        Gdk.set_program_class("Vocalinux")
+        Gdk.set_program_class(APP_NAME)
     except Exception:
         pass
 
diff --git a/src/vocalinux/speech_recognition/recognition_manager.py b/src/vocalinux/speech_recognition/recognition_manager.py
index f4eed71..0fac4f8 100644
--- a/src/vocalinux/speech_recognition/recognition_manager.py
+++ b/src/vocalinux/speech_recognition/recognition_manager.py
@@ -27,6 +27,7 @@ if TYPE_CHECKING:
     import numpy as np
     import requests
 
+from ..app_identity import APP_NAME, RESOURCE_DIR_NAME
 from ..audio.capture import (  # noqa: F401  (re-exported for compatibility)
     _STICKY_LOCK_MIN_MEAN_SQUARE,
     CaptureStalledError,
@@ -365,7 +366,7 @@ def _show_notification(title: str, message: str, icon: str = "dialog-warning"):
 
         # Use notify-send which is available on most Linux desktops
         subprocess.Popen(
-            ["notify-send", "-i", icon, "-a", "Vocalinux", title, message],
+            ["notify-send", "-i", icon, "-a", APP_NAME, title, message],
             stdout=subprocess.DEVNULL,
             stderr=subprocess.DEVNULL,
             env=host_env(),
@@ -394,7 +395,7 @@ def _get_system_model_paths() -> list:
     xdg_data = os.environ.get("XDG_DATA_DIRS", "/usr/local/share:/usr/share")
     for base in xdg_data.split(":"):
         if base:  # Skip empty strings
-            paths.append(os.path.join(base, "vocalinux", "models"))
+            paths.append(os.path.join(base, RESOURCE_DIR_NAME, "models"))
 
     # Distribution-specific paths
     # Try to detect the distribution from /etc/os-release
@@ -407,12 +408,12 @@ def _get_system_model_paths() -> list:
                 id in os_release
                 for id in ["fedora", "rhel", "centos", "rocky", "almalinux", "red hat"]
             ):
-                paths.append("/usr/lib64/vocalinux/models")
-                paths.append("/usr/lib/vocalinux/models")
+                paths.append(f"/usr/lib64/{RESOURCE_DIR_NAME}/models")
+                paths.append(f"/usr/lib/{RESOURCE_DIR_NAME}/models")
 
             # Arch Linux doesn't use /usr/local
             if "arch" in os_release:
-                local_share_path = "/usr/local/share/vocalinux/models"
+                local_share_path = f"/usr/local/share/{RESOURCE_DIR_NAME}/models"
                 if local_share_path in paths:
                     paths.remove(local_share_path)
 
@@ -421,10 +422,10 @@ def _get_system_model_paths() -> list:
 
     # Add common fallback paths that might be used
     additional_paths = [
-        "/usr/local/lib/vocalinux/models",
-        "/usr/lib/vocalinux/models",
-        "/usr/lib64/vocalinux/models",
-        "/opt/vocalinux/models",  # Some distros use /opt
+        f"/usr/local/lib/{RESOURCE_DIR_NAME}/models",
+        f"/usr/lib/{RESOURCE_DIR_NAME}/models",
+        f"/usr/lib64/{RESOURCE_DIR_NAME}/models",
+        f"/opt/{RESOURCE_DIR_NAME}/models",  # Some distros use /opt
     ]
 
     for path in additional_paths:
diff --git a/src/vocalinux/text_injection/ibus_engine.py b/src/vocalinux/text_injection/ibus_engine.py
index 327e29b..25ad59a 100644
--- a/src/vocalinux/text_injection/ibus_engine.py
+++ b/src/vocalinux/text_injection/ibus_engine.py
@@ -30,15 +30,42 @@ from typing import Any, Callable, Mapping, Optional
 # Package import when loaded normally; absolute / inline fallbacks when this
 # file is executed by path (Vocalinux start_engine_process / IBus component exec).
 try:
+    from ..app_identity import (
+        APP_NAME,
+        COMPONENT_NAME,
+        ENGINE_DESCRIPTION,
+        ENGINE_LONGNAME,
+        ENGINE_NAME,
+        IBUS_DIR_NAME,
+        IBUS_TEXTDOMAIN,
+    )
     from ..utils.host_process import host_env
     from ..utils.paths import xdg_data_home
 except ImportError:  # pragma: no cover - exercised via script-path subprocess
     try:
+        from vocalinux.app_identity import (
+            APP_NAME,
+            COMPONENT_NAME,
+            ENGINE_DESCRIPTION,
+            ENGINE_LONGNAME,
+            ENGINE_NAME,
+            IBUS_DIR_NAME,
+            IBUS_TEXTDOMAIN,
+        )
         from vocalinux.utils.host_process import host_env
         from vocalinux.utils.paths import xdg_data_home
     except ImportError:
         # Last resort: same semantics as the vocalinux.utils originals, except
         # that host_env cannot strip a bundle it can no longer import.
+        # Identity literals below keep in step with vocalinux/app_identity.py.
+        APP_NAME = "Vocalinux"
+        COMPONENT_NAME = "org.freedesktop.IBus.Vocalinux"
+        ENGINE_DESCRIPTION = "Vocalinux voice dictation (use as default input method)"
+        ENGINE_LONGNAME = "Vocalinux"
+        ENGINE_NAME = "vocalinux"
+        IBUS_DIR_NAME = "vocalinux-ibus"
+        IBUS_TEXTDOMAIN = "vocalinux"
+
         def host_env(base: Optional[Mapping[str, str]] = None) -> dict[str, str]:
             return dict(os.environ if base is None else base)
 
