diff --git a/studio/backend/run.py b/studio/backend/run.py
index 7460a2f5f6..7c4d52d3a9 100644
--- a/studio/backend/run.py
+++ b/studio/backend/run.py
@@ -1174,18 +1174,20 @@ def run_server(
     return app
 
 
-# For direct execution (also invoked by CLI via os.execvp / subprocess).
-if __name__ == "__main__":
-    import argparse
-    import signal
-    import traceback
+# Mirror unsloth_cli/commands/studio.py's _PARALLEL_*. Default 1 is for direct
+# backend launches; `unsloth studio run` always passes its own value (4).
+_PARALLEL_MIN = 1
+_PARALLEL_MAX = 64
+_PARALLEL_DEFAULT_PLAIN = 1
 
-    # Ensure stderr handles Unicode on Windows (non-ASCII path tracebacks).
-    if sys.platform == "win32" and hasattr(sys.stderr, "reconfigure"):
-        try:
-            sys.stderr.reconfigure(encoding = "utf-8", errors = "replace")
-        except Exception:
-            pass
+
+def _build_arg_parser():
+    """Build the backend CLI argument parser.
+
+    Extracted from the __main__ block so the flag wiring (notably the
+    --secure/--no-secure polarity and its --not-secure alias) stays unit-testable.
+    """
+    import argparse
 
     parser = argparse.ArgumentParser(description = "Run Unsloth UI Backend server")
     parser.add_argument(
@@ -1221,6 +1223,14 @@ if __name__ == "__main__":
         "if the tunnel can't start. Without it, --no-secure also serves the raw "
         "0.0.0.0 port, which is reachable from anywhere on the network",
     )
+    # Back-compat: accept --not-secure as a hidden alias for --no-secure.
+    parser.add_argument(
+        "--not-secure",
+        dest = "secure",
+        action = "store_false",
+        default = argparse.SUPPRESS,
+        help = argparse.SUPPRESS,
+    )
     # Tri-state tool policy: no flag -> None (tools on, per-request honored);
     # --enable-tools/--disable-tools force on/off.
     parser.add_argument(
@@ -1238,11 +1248,6 @@ if __name__ == "__main__":
         default = None,
         help = "Force server-side tools off for every request.",
     )
-    # Mirror unsloth_cli/commands/studio.py's _PARALLEL_*. Default 1 is for direct
-    # backend launches; `unsloth studio run` always passes its own value (4).
-    _PARALLEL_MIN = 1
-    _PARALLEL_MAX = 64
-    _PARALLEL_DEFAULT_PLAIN = 1
     parser.add_argument(
         "--parallel",
         "--n-parallel",
@@ -1253,7 +1258,22 @@ if __name__ == "__main__":
             f"Default {_PARALLEL_DEFAULT_PLAIN}; `unsloth studio run` uses 4."
         ),
     )
+    return parser
 
+
+# For direct execution (also invoked by CLI via os.execvp / subprocess).
+if __name__ == "__main__":
+    import signal
+    import traceback
+
+    # Ensure stderr handles Unicode on Windows (non-ASCII path tracebacks).
+    if sys.platform == "win32" and hasattr(sys.stderr, "reconfigure"):
+        try:
+            sys.stderr.reconfigure(encoding = "utf-8", errors = "replace")
+        except Exception:
+            pass
+
+    parser = _build_arg_parser()
     args = parser.parse_args()
     if not _PARALLEL_MIN <= args.parallel <= _PARALLEL_MAX:
         parser.error(f"--parallel must be between {_PARALLEL_MIN} and {_PARALLEL_MAX}")
diff --git a/studio/backend/tests/test_secure_tunnel_gate.py b/studio/backend/tests/test_secure_tunnel_gate.py
index 81ebf589f3..d254121c14 100644
--- a/studio/backend/tests/test_secure_tunnel_gate.py
+++ b/studio/backend/tests/test_secure_tunnel_gate.py
@@ -60,6 +60,20 @@ def test_run_server_accepts_secure_kwarg():
     assert inspect.signature(run.run_server).parameters["secure"].default is False
 
 
+def test_arg_parser_secure_polarity_and_not_secure_alias():
+    # --secure/--no-secure is the documented flag; --not-secure is a hidden,
+    # back-compat alias for --no-secure. Last flag wins (BooleanOptionalAction).
+    import run
+
+    parser = run._build_arg_parser()
+    assert parser.parse_args([]).secure is False
+    assert parser.parse_args(["--secure"]).secure is True
+    assert parser.parse_args(["--no-secure"]).secure is False
+    assert parser.parse_args(["--not-secure"]).secure is False
+    assert parser.parse_args(["--secure", "--not-secure"]).secure is False
+    assert parser.parse_args(["--not-secure", "--secure"]).secure is True
+
+
 def test_run_server_accepts_enable_tools_kwarg():
     import inspect
 
diff --git a/unsloth_cli/commands/studio.py b/unsloth_cli/commands/studio.py
index 097624422e..6ce6c5ea47 100644
--- a/unsloth_cli/commands/studio.py
+++ b/unsloth_cli/commands/studio.py
@@ -260,6 +260,28 @@ _PARALLEL_DEFAULT_RUN = 4  # pre-PR hardcoded for `unsloth studio run`
 _PARALLEL_DEFAULT_PLAIN = 1  # pre-PR effective for plain `unsloth studio`
 
