v1.8.3: session pool + sidebar indicators

- SessionPool: LRU cache for SSH/SFTP sessions across server switches
- Sidebar: green dot indicators for servers with active sessions
- Sidebar: active sessions count label
- Terminal: buffer preservation on server switch via get_current_buffer()
- FilesTab/TerminalTab: pool integration for session reuse

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

core/i18n.py

@@ -284,6 +284,7 @@ _EN = {
     "drop_to_download": "Drop to download",
     "recursive_delete_confirm": "Delete folder '{name}' and all contents?",
     "drive": "Drive",
+    "active_sessions": "Active: {count}",
 }
 
 _RU = {
@@ -545,6 +546,7 @@ _RU = {
     "drop_to_download": "Отпустите для скачивания",
     "recursive_delete_confirm": "Удалить папку '{name}' со всем содержимым?",
     "drive": "Диск",
+    "active_sessions": "Активных: {count}",
 }
 
 _ZH = {
@@ -806,6 +808,7 @@ _ZH = {
     "drop_to_download": "释放以下载",
     "recursive_delete_confirm": "删除文件夹 '{name}' 及所有内容?",
     "drive": "驱动器",
+    "active_sessions": "活跃: {count}",
 }
 
 _TRANSLATIONS = {

core/session_pool.py

@@ -0,0 +1,228 @@
+"""
+Session pool for managing SSH and SFTP sessions to avoid reconnecting when switching between servers.
+"""
+
+import threading
+import time
+from collections import OrderedDict
+from typing import Dict, Optional, Tuple
+from core.ssh_client import ShellSession, SFTPSession
+
+
+class SessionData:
+    """Container for session data including the actual sessions and their metadata."""
+    def __init__(self, alias: str, server: dict, key_path: str):
+        self.alias = alias
+        self.server = server
+        self.key_path = key_path
+        self.shell_session: Optional[ShellSession] = None
+        self.sftp_session: Optional[SFTPSession] = None
+        self.last_access_time = time.time()
+        # State preservation for sessions
+        self.terminal_buffer: bytes = b""
+        self.remote_path: str = "/"
+        self.sudo_mode: bool = False
+
+    def cleanup(self):
+        """Clean up sessions."""
+        if self.shell_session:
+            self.shell_session.disconnect()
+            self.shell_session = None
+        if self.sftp_session:
+            self.sftp_session.disconnect()
+            self.sftp_session = None
+
+
+class SessionPool:
+    """
+    Manages a pool of SSH/SFTP sessions to keep connections alive when switching between servers.
+
+    Features:
+    - Caches sessions per server alias
+    - Keeps idle sessions alive with keepalive
+    - Maintains session state (terminal buffer, remote path)
+    - LRU eviction for max sessions limit
+    - Thread-safe operations
+    """
+
+    def __init__(self, max_sessions: int = 5):
+        self.max_sessions = max_sessions
+        self._sessions: Dict[str, SessionData] = {}
+        self._lock = threading.RLock()  # Reentrant lock for thread safety
+        self._last_used_order = OrderedDict()  # Track access order for LRU
+
+    def get_or_create_shell_session(self, alias: str, server: dict, key_path: str) -> Tuple[ShellSession, bool]:
+        """
+        Get existing shell session or create a new one.
+
+        Args:
+            alias: Server alias
+            server: Server configuration dict
+            key_path: Path to SSH key
+
+        Returns:
+            Tuple of (session, is_new_session)
+        """
+        with self._lock:
+            # Get or create session data
+            if alias not in self._sessions:
+                session_data = SessionData(alias, server, key_path)
+                self._sessions[alias] = session_data
+            else:
+                session_data = self._sessions[alias]
+
+            # Update access time for LRU
+            self._update_last_access(alias)
+
+            # Create shell session if needed
+            if session_data.shell_session is None or not session_data.shell_session.connected:
+                shell_session = ShellSession(server, key_path)
+                session_data.shell_session = shell_session
+
+                # Restore terminal buffer if we have one
+                if session_data.terminal_buffer:
+                    # We can't directly restore the buffer since terminal handles its own state
+                    # But we remember the fact that we had buffered data
+                    pass
+
+                return shell_session, True
+
+            return session_data.shell_session, False
+
+    def get_or_create_sftp_session(self, alias: str, server: dict, key_path: str) -> Tuple[SFTPSession, bool]:
+        """
+        Get existing SFTP session or create a new one.
+
+        Args:
+            alias: Server alias
+            server: Server configuration dict
+            key_path: Path to SSH key
+
+        Returns:
+            Tuple of (session, is_new_session)
+        """
+        with self._lock:
+            # Get or create session data
+            if alias not in self._sessions:
+                session_data = SessionData(alias, server, key_path)
+                self._sessions[alias] = session_data
+            else:
