diff --git a/src/vs/sessions/browser/actions/vscodeActions.ts b/src/vs/sessions/browser/actions/vscodeActions.ts
index 59d159c103547..620be7f2fe144 100644
--- a/src/vs/sessions/browser/actions/vscodeActions.ts
+++ b/src/vs/sessions/browser/actions/vscodeActions.ts
@@ -16,7 +16,7 @@ import { IOpenerService } from '../../../platform/opener/common/opener.js';
 import { IProductService } from '../../../platform/product/common/productService.js';
 import { ITelemetryService } from '../../../platform/telemetry/common/telemetry.js';
 import { IsAuxiliaryWindowContext } from '../../../workbench/common/contextkeys.js';
-import { IsPhoneLayoutContext, SessionsWelcomeVisibleContext } from '../../common/contextkeys.js';
+import { IsPhoneLayoutContext, SessionsClassicWindowUnavailableContext, SessionsWelcomeVisibleContext } from '../../common/contextkeys.js';
 import { logSessionsInteraction } from '../../common/sessionsTelemetry.js';
 import { Menus } from '../../browser/menus.js';
 import { ISessionsService } from '../../services/sessions/browser/sessionsService.js';
@@ -36,12 +36,12 @@ export class OpenInVSCodeAction extends Action2 {
 			id: OpenInVSCodeAction.ID,
 			title: localize2('openInVSCode', 'Open in Editor'),
 			icon: Codicon.vscodeInsiders,
-			precondition: ContextKeyExpr.and(IsAuxiliaryWindowContext.toNegated(), SessionsWelcomeVisibleContext.toNegated()),
+			precondition: ContextKeyExpr.and(IsAuxiliaryWindowContext.toNegated(), SessionsWelcomeVisibleContext.toNegated(), SessionsClassicWindowUnavailableContext.toNegated()),
 			menu: [{
 				id: Menus.TitleBarCenterRight,
 				group: 'navigation',
 				order: 7,
-				when: ContextKeyExpr.and(IsAuxiliaryWindowContext.toNegated(), SessionsWelcomeVisibleContext.toNegated(), IsPhoneLayoutContext.negate()),
+				when: ContextKeyExpr.and(IsAuxiliaryWindowContext.toNegated(), SessionsWelcomeVisibleContext.toNegated(), SessionsClassicWindowUnavailableContext.toNegated(), IsPhoneLayoutContext.negate()),
 			}]
 		});
 	}
diff --git a/src/vs/sessions/common/contextkeys.ts b/src/vs/sessions/common/contextkeys.ts
index b998a1d4d558e..2147f03e84198 100644
--- a/src/vs/sessions/common/contextkeys.ts
+++ b/src/vs/sessions/common/contextkeys.ts
@@ -167,6 +167,13 @@ export const SinglePaneFilesTabAvailableContext = new RawContextKey<boolean>('ag
 
 //#endregion
 
+//#region < --- Classic Window --- >
+
+/** An opt-out, so consumers negate it rather than testing a positive key: unset means available. */
+export const SessionsClassicWindowUnavailableContext = new RawContextKey<boolean>('sessionsClassicWindowUnavailable', false, localize('sessionsClassicWindowUnavailable', "Whether opening a classic VS Code window is unavailable from the Agents window"));
+
+//#endregion
+
 //#region < --- Mobile Layout --- >
 
