diff --git a/README.md b/README.md
index 1880058..779b7a0 100644
--- a/README.md
+++ b/README.md
@@ -31,6 +31,62 @@ hqt
 | `Enter` | Attach to session (auto-resumes if not running) |
 | `r` | Rename session |
 | `s` | Stop session |
+| `h` / `l` | Focus the Projects / Sessions column |
+| `x` | Archive selected session (instant; keeps the row, kills the window) |
+| `A` | Toggle the Sessions column between active and archived |
+| `u` | Restore (unarchive) the selected session — archived view only |
+
+## tmux configuration
+
+hqt runs inside tmux and tags each harness window with an `@hqt_label` user
+option automatically — **it never edits your `~/.tmux.conf`**. The TUI itself
+needs no tmux config to run. The bindings below are opt-in: add the ones you
+want to your own `~/.tmux.conf` (`-n` = no prefix key).
+
+### Tool palette — `Alt+p` (required for the palette feature)
+
+Pops an fzf palette for the current session's project (nvim / lazygit / shell /
+clone / reset-windows) from inside a harness window. Requires `hqt` on your
+`PATH` (see Quick Start) and `fzf`. `run-shell` expands `#{window_name}` to a
+concrete window name before `hqt` builds its `display-popup`:
+
+```tmux
+bind -n M-p run-shell -b "hqt palette '#{window_name}'"
+```
+
+If you run hqt from a checkout instead of installing it, point `uv run` at the
+repo so the virtualenv self-heals when deps change:
+
+```tmux
+bind -n M-p run-shell -b "uv run --project /path/to/hq-term hqt palette '#{window_name}'"
+```
+
+### Session switcher — `Alt+o` (optional)
+
+Pops an fzf switcher over whatever you're doing (works inside a harness too).
+Rows are built from the `@hqt_label` hqt sets; `cut` takes the leading window
+index and `select-window` jumps to it:
+
+```tmux
+bind -n M-o display-popup -E -w 50% -h 40% -T ' switch session ' \
+  "tmux list-windows -F '#{window_index} #{?@hqt_label,#{@hqt_label},#{window_name}}' \
+   | fzf --reverse --no-info --prompt='session  ' \
+   | cut -d' ' -f1 \
+   | xargs -r tmux select-window -t"
+```
+
+### Scrollback passthrough — `PageUp` (optional)
+
+The TUI uses tmux's alternate screen. This sends `PageUp` straight through to
+full-screen apps (the TUI) while still entering copy-mode scrollback in normal
+panes:
+
+```tmux
+bind -n PageUp if-shell -F '#{alternate_on}' 'send-keys PageUp' 'copy-mode -eu'
+```
+
+After editing `~/.tmux.conf`, reload it with `tmux source-file ~/.tmux.conf`
+(or restart the server).
 
 ## Worktree-isolated sessions
 
diff --git a/src/hqt/sessions/service.py b/src/hqt/sessions/service.py
index 47c5826..d8d4a4b 100644
--- a/src/hqt/sessions/service.py
+++ b/src/hqt/sessions/service.py
@@ -826,6 +826,37 @@ class SessionService:
             db.delete(sess)
             db.commit()
 
+    async def archive_session(self, session_id: int) -> None:
+        """Archive a session: kill its tmux window but keep the DB row.
+
+        A recoverable "remove from view" — the window/harness process is torn
+        down (freeing resources) but the row, ``harness_session_id``, and any
+        worktree are preserved so the session can be restored or referenced
+        later. No-op if the session does not exist.
+        """
+        with self.factory() as db:
+            sess = db.get(Session, session_id)
+            if sess is None:
+                return
+            if await self.tmux.window_exists(sess.tmux_session_name):
+                await self.tmux.kill(sess.tmux_session_name)
+            sess.archived = True
+            db.commit()
+
+    async def unarchive_session(self, session_id: int) -> None:
+        """Restore an archived session by clearing its archived flag.
+
+        The tmux window stays gone (the session reads as dead until resumed);
+        this only makes the row visible in the active list again. No-op if the
+        session does not exist.
+        """
+        with self.factory() as db:
+            sess = db.get(Session, session_id)
+            if sess is None:
+                return
+            sess.archived = False
+            db.commit()
+
     async def worktree_state_for(self, session_id: int) -> WorktreeState | None:
         """Return the WorktreeState for a session's worktree, or None.
 
