Add cli_args/CLIArgs to Python and Go SDKs for cross-SDK consistency

go/README.md

@@ -109,6 +109,7 @@ Event types: `SessionLifecycleCreated`, `SessionLifecycleDeleted`, `SessionLifec
 **ClientOptions:**
 
 - `CLIPath` (string): Path to CLI executable (default: "copilot" or `COPILOT_CLI_PATH` env var)
+- `CLIArgs` ([]string): Extra arguments to pass to the CLI executable (inserted before SDK-managed args)
 - `CLIUrl` (string): URL of existing CLI server (e.g., `"localhost:8080"`, `"http://127.0.0.1:9000"`, or just `"8080"`). When provided, the client will not spawn a CLI process.
 - `Cwd` (string): Working directory for CLI process
 - `Port` (int): Server port for TCP mode (default: 0 for random)

go/client.go

@@ -143,6 +143,9 @@ func NewClient(options *ClientOptions) *Client {
 		if options.CLIPath != "" {
 			opts.CLIPath = options.CLIPath
 		}
+		if options.CLIArgs != nil {
+			opts.CLIArgs = append([]string{}, options.CLIArgs...)
+		}
 		if options.Cwd != "" {
 			opts.Cwd = options.Cwd
 		}
@@ -994,7 +997,11 @@ func (c *Client) verifyProtocolVersion(ctx context.Context) error {
 // This spawns the CLI server as a subprocess using the configured transport
 // mode (stdio or TCP).
 func (c *Client) startCLIServer(ctx context.Context) error {
-	args := []string{"--headless", "--no-auto-update", "--log-level", c.options.LogLevel}
+	// Start with user-provided CLI args (inserted before SDK-managed args)
+	args := append([]string{}, c.options.CLIArgs...)
+
+	// Add SDK-managed args
+	args = append(args, "--headless", "--no-auto-update", "--log-level", c.options.LogLevel)
 
 	// Choose transport mode
 	if c.useStdio {

go/client_test.go

@@ -330,6 +330,58 @@ func TestClient_AuthOptions(t *testing.T) {
 	})
 }
 
+func TestClient_CLIArgs(t *testing.T) {
+	t.Run("should default CLIArgs to nil when not provided", func(t *testing.T) {
+		client := NewClient(&ClientOptions{})
+
+		if client.options.CLIArgs != nil {
+			t.Errorf("Expected CLIArgs to be nil, got %v", client.options.CLIArgs)
+		}
+	})
+
+	t.Run("should accept CLIArgs option", func(t *testing.T) {
+		args := []string{"--custom-flag", "--another-arg", "value"}
+		client := NewClient(&ClientOptions{
+			CLIArgs: args,
+		})
+
+		if !reflect.DeepEqual(client.options.CLIArgs, args) {
+			t.Errorf("Expected CLIArgs to be %v, got %v", args, client.options.CLIArgs)
+		}
+	})
+
+	t.Run("should store empty CLIArgs slice", func(t *testing.T) {
+		client := NewClient(&ClientOptions{
+			CLIArgs: []string{},
+		})
+
+		if client.options.CLIArgs == nil {
+			t.Error("Expected CLIArgs to be non-nil empty slice")
+		}
+		if len(client.options.CLIArgs) != 0 {
+			t.Errorf("Expected 0 CLI args, got %d", len(client.options.CLIArgs))
+		}
+	})
+
+	t.Run("should store a copy of CLIArgs slice", func(t *testing.T) {
+		args := []string{"--custom-flag"}
+		client := NewClient(&ClientOptions{
+			CLIArgs: args,
+		})
+
+		// Modify the original slice
+		args = append(args, "--another-flag")
+
+		// The client's copy should not be affected
+		if len(client.options.CLIArgs) != 1 {
+			t.Errorf("Expected 1 CLI arg, got %d", len(client.options.CLIArgs))
+		}
+		if client.options.CLIArgs[0] != "--custom-flag" {
+			t.Errorf("Expected first arg to be '--custom-flag', got %q", client.options.CLIArgs[0])
+		}
+	})
+}
+
 func TestClient_EnvOptions(t *testing.T) {
 	t.Run("should store custom environment variables", func(t *testing.T) {
 		client := NewClient(&ClientOptions{