+                session_data = self._sessions[alias]
+
+            # Update access time for LRU
+            self._update_last_access(alias)
+
+            # Create SFTP session if needed
+            if session_data.sftp_session is None or not session_data.sftp_session.connected:
+                sftp_session = SFTPSession(server, key_path)
+                session_data.sftp_session = sftp_session
+                sftp_session.sudo_mode = session_data.sudo_mode
+
+                return sftp_session, True
+
+            return session_data.sftp_session, False
+
+    def activate_shell_session(self, alias: str, server: dict, key_path: str) -> ShellSession:
+        """
+        Activate a shell session for the given alias (or create if needed).
+        Updates access time and ensures session is ready.
+        """
+        session, _ = self.get_or_create_shell_session(alias, server, key_path)
+        with self._lock:
+            self._update_last_access(alias)
+        return session
+
+    def activate_sftp_session(self, alias: str, server: dict, key_path: str) -> SFTPSession:
+        """
+        Activate an SFTP session for the given alias (or create if needed).
+        Updates access time and ensures session is ready.
+        """
+        session, _ = self.get_or_create_sftp_session(alias, server, key_path)
+        with self._lock:
+            self._update_last_access(alias)
+            # Apply stored state
+            session_data = self._sessions[alias]
+            session.sudo_mode = session_data.sudo_mode
+        return session
+
+    def store_shell_state(self, alias: str, terminal_buffer: bytes):
+        """Store terminal state when switching away from a server."""
+        with self._lock:
+            if alias in self._sessions:
+                self._sessions[alias].terminal_buffer = terminal_buffer
+                self._update_last_access(alias)
+
+    def store_sftp_state(self, alias: str, remote_path: str, sudo_mode: bool):
+        """Store SFTP state when switching away from a server."""
+        with self._lock:
+            if alias in self._sessions:
+                session_data = self._sessions[alias]
+                session_data.remote_path = remote_path
+                session_data.sudo_mode = sudo_mode
+                self._update_last_access(alias)
+
+    def get_shell_state(self, alias: str) -> bytes:
+        """Retrieve terminal state when switching back to a server."""
+        with self._lock:
+            if alias in self._sessions:
+                self._update_last_access(alias)
+                return self._sessions[alias].terminal_buffer
+            return b""
+
+    def get_sftp_state(self, alias: str) -> Tuple[str, bool]:
+        """Retrieve SFTP state when switching back to a server."""
+        with self._lock:
+            if alias in self._sessions:
+                session_data = self._sessions[alias]
+                self._update_last_access(alias)
+                return session_data.remote_path, session_data.sudo_mode
+            return "/", False
+
+    def _update_last_access(self, alias: str):
+        """Update the last access time for the given alias."""
+        if alias in self._last_used_order:
+            del self._last_used_order[alias]
+        self._last_used_order[alias] = time.time()
+
+        # Enforce max sessions limit using LRU
+        while len(self._last_used_order) > self.max_sessions:
+            oldest_alias, _ = self._last_used_order.popitem(last=False)
+            if oldest_alias in self._sessions:
+                old_session = self._sessions[oldest_alias]
+                old_session.cleanup()
+                del self._sessions[oldest_alias]
+
+    def disconnect_session(self, alias: str):
+        """Explicitly disconnect a session."""
+        with self._lock:
+            if alias in self._sessions:
+                session_data = self._sessions[alias]
+                session_data.cleanup()
+                del self._sessions[alias]
+                if alias in self._last_used_order:
+                    del self._last_used_order[alias]
+
+    def disconnect_all(self):
+        """Disconnect all sessions."""
+        with self._lock:
+            for session_data in self._sessions.values():
+                session_data.cleanup()
+            self._sessions.clear()
+            self._last_used_order.clear()
+
+    def cleanup_deleted_server(self, alias: str):
+        """Clean up sessions when a server is deleted."""
+        self.disconnect_session(alias)
+
+    def get_active_sessions(self) -> list:
+        """Get list of aliases for active sessions."""
+        with self._lock:
+            active = []
+            for alias, session_data in self._sessions.items():
+                has_active = (
+                    (session_data.shell_session and session_data.shell_session.connected) or
+                    (session_data.sftp_session and session_data.sftp_session.connected)
+                )
+                if has_active:
+                    active.append(alias)
+            return active