@@ -881,7 +912,7 @@ class SessionService:
         return {prompt.session_id: prompt for prompt in prompts}
 
     async def list_sessions(
-        self, project_id: int, now: float | None = None
+        self, project_id: int, archived: bool = False, now: float | None = None
     ) -> list[SessionInfo]:
         if now is None:
             now = time.time()
@@ -889,7 +920,7 @@ class SessionService:
             sessions = (
                 db.query(Session)
                 .options(selectinload(Session.harness))
-                .filter_by(project_id=project_id, archived=False)
+                .filter_by(project_id=project_id, archived=archived)
                 .all()
             )
             names = [s.tmux_session_name for s in sessions]
diff --git a/src/hqt/tui/app.py b/src/hqt/tui/app.py
index e19ff82..b136da7 100644
--- a/src/hqt/tui/app.py
+++ b/src/hqt/tui/app.py
@@ -70,6 +70,11 @@ class HqtApp(App):
         Binding("a", "add_project", "Add Project"),
         Binding("e", "edit_project", "Edit Project"),
         Binding("tab", "toggle_focus", "Switch Panel"),
+        Binding("h", "focus_projects", "Projects"),
+        Binding("l", "focus_sessions", "Sessions"),
+        Binding("x", "archive_session", "Archive"),
+        Binding("A", "toggle_archived", "Show Archived"),
+        Binding("u", "unarchive_session", "Restore"),
         Binding("d", "delete_session", "Delete Session"),
         Binding("enter", "attach_session", "Attach", priority=True),
         Binding("r", "rename_session", "Rename"),
@@ -88,6 +93,9 @@ class HqtApp(App):
         self.register_theme(FRAPPE_THEME)
         self.theme = "catppuccin-frappe"
         self._selected_project_id: int | None = None
+        # When True, the Sessions column shows this project's archived sessions
+        # instead of its active ones. Persists across project switches.
+        self._show_archived = False
         # project_id -> last selected session_id, so switching projects restores
         # each project's previously highlighted session.
         self._selected_session_by_project: dict[int, int] = {}
@@ -178,7 +186,7 @@ class HqtApp(App):
         except ServiceError as err:
             log.warning("Session poll failed: %s", err)
             return
-        if self._selected_project_id is not None:
+        if self._selected_project_id is not None and not self._show_archived:
             subset = [
                 i for i in infos if i.session.project_id == self._selected_project_id
             ]
@@ -187,7 +195,9 @@ class HqtApp(App):
     async def _refresh_sessions(self, restore_selection: bool = False) -> None:
         if self._selected_project_id is None:
             return
-        infos = await self._sessions().list_sessions(self._selected_project_id)
+        infos = await self._sessions().list_sessions(
+            self._selected_project_id, archived=self._show_archived
+        )
         sl = self.query_one(SessionList)
         if restore_selection:
             # Project switch: restore this project's remembered session, or let the
@@ -213,6 +223,12 @@ class HqtApp(App):
     def action_toggle_focus(self) -> None:
         self.screen.focus_next()
 
+    def action_focus_projects(self) -> None:
+        self.query_one("#project-list").focus()
+
+    def action_focus_sessions(self) -> None:
+        self.query_one("#session-list").focus()
+
     def action_add_project(self) -> None:
         def on_dismiss(result: tuple[str, str] | None) -> None:
             if result:
@@ -334,6 +350,12 @@ class HqtApp(App):
         # the focused dialog widget.
         if action == "attach_session" and isinstance(self.screen, ModalScreen):
             return False
+        # Archive applies only to active sessions; restore only to archived ones.
+        # Hide the inapplicable one so the footer never advertises it.
+        if action == "archive_session" and self._show_archived:
+            return None
+        if action == "unarchive_session" and not self._show_archived:
+            return None
         return True
 
     def action_attach_session(self) -> None:
@@ -428,6 +450,33 @@ class HqtApp(App):
 
             self._run_service_worker(_do())
 