 export const IsPhoneLayoutContext = new RawContextKey<boolean>('sessionsIsPhoneLayout', false, localize('sessionsIsPhoneLayout', "Whether the current layout is the phone layout"));
diff --git a/src/vs/sessions/electron-browser/actions/vscodeActions.ts b/src/vs/sessions/electron-browser/actions/vscodeActions.ts
index 188a45b48de52..c4cafa63fbe04 100644
--- a/src/vs/sessions/electron-browser/actions/vscodeActions.ts
+++ b/src/vs/sessions/electron-browser/actions/vscodeActions.ts
@@ -12,11 +12,11 @@ import { localize2 } from '../../../nls.js';
 import { Action2 } from '../../../platform/actions/common/actions.js';
 import { IRemoteAgentHostService } from '../../../platform/agentHost/common/remoteAgentHostService.js';
 import { KeyCode, KeyMod } from '../../../base/common/keyCodes.js';
-import { ContextKeyExpr } from '../../../platform/contextkey/common/contextkey.js';
+import { ContextKeyExpr, IContextKeyService } from '../../../platform/contextkey/common/contextkey.js';
 import { KeybindingWeight } from '../../../platform/keybinding/common/keybindingsRegistry.js';
 import { ITelemetryService } from '../../../platform/telemetry/common/telemetry.js';
 import { IsAuxiliaryWindowContext } from '../../../workbench/common/contextkeys.js';
-import { IsPhoneLayoutContext, SessionsWelcomeVisibleContext } from '../../common/contextkeys.js';
+import { IsPhoneLayoutContext, SessionsClassicWindowUnavailableContext, SessionsWelcomeVisibleContext } from '../../common/contextkeys.js';
 import { logSessionsInteraction } from '../../common/sessionsTelemetry.js';
 import { Menus } from '../../browser/menus.js';
 import { ISessionsService } from '../../services/sessions/browser/sessionsService.js';
@@ -40,12 +40,12 @@ export class OpenSessionInVSCodeAction extends Action2 {
 			id: OpenSessionInVSCodeAction.ID,
 			title: localize2('openInVSCode', 'Open in Editor'),
 			icon: Codicon.vscodeInsiders,
-			precondition: ContextKeyExpr.and(IsAuxiliaryWindowContext.toNegated(), SessionsWelcomeVisibleContext.toNegated()),
+			precondition: ContextKeyExpr.and(IsAuxiliaryWindowContext.toNegated(), SessionsWelcomeVisibleContext.toNegated(), SessionsClassicWindowUnavailableContext.toNegated()),
 			menu: [{
 				id: Menus.TitleBarCenterRight,
 				group: 'navigation',
 				order: 7,
-				when: ContextKeyExpr.and(IsAuxiliaryWindowContext.toNegated(), SessionsWelcomeVisibleContext.toNegated(), IsPhoneLayoutContext.negate()),
+				when: ContextKeyExpr.and(IsAuxiliaryWindowContext.toNegated(), SessionsWelcomeVisibleContext.toNegated(), SessionsClassicWindowUnavailableContext.toNegated(), IsPhoneLayoutContext.negate()),
 			}]
 		});
 	}
@@ -98,6 +98,7 @@ export class OpenVSCodeWindowAction extends Action2 {
 		super({
 			id: OpenVSCodeWindowAction.ID,
 			title: localize2('openVSCodeWindow', 'Open VS Code Window'),
+			precondition: SessionsClassicWindowUnavailableContext.toNegated(),
 			f1: true,
 			keybinding: {
 				primary: KeyMod.CtrlCmd | KeyMod.Shift | KeyCode.KeyA,
@@ -146,6 +147,10 @@ export class ShouldShowReturnToVSCodeEditorAction extends Action2 {
 	}
 
