diff --git a/src/cmd/cli/command/color.go b/src/cmd/cli/command/color.go
index 5cd9ea0ab..108ef54a7 100644
--- a/src/cmd/cli/command/color.go
+++ b/src/cmd/cli/command/color.go
@@ -32,7 +32,7 @@ func (c *ColorMode) Set(value string) error {
 			return nil
 		}
 	}
-	return fmt.Errorf("color mode not one of %v", allColorModes)
+	return fmt.Errorf("invalid color: %q, not one of %v", value, allColorModes)
 }
 
 func (c ColorMode) Type() string {
diff --git a/src/cmd/cli/command/session.go b/src/cmd/cli/command/session.go
index 2362b9748..a087fef07 100644
--- a/src/cmd/cli/command/session.go
+++ b/src/cmd/cli/command/session.go
@@ -51,9 +51,7 @@ func newCommandSessionWithOpts(cmd *cobra.Command, opts commandSessionOpts) (*se
 }
 
 func newSessionLoaderOptionsForCommand(cmd *cobra.Command) session.SessionLoaderOptions {
-	stack, _ := cmd.Flags().GetString("stack")
 	configPaths, _ := cmd.Flags().GetStringArray("file")
-	provider, _ := cmd.Flag("provider").Value.(*client.ProviderID)
 	projectName, _ := cmd.Flags().GetString("project-name")
 
 	// Avoid common mistakes
@@ -77,9 +75,8 @@ func newSessionLoaderOptionsForCommand(cmd *cobra.Command) session.SessionLoader
 		ComposeFilePaths: configPaths,
 		ProjectName:      projectName,
 		GetStackOpts: stacks.GetStackOpts{
-			ProviderID:  *provider,
 			Interactive: !global.NonInteractive,
-			Stack:       stack,
+			Default:     global.Stack,
 		},
 	}
 }
diff --git a/src/pkg/session/session.go b/src/pkg/session/session.go
index 6268227c9..238375438 100644
--- a/src/pkg/session/session.go
+++ b/src/pkg/session/session.go
@@ -68,13 +68,6 @@ func (sl *SessionLoader) LoadSession(ctx context.Context) (*Session, error) {
 }
 
 func (sl *SessionLoader) loadStack(ctx context.Context) (*stacks.Parameters, string, error) {
-	if sl.sm == nil {
-		return &stacks.Parameters{
-			Name:     stacks.DefaultBeta,
-			Provider: sl.opts.ProviderID,
-		}, "no stack manager available", nil
-	}
-
 	stack, whence, err := sl.sm.GetStack(ctx, sl.opts.GetStackOpts)
 	if err != nil {
 		return nil, whence, err
diff --git a/src/pkg/session/session_test.go b/src/pkg/session/session_test.go
index 47afa6738..ef57ee4ca 100644
--- a/src/pkg/session/session_test.go
+++ b/src/pkg/session/session_test.go
@@ -91,7 +91,9 @@ func TestLoadSession(t *testing.T) {
 			name: "specified stack",
 			options: SessionLoaderOptions{
 				GetStackOpts: stacks.GetStackOpts{
-					Stack: "existingstack",
+					Default: stacks.Parameters{
+						Name: "existingstack",
+					},
 				},
 			},
 			existingStack: &stacks.Parameters{
@@ -122,9 +124,9 @@ func TestLoadSession(t *testing.T) {
 			sm := &mockStacksManager{}
 
 			if tt.existingStack == nil {
-				if tt.options.GetStackOpts.Stack != "" {
+				if tt.options.Default.Name != "" {
 					// For specified non-existing stack, return ErrNotExist
-					sm.On("GetStack", ctx, mock.Anything).Maybe().Return(nil, "", &stacks.ErrNotExist{StackName: tt.options.GetStackOpts.Stack})
+					sm.On("GetStack", ctx, mock.Anything).Maybe().Return(nil, "", &stacks.ErrNotExist{StackName: tt.options.Default.Name})
 				} else if tt.getStackError != nil {
 					sm.On("GetStack", ctx, mock.Anything).Maybe().Return(nil, "", tt.getStackError)
 				}
@@ -149,11 +151,11 @@ func TestLoadSession(t *testing.T) {
 			assert.NotNil(t, session.Loader)
 