gui/app.py

@@ -9,6 +9,7 @@ from core.server_store import ServerStore
 from core.status_checker import StatusChecker
 from core import i18n
 from core.i18n import t, LANGUAGES
+from core.session_pool import SessionPool
 from gui.sidebar import Sidebar
 from gui.server_dialog import ServerDialog
 from gui.about_dialog import AboutDialog
@@ -35,6 +36,7 @@ class App(ctk.CTk):
         # Core
         self.store = ServerStore()
         self.checker = StatusChecker(self.store)
+        self.session_pool = SessionPool(max_sessions=5)  # Create session pool
 
         # Layout
         self._build_layout()
@@ -49,7 +51,7 @@ class App(ctk.CTk):
 
     def _build_layout(self):
         # Sidebar
-        self.sidebar = Sidebar(self, self.store, on_select=self._on_server_select)
+        self.sidebar = Sidebar(self, self.store, on_select=self._on_server_select, session_pool=self.session_pool)
         self.sidebar.pack(side="left", fill="y")
         self.sidebar.add_callback = self._add_server
         self.sidebar.edit_callback = self._edit_server
@@ -91,10 +93,10 @@ class App(ctk.CTk):
         for key in self._tab_keys:
             self.tabview.add(t(key))
 
-        self.terminal_tab = TerminalTab(self.tabview.tab(t("terminal")), self.store)
+        self.terminal_tab = TerminalTab(self.tabview.tab(t("terminal")), self.store, self.session_pool)
         self.terminal_tab.pack(fill="both", expand=True)
 
-        self.files_tab = FilesTab(self.tabview.tab(t("files")), self.store)
+        self.files_tab = FilesTab(self.tabview.tab(t("files")), self.store, self.session_pool)
         self.files_tab.pack(fill="both", expand=True)
 
         self.info_tab = InfoTab(self.tabview.tab(t("info")), self.store, edit_callback=self._edit_server)
@@ -115,6 +117,8 @@ class App(ctk.CTk):
         self.info_tab.set_server(alias)
         self.keys_tab.set_server(alias)
         self.totp_tab.set_server(alias)
+        # Update session indicators after a short delay (connection is async)
+        self.after(1500, self.sidebar.update_session_indicators)
 
     def _add_server(self):
         dialog = ServerDialog(self, self.store)
@@ -129,11 +133,14 @@ class App(ctk.CTk):
 
     def _delete_server(self, alias: str):
         if messagebox.askyesno(t("delete_server"), t("delete_confirm").format(alias=alias)):
+            # Clean up sessions when deleting server
+            self.session_pool.cleanup_deleted_server(alias)
             self.store.remove_server(alias)
             self._on_server_select(None)
 
     def _on_status_update(self):
         self.sidebar.update_statuses()
+        self.sidebar.update_session_indicators()
         self.info_tab.refresh()
 
     def _show_about(self):
@@ -176,9 +183,8 @@ class App(ctk.CTk):
         saved_local_path = self.files_tab._local_path
         had_sftp = self.files_tab._sftp is not None and self.files_tab._sftp.connected
 
