diff --git a/eslint.config.js b/eslint.config.js
index 69a9a692433..ec79c24f295 100644
--- a/eslint.config.js
+++ b/eslint.config.js
@@ -253,7 +253,6 @@ export default tseslint.config(
 			'src/vs/platform/terminal/test/node/terminalEnvironment.test.ts',
 			'src/vs/workbench/api/browser/mainThreadChatSessions.ts',
 			'src/vs/workbench/api/browser/mainThreadDebugService.ts',
-			'src/vs/workbench/api/browser/mainThreadTerminalService.ts',
 			'src/vs/workbench/api/browser/mainThreadTesting.ts',
 			'src/vs/workbench/api/common/extHost.api.impl.ts',
 			'src/vs/workbench/api/common/extHostChatAgents2.ts',
@@ -263,7 +262,6 @@ export default tseslint.config(
 			'src/vs/workbench/api/common/extHostQuickOpen.ts',
 			'src/vs/workbench/api/common/extHostRequireInterceptor.ts',
 			'src/vs/workbench/api/common/extHostTelemetry.ts',
-			'src/vs/workbench/api/common/extHostTerminalService.ts',
 			'src/vs/workbench/api/common/extHostTypeConverters.ts',
 			'src/vs/workbench/api/common/extHostTypes.ts',
 			'src/vs/workbench/api/node/loopbackServer.ts',
diff --git a/src/vs/workbench/api/browser/mainThreadTerminalService.ts b/src/vs/workbench/api/browser/mainThreadTerminalService.ts
index 28ed1215289..a8f901b9a7c 100644
--- a/src/vs/workbench/api/browser/mainThreadTerminalService.ts
+++ b/src/vs/workbench/api/browser/mainThreadTerminalService.ts
@@ -26,6 +26,7 @@ import { ITerminalQuickFixService, ITerminalQuickFix, TerminalQuickFixType } fro
 import { TerminalCapability } from '../../../platform/terminal/common/capabilities/capabilities.js';
 import { ITerminalCompletionService } from '../../contrib/terminalContrib/suggest/browser/terminalCompletionService.js';
 import { IWorkbenchEnvironmentService } from '../../services/environment/common/environmentService.js';
+import { hasKey } from '../../../base/common/types.js';
 
 @extHostNamedCustomer(MainContext.MainThreadTerminalService)
 export class MainThreadTerminalService implements MainThreadTerminalServiceShape {
@@ -182,7 +183,7 @@ export class MainThreadTerminalService implements MainThreadTerminalServiceShape
 	}
 
 	private async _deserializeParentTerminal(location?: TerminalLocation | TerminalEditorLocationOptions | { parentTerminal: ExtHostTerminalIdentifier } | { splitActiveTerminal: boolean; location?: TerminalLocation }): Promise<TerminalLocation | TerminalEditorLocationOptions | { parentTerminal: ITerminalInstance } | { splitActiveTerminal: boolean } | undefined> {
-		if (typeof location === 'object' && 'parentTerminal' in location) {
+		if (typeof location === 'object' && hasKey(location, { parentTerminal: true })) {
 			const parentTerminal = await this._extHostTerminals.get(location.parentTerminal.toString());
 			return parentTerminal ? { parentTerminal } : undefined;
 		}
@@ -527,10 +528,10 @@ export function getOutputMatchForLines(lines: string[], outputMatcher: ITerminal
 
 function parseQuickFix(id: string, source: string, fix: TerminalQuickFix): ITerminalQuickFix {
 	let type = TerminalQuickFixType.TerminalCommand;
-	if ('uri' in fix) {
+	if (hasKey(fix, { uri: true })) {
 		fix.uri = URI.revive(fix.uri);
 		type = TerminalQuickFixType.Opener;
-	} else if ('id' in fix) {
+	} else if (hasKey(fix, { id: true })) {
 		type = TerminalQuickFixType.VscodeCommand;
 	}
 	return { id, type, source, ...fix };
diff --git a/src/vs/workbench/api/common/extHostTerminalService.ts b/src/vs/workbench/api/common/extHostTerminalService.ts
index effd94a2ce3..ce9a7667d6e 100644
--- a/src/vs/workbench/api/common/extHostTerminalService.ts
+++ b/src/vs/workbench/api/common/extHostTerminalService.ts
@@ -28,6 +28,7 @@ import { IExtHostCommands } from './extHostCommands.js';
 import { MarshalledId } from '../../../base/common/marshallingIds.js';
 import { ISerializedTerminalInstanceContext } from '../../contrib/terminal/common/terminal.js';
 import { isWindows } from '../../../base/common/platform.js';
+import { hasKey } from '../../../base/common/types.js';
 
