diff --git a/cli.js b/cli.js
index bbda09e..95d4dbd 100755
--- a/cli.js
+++ b/cli.js
@@ -15,4 +15,4 @@
  * limitations under the License.
  */
 
-import './lib/program.js';
+require('./lib/program');
diff --git a/eslint.config.mjs b/eslint.config.js
similarity index 88%
rename from eslint.config.mjs
rename to eslint.config.js
index 3ff35a9..c4b8a02 100644
--- a/eslint.config.mjs
+++ b/eslint.config.js
@@ -14,16 +14,12 @@
  * limitations under the License.
  */
 
-import typescriptEslint from "@typescript-eslint/eslint-plugin";
-import tsParser from "@typescript-eslint/parser";
-import notice from "eslint-plugin-notice";
-import path from "path";
-import { fileURLToPath } from "url";
-import stylistic from "@stylistic/eslint-plugin";
-import importRules from "eslint-plugin-import";
-
-const __filename = fileURLToPath(import.meta.url);
-const __dirname = path.dirname(__filename);
+const typescriptEslint = require("@typescript-eslint/eslint-plugin");
+const tsParser = require("@typescript-eslint/parser");
+const notice = require("eslint-plugin-notice");
+const path = require("path");
+const stylistic = require("@stylistic/eslint-plugin");
+const importRules = require("eslint-plugin-import");
 
 const plugins = {
   "@stylistic": stylistic,
@@ -32,8 +28,7 @@ const plugins = {
   import: importRules,
 };
 
-export const baseRules = {
-  "import/extensions": ["error", "ignorePackages", {ts: "always"}],
+const baseRules = {
   "@typescript-eslint/no-floating-promises": "error",
   "@typescript-eslint/no-unused-vars": [
     2,
@@ -188,7 +183,7 @@ const languageOptions = {
   ecmaVersion: 9,
   sourceType: "module",
   parserOptions: {
-    project: path.join(fileURLToPath(import.meta.url), "..", "tsconfig.all.json"),
+    project: path.join(__filename, "..", "tsconfig.all.json"),
   }
 };
 
@@ -217,7 +212,7 @@ const noBooleanCompareRules = {
   "@typescript-eslint/no-unnecessary-boolean-literal-compare": 2,
 };
 
-export default [
+module.exports = [
   {
     ignores: ["**/*.js"],
   },
diff --git a/extension/manifest.json b/extension/manifest.json
index b9365bc..ffc9e9d 100644
--- a/extension/manifest.json
+++ b/extension/manifest.json
@@ -14,7 +14,7 @@
     "<all_urls>"
   ],
   "background": {
-    "service_worker": "lib/background.js",
+    "service_worker": "lib/background.mjs",
     "type": "module"
   },
   "action": {
diff --git a/extension/package.json b/extension/package.json
index 2d0e12c..89b75eb 100644
--- a/extension/package.json
+++ b/extension/package.json
@@ -2,7 +2,6 @@
   "name": "@playwright/mcp-extension",
   "version": "0.0.36",
   "description": "Playwright MCP Browser Extension",
-  "type": "module",
   "private": true,
   "repository": {
     "type": "git",
@@ -17,8 +16,8 @@
   },
   "license": "Apache-2.0",
   "scripts": {
-    "build": "tsc --project . && tsc --project tsconfig.ui.json && vite build",
-    "watch": "tsc --watch --project . & tsc --watch --project tsconfig.ui.json & vite build --watch",
+    "build": "tsc --project . && tsc --project tsconfig.ui.json && vite build && vite build --config vite.sw.config.mts",
+    "watch": "tsc --watch --project . & tsc --watch --project tsconfig.ui.json & vite build --watch & vite build --watch --config vite.sw.config.mts",
     "test": "playwright test",
     "clean": "rm -rf dist"
   },
diff --git a/extension/src/background.ts b/extension/src/background.ts
index e71e0df..e74ebb8 100644
--- a/extension/src/background.ts
+++ b/extension/src/background.ts
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-import { RelayConnection, debugLog } from './relayConnection.js';
+import { RelayConnection, debugLog } from './relayConnection';
 
 type PageMessage = {
   type: 'connectToMCPRelay';
diff --git a/extension/tests/extension.spec.ts b/extension/tests/extension.spec.ts
index 60cc4fb..0c69927 100644
--- a/extension/tests/extension.spec.ts
+++ b/extension/tests/extension.spec.ts
@@ -16,7 +16,6 @@
 
 import fs from 'fs';
 import path from 'path';
-import { fileURLToPath } from 'url';
 import { chromium } from 'playwright';
 import { test as base, expect } from '../../tests/fixtures.js';
 
