diff --git a/tests_v2/test_pane_resize_preserves_visible_content.py b/tests_v2/test_pane_resize_preserves_visible_content.py
new file mode 100644
index 00000000..cba85eec
--- /dev/null
+++ b/tests_v2/test_pane_resize_preserves_visible_content.py
@@ -0,0 +1,200 @@
+#!/usr/bin/env python3
+"""Regression: pane.resize preserves terminal content drawn before resize."""
+
+from __future__ import annotations
+
+import os
+import secrets
+import sys
+import time
+from pathlib import Path
+
+sys.path.insert(0, str(Path(__file__).parent))
+from cmux import cmux, cmuxError
+
+
+DEFAULT_SOCKET_PATHS = ["/tmp/cmux-debug.sock", "/tmp/cmux.sock"]
+
+
+def _must(cond: bool, msg: str) -> None:
+    if not cond:
+        raise cmuxError(msg)
+
+
+def _wait_for(pred, timeout_s: float = 5.0, step_s: float = 0.05) -> None:
+    deadline = time.time() + timeout_s
+    while time.time() < deadline:
+        if pred():
+            return
+        time.sleep(step_s)
+    raise cmuxError("Timed out waiting for condition")
+
+
+def _layout_panes(client: cmux) -> list[dict]:
+    layout_payload = client.layout_debug() or {}
+    layout = layout_payload.get("layout") or {}
+    return list(layout.get("panes") or [])
+
+
+def _pane_extent(client: cmux, pane_id: str, axis: str) -> float:
+    panes = _layout_panes(client)
+    for pane in panes:
+        pid = str(pane.get("paneId") or pane.get("pane_id") or "")
+        if pid != pane_id:
+            continue
+        frame = pane.get("frame") or {}
+        return float(frame.get(axis) or 0.0)
+    raise cmuxError(f"Pane {pane_id} missing from debug layout panes: {panes}")
+
+
+def _pane_for_surface(client: cmux, surface_id: str) -> str:
+    for _idx, pane_id, _count, _focused in client.list_panes():
+        rows = client.list_pane_surfaces(pane_id)
+        if any(sid == surface_id for _row_idx, sid, _title, _selected in rows):
+            return pane_id
+    raise cmuxError(f"Surface {surface_id} is not present in current workspace panes")
+
+
+def _surface_scrollback_text(client: cmux, workspace_id: str, surface_id: str) -> str:
+    payload = client._call(
+        "surface.read_text",
+        {"workspace_id": workspace_id, "surface_id": surface_id, "scrollback": True},
+    ) or {}
+    return str(payload.get("text") or "")
+
+
+def _pick_resize_direction_for_pane(client: cmux, pane_ids: list[str], target_pane: str) -> tuple[str, str]:
+    panes = [p for p in _layout_panes(client) if str(p.get("paneId") or p.get("pane_id") or "") in pane_ids]
+    if len(panes) < 2:
+        raise cmuxError(f"Need >=2 panes for resize test, got {panes}")
+
+    def x_of(p: dict) -> float:
+        return float((p.get("frame") or {}).get("x") or 0.0)
+
+    def y_of(p: dict) -> float:
+        return float((p.get("frame") or {}).get("y") or 0.0)
+
+    x_span = max(x_of(p) for p in panes) - min(x_of(p) for p in panes)
+    y_span = max(y_of(p) for p in panes) - min(y_of(p) for p in panes)
+
+    if x_span >= y_span:
+        left_pane = min(panes, key=x_of)
+        left_id = str(left_pane.get("paneId") or left_pane.get("pane_id") or "")
+        return ("right" if target_pane == left_id else "left"), "width"
+
+    top_pane = min(panes, key=y_of)
+    top_id = str(top_pane.get("paneId") or top_pane.get("pane_id") or "")
+    return ("down" if target_pane == top_id else "up"), "height"
+
+
+def _run_once(socket_path: str) -> int:
+    workspace_id = ""
+    try:
+        with cmux(socket_path) as client:
+            workspace_id = client.new_workspace()
+            client.select_workspace(workspace_id)
+
+            surfaces = client.list_surfaces(workspace_id)
+            _must(bool(surfaces), f"workspace should have at least one surface: {workspace_id}")
+            surface_id = surfaces[0][1]
+
+            stamp = secrets.token_hex(4)
+            resize_lines = [f"CMUX_LOCAL_RESIZE_LINE_{stamp}_{index:02d}" for index in range(1, 33)]
