feat(cli): add --browser flag to login for Microsoft Edge SSO support

Some organizations enforce SSO policies that block authentication through
standalone Chromium but allow Microsoft Edge. This adds a --browser option
to the login command so users can authenticate via their system Edge browser.

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

Author: chkp-roniz

README.md

@@ -118,6 +118,8 @@ pip install git+https://github.com/teng-lin/notebooklm-py@main
 ```bash
 # 1. Authenticate (opens browser)
 notebooklm login
+# Or use Microsoft Edge (for orgs that require Edge for SSO)
+# notebooklm login --browser msedge
 
 # 2. Create a notebook and add sources
 notebooklm create "My Research"

src/notebooklm/cli/session.py

@@ -160,12 +160,20 @@ def register_session_commands(cli):
         default=None,
         help="Where to save storage_state.json (default: $NOTEBOOKLM_HOME/storage_state.json)",
     )
-    def login(storage):
+    @click.option(
+        "--browser",
+        type=click.Choice(["chromium", "msedge"], case_sensitive=False),
+        default="chromium",
+        help="Browser to use for login (default: chromium). Use 'msedge' for Microsoft Edge.",
+    )
+    def login(storage, browser):
         """Log in to NotebookLM via browser.
 
         Opens a browser window for Google login. After logging in,
         press ENTER in the terminal to save authentication.
 
+        Use --browser msedge if your organization requires Microsoft Edge for SSO.
+
         Note: Cannot be used when NOTEBOOKLM_AUTH_JSON is set (use file-based
         auth or unset the env var first).
         """
@@ -184,36 +192,43 @@ def login(storage):
         try:
             from playwright.sync_api import sync_playwright
         except ImportError:
-            console.print(
-                "[red]Playwright not installed. Run:[/red]\n"
-                "  pip install notebooklm[browser]\n"
-                "  playwright install chromium"
+            install_hint = (
+                "  pip install notebooklm[browser]"
+                if browser == "msedge"
+                else "  pip install notebooklm[browser]\n  playwright install chromium"
             )
+            console.print(f"[red]Playwright not installed. Run:[/red]\n{install_hint}")
             raise SystemExit(1) from None
 
-        # Pre-flight check: verify Chromium browser is installed
-        _ensure_chromium_installed()
+        # Pre-flight check: verify Chromium browser is installed (skip for Edge)
+        if browser == "chromium":
+            _ensure_chromium_installed()
 
         storage_path = Path(storage) if storage else get_storage_path()
         browser_profile = get_browser_profile_dir()
         storage_path.parent.mkdir(parents=True, exist_ok=True, mode=0o700)
         browser_profile.mkdir(parents=True, exist_ok=True, mode=0o700)
 
-        console.print("[yellow]Opening browser for Google login...[/yellow]")
+        browser_label = "Microsoft Edge" if browser == "msedge" else "Chromium"
+        console.print(f"[yellow]Opening {browser_label} for Google login...[/yellow]")
         console.print(f"[dim]Using persistent profile: {browser_profile}[/dim]")
 
         # Use context manager to restore ProactorEventLoop for Playwright on Windows
         # (fixes #89: NotImplementedError on Windows Python 3.12)
         with _windows_playwright_event_loop(), sync_playwright() as p:
-            context = p.chromium.launch_persistent_context(
-                user_data_dir=str(browser_profile),
-                headless=False,
-                args=[
+            launch_kwargs: dict[str, Any] = {
+                "user_data_dir": str(browser_profile),
+                "headless": False,
+                "args": [
                     "--disable-blink-features=AutomationControlled",
                     "--password-store=basic",  # Avoid macOS keychain encryption for headless compatibility
                 ],
-                ignore_default_args=["--enable-automation"],
-            )
+                "ignore_default_args": ["--enable-automation"],
+            }
+            if browser == "msedge":
+                launch_kwargs["channel"] = "msedge"
+
+            context = p.chromium.launch_persistent_context(**launch_kwargs)
 
             page = context.pages[0] if context.pages else context.new_page()
             page.goto(NOTEBOOKLM_URL)

tests/unit/cli/test_session.py

@@ -83,6 +83,105 @@ def test_login_blocked_when_notebooklm_auth_json_set(self, runner, monkeypatch):
         assert result.exit_code == 1