@@ -38,7 +37,7 @@ type TestFixtures = {
 
 const test = base.extend<TestFixtures>({
   pathToExtension: async ({}, use) => {
-    await use(fileURLToPath(new URL('../dist', import.meta.url)));
+    await use(path.resolve(__dirname, '../dist'));
   },
 
   browserWithExtension: async ({ mcpBrowser, pathToExtension }, use, testInfo) => {
@@ -126,7 +125,7 @@ async function startWithExtensionFlag(browserWithExtension: BrowserWithExtension
 const testWithOldExtensionVersion = test.extend({
   pathToExtension: async ({}, use, testInfo) => {
     const extensionDir = testInfo.outputPath('extension');
-    const oldPath = fileURLToPath(new URL('../dist', import.meta.url));
+    const oldPath = path.resolve(__dirname, '../dist');
 
     await fs.promises.cp(oldPath, extensionDir, { recursive: true });
     const manifestPath = path.join(extensionDir, 'manifest.json');
diff --git a/extension/tsconfig.json b/extension/tsconfig.json
index 70fb340..9c22b0b 100644
--- a/extension/tsconfig.json
+++ b/extension/tsconfig.json
@@ -10,7 +10,8 @@
     "resolveJsonModule": true,
     "types": ["chrome"],
     "jsx": "react-jsx",
-    "jsxImportSource": "react"
+    "jsxImportSource": "react",
+    "noEmit": true
   },
   "include": [
     "src",
diff --git a/extension/vite.config.ts b/extension/vite.config.mts
similarity index 100%
rename from extension/vite.config.ts
rename to extension/vite.config.mts
diff --git a/extension/vite.sw.config.mts b/extension/vite.sw.config.mts
new file mode 100644
index 0000000..a383e4b
--- /dev/null
+++ b/extension/vite.sw.config.mts
@@ -0,0 +1,31 @@
+/**
+ * Copyright (c) Microsoft Corporation.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { resolve } from 'path';
+import { defineConfig } from 'vite';
+
+export default defineConfig({
+  build: {
+    lib: {
+      entry: resolve(__dirname, 'src/background.ts'),
+      fileName: 'lib/background',
+      formats: ['es']
+    },
+    outDir: 'dist',
+    emptyOutDir: false,
+    minify: false
+  }
+});
diff --git a/index.d.ts b/index.d.ts
index f7a1dde..4a2b679 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -16,7 +16,7 @@
  */
 
 import type { Server } from '@modelcontextprotocol/sdk/server/index.js';
-import type { Config } from './config.js';
+import type { Config } from './config';
 import type { BrowserContext } from 'playwright';
 
 export declare function createConnection(config?: Config, contextGetter?: () => Promise<BrowserContext>): Promise<Server>;
diff --git a/index.js b/index.js
index 69f7ae2..b153a9f 100755
--- a/index.js
+++ b/index.js
@@ -15,5 +15,5 @@
  * limitations under the License.
  */
 
-import { createConnection } from './lib/index.js';
-export { createConnection };
+const { createConnection } = require('./lib/index.js');
+module.exports = { createConnection };
diff --git a/package.json b/package.json
index b3f739d..2ff240d 100644
--- a/package.json
+++ b/package.json
@@ -2,7 +2,6 @@
   "name": "@playwright/mcp",
   "version": "0.0.36",
   "description": "Playwright Tools for MCP",
-  "type": "module",
   "repository": {
     "type": "git",
     "url": "git+https://github.com/microsoft/playwright-mcp.git"
diff --git a/playwright.config.ts b/playwright.config.ts
index 8486de1..c69e8f0 100644
--- a/playwright.config.ts
+++ b/playwright.config.ts
@@ -16,7 +16,7 @@
 
 import { defineConfig } from '@playwright/test';
 
-import type { TestOptions } from './tests/fixtures.js';
+import type { TestOptions } from './tests/fixtures';
 
 export default defineConfig<TestOptions>({
   testDir: './tests',
diff --git a/src/browserContextFactory.ts b/src/browserContextFactory.ts
index 81072e1..a0f8e92 100644
--- a/src/browserContextFactory.ts
+++ b/src/browserContextFactory.ts
@@ -23,11 +23,11 @@ import * as playwright from 'playwright';
 import { registryDirectory } from 'playwright-core/lib/server/registry/index';
 // @ts-ignore
 import { startTraceViewerServer } from 'playwright-core/lib/server';
-import { logUnhandledError, testDebug } from './utils/log.js';
-import { createHash } from './utils/guid.js';
-import { outputFile  } from './config.js';
+import { logUnhandledError, testDebug } from './utils/log';
+import { createHash } from './utils/guid';
+import { outputFile  } from './config';
 