+    def action_archive_session(self) -> None:
+        sid = self.query_one(SessionList).get_selected_session_id()
+        if not sid:
+            return
+
+        async def _do() -> None:
+            await self._sessions().archive_session(sid)
+            await self._refresh_sessions()
+
+        self._run_service_worker(_do())
+
+    def action_unarchive_session(self) -> None:
+        sid = self.query_one(SessionList).get_selected_session_id()
+        if not sid:
+            return
+
+        async def _do() -> None:
+            await self._sessions().unarchive_session(sid)
+            await self._refresh_sessions()
+
+        self._run_service_worker(_do())
+
+    def action_toggle_archived(self) -> None:
+        self._show_archived = not self._show_archived
+        self.query_one(SessionList).set_mode(archived=self._show_archived)
+        self._run_service_worker(self._refresh_sessions(restore_selection=True))
+
     def action_schedule_prompt(self) -> None:
         sid = self.query_one(SessionList).get_selected_session_id()
         if sid is None:
diff --git a/src/hqt/tui/widgets/session_list.py b/src/hqt/tui/widgets/session_list.py
index 3b8da7d..98e3fdc 100644
--- a/src/hqt/tui/widgets/session_list.py
+++ b/src/hqt/tui/widgets/session_list.py
@@ -72,6 +72,11 @@ class SessionList(Widget, can_focus=False):
         yield Label("Sessions", id="session-header")
         yield VimListView(id="session-list")
 
+    def set_mode(self, archived: bool) -> None:
+        """Swap the column header to reflect whether archived sessions are shown."""
+        header = self.query_one("#session-header", Label)
+        header.update("Sessions (archived)" if archived else "Sessions")
+
     async def refresh_sessions(
         self, session_infos: list, select_session_id=_UNSET
     ) -> None:
diff --git a/tests/test_sessions.py b/tests/test_sessions.py
index e6c3500..5a5d271 100644
--- a/tests/test_sessions.py
+++ b/tests/test_sessions.py
@@ -2150,3 +2150,63 @@ async def test_stop_session_for_window_kills_by_name(service, db, tmux):
 async def test_stop_session_for_window_unknown_window_raises(service):
     with pytest.raises(ServiceError):
         await service.stop_session_for_window("not-an-hqt-window")
+
+
+@pytest.mark.asyncio
+async def test_list_sessions_archived_filter(service, db, tmux):
+    h = db.query(Harness).filter_by(name="claude-code").first()
+    active = Session(
+        project_id=1, harness_id=h.id, tmux_session_name="hqt-active", archived=False
+    )
+    arch = Session(
+        project_id=1, harness_id=h.id, tmux_session_name="hqt-arch", archived=True
+    )
+    db.add_all([active, arch])
+    db.commit()
+    active_id, arch_id = active.id, arch.id
+
+    default = await service.list_sessions(project_id=1)
+    assert [i.session.id for i in default] == [active_id]
+
+    archived = await service.list_sessions(project_id=1, archived=True)
+    assert [i.session.id for i in archived] == [arch_id]
+
+
+@pytest.mark.asyncio
+async def test_archive_session_kills_window_and_keeps_row(service, db, tmux):
+    await service.create_session(project_id=1, harness_name="claude-code")
+    await service.archive_session(1)
+
+    tmux.kill.assert_called_once_with("hqt-1")
+    db.expire_all()
+    row = db.get(Session, 1)
+    assert row is not None
+    assert row.archived is True
+    # Excluded from the default (active) listing.
+    assert await service.list_sessions(project_id=1) == []
+
+
+@pytest.mark.asyncio
+async def test_archive_session_no_kill_when_window_missing(service, db, tmux):
+    await service.create_session(project_id=1, harness_name="claude-code")
+    tmux.window_exists = AsyncMock(return_value=False)
+    tmux.kill.reset_mock()
+
+    await service.archive_session(1)
+
+    tmux.kill.assert_not_called()
+    db.expire_all()
+    assert db.get(Session, 1).archived is True
+
+
+@pytest.mark.asyncio
+async def test_unarchive_session_restores_to_active_list(service, db, tmux):
+    await service.create_session(project_id=1, harness_name="claude-code")
+    await service.archive_session(1)
+
+    await service.unarchive_session(1)
+
+    db.expire_all()
+    assert db.get(Session, 1).archived is False
+    active = await service.list_sessions(project_id=1)
+    assert [i.session.id for i in active] == [1]
diff --git a/tests/test_tui.py b/tests/test_tui.py
index dd99b55..5f86a9d 100644
--- a/tests/test_tui.py
+++ b/tests/test_tui.py
@@ -310,7 +310,7 @@ async def test_new_session_on_dismiss_sequential_create_then_refresh():
                 session=MagicMock(), spawn_ok=True, spawn_error=""
             )
 