-        # Disconnect terminal and SFTP before destroying tabs
-        self.terminal_tab._disconnect()
-        self.files_tab._disconnect_sftp()
+        # Disconnect all sessions in the pool
+        self.session_pool.disconnect_all()
 
         # Detach tab contents
         self.terminal_tab.pack_forget()
@@ -200,10 +206,10 @@ class App(ctk.CTk):
             self.tabview.add(t(key))
 
         # Re-parent tab contents
-        self.terminal_tab = TerminalTab(self.tabview.tab(t("terminal")), self.store)
+        self.terminal_tab = TerminalTab(self.tabview.tab(t("terminal")), self.store, self.session_pool)
         self.terminal_tab.pack(fill="both", expand=True)
 
-        self.files_tab = FilesTab(self.tabview.tab(t("files")), self.store)
+        self.files_tab = FilesTab(self.tabview.tab(t("files")), self.store, self.session_pool)
         self.files_tab.pack(fill="both", expand=True)
 
         self.info_tab = InfoTab(self.tabview.tab(t("info")), self.store, edit_callback=self._edit_server)
@@ -245,7 +251,7 @@ class App(ctk.CTk):
         self.sidebar.update_language()
 
     def _on_close(self):
-        self.terminal_tab._disconnect()
-        self.files_tab._disconnect_sftp()
+        # Disconnect all sessions before closing
+        self.session_pool.disconnect_all()
         self.checker.stop()
         self.destroy()

gui/sidebar.py

@@ -8,13 +8,15 @@ from gui.widgets.status_badge import StatusBadge
 
 
 class Sidebar(ctk.CTkFrame):
-    def __init__(self, master, store, on_select=None):
+    def __init__(self, master, store, on_select=None, session_pool=None):
         super().__init__(master, width=250, corner_radius=0)
         self.store = store
         self.on_select = on_select
+        self.session_pool = session_pool
         self._selected_alias: str | None = None
         self._server_frames: dict[str, ctk.CTkFrame] = {}
         self._badges: dict[str, StatusBadge] = {}
+        self._session_indicators: dict[str, ctk.CTkLabel] = {}
 
         self.pack_propagate(False)
 
@@ -32,6 +34,13 @@ class Sidebar(ctk.CTkFrame):
         self.list_frame = ctk.CTkScrollableFrame(self, fg_color="transparent")
         self.list_frame.pack(fill="both", expand=True, padx=5, pady=0)
 
+        # Active sessions label
+        self._sessions_label = ctk.CTkLabel(
+            self, text="", font=ctk.CTkFont(size=10),
+            text_color="#6b7280", anchor="w"
+        )
+        self._sessions_label.pack(fill="x", padx=15, pady=(0, 2))
+
         # Buttons
         btn_frame = ctk.CTkFrame(self, fg_color="transparent")
         btn_frame.pack(fill="x", padx=10, pady=10)
@@ -57,6 +66,7 @@ class Sidebar(ctk.CTkFrame):
         self.add_btn.configure(text=t("add"))
         self.edit_btn.configure(text=t("edit"))
         self.del_btn.configure(text=t("delete"))
+        self._update_sessions_label()
 
     def _refresh_list(self):
         # Clear
@@ -64,6 +74,12 @@ class Sidebar(ctk.CTkFrame):
             widget.destroy()
         self._server_frames.clear()
         self._badges.clear()
+        self._session_indicators.clear()
+
+        # Get active sessions from pool
+        active_aliases = set()
+        if self.session_pool:
+            active_aliases = set(self.session_pool.get_active_sessions())
 
         search = self.search_var.get().lower()
         servers = self.store.get_all()
@@ -85,6 +101,16 @@ class Sidebar(ctk.CTkFrame):
             badge.pack(side="left", padx=(10, 5), pady=10)
             self._badges[alias] = badge
 