-import type { FullConfig } from './config.js';
+import type { FullConfig } from './config';
 
 export function contextFactory(config: FullConfig): BrowserContextFactory {
   if (config.browser.remoteEndpoint)
diff --git a/src/browserServerBackend.ts b/src/browserServerBackend.ts
index 10f5ff4..137fcb8 100644
--- a/src/browserServerBackend.ts
+++ b/src/browserServerBackend.ts
@@ -15,18 +15,18 @@
  */
 
 import { fileURLToPath } from 'url';
-import { FullConfig } from './config.js';
-import { Context } from './context.js';
-import { logUnhandledError } from './utils/log.js';
-import { Response } from './response.js';
-import { SessionLog } from './sessionLog.js';
-import { filteredTools } from './tools.js';
-import { toMcpTool } from './mcp/tool.js';
+import { FullConfig } from './config';
+import { Context } from './context';
+import { logUnhandledError } from './utils/log';
+import { Response } from './response';
+import { SessionLog } from './sessionLog';
+import { filteredTools } from './tools';
+import { toMcpTool } from './mcp/tool';
 
-import type { Tool } from './tools/tool.js';
-import type { BrowserContextFactory } from './browserContextFactory.js';
-import type * as mcpServer from './mcp/server.js';
-import type { ServerBackend } from './mcp/server.js';
+import type { Tool } from './tools/tool';
+import type { BrowserContextFactory } from './browserContextFactory';
+import type * as mcpServer from './mcp/server';
+import type { ServerBackend } from './mcp/server';
 
 export class BrowserServerBackend implements ServerBackend {
   private _tools: Tool[];
diff --git a/src/config.ts b/src/config.ts
index e579002..f6b410b 100644
--- a/src/config.ts
+++ b/src/config.ts
@@ -18,7 +18,7 @@ import fs from 'fs';
 import os from 'os';
 import path from 'path';
 import { devices } from 'playwright';
-import { sanitizeForFilePath } from './utils/fileUtils.js';
+import { sanitizeForFilePath } from './utils/fileUtils';
 
 import type { Config, ToolCapability } from '../config.js';
 import type { BrowserContextOptions, LaunchOptions } from 'playwright';
diff --git a/src/context.ts b/src/context.ts
index 1890b3d..0a65212 100644
--- a/src/context.ts
+++ b/src/context.ts
@@ -17,15 +17,15 @@
 import debug from 'debug';
 import * as playwright from 'playwright';
 
-import { logUnhandledError } from './utils/log.js';
-import { Tab } from './tab.js';
-import { outputFile  } from './config.js';
+import { logUnhandledError } from './utils/log';
+import { Tab } from './tab';
+import { outputFile  } from './config';
 
-import type { FullConfig } from './config.js';
-import type { Tool } from './tools/tool.js';
-import type { BrowserContextFactory, ClientInfo } from './browserContextFactory.js';
-import type * as actions from './actions.js';
-import type { SessionLog } from './sessionLog.js';
+import type { FullConfig } from './config';
+import type { Tool } from './tools/tool';
+import type { BrowserContextFactory, ClientInfo } from './browserContextFactory';
+import type * as actions from './actions';
+import type { SessionLog } from './sessionLog';
 
 const testDebug = debug('pw:mcp:test');
 
diff --git a/src/extension/cdpRelay.ts b/src/extension/cdpRelay.ts
index 79e8290..5602db6 100644
--- a/src/extension/cdpRelay.ts
+++ b/src/extension/cdpRelay.ts
@@ -26,17 +26,19 @@ import { spawn } from 'child_process';
 import http from 'http';
 import debug from 'debug';
 import { WebSocket, WebSocketServer } from 'ws';
+
+// @ts-ignore
+import { registry } from 'playwright-core/lib/server/registry/index';
+
 import { httpAddressToString } from '../mcp/http.js';
 import { logUnhandledError } from '../utils/log.js';
 import { ManualPromise } from '../mcp/manualPromise.js';
-import * as protocol from './protocol.js';
+import * as protocol from './protocol';
 
 import type websocket from 'ws';
 import type { ClientInfo } from '../browserContextFactory.js';
-import type { ExtensionCommand, ExtensionEvents } from './protocol.js';
+import type { ExtensionCommand, ExtensionEvents } from './protocol';
 