         assert "Cannot run 'login' when NOTEBOOKLM_AUTH_JSON is set" in result.output
 
+    def test_login_help_shows_browser_option(self, runner):
+        """Test login --help shows --browser option with chromium/msedge choices."""
+        result = runner.invoke(cli, ["login", "--help"])
+
+        assert result.exit_code == 0
+        assert "--browser" in result.output
+        assert "chromium" in result.output
+        assert "msedge" in result.output
+
+    def test_login_rejects_invalid_browser(self, runner):
+        """Test login rejects invalid --browser values."""
+        result = runner.invoke(cli, ["login", "--browser", "firefox"])
+
+        assert result.exit_code != 0
+
+    def test_login_msedge_skips_chromium_install(self, runner, tmp_path):
+        """Test --browser msedge skips _ensure_chromium_installed."""
+        with (
+            patch("notebooklm.cli.session._ensure_chromium_installed") as mock_ensure,
+            patch("playwright.sync_api.sync_playwright") as mock_pw,
+            patch(
+                "notebooklm.cli.session.get_storage_path", return_value=tmp_path / "storage.json"
+            ),
+            patch(
+                "notebooklm.cli.session.get_browser_profile_dir",
+                return_value=tmp_path / "profile",
+            ),
+            patch("notebooklm.cli.session._sync_server_language_to_config"),
+            patch("builtins.input", return_value=""),
+        ):
+            mock_context = MagicMock()
+            mock_page = MagicMock()
+            mock_page.url = "https://notebooklm.google.com/"
+            mock_context.pages = [mock_page]
+            mock_pw.return_value.__enter__.return_value.chromium.launch_persistent_context.return_value = mock_context
+
+            runner.invoke(cli, ["login", "--browser", "msedge"])
+
+        mock_ensure.assert_not_called()
+
+    def test_login_msedge_passes_channel_param(self, runner, tmp_path):
+        """Test --browser msedge passes channel='msedge' to launch_persistent_context."""
+        with (
+            patch("notebooklm.cli.session._ensure_chromium_installed"),
+            patch("playwright.sync_api.sync_playwright") as mock_pw,
+            patch(
+                "notebooklm.cli.session.get_storage_path", return_value=tmp_path / "storage.json"
+            ),
+            patch(
+                "notebooklm.cli.session.get_browser_profile_dir",
+                return_value=tmp_path / "profile",
+            ),
+            patch("notebooklm.cli.session._sync_server_language_to_config"),
+            patch("builtins.input", return_value=""),
+        ):
+            mock_context = MagicMock()
+            mock_page = MagicMock()
+            mock_page.url = "https://notebooklm.google.com/"
+            mock_context.pages = [mock_page]
+            mock_launch = (
+                mock_pw.return_value.__enter__.return_value.chromium.launch_persistent_context
+            )
+            mock_launch.return_value = mock_context
+
+            runner.invoke(cli, ["login", "--browser", "msedge"])
+
+        call_kwargs = mock_launch.call_args[1]
+        assert call_kwargs.get("channel") == "msedge"
+
+    def test_login_chromium_default_no_channel(self, runner, tmp_path):
+        """Test default chromium does not pass channel and calls _ensure_chromium_installed."""
+        with (
+            patch("notebooklm.cli.session._ensure_chromium_installed") as mock_ensure,
+            patch("playwright.sync_api.sync_playwright") as mock_pw,
+            patch(
+                "notebooklm.cli.session.get_storage_path", return_value=tmp_path / "storage.json"
+            ),
+            patch(
+                "notebooklm.cli.session.get_browser_profile_dir",
+                return_value=tmp_path / "profile",
+            ),
+            patch("notebooklm.cli.session._sync_server_language_to_config"),
+            patch("builtins.input", return_value=""),
+        ):
+            mock_context = MagicMock()
+            mock_page = MagicMock()
+            mock_page.url = "https://notebooklm.google.com/"
+            mock_context.pages = [mock_page]
+            mock_launch = (
+                mock_pw.return_value.__enter__.return_value.chromium.launch_persistent_context
+            )
+            mock_launch.return_value = mock_context
+
+            runner.invoke(cli, ["login", "--browser", "chromium"])
+
+        mock_ensure.assert_called_once()
+        call_kwargs = mock_launch.call_args[1]
+        assert "channel" not in call_kwargs
+
 
 # =============================================================================
 # USE COMMAND TESTS