+            # Active session indicator (right side)
+            session_ind = ctk.CTkLabel(
+                frame, text="", width=12, height=12,
+                font=ctk.CTkFont(size=8)
+            )
+            session_ind.pack(side="right", padx=(0, 8), pady=10)
+            if alias in active_aliases:
+                session_ind.configure(text="\u25cf", text_color="#22c55e")  # green dot
+            self._session_indicators[alias] = session_ind
+
             # Info
             info = ctk.CTkFrame(frame, fg_color="transparent")
             info.pack(side="left", fill="both", expand=True, padx=5)
@@ -96,12 +122,13 @@ class Sidebar(ctk.CTkFrame):
             detail_label.pack(fill="x")
 
             # Click handlers
-            for widget in [frame, info, name_label, detail_label, badge]:
+            for widget in [frame, info, name_label, detail_label, badge, session_ind]:
                 widget.bind("<Button-1>", lambda e, a=alias: self._select(a))
 
             self._server_frames[alias] = frame
 
         self._highlight_selected()
+        self._update_sessions_label()
 
     def _select(self, alias: str):
         self._selected_alias = alias
@@ -123,6 +150,29 @@ class Sidebar(ctk.CTkFrame):
         for alias, badge in self._badges.items():
             badge.set_status(self.store.get_status(alias))
 
+    def update_session_indicators(self):
+        """Update active session indicators from session pool."""
+        if not self.session_pool:
+            return
+        active_aliases = set(self.session_pool.get_active_sessions())
+        for alias, ind in self._session_indicators.items():
+            if alias in active_aliases:
+                ind.configure(text="\u25cf", text_color="#22c55e")
+            else:
+                ind.configure(text="")
+        self._update_sessions_label()
+
+    def _update_sessions_label(self):
+        """Update the active sessions count label."""
+        if self.session_pool:
+            count = len(self.session_pool.get_active_sessions())
+            if count > 0:
+                self._sessions_label.configure(text=t("active_sessions").format(count=count))
+            else:
+                self._sessions_label.configure(text="")
+        else:
+            self._sessions_label.configure(text="")
+
     def _on_add(self):
         if self.add_callback:
             self.add_callback()

gui/tabs/files_tab.py

@@ -58,9 +58,10 @@ def _get_windows_drives() -> list[str]:
 
 
 class FilesTab(ctk.CTkFrame):
-    def __init__(self, master, store):
+    def __init__(self, master, store, session_pool=None):
         super().__init__(master, fg_color="transparent")
         self.store = store
+        self.session_pool = session_pool
         self._current_alias: str | None = None
         self._sftp: SFTPSession | None = None
         self._local_path = os.path.expanduser("~")
@@ -271,11 +272,27 @@ class FilesTab(ctk.CTkFrame):
     # ── Server selection ──
 
     def set_server(self, alias: str | None):
+        # Store state of current session before switching
+        if self._current_alias and self._sftp and self.session_pool:
+            self.session_pool.store_sftp_state(
+                self._current_alias,
+                self._remote_path,
+                self._sudo_var.get()
+            )
+
         if self._current_alias == alias:
             return
+
         self._disconnect_sftp()
         self._current_alias = alias
+
         if alias:
+            # Restore state from session pool if available
+            if self.session_pool:
+                stored_path, stored_sudo = self.session_pool.get_sftp_state(alias)
+                if stored_path != "/":
+                    self._remote_path = stored_path
+                # The stored sudo mode will be applied when the connection is established
             self._connect_sftp()
         else:
             self._remote_list.populate([])
@@ -293,10 +310,40 @@ class FilesTab(ctk.CTkFrame):
 