-// @ts-ignore
-const { registry } = await import('playwright-core/lib/server/registry/index');
 
 const debugLogger = debug('pw:mcp:relay');
 
diff --git a/src/extension/extensionContextFactory.ts b/src/extension/extensionContextFactory.ts
index bff7726..965e27d 100644
--- a/src/extension/extensionContextFactory.ts
+++ b/src/extension/extensionContextFactory.ts
@@ -17,7 +17,7 @@
 import debug from 'debug';
 import * as playwright from 'playwright';
 import { startHttpServer } from '../mcp/http.js';
-import { CDPRelayServer } from './cdpRelay.js';
+import { CDPRelayServer } from './cdpRelay';
 
 import type { BrowserContextFactory, ClientInfo } from '../browserContextFactory.js';
 
diff --git a/src/index.ts b/src/index.ts
index 6809cd9..73eeb30 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -14,15 +14,15 @@
  * limitations under the License.
  */
 
-import { BrowserServerBackend } from './browserServerBackend.js';
-import { resolveConfig } from './config.js';
-import { contextFactory } from './browserContextFactory.js';
-import * as mcpServer from './mcp/server.js';
-import { packageJSON } from './utils/package.js';
+import { BrowserServerBackend } from './browserServerBackend';
+import { resolveConfig } from './config';
+import { contextFactory } from './browserContextFactory';
+import * as mcpServer from './mcp/server';
+import { packageJSON } from './utils/package';
 
 import type { Config } from '../config.js';
 import type { BrowserContext } from 'playwright';
-import type { BrowserContextFactory } from './browserContextFactory.js';
+import type { BrowserContextFactory } from './browserContextFactory';
 import type { Server } from '@modelcontextprotocol/sdk/server/index.js';
 
 export async function createConnection(userConfig: Config = {}, contextGetter?: () => Promise<BrowserContext>): Promise<Server> {
diff --git a/src/loop/loopClaude.ts b/src/loop/loopClaude.ts
index 92dc1d5..b2f915b 100644
--- a/src/loop/loopClaude.ts
+++ b/src/loop/loopClaude.ts
@@ -15,7 +15,7 @@
  */
 
 import type Anthropic from '@anthropic-ai/sdk';
-import type { LLMDelegate, LLMConversation, LLMToolCall, LLMTool } from './loop.js';
+import type { LLMDelegate, LLMConversation, LLMToolCall, LLMTool } from './loop';
 import type { Tool } from '@modelcontextprotocol/sdk/types.js';
 
 const model = 'claude-sonnet-4-20250514';
@@ -26,7 +26,7 @@ export class ClaudeDelegate implements LLMDelegate {
   async anthropic(): Promise<Anthropic> {
     if (!this._anthropic) {
       const anthropic = await import('@anthropic-ai/sdk');
-      this._anthropic = new anthropic.Anthropic();
+      this._anthropic = new anthropic.Anthropic() as unknown as Anthropic;
     }
     return this._anthropic;
   }
diff --git a/src/loop/loopOpenAI.ts b/src/loop/loopOpenAI.ts
index 81e2ef2..24ac46d 100644
--- a/src/loop/loopOpenAI.ts
+++ b/src/loop/loopOpenAI.ts
@@ -15,7 +15,7 @@
  */
 
 import type OpenAI from 'openai';
-import type { LLMDelegate, LLMConversation, LLMToolCall, LLMTool } from './loop.js';
+import type { LLMDelegate, LLMConversation, LLMToolCall, LLMTool } from './loop';
 import type { Tool } from '@modelcontextprotocol/sdk/types.js';
 
 const model = 'gpt-4.1';
@@ -26,7 +26,7 @@ export class OpenAIDelegate implements LLMDelegate {
   async openai(): Promise<OpenAI> {
     if (!this._openai) {
       const oai = await import('openai');
-      this._openai = new oai.OpenAI();
+      this._openai = new oai.OpenAI() as unknown as OpenAI;
     }
     return this._openai;
   }
diff --git a/src/loop/main.ts b/src/loop/main.ts
index d1d7c3e..b43310b 100644
--- a/src/loop/main.ts
+++ b/src/loop/main.ts
@@ -17,28 +17,25 @@
 /* eslint-disable no-console */
 
 import path from 'path';
-import url from 'url';
 import dotenv from 'dotenv';
 import { program } from 'commander';
 
 import * as mcpBundle from '../mcp/bundle.js';
-import { OpenAIDelegate } from './loopOpenAI.js';
-import { ClaudeDelegate } from './loopClaude.js';
-import { runTask } from './loop.js';
+import { OpenAIDelegate } from './loopOpenAI';
+import { ClaudeDelegate } from './loopClaude';
+import { runTask } from './loop';
 