+            clear_and_draw = "printf '\\033[2J\\033[H'; " + "; ".join(
+                f"printf '{line}\\n'" for line in resize_lines
+            )
+            client.send_surface(surface_id, f"{clear_and_draw}\n")
+            _wait_for(lambda: resize_lines[-1] in _surface_scrollback_text(client, workspace_id, surface_id), timeout_s=8.0)
+
+            pre_resize_visible = client.read_terminal_text(surface_id)
+            pre_visible_lines = [line for line in resize_lines if line in pre_resize_visible]
+            _must(
+                len(pre_visible_lines) >= 4,
+                f"pre-resize viewport did not contain enough lines: {pre_visible_lines}",
+            )
+
+            client.new_split("right")
+            time.sleep(0.3)
+
+            pane_ids = [pid for _idx, pid, _count, _focused in client.list_panes()]
+            pane_id = _pane_for_surface(client, surface_id)
+            resize_direction, resize_axis = _pick_resize_direction_for_pane(client, pane_ids, pane_id)
+            pre_extent = _pane_extent(client, pane_id, resize_axis)
+
+            resize_result = client._call(
+                "pane.resize",
+                {
+                    "workspace_id": workspace_id,
+                    "pane_id": pane_id,
+                    "direction": resize_direction,
+                    "amount": 80,
+                },
+            ) or {}
+            _must(
+                str(resize_result.get("pane_id") or "") == pane_id,
+                f"pane.resize response missing expected pane_id: {resize_result}",
+            )
+            _wait_for(lambda: _pane_extent(client, pane_id, resize_axis) > pre_extent + 1.0, timeout_s=5.0)
+
+            post_resize_visible = client.read_terminal_text(surface_id)
+            visible_overlap = [line for line in pre_visible_lines if line in post_resize_visible]
+            _must(
+                bool(visible_overlap),
+                f"resize lost all pre-resize visible lines from viewport: {pre_visible_lines}",
+            )
+
+            post_token = f"CMUX_LOCAL_RESIZE_POST_{stamp}"
+            client.send_surface(surface_id, f"printf '{post_token}\\n'\n")
+            _wait_for(lambda: post_token in client.read_terminal_text(surface_id), timeout_s=8.0)
+
+            scrollback_text = _surface_scrollback_text(client, workspace_id, surface_id)
+            _must(
+                resize_lines[0] in scrollback_text and resize_lines[-1] in scrollback_text,
+                "terminal scrollback lost pre-resize lines after pane resize",
+            )
+            _must(
+                post_token in scrollback_text,
+                "terminal scrollback missing post-resize token after pane resize",
+            )
+
+            client.close_workspace(workspace_id)
+            workspace_id = ""
+
+        print("PASS: pane.resize preserves pre-resize visible content and scrollback anchors")
+        return 0
+    finally:
+        if workspace_id:
+            try:
+                with cmux(socket_path) as cleanup_client:
+                    cleanup_client.close_workspace(workspace_id)
+            except Exception:
+                pass
+
+
+def main() -> int:
+    env_socket = os.environ.get("CMUX_SOCKET")
+    if env_socket:
+        return _run_once(env_socket)
+
+    last_error: Exception | None = None
+    for socket_path in DEFAULT_SOCKET_PATHS:
+        try:
+            return _run_once(socket_path)
+        except cmuxError as exc:
+            text = str(exc)
+            recoverable = (
+                "Failed to connect",
+                "Socket not found",
+            )
+            if not any(token in text for token in recoverable):
+                raise
+            last_error = exc
+            continue
+
+    if last_error is not None:
+        raise last_error