 
+def _resolve_secure(secure: bool, not_secure: bool) -> bool:
+    """Reconcile the deprecated --not-secure alias with --secure/--no-secure.
+
+    Typer parses --secure and --not-secure as independent options, so the alias
+    cannot lean on Click's last-wins ordering the way --secure/--no-secure do.
+    Restore that ordering from argv: --not-secure only forces secure off when it
+    is the last of the secure flags on the command line, matching the backend's
+    BooleanOptionalAction.
+    """
+    if not not_secure:
+        return secure
+    last_secure = max(
+        (i for i, a in enumerate(sys.argv) if a in ("--secure", "--no-secure")),
+        default = -1,
+    )
+    last_not_secure = max(
+        (i for i, a in enumerate(sys.argv) if a == "--not-secure"),
+        default = -1,
+    )
+    return secure if last_secure > last_not_secure else False
+
+
 def _iter_editable_studio_source_roots(venv_dir: Path):
     """Yield repo roots from setuptools `__editable___*_finder.py` files in
     *venv_dir*'s site-packages whose MAPPING includes a `studio` entry.
@@ -675,6 +697,12 @@ def studio_default(
         "if the tunnel can't start. Without it, --no-secure also serves the raw "
         "0.0.0.0 port, which is reachable from anywhere on the network.",
     ),
+    not_secure: bool = typer.Option(
+        False,
+        "--not-secure",
+        hidden = True,
+        help = "Deprecated alias for --no-secure.",
+    ),
     verbose: bool = typer.Option(
         False,
         "--verbose",
@@ -690,6 +718,8 @@ def studio_default(
     ),
 ):
     """Launch the Unsloth Studio server."""
+    # Back-compat: --not-secure is a deprecated alias for --no-secure.
+    secure = _resolve_secure(secure, not_secure)
     # Runs before every subcommand (run/setup/update/...).
     _ensure_studio_env_exported()
     if ctx.invoked_subcommand is not None:
@@ -1039,6 +1069,12 @@ def run(
         "if the tunnel can't start. Without it, --no-secure also serves the raw "
         "0.0.0.0 port, which is reachable from anywhere on the network.",
     ),
+    not_secure: bool = typer.Option(
+        False,
+        "--not-secure",
+        hidden = True,
+        help = "Deprecated alias for --no-secure.",
+    ),
     tensor_parallel: bool = typer.Option(
         False,
         "--tensor-parallel/--no-tensor-parallel",
@@ -1066,6 +1102,8 @@ def run(
         unsloth studio run --model some-model --chat-template-file /path/to/tpl.jinja
         unsloth studio run --model unsloth/Qwen3-27B-GGUF --gguf-variant Q8_0 --tensor-parallel
     """
+    # Back-compat: --not-secure is a deprecated alias for --no-secure.
+    secure = _resolve_secure(secure, not_secure)
     extra_llama_args: List[str] = list(ctx.args) if ctx.args else []
 
     # Set before any re-exec so the in-venv server inherits it via the env.
diff --git a/unsloth_cli/tests/test_studio_secure_flag.py b/unsloth_cli/tests/test_studio_secure_flag.py
index ab19a963de..61b64ff65d 100644
--- a/unsloth_cli/tests/test_studio_secure_flag.py
+++ b/unsloth_cli/tests/test_studio_secure_flag.py
@@ -48,6 +48,17 @@ def test_studio_default_exposes_secure_option_default_off():
     assert getattr(opt, "default", None) is False
 
 
+def test_secure_exposes_hidden_not_secure_alias():
+    # --not-secure is a hidden, deprecated alias for --no-secure on both commands.
+    import inspect
+    for fn in (_studio().run, _studio().studio_default):
+        opt = inspect.signature(fn).parameters["not_secure"].default
+        decls = set(getattr(opt, "param_decls", []) or [])
+        assert "--not-secure" in decls
+        assert getattr(opt, "hidden", False) is True
+        assert getattr(opt, "default", None) is False
+
+
 # ── re-exec capture plumbing (mirrors test_studio_cloudflare_flag.py) ─
 
 
@@ -132,6 +143,7 @@ def _invoke_studio_default(monkeypatch, args):
         (None, "--no-secure", "--secure"),  # default off
         ("--secure", "--secure", "--no-secure"),
         ("--no-secure", "--no-secure", "--secure"),
+        ("--not-secure", "--no-secure", "--secure"),  # deprecated alias -> canonical
     ],
 )
 def test_run_reexec_forwards_secure_polarity(monkeypatch, user_flag, expected, unexpected):
@@ -160,6 +172,31 @@ def test_studio_default_reexec_forwards_secure(monkeypatch):
     assert argv[argv.index("--host") + 1] == "127.0.0.1", argv
 
 
+def test_studio_default_not_secure_alias_forwards_no_secure(monkeypatch):
+    # --not-secure on `unsloth studio` forwards the canonical --no-secure.
+    captured = _invoke_studio_default(monkeypatch, ["--not-secure"])
+    assert len(captured) == 1, captured
+    argv = captured[0]
+    assert "--no-secure" in argv and "--secure" not in argv, argv
+
+
+@pytest.mark.parametrize(
+    "argv_order,expected,unexpected",
+    [
+        # --not-secure tracks --no-secure: the last secure flag on argv wins,
+        # matching the backend BooleanOptionalAction.
+        (["--secure", "--not-secure"], "--no-secure", "--secure"),
+        (["--not-secure", "--secure"], "--secure", "--no-secure"),
+    ],
+)
+def test_run_not_secure_alias_respects_last_wins(monkeypatch, argv_order, expected, unexpected):
+    monkeypatch.setattr(sys, "argv", ["unsloth", "studio", "run", *argv_order])
+    captured = _invoke_run(monkeypatch, _BASE + argv_order)
+    assert len(captured) == 1, captured
+    argv = captured[0]
+    assert expected in argv and unexpected not in argv, argv
+
+
 # ── in-venv path forwards secure + forced host into run_server ────────