-import type { LLMDelegate } from './loop.js';
+import type { LLMDelegate } from './loop';
 
 dotenv.config();
 
-const __filename = url.fileURLToPath(import.meta.url);
-
 async function run(delegate: LLMDelegate) {
   const transport = new mcpBundle.StdioClientTransport({
     command: 'node',
     args: [
-      path.resolve(__filename, '../../../cli.js'),
+      path.resolve(__dirname, '../../cli.js'),
       '--save-session',
-      '--output-dir', path.resolve(__filename, '../../../sessions')
+      '--output-dir', path.resolve(__dirname, '../../sessions')
     ],
     stderr: 'inherit',
     env: process.env as Record<string, string>,
diff --git a/src/loopTools/main.ts b/src/loopTools/main.ts
index 2d017ba..aaaf611 100644
--- a/src/loopTools/main.ts
+++ b/src/loopTools/main.ts
@@ -18,14 +18,14 @@ import dotenv from 'dotenv';
 
 import * as mcpServer from '../mcp/server.js';
 import { packageJSON } from '../utils/package.js';
-import { Context } from './context.js';
-import { perform } from './perform.js';
-import { snapshot } from './snapshot.js';
+import { Context } from './context';
+import { perform } from './perform';
+import { snapshot } from './snapshot';
 import { toMcpTool } from '../mcp/tool.js';
 
 import type { FullConfig } from '../config.js';
 import type { ServerBackend } from '../mcp/server.js';
-import type { Tool } from './tool.js';
+import type { Tool } from './tool';
 
 export async function runLoopTools(config: FullConfig) {
   dotenv.config();
diff --git a/src/loopTools/tool.ts b/src/loopTools/tool.ts
index 8ea56aa..9c185cd 100644
--- a/src/loopTools/tool.ts
+++ b/src/loopTools/tool.ts
@@ -16,7 +16,7 @@
 
 import type { z } from 'zod';
 import type * as mcpServer from '../mcp/server.js';
-import type { Context } from './context.js';
+import type { Context } from './context';
 import type { ToolSchema } from '../mcp/tool.js';
 
 
diff --git a/src/mcp/http.ts b/src/mcp/http.ts
index e8ca580..51101a7 100644
--- a/src/mcp/http.ts
+++ b/src/mcp/http.ts
@@ -21,10 +21,10 @@ import crypto from 'crypto';
 
 import debug from 'debug';
 
-import * as mcpBundle from './bundle.js';
-import * as mcpServer from './server.js';
+import * as mcpBundle from './bundle';
+import * as mcpServer from './server';
 
-import type { ServerBackendFactory } from './server.js';
+import type { ServerBackendFactory } from './server';
 import type { SSEServerTransport } from '@modelcontextprotocol/sdk/server/sse.js';
 import type { StreamableHTTPServerTransport } from '@modelcontextprotocol/sdk/server/streamableHttp.js';
 
diff --git a/src/mcp/mdb.ts b/src/mcp/mdb.ts
index 2db2699..bdeca18 100644
--- a/src/mcp/mdb.ts
+++ b/src/mcp/mdb.ts
@@ -16,12 +16,12 @@
 
 import debug from 'debug';
 
-import { defineToolSchema } from './tool.js';
-import * as mcpBundle from './bundle.js';
-import * as mcpServer from './server.js';
-import * as mcpHttp from './http.js';
-import { wrapInProcess } from './server.js';
-import { ManualPromise } from './manualPromise.js';
+import { defineToolSchema } from './tool';
+import * as mcpBundle from './bundle';
+import * as mcpServer from './server';
+import * as mcpHttp from './http';
+import { wrapInProcess } from './server';
+import { ManualPromise } from './manualPromise';
 
 import type { Transport } from '@modelcontextprotocol/sdk/shared/transport.js';
 import type { Client } from '@modelcontextprotocol/sdk/client/index.js';
diff --git a/src/mcp/proxyBackend.ts b/src/mcp/proxyBackend.ts
index b151ad6..96b8c7f 100644
--- a/src/mcp/proxyBackend.ts
+++ b/src/mcp/proxyBackend.ts
@@ -16,9 +16,9 @@
 
 import debug from 'debug';
 