+    raise cmuxError("No socket candidates configured")
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())
diff --git a/tests_v2/test_ssh_remote_shell_integration.py b/tests_v2/test_ssh_remote_shell_integration.py
index 248ab110..1ab712c7 100755
--- a/tests_v2/test_ssh_remote_shell_integration.py
+++ b/tests_v2/test_ssh_remote_shell_integration.py
@@ -190,6 +190,99 @@ def _read_probe_payload(client: cmux, surface_id: str, payload_command: str, tim
     raise cmuxError(f"Timed out waiting for payload token for command: {payload_command}")
 
 
+def _wait_for(pred, timeout_s: float = 5.0, step_s: float = 0.05) -> None:
+    deadline = time.time() + timeout_s
+    while time.time() < deadline:
+        if pred():
+            return
+        time.sleep(step_s)
+    raise cmuxError("Timed out waiting for condition")
+
+
+def _surface_text_scrollback(client: cmux, workspace_id: str, surface_id: str) -> str:
+    payload = client._call(
+        "surface.read_text",
+        {"workspace_id": workspace_id, "surface_id": surface_id, "scrollback": True},
+    ) or {}
+    return str(payload.get("text") or "")
+
+
+def _wait_surface_contains(
+    client: cmux,
+    workspace_id: str,
+    surface_id: str,
+    token: str,
+    *,
+    timeout: float = 20.0,
+) -> None:
+    deadline = time.time() + timeout
+    saw_missing_surface = False
+    while time.time() < deadline:
+        try:
+            if token in _surface_text_scrollback(client, workspace_id, surface_id):
+                return
+        except cmuxError as exc:
+            if _is_terminal_surface_not_found(exc):
+                saw_missing_surface = True
+                time.sleep(0.2)
+                continue
+            raise
+        time.sleep(0.2)
+
+    if saw_missing_surface:
+        raise cmuxError("terminal surface not found")
+    raise cmuxError(f"Timed out waiting for terminal token: {token}")
+
+
+def _layout_panes(client: cmux) -> list[dict]:
+    layout_payload = client.layout_debug() or {}
+    layout = layout_payload.get("layout") or {}
+    return list(layout.get("panes") or [])
+
+
+def _pane_extent(client: cmux, pane_id: str, axis: str) -> float:
+    panes = _layout_panes(client)
+    for pane in panes:
+        pid = str(pane.get("paneId") or pane.get("pane_id") or "")
+        if pid != pane_id:
+            continue
+        frame = pane.get("frame") or {}
+        return float(frame.get(axis) or 0.0)
+    raise cmuxError(f"Pane {pane_id} missing from debug layout panes: {panes}")
+
+
+def _pane_for_surface(client: cmux, surface_id: str) -> str:
+    for _idx, pane_id, _count, _focused in client.list_panes():
+        rows = client.list_pane_surfaces(pane_id)
+        if any(sid == surface_id for _row_idx, sid, _title, _selected in rows):
+            return pane_id
+    raise cmuxError(f"Surface {surface_id} is not present in current workspace panes")
+
+
+def _pick_resize_direction_for_pane(client: cmux, pane_ids: list[str], target_pane: str) -> tuple[str, str]:
+    panes = [p for p in _layout_panes(client) if str(p.get("paneId") or p.get("pane_id") or "") in pane_ids]
+    if len(panes) < 2:
+        raise cmuxError(f"Need >=2 panes for resize test, got {panes}")
+
+    def x_of(p: dict) -> float:
+        return float((p.get("frame") or {}).get("x") or 0.0)
+
+    def y_of(p: dict) -> float:
+        return float((p.get("frame") or {}).get("y") or 0.0)
+
+    x_span = max(x_of(p) for p in panes) - min(x_of(p) for p in panes)
+    y_span = max(y_of(p) for p in panes) - min(y_of(p) for p in panes)
+
+    if x_span >= y_span:
+        left_pane = min(panes, key=x_of)
+        left_id = str(left_pane.get("paneId") or left_pane.get("pane_id") or "")
+        return ("right" if target_pane == left_id else "left"), "width"
+
+    top_pane = min(panes, key=y_of)
+    top_id = str(top_pane.get("paneId") or top_pane.get("pane_id") or "")