 			assert.NotNil(t, session.Provider)
-			if tt.options.ProviderID == client.ProviderAWS {
+			if tt.options.Default.Provider == client.ProviderAWS {
 				_, ok := session.Provider.(*aws.ByocAws)
 				assert.True(t, ok)
 			}
-			if tt.options.ProviderID == client.ProviderGCP {
+			if tt.options.Default.Provider == client.ProviderGCP {
 				_, ok := session.Provider.(*gcp.ByocGcp)
 				assert.True(t, ok)
 			}
@@ -175,18 +177,3 @@ func TestLoadSession(t *testing.T) {
 		})
 	}
 }
-
-func TestLoadSession_NoStackManager(t *testing.T) {
-	ctx := t.Context()
-
-	options := SessionLoaderOptions{
-		GetStackOpts: stacks.GetStackOpts{
-			ProviderID: client.ProviderDefang,
-		},
-	}
-
-	loader := NewSessionLoader(client.MockFabricClient{}, nil, options)
-	session, err := loader.LoadSession(ctx)
-	require.NoError(t, err)
-	assert.NotNil(t, session)
-}
diff --git a/src/pkg/stacks/manager.go b/src/pkg/stacks/manager.go
index 3d98ce857..d7c2c246c 100644
--- a/src/pkg/stacks/manager.go
+++ b/src/pkg/stacks/manager.go
@@ -201,47 +201,43 @@ func (sm *manager) Create(params Parameters) (string, error) {
 }
 
 type GetStackOpts struct {
-	ProviderID         client.ProviderID
-	Stack              string
-	Interactive        bool
-	AllowStackCreation bool
+	Default     Parameters
+	Interactive bool
+	SelectStackOptions
 }
 
-func (sl *manager) GetStack(ctx context.Context, opts GetStackOpts) (*Parameters, string, error) {
+func (sm *manager) GetStack(ctx context.Context, opts GetStackOpts) (*Parameters, string, error) {
 	// use --stack if available
-	if opts.Stack != "" {
-		return sl.getSpecifiedStack(ctx, opts.Stack)
+	if opts.Default.Name != "" {
+		return sm.getSpecifiedStack(ctx, opts.Default.Name) // TODO: merge with opts.Default?
 	}
 	// use --provider if available
-	if opts.ProviderID != client.ProviderAuto && opts.ProviderID != "" {
+	if opts.Default.Provider != client.ProviderAuto && opts.Default.Provider != "" {
 		whence := "DEFANG_PROVIDER"
-		envProvider := os.Getenv("DEFANG_PROVIDER")
-		if envProvider != opts.ProviderID.String() {
+		var fromEnv client.ProviderID
+		if err := fromEnv.Set(os.Getenv("DEFANG_PROVIDER")); err == nil && fromEnv != opts.Default.Provider {
 			whence = "--provider flag"
 		}
-		return &Parameters{
-			Name:     DefaultBeta,
-			Provider: opts.ProviderID,
-		}, whence, nil
+		fallback := opts.Default
+		fallback.Name = DefaultBeta
+		return &fallback, whence, nil
 	}
 	// fallback to interactive
 	if opts.Interactive {
-		return sl.getStackInteractively(ctx, opts)
+		return sm.getStackInteractively(ctx, opts) // TODO: merge with opts.Default?
 	}
-	// fallback to default stack
-	stack, whence, err := sl.getDefaultStack(ctx)
+	// fallback to default stack for project
+	stack, whence, err := sm.getDefaultStack(ctx)
 	if err != nil {
 		if !errors.Is(err, ErrDefaultStackNotSet) {
 			return nil, "", err
 		}
-		whence := "fallback stack"
 