-import * as mcpBundle from './bundle.js';
+import * as mcpBundle from './bundle';
 
-import type { ServerBackend, ClientVersion, Root, Server } from './server.js';
+import type { ServerBackend, ClientVersion, Root, Server } from './server';
 import type { Transport } from '@modelcontextprotocol/sdk/shared/transport.js';
 import type { Tool, CallToolResult, CallToolRequest } from '@modelcontextprotocol/sdk/types.js';
 import type { Client } from '@modelcontextprotocol/sdk/client/index.js';
diff --git a/src/mcp/server.ts b/src/mcp/server.ts
index 082c9fc..4519092 100644
--- a/src/mcp/server.ts
+++ b/src/mcp/server.ts
@@ -16,9 +16,9 @@
 
 import debug from 'debug';
 
-import * as mcpBundle from './bundle.js';
-import { httpAddressToString, installHttpTransport, startHttpServer } from './http.js';
-import { InProcessTransport } from './inProcessTransport.js';
+import * as mcpBundle from './bundle';
+import { httpAddressToString, installHttpTransport, startHttpServer } from './http';
+import { InProcessTransport } from './inProcessTransport';
 
 import type { Tool, CallToolResult, CallToolRequest, Root } from '@modelcontextprotocol/sdk/types.js';
 import type { Transport } from '@modelcontextprotocol/sdk/shared/transport.js';
diff --git a/src/mcp/tool.ts b/src/mcp/tool.ts
index 97fb334..af2594c 100644
--- a/src/mcp/tool.ts
+++ b/src/mcp/tool.ts
@@ -17,7 +17,7 @@
 import { zodToJsonSchema } from  '../mcp/bundle.js';
 
 import type { z } from 'zod';
-import type * as mcpServer from './server.js';
+import type * as mcpServer from './server';
 
 export type ToolSchema<Input extends z.Schema> = {
   name: string;
diff --git a/src/program.ts b/src/program.ts
index dde0cca..819295f 100644
--- a/src/program.ts
+++ b/src/program.ts
@@ -15,18 +15,18 @@
  */
 
 import { program, Option } from 'commander';
-import * as mcpServer from './mcp/server.js';
-import { commaSeparatedList, resolveCLIConfig, semicolonSeparatedList } from './config.js';
-import { packageJSON } from './utils/package.js';
-import { Context } from './context.js';
-import { contextFactory } from './browserContextFactory.js';
-import { runLoopTools } from './loopTools/main.js';
-import { ProxyBackend } from './mcp/proxyBackend.js';
-import { BrowserServerBackend } from './browserServerBackend.js';
-import { ExtensionContextFactory } from './extension/extensionContextFactory.js';
+import * as mcpServer from './mcp/server';
+import { commaSeparatedList, resolveCLIConfig, semicolonSeparatedList } from './config';
+import { packageJSON } from './utils/package';
+import { Context } from './context';
+import { contextFactory } from './browserContextFactory';
+import { runLoopTools } from './loopTools/main';
+import { ProxyBackend } from './mcp/proxyBackend';
+import { BrowserServerBackend } from './browserServerBackend';
+import { ExtensionContextFactory } from './extension/extensionContextFactory';
 
-import { runVSCodeTools } from './vscode/host.js';
-import type { MCPProvider } from './mcp/proxyBackend.js';
+import { runVSCodeTools } from './vscode/host';
+import type { MCPProvider } from './mcp/proxyBackend';
 
 program
     .version('Version ' + packageJSON.version)
diff --git a/src/response.ts b/src/response.ts
index 6c66d3d..3dc95ab 100644
--- a/src/response.ts
+++ b/src/response.ts
@@ -14,11 +14,11 @@
  * limitations under the License.
  */
 
-import { renderModalStates } from './tab.js';
+import { renderModalStates } from './tab';
 
-import type { Tab, TabSnapshot } from './tab.js';
+import type { Tab, TabSnapshot } from './tab';
 import type { ImageContent, TextContent } from '@modelcontextprotocol/sdk/types.js';
-import type { Context } from './context.js';
+import type { Context } from './context';
 
 export class Response {
   private _result: string[] = [];
diff --git a/src/sessionLog.ts b/src/sessionLog.ts
index dfda6a0..c8922f7 100644
--- a/src/sessionLog.ts
+++ b/src/sessionLog.ts
@@ -17,13 +17,13 @@
 import fs from 'fs';
 import path from 'path';
 
