Add support for allowed session targets in chat components

- Introduced `SessionsChatViewPane` to restrict session targets to Local and Cloud.
- Updated interfaces and classes to include optional `allowedSessionTargets` for session target and delegation pickers.
- Enhanced visibility logic in `DelegationSessionPickerActionItem` and `SessionTypePickerActionItem` to respect allowed targets.

src/vs/sessions/contrib/chat/browser/chat.contribution.ts

@@ -37,6 +37,17 @@ import { ViewPaneContainer } from '../../../../workbench/browser/parts/views/vie
 import { registerIcon } from '../../../../platform/theme/common/iconRegistry.js';
 import { ChatViewPane } from '../../../../workbench/contrib/chat/browser/widgetHosts/viewPane/chatViewPane.js';
 
+/**
+ * Sessions-window subclass of {@link ChatViewPane} that restricts the session
+ * target and delegation pickers to only show targets supported by the agent
+ * sessions window (Local and Cloud).
+ */
+class SessionsChatViewPane extends ChatViewPane {
+	protected override getAllowedSessionTargets(): ReadonlySet<AgentSessionProviders> {
+		return new Set([AgentSessionProviders.Local, AgentSessionProviders.Cloud]);
+	}
+}
+
 export class OpenSessionWorktreeInVSCodeAction extends Action2 {
 	static readonly ID = 'chat.openSessionWorktreeInVSCode';
 
@@ -201,7 +212,7 @@ class RegisterChatViewContainerContribution implements IWorkbenchContribution {
 			name: localize2('chat.viewContainer.label', "Chat"),
 			canToggleVisibility: false,
 			canMoveView: false,
-			ctorDescriptor: new SyncDescriptor(ChatViewPane),
+			ctorDescriptor: new SyncDescriptor(SessionsChatViewPane),
 			when: IsNewChatSessionContext.negate(),
 			windowVisibility: WindowVisibility.Sessions
 		}, {

src/vs/workbench/contrib/chat/browser/chat.ts

@@ -91,6 +91,13 @@ export interface ISessionTypePickerDelegate {
 	 * this stores the target for delegation on the next submit instead of immediately creating a new session.
 	 */
 	setPendingDelegationTarget?(provider: AgentSessionProviders): void;
+	/**
+	 * Optional getter for the set of allowed session targets.
+	 * When provided, the session target and delegation pickers will only show targets
+	 * in this set. This allows host contexts (e.g. the agent sessions window) to restrict
+	 * visible targets without adding host-specific dependencies to chat core.
+	 */
+	getAllowedTargets?(): ReadonlySet<AgentSessionProviders> | undefined;
 	/**
 	 * Optional event that fires when the active session provider changes.
 	 * When provided, listeners (like chatInputPart) can react to session type changes
@@ -272,6 +279,14 @@ export interface IChatWidgetViewOptions {
 	 */
 	sessionTypePickerDelegate?: ISessionTypePickerDelegate;
 
+	/**
+	 * Optional set of allowed session targets for the pickers.
+	 * When provided, only targets in this set will be visible in the session target
+	 * and delegation pickers. This allows host contexts (e.g. the agent sessions window)
+	 * to restrict the available targets.
+	 */
+	allowedSessionTargets?: ReadonlySet<AgentSessionProviders>;
+
 	/**
 	 * Optional delegate for the workspace picker.
 	 * When provided, shows a workspace picker in the chat input allowing users to select

src/vs/workbench/contrib/chat/browser/widget/chatWidget.ts

@@ -1832,6 +1832,7 @@ export class ChatWidget extends Disposable implements IChatWidget {
 			widgetViewKindTag: this.getWidgetViewKindTag(),
 			defaultMode: this.viewOptions.defaultMode,
 			sessionTypePickerDelegate: this.viewOptions.sessionTypePickerDelegate,
+			allowedSessionTargets: this.viewOptions.allowedSessionTargets,
 			workspacePickerDelegate: this.viewOptions.workspacePickerDelegate,
 		};
 