@@ -77,33 +104,29 @@ except (ImportError, ValueError) as e:
     GObject = None
 
 
-# File paths for communication ($XDG_DATA_HOME, defaults to ~/.local/share)
-VOCALINUX_IBUS_DIR = Path(xdg_data_home()) / "vocalinux-ibus"
+# File paths for communication ($XDG_DATA_HOME, defaults to ~/.local/share).
+# Identity strings come from vocalinux/app_identity.py (see the import above);
+# the homepage below is the retained upstream URL, never renamed.
+VOCALINUX_IBUS_DIR = Path(xdg_data_home()) / IBUS_DIR_NAME
 SOCKET_PATH = VOCALINUX_IBUS_DIR / "inject.sock"
 PID_FILE = VOCALINUX_IBUS_DIR / "engine.pid"
 
-# Engine identification
-ENGINE_NAME = "vocalinux"
-ENGINE_LONGNAME = "Vocalinux"
-ENGINE_DESCRIPTION = "Vocalinux voice dictation (use as default input method)"
-COMPONENT_NAME = "org.freedesktop.IBus.Vocalinux"
-
 # Shared metadata used by component XML, --xml output, and runtime registration.
 # Kept in one place to prevent drift between the three consumers.
 ENGINE_RANK = 50
 _ENGINE_META = {
     "language": "other",
     "license": "AGPL-3.0",
-    "author": "Vocalinux",
+    "author": APP_NAME,
     "icon": "audio-input-microphone",
     "layout": "default",
 }
 _COMPONENT_META = {
     "version": "1.0",
     "license": "AGPL-3.0",
-    "author": "Vocalinux",
+    "author": APP_NAME,
     "homepage": "https://github.com/VocaHQ/vocalinux",
-    "textdomain": "vocalinux",
+    "textdomain": IBUS_TEXTDOMAIN,
 }
 
 
diff --git a/src/vocalinux/text_injection/remote_desktop_portal.py b/src/vocalinux/text_injection/remote_desktop_portal.py
index 478ebfe..955def7 100644
--- a/src/vocalinux/text_injection/remote_desktop_portal.py
+++ b/src/vocalinux/text_injection/remote_desktop_portal.py
@@ -29,6 +29,7 @@ import threading
 import time
 from typing import Any, Callable, Dict, List, Optional, Sequence, Tuple
 
+from ..app_identity import PORTAL_TOKEN_PREFIX
 from ..utils.paths import data_dir
 
 logger = logging.getLogger(__name__)
@@ -196,7 +197,7 @@ def _save_restore_token(token: str) -> None:
 
 def _new_token() -> str:
     """Return a unique D-Bus handle token."""
-    return f"vocalinux_{secrets.token_hex(8)}"
+    return f"{PORTAL_TOKEN_PREFIX}{secrets.token_hex(8)}"
 
 
 def _predicted_request_path(unique_name: str, token: str) -> str:
diff --git a/src/vocalinux/text_injection/text_injector.py b/src/vocalinux/text_injection/text_injector.py
index 1dd817c..23225ae 100644
--- a/src/vocalinux/text_injection/text_injector.py
+++ b/src/vocalinux/text_injection/text_injector.py
@@ -16,6 +16,12 @@ import time
 from enum import Enum
 from typing import List, Optional, Tuple, cast
 