go/types.go

@@ -16,6 +16,8 @@ const (
 type ClientOptions struct {
 	// CLIPath is the path to the Copilot CLI executable (default: "copilot")
 	CLIPath string
+	// CLIArgs are extra arguments to pass to the CLI executable (inserted before SDK-managed args)
+	CLIArgs []string
 	// Cwd is the working directory for the CLI process (default: "" = inherit from current process)
 	Cwd string
 	// Port for TCP transport (default: 0 = random port)

python/README.md

@@ -88,6 +88,7 @@ await client.stop()
 **CopilotClient Options:**
 
 - `cli_path` (str): Path to CLI executable (default: "copilot" or `COPILOT_CLI_PATH` env var)
+- `cli_args` (list[str]): Extra arguments to pass to the CLI executable (inserted before SDK-managed args)
 - `cli_url` (str): URL of existing CLI server (e.g., `"localhost:8080"`, `"http://127.0.0.1:9000"`, or just `"8080"`). When provided, the client will not spawn a CLI process.
 - `cwd` (str): Working directory for CLI process
 - `port` (int): Server port for TCP mode (default: 0 for random)

python/copilot/client.py

@@ -175,6 +175,7 @@ def __init__(self, options: Optional[CopilotClientOptions] = None):
 
         self.options: CopilotClientOptions = {
             "cli_path": default_cli_path,
+            "cli_args": list(opts.get("cli_args", [])),
             "cwd": opts.get("cwd", os.getcwd()),
             "port": opts.get("port", 0),
             "use_stdio": False if opts.get("cli_url") else opts.get("use_stdio", True),
@@ -1116,7 +1117,11 @@ async def _start_cli_server(self) -> None:
         if not os.path.exists(cli_path):
             raise RuntimeError(f"Copilot CLI not found at {cli_path}")
 
-        args = ["--headless", "--no-auto-update", "--log-level", self.options["log_level"]]
+        # Start with user-provided CLI args (inserted before SDK-managed args)
+        args = list(self.options.get("cli_args", []))
+
+        # Add SDK-managed args
+        args.extend(["--headless", "--no-auto-update", "--log-level", self.options["log_level"]])
 
         # Add auth-related flags
         if self.options.get("github_token"):

python/copilot/types.py

@@ -73,6 +73,7 @@ class CopilotClientOptions(TypedDict, total=False):
     """Options for creating a CopilotClient"""
 
     cli_path: str  # Path to the Copilot CLI executable (default: "copilot")
+    cli_args: list[str]  # Extra arguments to pass to the CLI executable (inserted before SDK-managed args)
     # Working directory for the CLI process (default: current process's cwd)
     cwd: str
     port: int  # Port for the CLI server (TCP mode only, default: 0)

python/test_client.py

@@ -147,3 +147,26 @@ 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 TestCliArgs:
+    def test_default_cli_args_empty_list(self):
+        client = CopilotClient({"cli_path": CLI_PATH, "log_level": "error"})
+        assert client.options.get("cli_args") == []
+
+    def test_accepts_cli_args(self):
+        cli_args = ["--custom-flag", "--another-arg", "value"]
+        client = CopilotClient(
+            {"cli_path": CLI_PATH, "cli_args": cli_args, "log_level": "error"}
+        )
+        assert client.options.get("cli_args") == cli_args
+
+    def test_cli_args_list_is_separate_copy(self):
+        cli_args = ["--custom-flag"]
+        client = CopilotClient(
+            {"cli_path": CLI_PATH, "cli_args": cli_args, "log_level": "error"}
+        )
+        # Modifying the original list should not affect the client's copy
+        cli_args.append("--another-flag")
+        assert client.options.get("cli_args") == ["--custom-flag"]
+