src/vs/workbench/contrib/chat/browser/widget/input/chatInputPart.ts

@@ -159,6 +159,12 @@ export interface IChatInputPartOptions {
 	 * When provided, allows the input part to maintain independent state for the selected session type.
 	 */
 	sessionTypePickerDelegate?: ISessionTypePickerDelegate;
+	/**
+	 * Optional set of allowed session targets for the pickers.
+	 * When provided, only targets in this set will be visible in the session target
+	 * and delegation pickers.
+	 */
+	allowedSessionTargets?: ReadonlySet<AgentSessionProviders>;
 	/**
 	 * Optional delegate for the workspace picker.
 	 * When provided, shows a workspace picker allowing users to select a target workspace
@@ -2199,6 +2205,7 @@ export class ChatInputPart extends Disposable implements IHistoryNavigationWidge
 						const sessionResource = this._widget?.viewModel?.sessionResource;
 						return sessionResource ? getAgentSessionProvider(sessionResource) : undefined;
 					};
+					const allowedSessionTargets = this.options.allowedSessionTargets;
 					const delegate: ISessionTypePickerDelegate = this.options.sessionTypePickerDelegate ?? {
 						getActiveSessionProvider: () => {
 							return getActiveSessionType();
@@ -2213,6 +2220,7 @@ export class ChatInputPart extends Disposable implements IHistoryNavigationWidge
 							this.updateAgentSessionTypeContextKey();
 							this.refreshChatSessionPickers();
 						},
+						getAllowedTargets: allowedSessionTargets ? () => allowedSessionTargets : undefined,
 					};
 					const isWelcomeViewMode = !!this.options.sessionTypePickerDelegate?.setActiveSessionProvider;
 					const Picker = (action.id === OpenSessionTargetPickerAction.ID || isWelcomeViewMode) ? SessionTypePickerActionItem : DelegationSessionPickerActionItem;

src/vs/workbench/contrib/chat/browser/widget/input/delegationSessionPickerActionItem.ts

@@ -50,6 +50,11 @@ export class DelegationSessionPickerActionItem extends SessionTypePickerActionIt
 	}
 
 	protected override _isVisible(type: AgentSessionProviders): boolean {
+		const allowedTargets = this.delegate.getAllowedTargets?.();
+		if (allowedTargets && !allowedTargets.has(type)) {
+			return false;
+		}
+
 		if (this.delegate.getActiveSessionProvider() === type) {
 			return true; // Always show active session type
 		}

src/vs/workbench/contrib/chat/browser/widget/input/sessionTargetPickerActionItem.ts

@@ -181,6 +181,10 @@ export class SessionTypePickerActionItem extends ChatInputPickerActionViewItem {
 	}
 
 	protected _isVisible(type: AgentSessionProviders): boolean {
+		const allowedTargets = this.delegate.getAllowedTargets?.();
+		if (allowedTargets && !allowedTargets.has(type)) {
+			return false;
+		}
 		return true;
 	}
 

src/vs/workbench/contrib/chat/browser/widgetHosts/viewPane/chatViewPane.ts

@@ -49,6 +49,7 @@ import { IChatSessionsService, localChatSessionType } from '../../../common/chat
 import { LocalChatSessionUri, getChatSessionType } from '../../../common/model/chatUri.js';
 import { ChatAgentLocation, ChatConfiguration, ChatModeKind } from '../../../common/constants.js';
 import { AgentSessionsControl } from '../../agentSessions/agentSessionsControl.js';
+import { AgentSessionProviders } from '../../agentSessions/agentSessions.js';
 import { ACTION_ID_NEW_CHAT } from '../../actions/chatActions.js';
 import { ChatWidget } from '../../widget/chatWidget.js';
 import { ChatViewWelcomeController, IViewWelcomeDelegate } from '../../viewsWelcome/chatViewWelcomeController.js';
@@ -530,6 +531,7 @@ export class ChatViewPane extends ViewPane implements IViewWelcomeDelegate {
 					: 'explicit',
 				supportsChangingModes: true,
 				dndContainer: parent,
+				allowedSessionTargets: this.getAllowedSessionTargets(),
 			},
 			{
 				listForeground: SIDE_BAR_FOREGROUND,
@@ -547,6 +549,15 @@ export class ChatViewPane extends ViewPane implements IViewWelcomeDelegate {
 		return this._widget;
 	}
 
+	/**
+	 * Returns the set of allowed session targets for the pickers, or undefined to allow all.
+	 * Subclasses (e.g. in the agent sessions window) can override this to restrict
+	 * the visible targets in the session target and delegation pickers.
+	 */
+	protected getAllowedSessionTargets(): ReadonlySet<AgentSessionProviders> | undefined {
+		return undefined;
+	}
+
 	private createChatTitleControl(parent: HTMLElement): void {
 		this.titleControl = this._register(this.instantiationService.createInstance(ChatViewTitleControl,
 			parent,