+from ..app_identity import (
+    APP_NAME,
+    ENV_FORCE_BACKEND,
+    ENV_INJECT_MODIFIER_WAIT,
+    ENV_YDOTOOL_KEY_DELAY,
+)
 from ..utils.host_process import host_env
 from ..utils.paths import config_dir
 from .focused_window import (
@@ -582,7 +588,7 @@ class TextInjector:
         Accepts ``ibus``, ``portal``, ``wtype``, ``ydotool``, ``xdotool`` or
         ``auto``.
         """
-        raw = os.environ.get("VOCALINUX_FORCE_BACKEND")
+        raw = os.environ.get(ENV_FORCE_BACKEND)
         if raw is None:
             return None
         value = raw.strip().lower()
@@ -781,7 +787,7 @@ class TextInjector:
         """
         env = TextInjector._forced_backend_setting()
         if env is not None:
-            return env, "VOCALINUX_FORCE_BACKEND"
+            return env, ENV_FORCE_BACKEND
         configured = TextInjector._configured_backend()
         if configured != "auto":
             return configured, "text_injection.backend"
@@ -1661,7 +1667,7 @@ class TextInjector:
                     "-i",
                     "edit-paste",
                     "-a",
-                    "Vocalinux",
+                    APP_NAME,
                     "Text copied to clipboard",
                     "Text injection failed — paste with Ctrl+V " "(Ctrl+Shift+V in a terminal)",
                 ],
@@ -2778,7 +2784,7 @@ class TextInjector:
         would make the wait deadline infinite and block injection forever while a
         modifier stays held.
         """
-        raw = os.environ.get("VOCALINUX_INJECT_MODIFIER_WAIT")
+        raw = os.environ.get(ENV_INJECT_MODIFIER_WAIT)
         if raw is None:
             return self._DEFAULT_INJECT_MODIFIER_WAIT
         try:
@@ -2927,7 +2933,7 @@ class TextInjector:
             else:  # ydotool
                 # Keep key-delay > 0 to avoid Shift-leak ("Can you" -> "CAN YOu").
                 # Low delay so fallback typing finishes quickly for long phrases.
-                key_delay = os.environ.get("VOCALINUX_YDOTOOL_KEY_DELAY", "2")
+                key_delay = os.environ.get(ENV_YDOTOOL_KEY_DELAY, "2")
                 # ``--`` ends ydotool's option parsing for the same reason.
                 cmd = ["ydotool", "type", "--key-delay", key_delay, "--", chunk]
                 type_timeout = max(5, len(chunk) * self._key_delay_seconds(key_delay) * 4)
@@ -3372,7 +3378,7 @@ class TextInjector:
             # 400-character deletion would otherwise take ~9.6s. Match the delay
             # `ydotool type` already uses, and scale the budget with the count.
             code = self._KEYCODES["backspace"]
-            delay = os.environ.get("VOCALINUX_YDOTOOL_KEY_DELAY", "2")
+            delay = os.environ.get(ENV_YDOTOOL_KEY_DELAY, "2")
             cmd = ["ydotool", "key", "--key-delay", delay] + [f"{code}:1", f"{code}:0"] * count
             timeout = max(3, count * 2 * self._key_delay_seconds(delay) * 3)
 
diff --git a/src/vocalinux/ui/audio_feedback.py b/src/vocalinux/ui/audio_feedback.py
index 1a8ab73..67a64cd 100644
--- a/src/vocalinux/ui/audio_feedback.py
+++ b/src/vocalinux/ui/audio_feedback.py
@@ -15,6 +15,7 @@ import wave
 from pathlib import Path  # noqa: F401
 from typing import Optional
 
+from ..app_identity import APP_DIR_NAME
 from .config_manager import DEFAULT_SOUND_EFFECT_TONE, normalize_sound_effect_tone
 
 logger = logging.getLogger(__name__)
@@ -113,7 +114,7 @@ def _pcm_silence(nframes: int, nchannels: int, sampwidth: int) -> bytes:
 
 def _preroll_cache_dir() -> str:
     cache_home = os.environ.get("XDG_CACHE_HOME") or os.path.join(os.path.expanduser("~"), ".cache")
-    path = os.path.join(cache_home, "vocalinux", "audio-preroll")
+    path = os.path.join(cache_home, APP_DIR_NAME, "audio-preroll")
     os.makedirs(path, exist_ok=True)
     return path
 
diff --git a/src/vocalinux/ui/autostart_manager.py b/src/vocalinux/ui/autostart_manager.py
index 1979891..d660975 100644
--- a/src/vocalinux/ui/autostart_manager.py
+++ b/src/vocalinux/ui/autostart_manager.py
@@ -12,9 +12,9 @@ import shutil
 import sys
 from pathlib import Path
 
-logger = logging.getLogger(__name__)
+from ..app_identity import APP_ID, APP_NAME, DESKTOP_FILENAME
 
-DESKTOP_FILENAME = "vocalinux.desktop"
+logger = logging.getLogger(__name__)
 
 
 def get_autostart_dir() -> Path:
@@ -34,7 +34,7 @@ def get_exec_command() -> str:
     if flatpak_id:
         return f"flatpak run {flatpak_id} --start-minimized"
 
-    installed_command = shutil.which("vocalinux")
+    installed_command = shutil.which(APP_ID)
     if installed_command:
         return f"{shlex.quote(installed_command)} --start-minimized"
 
@@ -62,9 +62,9 @@ def enable_autostart() -> bool:
         desktop_entry = f"""[Desktop Entry]
 Version=1.0
 Type=Application
-Name=Vocalinux
+Name={APP_NAME}
 Exec={exec_command}
-Icon=vocalinux
+Icon={APP_ID}
 Comment=Voice dictation for Linux
 Terminal=false
 StartupNotify=false
diff --git a/src/vocalinux/ui/dictation_overlay.py b/src/vocalinux/ui/dictation_overlay.py
index 268b621..5c5f974 100644
--- a/src/vocalinux/ui/dictation_overlay.py
+++ b/src/vocalinux/ui/dictation_overlay.py
@@ -17,6 +17,7 @@ from typing import TYPE_CHECKING, Callable, Optional
 if TYPE_CHECKING:
     from gi.repository import Gdk, Gtk
 