 export interface IExtHostTerminalService extends ExtHostTerminalServiceShape, IDisposable {
 
@@ -218,11 +219,11 @@ export class ExtHostTerminal extends Disposable {
 
 	private _serializeParentTerminal(location?: TerminalLocation | vscode.TerminalEditorLocationOptions | vscode.TerminalSplitLocationOptions, parentTerminal?: ExtHostTerminalIdentifier): TerminalLocation | { viewColumn: EditorGroupColumn; preserveFocus?: boolean } | { parentTerminal: ExtHostTerminalIdentifier } | undefined {
 		if (typeof location === 'object') {
-			if ('parentTerminal' in location && location.parentTerminal && parentTerminal) {
+			if (hasKey(location, { parentTerminal: true }) && location.parentTerminal && parentTerminal) {
 				return { parentTerminal };
 			}
 
-			if ('viewColumn' in location) {
+			if (hasKey(location, { viewColumn: true })) {
 				return { viewColumn: ViewColumn.from(location.viewColumn), preserveFocus: location.preserveFocus };
 			}
 
@@ -527,7 +528,7 @@ export abstract class BaseExtHostTerminalService extends Disposable implements I
 
 	protected _serializeParentTerminal(options: vscode.TerminalOptions, internalOptions?: ITerminalInternalOptions): ITerminalInternalOptions {
 		internalOptions = internalOptions ? internalOptions : {};
-		if (options.location && typeof options.location === 'object' && 'parentTerminal' in options.location) {
+		if (options.location && typeof options.location === 'object' && hasKey(options.location, { parentTerminal: true })) {
 			const parentTerminal = options.location.parentTerminal;
 			if (parentTerminal) {
 				const parentExtHostTerminal = this._terminals.find(t => t.value === parentTerminal);
@@ -537,7 +538,7 @@ export abstract class BaseExtHostTerminalService extends Disposable implements I
 			}
 		} else if (options.location && typeof options.location !== 'object') {
 			internalOptions.location = options.location;
-		} else if (internalOptions.location && typeof internalOptions.location === 'object' && 'splitActiveTerminal' in internalOptions.location) {
+		} else if (internalOptions.location && typeof internalOptions.location === 'object' && hasKey(internalOptions.location, { splitActiveTerminal: true })) {
 			internalOptions.location = { splitActiveTerminal: true };
 		}
 		return internalOptions;
@@ -850,15 +851,15 @@ export abstract class BaseExtHostTerminalService extends Disposable implements I
 		if (token.isCancellationRequested) {
 			return;
 		}
-		if (profile && !('options' in profile)) {
+		if (profile && !hasKey(profile, { options: true })) {
 			profile = { options: profile };
 		}
 
-		if (!profile || !('options' in profile)) {
+		if (!profile || !hasKey(profile, { options: true })) {
 			throw new Error(`No terminal profile options provided for id "${id}"`);
 		}
 
-		if ('pty' in profile.options) {
+		if (hasKey(profile.options, { pty: true })) {
 			this.createExtensionTerminal(profile.options, options);
 			return;
 		}
@@ -1270,7 +1271,7 @@ function asTerminalIcon(iconPath?: vscode.Uri | { light: vscode.Uri; dark: vscod
 		return undefined;
 	}
 
-	if (!('id' in iconPath)) {
+	if (!hasKey(iconPath, { id: true })) {
 		return iconPath;
 	}