Make hiding CLI window default behavior across all SDKs

- Python: Always hide window on Windows (removed hide_cli_window option)
- Node.js: Add windowsHide: true to spawn options
- Go: Add SysProcAttr with HideWindow on Windows via platform-specific files
- .NET: Already had CreateNoWindow = true

This ensures consistent behavior across all SDKs where the CLI subprocess
console window is hidden on Windows to avoid distracting users in GUI apps.

Co-authored-by: SteveSandersonMS <1101362+SteveSandersonMS@users.noreply.github.com>

Author: Copilot

go/client.go

@@ -1056,6 +1056,9 @@ func (c *Client) startCLIServer(ctx context.Context) error {
 
 	c.process = exec.CommandContext(ctx, command, args...)
 
+	// Configure platform-specific process attributes (e.g., hide window on Windows)
+	configureProcAttr(c.process)
+
 	// Set working directory if specified
 	if c.options.Cwd != "" {
 		c.process.Dir = c.options.Cwd

go/process_other.go

@@ -0,0 +1,11 @@
+// go:build !windows
+
+package copilot
+
+import "os/exec"
+
+// configureProcAttr configures platform-specific process attributes.
+// On non-Windows platforms, this is a no-op.
+func configureProcAttr(cmd *exec.Cmd) {
+	// No special configuration needed on non-Windows platforms
+}

go/process_windows.go

@@ -0,0 +1,16 @@
+// go:build windows
+
+package copilot
+
+import (
+	"os/exec"
+	"syscall"
+)
+
+// configureProcAttr configures platform-specific process attributes.
+// On Windows, this hides the console window to avoid distracting users in GUI apps.
+func configureProcAttr(cmd *exec.Cmd) {
+	cmd.SysProcAttr = &syscall.SysProcAttr{
+		HideWindow: true,
+	}
+}

nodejs/src/client.ts

@@ -1053,12 +1053,14 @@ export class CopilotClient {
                     stdio: stdioConfig,
                     cwd: this.options.cwd,
                     env: envWithoutNodeDebug,
+                    windowsHide: true,
                 });
             } else {
                 this.cliProcess = spawn(this.options.cliPath, args, {
                     stdio: stdioConfig,
                     cwd: this.options.cwd,
                     env: envWithoutNodeDebug,
+                    windowsHide: true,
                 });
             }
 

python/README.md

@@ -97,7 +97,8 @@ await client.stop()
 - `auto_restart` (bool): Auto-restart on crash (default: True)
 - `github_token` (str): GitHub token for authentication. When provided, takes priority over other auth methods.
 - `use_logged_in_user` (bool): Whether to use logged-in user for authentication (default: True, but False when `github_token` is provided). Cannot be used with `cli_url`.
-- `hide_cli_window` (bool): Hide console window when spawning CLI process on Windows (default: False). Useful for GUI applications to prevent terminal windows from appearing.
+
+> **Note:** On Windows, the SDK automatically hides the console window when spawning the CLI process to avoid distracting users in GUI applications.
 
 **SessionConfig Options (for `create_session`):**
 

python/copilot/client.py

@@ -184,7 +184,6 @@ def __init__(self, options: Optional[CopilotClientOptions] = None):
             "auto_start": opts.get("auto_start", True),
             "auto_restart": opts.get("auto_restart", True),
             "use_logged_in_user": use_logged_in_user,
-            "hide_cli_window": opts.get("hide_cli_window", False),
         }
         if opts.get("cli_url"):
             self.options["cli_url"] = opts["cli_url"]
@@ -1174,9 +1173,8 @@ async def _start_cli_server(self) -> None:
             "env": env,
         }
 
-        # Add creation flags for Windows to hide console window if requested
-        if sys.platform == "win32" and self.options.get("hide_cli_window", False):
-            # CREATE_NO_WINDOW flag prevents console window from appearing on Windows
+        # On Windows, hide the console window to avoid distracting users in GUI apps
+        if sys.platform == "win32":
             popen_kwargs["creationflags"] = subprocess.CREATE_NO_WINDOW
 
         # Choose transport mode

python/copilot/types.py

@@ -95,11 +95,6 @@ class CopilotClientOptions(TypedDict, total=False):
     # When False, only explicit tokens (github_token or environment variables) are used.
     # Default: True (but defaults to False when github_token is provided)
     use_logged_in_user: bool
-    # Whether to hide the console window when spawning the CLI process on Windows.
-    # When True, prevents the CLI subprocess from showing a console window on Windows.
-    # This is useful for GUI applications that should not display terminal windows.
-    # Default: False (console window is visible)
-    hide_cli_window: bool
 
 
 ToolResultType = Literal["success", "failure", "rejected", "denied"]

python/test_client.py

@@ -147,17 +147,3 @@ def test_use_logged_in_user_with_cli_url_raises(self):
             CopilotClient(
                 {"cli_url": "localhost:8080", "use_logged_in_user": False, "log_level": "error"}
             )
-
-
-class TestHideCliWindow:
-    def test_hide_cli_window_default_false(self):
-        client = CopilotClient({"log_level": "error"})
-        assert not client.options.get("hide_cli_window")
-
-    def test_hide_cli_window_explicit_true(self):
-        client = CopilotClient({"hide_cli_window": True, "log_level": "error"})
-        assert client.options.get("hide_cli_window")
-
-    def test_hide_cli_window_explicit_false(self):
-        client = CopilotClient({"hide_cli_window": False, "log_level": "error"})
-        assert not client.options.get("hide_cli_window")