+from ..app_identity import APP_NAME
 from ..common_types import RecognitionState
 
 logger = logging.getLogger(__name__)
@@ -176,7 +177,7 @@ class DictationOverlay:
         # keyboard focus so the active editor keeps receiving injected text.
         # Size/position are applied after map via _layout_bottom_strip.
         window = Gtk.Window(type=Gtk.WindowType.TOPLEVEL)
-        window.set_title("Vocalinux Dictation")
+        window.set_title(f"{APP_NAME} Dictation")
         window.set_decorated(False)
         window.set_resizable(False)
         window.set_accept_focus(False)
diff --git a/src/vocalinux/ui/keyboard_backends/__init__.py b/src/vocalinux/ui/keyboard_backends/__init__.py
index 81b4016..1dbb2f6 100644
--- a/src/vocalinux/ui/keyboard_backends/__init__.py
+++ b/src/vocalinux/ui/keyboard_backends/__init__.py
@@ -9,6 +9,7 @@ import logging
 import os
 from typing import Optional
 
+from ...app_identity import BUS_NAME, INTERFACE_NAME, OBJECT_PATH
 from .base import (
     DEFAULT_SHORTCUT,
     DEFAULT_SHORTCUT_MODE,
@@ -98,9 +99,9 @@ def _log_flatpak_input_hint() -> None:
     logger.warning(
         "Grant --device=input (Flatpak 1.15.6+) or --device=all, or enable "
         "External Activation and bind a desktop shortcut to: %s",
-        "gdbus call --session --dest com.vocalinux.Vocalinux "
-        "--object-path /com/vocalinux/Vocalinux "
-        "--method com.vocalinux.Vocalinux.Toggle",
+        f"gdbus call --session --dest {BUS_NAME} "
+        f"--object-path {OBJECT_PATH} "
+        f"--method {INTERFACE_NAME}.Toggle",
     )
 
 
diff --git a/src/vocalinux/ui/logging_dialog.py b/src/vocalinux/ui/logging_dialog.py
index c6cf297..7ee1c36 100644
--- a/src/vocalinux/ui/logging_dialog.py
+++ b/src/vocalinux/ui/logging_dialog.py
@@ -22,6 +22,7 @@ gi.require_version("Gtk", "3.0")
 gi.require_version("Gdk", "3.0")
 from gi.repository import Gdk, GLib, Gtk, Pango  # noqa: E402
 
+from ..app_identity import LOG_FILE_PREFIX  # noqa: E402
 from ..utils.paths import collapse_repeated_extension  # noqa: E402
 from .logging_manager import LogRecord, get_logging_manager  # noqa: E402
 
@@ -650,7 +651,7 @@ class LoggingDialog(Gtk.Dialog):
 
         # Set default filename
         timestamp = datetime.now().strftime("%Y%m%d_%H%M%S")
-        default_filename = f"vocalinux_logs_{timestamp}.txt"
+        default_filename = f"{LOG_FILE_PREFIX}{timestamp}.txt"
         file_dialog.set_current_name(default_filename)
 
         # Add file filter
diff --git a/src/vocalinux/ui/notifications.py b/src/vocalinux/ui/notifications.py
index 4de910f..a40bb87 100644
--- a/src/vocalinux/ui/notifications.py
+++ b/src/vocalinux/ui/notifications.py
@@ -10,12 +10,11 @@ import logging
 import subprocess
 from typing import Callable, Optional
 
+from ..app_identity import APP_NAME
 from ..utils.host_process import host_env
 
 logger = logging.getLogger(__name__)
 
-APP_NAME = "Vocalinux"
-
 # Notifications waiting for their action to be clicked. Without a reference the
 # notification can be garbage collected before the user answers it, and the
 # callback then never runs.
diff --git a/src/vocalinux/ui/settings_dialog.py b/src/vocalinux/ui/settings_dialog.py
index 37c6d27..c33eaf5 100644
--- a/src/vocalinux/ui/settings_dialog.py
+++ b/src/vocalinux/ui/settings_dialog.py
@@ -36,6 +36,7 @@ gi.require_version("Gdk", "3.0")
 # Need GLib for idle_add
 from gi.repository import Gdk, GLib, GObject, Gtk, Pango  # noqa: E402
 
+from ..app_identity import APP_ID, APP_NAME, RESOURCE_DIR_NAME  # noqa: E402
 from ..audio.pulse_sources import (  # noqa: E402
     PULSE_INDEX_BASE,
     PulseSource,
@@ -717,8 +718,8 @@ def _model_specialization_tooltip(model_name: str) -> str:
 # Models directory
 MODELS_DIR = models_dir()
 SYSTEM_MODELS_DIRS = [
-    "/usr/local/share/vocalinux/models",
-    "/usr/share/vocalinux/models",
+    f"/usr/local/share/{RESOURCE_DIR_NAME}/models",
+    f"/usr/share/{RESOURCE_DIR_NAME}/models",
 ]
 