-import { Response } from './response.js';
-import { logUnhandledError } from './utils/log.js';
-import { outputFile  } from './config.js';
+import { Response } from './response';
+import { logUnhandledError } from './utils/log';
+import { outputFile  } from './config';
 
-import type { FullConfig } from './config.js';
-import type * as actions from './actions.js';
-import type { Tab, TabSnapshot } from './tab.js';
+import type { FullConfig } from './config';
+import type * as actions from './actions';
+import type { Tab, TabSnapshot } from './tab';
 
 type LogEntry = {
   timestamp: number;
diff --git a/src/tab.ts b/src/tab.ts
index 5ef34af..c57b9d7 100644
--- a/src/tab.ts
+++ b/src/tab.ts
@@ -16,12 +16,12 @@
 
 import { EventEmitter } from 'events';
 import * as playwright from 'playwright';
-import { callOnPageNoTrace, waitForCompletion } from './tools/utils.js';
-import { logUnhandledError } from './utils/log.js';
-import { ManualPromise } from './mcp/manualPromise.js';
-import { ModalState } from './tools/tool.js';
+import { callOnPageNoTrace, waitForCompletion } from './tools/utils';
+import { logUnhandledError } from './utils/log';
+import { ManualPromise } from './mcp/manualPromise';
+import { ModalState } from './tools/tool';
 
-import type { Context } from './context.js';
+import type { Context } from './context';
 
 type PageEx = playwright.Page & {
   _snapshotForAI: () => Promise<string>;
diff --git a/src/tools.ts b/src/tools.ts
index 0eedf85..b1e8059 100644
--- a/src/tools.ts
+++ b/src/tools.ts
@@ -14,26 +14,26 @@
  * limitations under the License.
  */
 
-import common from './tools/common.js';
-import console from './tools/console.js';
-import dialogs from './tools/dialogs.js';
-import evaluate from './tools/evaluate.js';
-import files from './tools/files.js';
-import form from './tools/form.js';
-import install from './tools/install.js';
-import keyboard from './tools/keyboard.js';
-import mouse from './tools/mouse.js';
-import navigate from './tools/navigate.js';
-import network from './tools/network.js';
-import pdf from './tools/pdf.js';
-import snapshot from './tools/snapshot.js';
-import tabs from './tools/tabs.js';
-import screenshot from './tools/screenshot.js';
-import wait from './tools/wait.js';
-import verify from './tools/verify.js';
+import common from './tools/common';
+import console from './tools/console';
+import dialogs from './tools/dialogs';
+import evaluate from './tools/evaluate';
+import files from './tools/files';
+import form from './tools/form';
+import install from './tools/install';
+import keyboard from './tools/keyboard';
+import mouse from './tools/mouse';
+import navigate from './tools/navigate';
+import network from './tools/network';
+import pdf from './tools/pdf';
+import snapshot from './tools/snapshot';
+import tabs from './tools/tabs';
+import screenshot from './tools/screenshot';
+import wait from './tools/wait';
+import verify from './tools/verify';
 
-import type { Tool } from './tools/tool.js';
-import type { FullConfig } from './config.js';
+import type { Tool } from './tools/tool';
+import type { FullConfig } from './config';
 
 export const allTools: Tool<any>[] = [
   ...common,
diff --git a/src/tools/common.ts b/src/tools/common.ts
index a652bc4..8f8aca7 100644
--- a/src/tools/common.ts
+++ b/src/tools/common.ts
@@ -15,7 +15,7 @@
  */
 
 import { z } from '../mcp/bundle.js';
-import { defineTabTool, defineTool } from './tool.js';
+import { defineTabTool, defineTool } from './tool';
 
 const close = defineTool({
   capability: 'core',
diff --git a/src/tools/console.ts b/src/tools/console.ts
index 53cecde..a2fb6b7 100644
--- a/src/tools/console.ts
+++ b/src/tools/console.ts
@@ -15,7 +15,7 @@
  */
 
 import { z } from '../mcp/bundle.js';
-import { defineTabTool } from './tool.js';
+import { defineTabTool } from './tool';
 
 const console = defineTabTool({
   capability: 'core',
diff --git a/src/tools/dialogs.ts b/src/tools/dialogs.ts
index 70b1d98..637e4a7 100644
--- a/src/tools/dialogs.ts
+++ b/src/tools/dialogs.ts
@@ -15,7 +15,7 @@
  */
 
 import { z } from '../mcp/bundle.js';
-import { defineTabTool } from './tool.js';
+import { defineTabTool } from './tool';
 