-        async def fake_list(project_id):
+        async def fake_list(project_id, archived=False):
             call_order.append("list")
             return []
 
@@ -1983,3 +1983,215 @@ def test_policy_reflects_suboptions_when_sandbox_on():
     assert policy is not None
     assert policy.fs == "ro"
     assert policy.net is False
+
+
+# ---------------------------------------------------------------------------
+# Task 3: h/l column focus navigation
+# ---------------------------------------------------------------------------
+
+
+@pytest.mark.asyncio
+async def test_hl_focus_bindings_exist():
+    bindings = {b.key: b for b in HqtApp.BINDINGS}
+    assert bindings["h"].action == "focus_projects"
+    assert bindings["l"].action == "focus_sessions"
+
+
+@pytest.mark.asyncio
+async def test_h_focuses_projects_l_focuses_sessions(tmp_path):
+    app = HqtApp()
+    async with app.run_test(size=(120, 40)) as pilot:
+        d = tmp_path / "hl-proj"
+        d.mkdir()
+        app._project_service.create("hl", str(d))
+        app._load_projects()
+        await app.workers.wait_for_complete()
+        await pilot.pause()
+
+        await pilot.press("l")
+        await pilot.pause()
+        assert app.focused is app.query_one("#session-list")
+
+        await pilot.press("h")
+        await pilot.pause()
+        assert app.focused is app.query_one("#project-list")
+
+
+@pytest.mark.asyncio
+async def test_session_list_header_reflects_archived_mode():
+    app = HqtApp()
+    async with app.run_test(size=(120, 40)) as pilot:
+        from hqt.tui.widgets.session_list import SessionList
+        from textual.widgets import Label
+
+        sl = app.query_one(SessionList)
+        header = sl.query_one("#session-header", Label)
+        assert str(header.render()) == "Sessions"
+
+        sl.set_mode(archived=True)
+        await pilot.pause()
+        assert "archived" in str(header.render()).lower()
+
+        sl.set_mode(archived=False)
+        await pilot.pause()
+        assert str(header.render()) == "Sessions"
+
+
+@pytest.mark.asyncio
+async def test_archive_session_binding_exists():
+    bindings = {b.key: b for b in HqtApp.BINDINGS}
+    assert bindings["x"].action == "archive_session"
+
+
+@pytest.mark.asyncio
+async def test_archive_session_action_calls_service_and_refreshes():
+    app = HqtApp()
+    async with app.run_test(size=(120, 40)) as pilot:
+        from hqt.db.models import Project, Harness, Session
+        from hqt.tui.widgets.session_list import SessionList
+
+        seed_db = app._db_factory()
+        proj = Project(name="arch-proj", path="/tmp/arch-proj")
+        seed_db.add(proj)
+        seed_db.flush()
+        harness = seed_db.query(Harness).first()
+        sess = Session(
+            project_id=proj.id,
+            harness_id=harness.id,
+            tmux_session_name="hqt-arch-action",
+            archived=False,
+        )
+        seed_db.add(sess)
+        seed_db.commit()
+        proj_id = proj.id
+        sess_id = sess.id
+        seed_db.close()
+
+        app._selected_project_id = proj_id
+        await app._refresh_sessions()
+        await pilot.pause()
+
+        sl = app.query_one(SessionList)
+        sl.query_one("#session-list").focus()
+        await pilot.press("down")
+        await pilot.pause()
+        assert sl.get_selected_session_id() == sess_id
+
+        mock_service = MagicMock()
+        mock_service.archive_session = AsyncMock()
+        mock_service.list_sessions = AsyncMock(return_value=[])
+        mock_service.sync_window_labels = AsyncMock(return_value=[])
+        app._session_service = mock_service
+
+        await app.run_action("archive_session")
+        await pilot.pause()
+
+        mock_service.archive_session.assert_awaited_once_with(sess_id)