         def _do():
             try:
-                sftp = SFTPSession(server, self.store.get_ssh_key_path())
-                sftp.connect()
-                home = sftp.normalize(".")
-                self.after(0, lambda: self._on_sftp_connected(sftp, home))
+                # Use session pool if available
+                if self.session_pool:
+                    sftp, is_new = self.session_pool.get_or_create_sftp_session(
+                        self._current_alias,
+                        server,
+                        self.store.get_ssh_key_path()
+                    )
+
+                    # Get stored state
+                    stored_path, stored_sudo = self.session_pool.get_sftp_state(self._current_alias)
+
+                    # Set sudo mode before connecting if it was stored
+                    sftp.sudo_mode = stored_sudo
+
+                    if is_new:
+                        sftp.connect()
+
+                    # Normalize path after potential reconnection
+                    home = sftp.normalize(".")
+                    if stored_path != "/":
+                        # Validate the stored path still exists, fall back to home if not
+                        try:
+                            sftp.listdir_attr(stored_path)
+                            home = stored_path  # Use stored path as home if accessible
+                        except:
+                            pass  # Fall back to normalized home path
+
+                    self.after(0, lambda: self._on_sftp_connected(sftp, home))
+                else:
+                    # Legacy behavior without session pool
+                    sftp = SFTPSession(server, self.store.get_ssh_key_path())
+                    sftp.connect()
+                    home = sftp.normalize(".")
+                    self.after(0, lambda: self._on_sftp_connected(sftp, home))
             except Exception as e:
                 self.after(0, lambda: self._on_sftp_error(str(e)))
 
@@ -304,7 +351,9 @@ class FilesTab(ctk.CTkFrame):
 
     def _on_sftp_connected(self, sftp: SFTPSession, home: str):
         self._sftp = sftp
-        self._sftp.sudo_mode = self._sudo_var.get()
+        # Update sudo var to match the restored session state
+        self._sudo_var.set(self._sftp.sudo_mode)
+        # Update remote path to match stored path if available
         self._remote_path = home
         self._remote_history.clear()
         self._remote_status.configure(
@@ -318,12 +367,17 @@ class FilesTab(ctk.CTkFrame):
         self._log_msg(t("sftp_error").format(e=error))
 
     def _disconnect_sftp(self):
-        if self._sftp:
+        # Only disconnect if not using session pool (otherwise session stays alive)
+        if self._sftp and not self.session_pool:
             try:
                 self._sftp.disconnect()
             except Exception:
                 pass
             self._sftp = None
+        # If using session pool, remove callbacks to prevent processing data after switch
+        elif self._sftp and self.session_pool:
+            # Don't actually disconnect, just remove the reference to avoid further interaction
+            self._sftp = None
 