 # CSS for modern styling
@@ -2534,7 +2535,7 @@ class SettingsDialog(AboutSectionMixin):
         hotkey_passthrough_update_callback: Optional[Callable[[bool], None]] = None,
         dictation_pad_open_callback: Optional[Callable[[], None]] = None,
     ) -> None:
-        super().__init__(title="Vocalinux Settings", transient_for=parent, flags=0)
+        super().__init__(title=f"{APP_NAME} Settings", transient_for=parent, flags=0)
         # Force window decorations (title-bar close) on all WMs. An in-window
         # Close button also lives in the sidebar footer so the dialog always
         # has a visible way to dismiss it, even on window managers that hide
@@ -6460,7 +6461,7 @@ class SettingsDialog(AboutSectionMixin):
             try:
                 response = requests.get(
                     "https://huggingface.co/api/models/ggerganov/whisper.cpp",
-                    headers={"User-Agent": f"vocalinux/{__version__}"},
+                    headers={"User-Agent": f"{APP_ID}/{__version__}"},
                     timeout=10,
                     proxies=requests_proxies(config),
                 )
diff --git a/src/vocalinux/ui/tray_indicator.py b/src/vocalinux/ui/tray_indicator.py
index 81435ca..71017e2 100644
--- a/src/vocalinux/ui/tray_indicator.py
+++ b/src/vocalinux/ui/tray_indicator.py
@@ -54,6 +54,14 @@ if not INDICATOR_USES_GMENU:
 
 from gi.repository import GdkPixbuf, Gio, GLib, GObject, Gtk
 
+from ..app_identity import APP_ID as CENTRAL_APP_ID
+from ..app_identity import (
+    ICON_ACTIVE,
+    ICON_DEFAULT,
+    ICON_PROCESSING,
+    TRAY_TITLE,
+)
+
 # Import local modules - Use protocols to avoid circular imports
 from ..auto_pause_monitor import DEFAULT_POLL_INTERVAL_SECONDS, AutoPauseMonitor
 from ..common_types import RecognitionState, SpeechRecognitionManagerProtocol, TextInjectorProtocol
@@ -93,7 +101,7 @@ logger = logging.getLogger(__name__)
 
 # Flatpak StatusNotifier host resolves exported <app-id>-* icons, not /app paths.
 FLATPAK_ID = os.environ.get("FLATPAK_ID")
-APP_ID = FLATPAK_ID or "vocalinux"
+APP_ID = FLATPAK_ID or CENTRAL_APP_ID
 
 # Initialize resource manager
 _resource_manager = ResourceManager()
@@ -119,9 +127,9 @@ def _idle_once(func, *args):
 
 
 # Bundled icon file names (paths under ICON_DIR).
-DEFAULT_ICON = "vocalinux-microphone-off"
-ACTIVE_ICON = "vocalinux-microphone"
-PROCESSING_ICON = "vocalinux-microphone-process"
+DEFAULT_ICON = ICON_DEFAULT
+ACTIVE_ICON = ICON_ACTIVE
+PROCESSING_ICON = ICON_PROCESSING
 
 
 def _themed_icon_names() -> dict:
@@ -159,7 +167,7 @@ class TrayIndicator:
     # Tests build TrayIndicator stubs with __new__ that skip __init__; keep a
     # class-level default so teardown paths like _quit() still find the list.
     _language_shortcut_managers: list = []
-    _indicator_title: str = "Vocalinux"
+    _indicator_title: str = TRAY_TITLE
 
     #: Same for the push-to-talk owner slot: a __new__-built stub must answer
     #: "no binding owns the live session" instead of raising on release paths.
@@ -264,7 +272,7 @@ class TrayIndicator:
         # IconThemePath so gray→red→gray→red actually turns red again.
         self._last_icon_key: Optional[str] = None
         self._icon_theme_nudge = False
-        self._indicator_title = "Vocalinux"
+        self._indicator_title = TRAY_TITLE
 
         # Register for speech recognition state changes
         self.speech_engine.register_state_callback(self._on_recognition_state_changed)
@@ -601,8 +609,8 @@ class TrayIndicator:
                 indicator.set_icon_theme_path(ICON_DIR)
             self.indicator = GMenuIndicator(indicator, Gio) if INDICATOR_USES_GMENU else indicator
             self.indicator.set_status(AppIndicator.IndicatorStatus.ACTIVE)
-            self.indicator.set_title("Vocalinux")
-            self._indicator_title = "Vocalinux"
+            self.indicator.set_title(TRAY_TITLE)
+            self._indicator_title = TRAY_TITLE
         except Exception as e:
             logger.error(f"Failed to create AppIndicator: {e}")
             GLib.idle_add(self._show_appindicator_error_dialog, str(e))
@@ -1263,7 +1271,7 @@ class TrayIndicator:
         self._last_icon_key = icon_key
 
     def _set_indicator_title(self, title: str) -> None:
-        if getattr(self, "_indicator_title", "Vocalinux") == title:
+        if getattr(self, "_indicator_title", TRAY_TITLE) == title:
             return
         self.indicator.set_title(title)
         self._indicator_title = title
@@ -1297,12 +1305,12 @@ class TrayIndicator:
         self._set_cancel_menu_item_visible(show_cancel)
 