+        mock_service.list_sessions.assert_awaited()
+
+
+@pytest.mark.asyncio
+async def test_toggle_archived_binding_exists():
+    bindings = {b.key: b for b in HqtApp.BINDINGS}
+    assert bindings["A"].action == "toggle_archived"
+
+
+@pytest.mark.asyncio
+async def test_toggle_archived_switches_list_and_header():
+    app = HqtApp()
+    async with app.run_test(size=(120, 40)) as pilot:
+        from hqt.tui.widgets.session_list import SessionList
+        from textual.widgets import Label
+
+        proj_id = 42
+        app._selected_project_id = proj_id
+
+        mock_service = MagicMock()
+        mock_service.list_sessions = AsyncMock(return_value=[])
+        mock_service.sync_window_labels = AsyncMock(return_value=[])
+        app._session_service = mock_service
+
+        assert app._show_archived is False
+
+        await app.run_action("toggle_archived")
+        await pilot.pause()
+
+        assert app._show_archived is True
+        mock_service.list_sessions.assert_awaited_with(proj_id, archived=True)
+        header = app.query_one(SessionList).query_one("#session-header", Label)
+        assert "archived" in str(header.render()).lower()
+
+        await app.run_action("toggle_archived")
+        await pilot.pause()
+
+        assert app._show_archived is False
+        mock_service.list_sessions.assert_awaited_with(proj_id, archived=False)
+        assert str(header.render()) == "Sessions"
+
+
+@pytest.mark.asyncio
+async def test_unarchive_binding_exists():
+    bindings = {b.key: b for b in HqtApp.BINDINGS}
+    assert bindings["u"].action == "unarchive_session"
+
+
+@pytest.mark.asyncio
+async def test_unarchive_action_calls_service_and_refreshes():
+    app = HqtApp()
+    async with app.run_test(size=(120, 40)) as pilot:
+        from hqt.db.models import Project, Harness, Session
+        from hqt.tui.widgets.session_list import SessionList
+
+        seed_db = app._db_factory()
+        proj = Project(name="restore-proj", path="/tmp/restore-proj")
+        seed_db.add(proj)
+        seed_db.flush()
+        harness = seed_db.query(Harness).first()
+        sess = Session(
+            project_id=proj.id,
+            harness_id=harness.id,
+            tmux_session_name="hqt-restore",
+            archived=True,
+        )
+        seed_db.add(sess)
+        seed_db.commit()
+        proj_id = proj.id
+        sess_id = sess.id
+        seed_db.close()
+
+        app._selected_project_id = proj_id
+        app._show_archived = True
+        await app._refresh_sessions()
+        await pilot.pause()
+
+        sl = app.query_one(SessionList)
+        sl.query_one("#session-list").focus()
+        await pilot.press("down")
+        await pilot.pause()
+        assert sl.get_selected_session_id() == sess_id
+
+        mock_service = MagicMock()
+        mock_service.unarchive_session = AsyncMock()
+        mock_service.list_sessions = AsyncMock(return_value=[])
+        mock_service.sync_window_labels = AsyncMock(return_value=[])
+        app._session_service = mock_service
+
+        await app.run_action("unarchive_session")
+        await pilot.pause()
+
+        mock_service.unarchive_session.assert_awaited_once_with(sess_id)
+        mock_service.list_sessions.assert_awaited()
+
+
+@pytest.mark.asyncio
+async def test_archive_restore_actions_gated_by_view():
+    app = HqtApp()
+    async with app.run_test(size=(120, 40)):
+        # Active view (default): archive offered, restore hidden.
+        assert app.check_action("archive_session", ()) is True
+        assert app.check_action("unarchive_session", ()) is None
+
+        # Archived view: restore offered, archive hidden.
+        app._show_archived = True
+        assert app.check_action("archive_session", ()) is None
+        assert app.check_action("unarchive_session", ()) is True