-		// fallback to fallback
-		stack = &Parameters{
-			Name:     DefaultBeta,
-			Provider: client.ProviderDefang,
-		}
-		return stack, whence, nil
+		// no default stack for project; use fallback
+		whence := "fallback stack"
+		fallback := opts.Default
+		fallback.Name = DefaultBeta
+		return &fallback, whence, nil
 	}
 
 	return stack, whence, nil
@@ -289,9 +285,8 @@ func (sm *manager) getSpecifiedStack(ctx context.Context, name string) (*Paramet
 
 func (sm *manager) getStackInteractively(ctx context.Context, opts GetStackOpts) (*Parameters, string, error) {
 	stackSelector := NewSelector(sm.ec, sm)
-	stack, err := stackSelector.SelectStack(ctx, SelectStackOptions{
-		AllowStackCreation: opts.AllowStackCreation,
-	})
+	// TODO: pass fallback stack to selector wizard for pre-filling
+	stack, err := stackSelector.SelectStack(ctx, opts.SelectStackOptions)
 	if err != nil {
 		return nil, "", fmt.Errorf("failed to select stack: %w", err)
 	}
diff --git a/src/pkg/stacks/manager_test.go b/src/pkg/stacks/manager_test.go
index 347ddcaf3..366a7b7c1 100644
--- a/src/pkg/stacks/manager_test.go
+++ b/src/pkg/stacks/manager_test.go
@@ -664,7 +664,7 @@ func TestGetStack(t *testing.T) {
 			name:        "stack specified but not found",
 			projectName: "foo",
 			options: GetStackOpts{
-				Stack: "missingstack",
+				Default: Parameters{Name: "missingstack"},
 			},
 			expectedError: "stack \"missingstack\" does not exist",
 			expectedEnv:   map[string]string{},
@@ -673,7 +673,7 @@ func TestGetStack(t *testing.T) {
 			name:        "local stack specified",
 			projectName: "foo",
 			options: GetStackOpts{
-				Stack: "localstack",
+				Default: Parameters{Name: "localstack"},
 			},
 			localStack: &Parameters{
 				Name:     "localstack",
@@ -698,7 +698,7 @@ func TestGetStack(t *testing.T) {
 			name:        "remote stack specified",
 			projectName: "foo",
 			options: GetStackOpts{
-				Stack: "remotestack",
+				Default: Parameters{Name: "remotestack"},
 			},
 			remoteStack: &Parameters{
 				Name:     "remotestack",
@@ -725,7 +725,7 @@ func TestGetStack(t *testing.T) {
 			name:        "local and remote stack",
 			projectName: "foo",
 			options: GetStackOpts{
-				Stack: "bothstack",
+				Default: Parameters{Name: "bothstack"},
 			},
 			localStack: &Parameters{
 				Name:     "bothstack",
@@ -767,8 +767,10 @@ func TestGetStack(t *testing.T) {
 			name:        "interactive selection",
 			projectName: "foo",
 			options: GetStackOpts{
-				Interactive:        true,
-				AllowStackCreation: true,
+				Interactive: true,
+				SelectStackOptions: SelectStackOptions{
+					AllowStackCreation: true,
+				},
 			},
 			remoteStack: &Parameters{
 				Name:     "existingstack",
@@ -784,9 +786,14 @@ func TestGetStack(t *testing.T) {
 				"stack": "existingstack",
 			},
 			expectedStack: &Parameters{
-				Name:      "existingstack",
-				Provider:  client.ProviderGCP,
-				Variables: map[string]string{},
+				Name:     "existingstack",
+				Provider: client.ProviderGCP,
+				Region:   "us-central1",
+				Variables: map[string]string{
+					"DEFANG_PROVIDER": "gcp",
+					"GCP_PROJECT":     "existing-gcp-project",
+					"FOO":             "existing-bar",
+				},
 			},
 			expectedEnv: map[string]string{
 				"DEFANG_PROVIDER": "gcp",
@@ -798,7 +805,7 @@ func TestGetStack(t *testing.T) {
 			name:        "stack with compose vars updates loader",
 			projectName: "foo",
 			options: GetStackOpts{
-				Stack: "composestack",
+				Default: Parameters{Name: "composestack"},
 			},
 			localStack: &Parameters{
 				Name:     "composestack",