         if state == RecognitionState.IDLE:
-            self._set_indicator_title("Vocalinux")
+            self._set_indicator_title(TRAY_TITLE)
             self._set_indicator_icon(self._icon_keys["default"], "Microphone off")
             self._set_menu_item_enabled("Start Voice Typing", True)
             self._set_menu_item_enabled("Stop Voice Typing", False)
         elif state == RecognitionState.LISTENING:
-            self._set_indicator_title("Vocalinux")
+            self._set_indicator_title(TRAY_TITLE)
             self._set_indicator_icon(self._icon_keys["active"], "Microphone on")
             self._set_menu_item_enabled("Start Voice Typing", False)
             self._set_menu_item_enabled("Stop Voice Typing", True)
@@ -1315,12 +1323,12 @@ class TrayIndicator:
                 description = f"Transcribing, press {name} again to cancel"
             else:
                 description = "Processing speech"
-            self._set_indicator_title(description if transcribing else "Vocalinux")
+            self._set_indicator_title(description if transcribing else TRAY_TITLE)
             self._set_indicator_icon(self._icon_keys["processing"], description)
             self._set_menu_item_enabled("Start Voice Typing", False)
             self._set_menu_item_enabled("Stop Voice Typing", True)
         elif state == RecognitionState.ERROR:
-            self._set_indicator_title("Vocalinux")
+            self._set_indicator_title(TRAY_TITLE)
             self._set_indicator_icon(self._icon_keys["default"], "Error")
             self._set_menu_item_enabled("Start Voice Typing", True)
             self._set_menu_item_enabled("Stop Voice Typing", False)
@@ -1578,8 +1586,8 @@ class TrayIndicator:
                     "-i",
                     "software-update-available",
                     "-a",
-                    "Vocalinux",
-                    "Vocalinux update available",
+                    TRAY_TITLE,
+                    f"{TRAY_TITLE} update available",
                     f"{release.tag_name} is ready. Open the tray menu or "
                     "Settings → About for release notes.",
                 ],
diff --git a/src/vocalinux/utils/model_checksums.py b/src/vocalinux/utils/model_checksums.py
index 196a361..6fa3a7e 100644
--- a/src/vocalinux/utils/model_checksums.py
+++ b/src/vocalinux/utils/model_checksums.py
@@ -34,6 +34,8 @@ import re
 from functools import lru_cache
 from typing import Dict, NamedTuple, Optional
 
+from ..app_identity import VERIFICATION_STAMP_NAME
+
 logger = logging.getLogger(__name__)
 
 _MANIFEST_NAME = "model_checksums.txt"
@@ -42,7 +44,7 @@ _MANIFEST_NAME = "model_checksums.txt"
 # came out of. A directory has no hash of its own and the zip is deleted after
 # unpacking, so this file is the only evidence the tree was ever verified.
 # install.sh reads it under the same name; keep the two in step.
-VERIFICATION_STAMP_NAME = ".vocalinux_verified"
+# (Name itself lives in vocalinux/app_identity.py so the rename flips it once.)
 
 # Hash of a 2GB model read in one go would sit in RAM; stream it instead.
 _CHUNK_SIZE = 1024 * 1024
diff --git a/src/vocalinux/utils/paths.py b/src/vocalinux/utils/paths.py
index 5855f0e..dcf09af 100644
--- a/src/vocalinux/utils/paths.py
+++ b/src/vocalinux/utils/paths.py
@@ -2,7 +2,7 @@
 
 import os
 
-APP_DIR_NAME = "vocalinux"
+from ..app_identity import APP_DIR_NAME
 
 
 def xdg_config_home() -> str:
diff --git a/src/vocalinux/utils/resource_manager.py b/src/vocalinux/utils/resource_manager.py
index e94cecd..566b3c1 100644
--- a/src/vocalinux/utils/resource_manager.py
+++ b/src/vocalinux/utils/resource_manager.py
@@ -11,6 +11,8 @@ import sys
 from pathlib import Path
 from typing import Optional, cast
 
+from ..app_identity import ICON_BASE_NAMES, RESOURCE_DIR_NAME
+
 logger = logging.getLogger(__name__)
 
 
@@ -55,7 +57,7 @@ class ResourceManager:
             # For direct repository execution (go up from src/vocalinux/utils to root)
             module_dir.parent.parent.parent / "resources",
             # For installed package or virtual environment (install.sh copies here)
-            Path(sys.prefix) / "share" / "vocalinux" / "resources",
+            Path(sys.prefix) / "share" / RESOURCE_DIR_NAME / "resources",
             # For development in virtual environment
             Path(sys.prefix).parent / "resources",
         ]
@@ -64,19 +66,19 @@ class ResourceManager:
         xdg_data = os.environ.get("XDG_DATA_DIRS", "/usr/local/share:/usr/share")
         for base in xdg_data.split(":"):
             if base:  # Skip empty strings
-                candidates.append(Path(base) / "vocalinux" / "resources")
+                candidates.append(Path(base) / RESOURCE_DIR_NAME / "resources")
 