 	override async run(accessor: ServicesAccessor): Promise<boolean> {
+		// The sign-in dialog invokes the command directly, which no precondition can gate.
+		if (SessionsClassicWindowUnavailableContext.getValue(accessor.get(IContextKeyService)) === true) {
+			return false;
+		}
 		const nativeHostService = accessor.get(INativeHostService);
 		const windows = await nativeHostService.getWindows({ includeAuxiliaryWindows: false });
 		return shouldShowReturnToVSCodeEditor(windows, getWindowId(mainWindow));
diff --git a/src/vs/sessions/test/electron-browser/vscodeActions.test.ts b/src/vs/sessions/test/electron-browser/vscodeActions.test.ts
index 10267fdeb4334..19b36ba689b89 100644
--- a/src/vs/sessions/test/electron-browser/vscodeActions.test.ts
+++ b/src/vs/sessions/test/electron-browser/vscodeActions.test.ts
@@ -10,7 +10,9 @@ import { INativeHostService } from '../../../platform/native/common/native.js';
 import { IOpenedMainWindow } from '../../../platform/window/common/window.js';
 import { constObservable } from '../../../base/common/observable.js';
 import { URI } from '../../../base/common/uri.js';
-import { getChatSessionToOpenInEditor, returnToVSCodeEditor, shouldShowReturnToVSCodeEditor } from '../../electron-browser/actions/vscodeActions.js';
+import { getChatSessionToOpenInEditor, OpenSessionInVSCodeAction, OpenVSCodeWindowAction, returnToVSCodeEditor, shouldShowReturnToVSCodeEditor, ShouldShowReturnToVSCodeEditorAction } from '../../electron-browser/actions/vscodeActions.js';
+import { IContext, IContextKeyService } from '../../../platform/contextkey/common/contextkey.js';
+import { ServiceIdentifier, ServicesAccessor } from '../../../platform/instantiation/common/instantiation.js';
 import { IActiveSession } from '../../services/sessions/common/sessionsManagement.js';
 
 suite('VS Code Actions', () => {
@@ -33,6 +35,60 @@ suite('VS Code Actions', () => {
 		});
 	});
 
+	test('classic-window actions stay available unless a product opts out', () => {
+		// Nothing binds this key, so an expression that is false when unset would hide these actions.
+		const context = (unavailable: boolean | undefined) => new class extends mock<IContext>() {
+			override getValue<T>(key: string): T | undefined {
+				return (key === 'sessionsClassicWindowUnavailable' ? unavailable : undefined) as T | undefined;
+			}
+		};
+		// The bare precondition and one inside a conjunction, because `and()` canonicalizes too.
+		const bare = new OpenVSCodeWindowAction().desc.precondition;
+		const conjoined = new OpenSessionInVSCodeAction().desc.precondition;
+
+		assert.deepStrictEqual({
+			unset: [bare?.evaluate(context(undefined)), conjoined?.evaluate(context(undefined))],
+			optedOut: [bare?.evaluate(context(true)), conjoined?.evaluate(context(true))],
+			optedIn: [bare?.evaluate(context(false)), conjoined?.evaluate(context(false))],
+		}, {
+			unset: [true, true],
+			optedOut: [false, false],
+			optedIn: [true, true],
+		});
+	});
+
+	test('the sign-in dialog is not offered a return action when a product opts out', async () => {
+		const run = async (unavailable: boolean | undefined) => {
+			let queriedWindows = false;
+			const accessor: ServicesAccessor = {
+				get: <T>(id: ServiceIdentifier<T>): T => (id === IContextKeyService
+					? new class extends mock<IContextKeyService>() {
+						override getContextKeyValue<V>(key: string): V | undefined {
+							return (key === 'sessionsClassicWindowUnavailable' ? unavailable : undefined) as V | undefined;
+						}
+					}
+					: new class extends mock<INativeHostService>() {
+						override async getWindows(): Promise<IOpenedMainWindow[]> {
+							queriedWindows = true;
+							return [];
+						}
+					}) as T
+			};
+			return { shown: await new ShouldShowReturnToVSCodeEditorAction().run(accessor), queriedWindows };
+		};
+
+		assert.deepStrictEqual({
+			unset: await run(undefined),
+			optedIn: await run(false),
+			optedOut: await run(true),
+		}, {
+			unset: { shown: true, queriedWindows: true },
+			optedIn: { shown: true, queriedWindows: true },
+			// Opting out short-circuits before the native host is asked.
+			optedOut: { shown: false, queriedWindows: false },
+		});
+	});
+
 	test('opens an editor window before closing the Agents window', async () => {
 		const calls: string[] = [];
 		const nativeHostService = new class extends mock<INativeHostService>() {