+    return ("down" if target_pane == top_id else "up"), "height"
+
+
 def main() -> int:
     if not _docker_available():
         print("SKIP: docker is not available")
@@ -308,6 +401,65 @@ def main() -> int:
             term_program_version = _read_probe_payload(client, surface_id, "printf '%s' \"${TERM_PROGRAM_VERSION:-}\"")
             _must(bool(term_program_version), "ssh-env should propagate non-empty TERM_PROGRAM_VERSION")
 
+            resize_stamp = secrets.token_hex(4)
+            resize_lines = [f"CMUX_RESIZE_LINE_{resize_stamp}_{index:02d}" for index in range(1, 33)]
+            clear_and_draw = "printf '\\033[2J\\033[H'; " + "; ".join(
+                f"printf '{line}\\n'" for line in resize_lines
+            )
+            client.send_surface(surface_id, f"{clear_and_draw}\n")
+            _wait_surface_contains(client, workspace_id, surface_id, resize_lines[-1])
+            pre_resize_visible = client.read_terminal_text(surface_id)
+            pre_visible_lines = [line for line in resize_lines if line in pre_resize_visible]
+            _must(
+                len(pre_visible_lines) >= 4,
+                "pre-resize viewport did not contain enough reference lines for continuity checks",
+            )
+
+            client.select_workspace(workspace_id)
+            client.new_split("right")
+            time.sleep(0.3)
+
+            pane_ids = [pid for _idx, pid, _count, _focused in client.list_panes()]
+            pane_id = _pane_for_surface(client, surface_id)
+            resize_direction, resize_axis = _pick_resize_direction_for_pane(client, pane_ids, pane_id)
+            pre_extent = _pane_extent(client, pane_id, resize_axis)
+
+            resize_result = client._call(
+                "pane.resize",
+                {
+                    "workspace_id": workspace_id,
+                    "pane_id": pane_id,
+                    "direction": resize_direction,
+                    "amount": 80,
+                },
+            ) or {}
+            _must(
+                str(resize_result.get("pane_id") or "") == pane_id,
+                f"pane.resize response missing expected pane_id: {resize_result}",
+            )
+            _wait_for(lambda: _pane_extent(client, pane_id, resize_axis) > pre_extent + 1.0, timeout_s=5.0)
+
+            post_resize_visible = client.read_terminal_text(surface_id)
+            visible_overlap = [line for line in pre_visible_lines if line in post_resize_visible]
+            _must(
+                bool(visible_overlap),
+                f"resize lost all pre-resize visible lines from viewport: {pre_visible_lines}",
+            )
+
+            resize_post_token = f"CMUX_RESIZE_POST_{secrets.token_hex(6)}"
+            client.send_surface(surface_id, f"printf '{resize_post_token}\\n'\n")
+            _wait_surface_contains(client, workspace_id, surface_id, resize_post_token)
+
+            scrollback_text = _surface_text_scrollback(client, workspace_id, surface_id)
+            _must(
+                resize_lines[0] in scrollback_text and resize_lines[-1] in scrollback_text,
+                "terminal scrollback lost pre-resize lines after pane resize",
+            )
+            _must(
+                resize_post_token in scrollback_text,
+                f"terminal scrollback missing post-resize token after pane resize: {resize_post_token}",
+            )
+
             try:
                 client.close_workspace(workspace_id)
                 workspace_id = ""
@@ -315,7 +467,7 @@ def main() -> int:
                 pass
 
         print(
-            "PASS: cmux ssh enables Ghostty shell integration niceties "
+            "PASS: cmux ssh enables Ghostty shell integration niceties and preserves pre-resize terminal content "
             f"(TERM={term_value}, COLORTERM={colorterm_value}, TERM_PROGRAM={term_program})"
         )
         return 0