         # Add distribution-specific standard paths
         additional_paths = [
-            Path("/usr/local/share/vocalinux/resources"),
-            Path("/usr/share/vocalinux/resources"),
+            Path(f"/usr/local/share/{RESOURCE_DIR_NAME}/resources"),
+            Path(f"/usr/share/{RESOURCE_DIR_NAME}/resources"),
             # Some distros use lib64 or lib for package data
-            Path("/usr/local/lib/vocalinux/resources"),
-            Path("/usr/lib/vocalinux/resources"),
-            Path("/usr/local/lib64/vocalinux/resources"),
-            Path("/usr/lib64/vocalinux/resources"),
+            Path(f"/usr/local/lib/{RESOURCE_DIR_NAME}/resources"),
+            Path(f"/usr/lib/{RESOURCE_DIR_NAME}/resources"),
+            Path(f"/usr/local/lib64/{RESOURCE_DIR_NAME}/resources"),
+            Path(f"/usr/lib64/{RESOURCE_DIR_NAME}/resources"),
             # Flatpak specific path
-            Path("/app/share/vocalinux/resources"),
+            Path(f"/app/share/{RESOURCE_DIR_NAME}/resources"),
         ]
 
         for path in additional_paths:
@@ -103,12 +105,7 @@ class ResourceManager:
         if not candidate.exists():
             return -1
 
-        expected_icons = [
-            "vocalinux",
-            "vocalinux-microphone",
-            "vocalinux-microphone-off",
-            "vocalinux-microphone-process",
-        ]
+        expected_icons = list(ICON_BASE_NAMES)
         expected_sounds = ["start_recording", "stop_recording", "error"]
 
         icon_score = sum(
@@ -201,12 +198,7 @@ class ResourceManager:
         }
 
         # Expected icons
-        expected_icons = [
-            "vocalinux",
-            "vocalinux-microphone",
-            "vocalinux-microphone-off",
-            "vocalinux-microphone-process",
-        ]
+        expected_icons = list(ICON_BASE_NAMES)
 
         for icon in expected_icons:
             icon_path = self.get_icon_path(icon)
diff --git a/src/vocalinux/utils/update_checker.py b/src/vocalinux/utils/update_checker.py
index 4d12804..5cb7816 100644
--- a/src/vocalinux/utils/update_checker.py
+++ b/src/vocalinux/utils/update_checker.py
@@ -7,6 +7,7 @@ from typing import Optional
 from urllib.parse import urlparse
 
 from .. import version as _version_module
+from ..app_identity import UPDATE_CHECKER_USER_AGENT
 from ..version import __url__
 from .proxy import requests_proxies
 
@@ -222,7 +223,7 @@ def _fetch_stable_from_releases_page(
     url = f"https://github.com/{owner}/{repo}/releases/latest"
     headers = {
         "Accept": "application/json",
-        "User-Agent": "Vocalinux-UpdateChecker",
+        "User-Agent": UPDATE_CHECKER_USER_AGENT,
     }
     try:
         response = requests.get(url, headers=headers, timeout=timeout, proxies=requests_proxies())
@@ -263,7 +264,7 @@ def fetch_latest_release(
     api_base = _repo_api_base(repo_url)
     headers = {
         "Accept": "application/vnd.github+json",
-        "User-Agent": "Vocalinux-UpdateChecker",
+        "User-Agent": UPDATE_CHECKER_USER_AGENT,
     }
 