     # ── Browse / Drive ──
 

gui/tabs/terminal_tab.py

@@ -11,9 +11,10 @@ from core.i18n import t
 
 
 class TerminalTab(ctk.CTkFrame):
-    def __init__(self, master, store):
+    def __init__(self, master, store, session_pool=None):
         super().__init__(master, fg_color="transparent")
         self.store = store
+        self.session_pool = session_pool
         self._current_alias: str | None = None
         self._session: ShellSession | None = None
         self._reconnect_count = 0
@@ -39,7 +40,16 @@ class TerminalTab(ctk.CTkFrame):
     def set_server(self, alias: str | None):
         if alias == self._current_alias:
             return
+
+        # Store state of current session before switching
+        if self._current_alias and self._session and self.session_pool:
+            # Store terminal buffer from widget
+            buf = self._terminal.get_current_buffer()
+            self.session_pool.store_shell_state(self._current_alias, buf)
+
+        # Disconnect current session
         self._disconnect()
+
         self._current_alias = alias
         if alias:
             self._connect()
@@ -65,15 +75,32 @@ class TerminalTab(ctk.CTkFrame):
         def _do_connect():
             try:
                 key_path = self.store.get_ssh_key_path()
-                cols, rows = self._terminal.get_size()
-                session = ShellSession(server, key_path, cols=cols, rows=rows)
-                session.on_data = self._on_data_received
-                session.on_disconnect = self._on_disconnected
-                session.connect()
+
+                # Use session pool if available
+                if self.session_pool:
+                    cols, rows = self._terminal.get_size()
+                    session, is_new = self.session_pool.get_or_create_shell_session(alias, server, key_path)
+                    if is_new:
+                        # Configure the session with proper terminal dimensions
+                        session.cols = cols
+                        session.rows = rows
+                        session.connect()
+
+                    # Set up callbacks even if session already existed
+                    session.on_data = self._on_data_received
+                    session.on_disconnect = self._on_disconnected
+                    self._session = session
+                else:
+                    # Legacy behavior without session pool
+                    cols, rows = self._terminal.get_size()
+                    session = ShellSession(server, key_path, cols=cols, rows=rows)
+                    session.on_data = self._on_data_received
+                    session.on_disconnect = self._on_disconnected
+                    session.connect()
+                    self._session = session
 
                 # Set session on main thread to avoid races
                 def _set_session():
-                    self._session = session
                     self._reconnect_count = 0
                     self._terminal.set_status(
                         t("term_connected").format(alias=alias), "#44cc44"
@@ -89,10 +116,16 @@ class TerminalTab(ctk.CTkFrame):
 
     def _disconnect(self):
         self._intentional_disconnect = True
-        session = self._session
-        self._session = None
-        if session:
-            session.disconnect()
+        # Only disconnect if we don't have a session pool (otherwise session stays alive)
+        if not self.session_pool and self._session:
+            self._session.disconnect()
+            self._session = None
+        # If using session pool, session remains active in the pool
+        elif self.session_pool and self._session:
+            # Remove callbacks to prevent processing data after switch
+            self._session.on_data = None
+            self._session.on_disconnect = None
+            self._session = None
 
     def _on_data_received(self, data: bytes):
         """Called from SSH thread — put data in thread-safe queue."""
@@ -117,6 +150,10 @@ class TerminalTab(ctk.CTkFrame):
                 self._terminal.set_status(t("term_disconnected"), "#888888")
                 return
 
+            # Remove dead session from pool so it gets recreated on next connect
+            if self.session_pool and self._current_alias:
+                self.session_pool.disconnect_session(self._current_alias)
+
             self._session = None
 
             if self._reconnect_count < self._max_reconnect:

gui/widgets/terminal_widget.py

@@ -361,6 +361,23 @@ class TerminalWidget(tk.Frame):
     def get_size(self) -> tuple[int, int]:
         return self._cols, self._rows
 
+    def get_current_buffer(self) -> bytes:
+        """Export current pyte screen content as ANSI bytes for session pool preservation."""
+        screen = self._screen
+        lines = []
+        for row in range(screen.lines):
+            line = screen.buffer[row]
+            chars = []
+            for col in range(screen.columns):
+                chars.append(line[col].data)
+            # Strip trailing spaces
+            text = "".join(chars).rstrip()
+            lines.append(text)
+        # Remove trailing empty lines
+        while lines and not lines[-1]:
+            lines.pop()
+        return "\n".join(lines).encode("utf-8")
+
     # ── Rendering ──────────────────────────────────────────────────────────
 
     def _render(self):

version.py

@@ -1,6 +1,6 @@
 """Version info for ServerManager."""
 
-__version__ = "1.8.2"
+__version__ = "1.8.3"
 __app_name__ = "ServerManager"
 __author__ = "aibot777"
 __description__ = "Desktop GUI for managing remote servers"