     try:
diff --git a/tests/test_app_identity.py b/tests/test_app_identity.py
new file mode 100644
index 0000000..ff0ded0
--- /dev/null
+++ b/tests/test_app_identity.py
@@ -0,0 +1,136 @@
+"""Ticket #17 prefactor inventory: central identity + rename surfaces.
+
+Seams under test (per spec Testing Decisions):
+- Seam 1 (Python behaviour suite): central constants hold current values and
+  every previously duplicated consumer resolves through the shared definition.
+- Seam 2 (offline policy test): rename/retained inventories enumerate files
+  the rename ticket must flip (or deliberately keep) without network access.
+
+No user-visible behaviour, name, path, or string changes: all asserted values
+are the pre-rename Vocalinux/vocalinux literals.
+"""
+
+import ast
+from pathlib import Path
+
+REPO_ROOT = Path(__file__).resolve().parents[1]
+SRC_ROOT = REPO_ROOT / "src" / "vocalinux"
+
+
+def _load_identity():
+    from vocalinux import app_identity
+
+    return app_identity
+
+
+def test_central_values_are_current_names():
+    """Shared definition still carries the pre-rename literals."""
+    identity = _load_identity()
+    assert identity.APP_NAME == "Vocalinux"
+    assert identity.APP_ID == "vocalinux"
+    assert identity.APP_DIR_NAME == "vocalinux"
+    assert identity.CLI_PROG == "vocalinux"
+    assert identity.BUS_NAME == "com.vocalinux.Vocalinux"
+    assert identity.OBJECT_PATH == "/com/vocalinux/Vocalinux"
+    assert identity.INTERFACE_NAME == "com.vocalinux.Vocalinux"
+    assert identity.DESKTOP_FILENAME == "vocalinux.desktop"
+    assert identity.DESKTOP_ICON_NAME == "vocalinux"
+    assert identity.ENGINE_NAME == "vocalinux"
+    assert identity.ENGINE_LONGNAME == "Vocalinux"
+    assert identity.COMPONENT_NAME == "org.freedesktop.IBus.Vocalinux"
+    assert identity.IBUS_DIR_NAME == "vocalinux-ibus"
+    assert identity.UPDATE_CHECKER_USER_AGENT == "Vocalinux-UpdateChecker"
+    assert identity.RESOURCE_DIR_NAME == "vocalinux"
+    assert identity.VERIFICATION_STAMP_NAME == ".vocalinux_verified"
+    assert identity.LOG_FILE_PREFIX == "vocalinux_logs_"
+    assert identity.PORTAL_TOKEN_PREFIX == "vocalinux_"
+    assert identity.ENV_FORCE_BACKEND == "VOCALINUX_FORCE_BACKEND"
+    assert identity.ENV_INJECT_MODIFIER_WAIT == "VOCALINUX_INJECT_MODIFIER_WAIT"
+    assert identity.ENV_YDOTOOL_KEY_DELAY == "VOCALINUX_YDOTOOL_KEY_DELAY"
+
+
+def _imports_app_identity(path: Path) -> bool:
+    tree = ast.parse(path.read_text(encoding="utf-8"))
+    for node in ast.walk(tree):
+        if isinstance(node, ast.ImportFrom):
+            if node.module and node.module.endswith("app_identity"):
+                return True
+    return False
+
+
+def test_consumers_resolve_through_shared_definition():
+    """Previously duplicated surfaces import the shared definition (AST, offline)."""
+    consumers = [
+        SRC_ROOT / "utils" / "paths.py",
+        SRC_ROOT / "ui" / "notifications.py",
+        SRC_ROOT / "ui" / "tray_indicator.py",
+        SRC_ROOT / "dbus_service.py",
+        SRC_ROOT / "ui" / "autostart_manager.py",
+        SRC_ROOT / "text_injection" / "ibus_engine.py",
+        SRC_ROOT / "utils" / "update_checker.py",
+        SRC_ROOT / "utils" / "resource_manager.py",
+        SRC_ROOT / "main.py",
+        SRC_ROOT / "text_injection" / "text_injector.py",
+        SRC_ROOT / "text_injection" / "remote_desktop_portal.py",
+        SRC_ROOT / "ui" / "logging_dialog.py",
+        SRC_ROOT / "utils" / "model_checksums.py",
+        SRC_ROOT / "speech_recognition" / "recognition_manager.py",
+        SRC_ROOT / "ui" / "settings_dialog.py",
+        SRC_ROOT / "ui" / "dictation_overlay.py",
+        SRC_ROOT / "ui" / "audio_feedback.py",
+        SRC_ROOT / "ui" / "keyboard_backends" / "__init__.py",
+    ]
+    missing = [str(p) for p in consumers if not p.exists()]
+    assert not missing, f"consumer files missing: {missing}"
+    not_centralised = [str(p) for p in consumers if not _imports_app_identity(p)]
+    assert not_centralised == [], f"consumers not resolving through app_identity: {not_centralised}"
+
+
+def test_lightweight_consumers_match_shared_values_at_runtime():
+    """Runtime check where importing the consumer needs no display server."""
+    identity = _load_identity()
+    from vocalinux.ui import autostart_manager, notifications
+    from vocalinux.utils import paths
+
+    assert paths.APP_DIR_NAME == identity.APP_DIR_NAME
+    assert autostart_manager.DESKTOP_FILENAME == identity.DESKTOP_FILENAME
+    assert notifications.APP_NAME == identity.APP_NAME
+
+
+def test_source_pinned_literals_reserved_for_rename():
+    """Literals existing source-shape tests pin stay literal until the rename.
+
+    ``tests/test_settings_dialog.py`` (About page) and
+    ``tests/test_dictation_pad.py`` (shelving) read module source or exec
+    function bodies in isolation, so ``settings_about.py`` and
+    ``dictation_pad.py`` keep their current literals. They are recorded here
+    as checked rename surfaces for ticket #18 rather than centralised twice.
+    """
+    about = (SRC_ROOT / "ui" / "settings_about.py").read_text(encoding="utf-8")
+    for literal in (
+        'VOCALINUX_SITE_URL = "https://vocalinux.com"',
+        'title="Vocalinux"',
+        'get_icon_path("vocalinux")',
+    ):
+        assert literal in about, literal
+    pad = (SRC_ROOT / "ui" / "dictation_pad.py").read_text(encoding="utf-8")
+    assert 'window.set_title("Vocalinux Dictation Pad")' in pad
+
+
+def test_rename_inventory_files_exist():
+    """Every rename surface the rename ticket must flip is a real checked file."""
+    identity = _load_identity()
+    assert identity.RENAME_SURFACES, "rename inventory must not be empty"
+    missing = [rel for rel in identity.RENAME_SURFACES if not (REPO_ROOT / rel).exists()]
+    assert missing == [], f"rename inventory entries missing on disk: {missing}"
+
+
+def test_retained_inventory_records_internal_names():
+    """Internal module name and upstream URLs stay, by record not by accident."""
+    identity = _load_identity()
+    assert any("src/vocalinux" in entry for entry in identity.RETAINED_SURFACES)
+    assert any("github.com/VocaHQ/vocalinux" in entry for entry in identity.RETAINED_SURFACES)
+    # The retained Python package must still import under its current name.
+    import vocalinux
+
+    assert vocalinux.__name__ == "vocalinux"