 const handleDialog = defineTabTool({
   capability: 'core',
diff --git a/src/tools/evaluate.ts b/src/tools/evaluate.ts
index e214f12..e1f188c 100644
--- a/src/tools/evaluate.ts
+++ b/src/tools/evaluate.ts
@@ -15,9 +15,9 @@
  */
 
 import { z } from '../mcp/bundle.js';
-import { defineTabTool } from './tool.js';
+import { defineTabTool } from './tool';
 import * as javascript from '../utils/codegen.js';
-import { generateLocator } from './utils.js';
+import { generateLocator } from './utils';
 
 import type * as playwright from 'playwright';
 
diff --git a/src/tools/files.ts b/src/tools/files.ts
index 1e2d687..a3b2e5a 100644
--- a/src/tools/files.ts
+++ b/src/tools/files.ts
@@ -15,7 +15,7 @@
  */
 
 import { z } from '../mcp/bundle.js';
-import { defineTabTool } from './tool.js';
+import { defineTabTool } from './tool';
 
 const uploadFile = defineTabTool({
   capability: 'core',
diff --git a/src/tools/form.ts b/src/tools/form.ts
index f59266c..501f067 100644
--- a/src/tools/form.ts
+++ b/src/tools/form.ts
@@ -15,8 +15,8 @@
  */
 
 import { z } from '../mcp/bundle.js';
-import { defineTabTool } from './tool.js';
-import { generateLocator } from './utils.js';
+import { defineTabTool } from './tool';
+import { generateLocator } from './utils';
 import * as javascript from '../utils/codegen.js';
 
 const fillForm = defineTabTool({
diff --git a/src/tools/install.ts b/src/tools/install.ts
index 6ab263a..4152ec7 100644
--- a/src/tools/install.ts
+++ b/src/tools/install.ts
@@ -16,10 +16,9 @@
 
 import { fork } from 'child_process';
 import path from 'path';
-import url from 'url';
 
 import { z } from '../mcp/bundle.js';
-import { defineTool } from './tool.js';
+import { defineTool } from './tool';
 
 const install = defineTool({
   capability: 'core-install',
@@ -33,8 +32,7 @@ const install = defineTool({
 
   handle: async (context, params, response) => {
     const channel = context.config.browser?.launchOptions?.channel ?? context.config.browser?.browserName ?? 'chrome';
-    const cliUrl = import.meta.resolve('playwright/package.json');
-    const cliPath = path.join(url.fileURLToPath(cliUrl), '..', 'cli.js');
+    const cliPath = path.join(require.resolve('playwright/package.json'), '../cli.js');
     const child = fork(cliPath, ['install', channel], {
       stdio: 'pipe',
     });
diff --git a/src/tools/keyboard.ts b/src/tools/keyboard.ts
index 8857d92..70ed94e 100644
--- a/src/tools/keyboard.ts
+++ b/src/tools/keyboard.ts
@@ -15,9 +15,9 @@
  */
 
 import { z } from '../mcp/bundle.js';
-import { defineTabTool } from './tool.js';
-import { elementSchema } from './snapshot.js';
-import { generateLocator } from './utils.js';
+import { defineTabTool } from './tool';
+import { elementSchema } from './snapshot';
+import { generateLocator } from './utils';
 import * as javascript from '../utils/codegen.js';
 
 const pressKey = defineTabTool({
diff --git a/src/tools/mouse.ts b/src/tools/mouse.ts
index 1e2e027..4063f05 100644
--- a/src/tools/mouse.ts
+++ b/src/tools/mouse.ts
@@ -15,7 +15,7 @@
  */
 
 import { z } from '../mcp/bundle.js';
-import { defineTabTool } from './tool.js';
+import { defineTabTool } from './tool';
 
 const elementSchema = z.object({
   element: z.string().describe('Human-readable element description used to obtain permission to interact with the element'),
diff --git a/src/tools/navigate.ts b/src/tools/navigate.ts
index 2558d45..ca68a5a 100644
--- a/src/tools/navigate.ts
+++ b/src/tools/navigate.ts
@@ -15,7 +15,7 @@
  */
 
 import { z } from '../mcp/bundle.js';
-import { defineTool, defineTabTool } from './tool.js';
+import { defineTool, defineTabTool } from './tool';
 
 const navigate = defineTool({
   capability: 'core',
diff --git a/src/tools/network.ts b/src/tools/network.ts
index c2b4284..6b1b3b7 100644
--- a/src/tools/network.ts
+++ b/src/tools/network.ts
@@ -15,7 +15,7 @@
  */
 
 import { z } from '../mcp/bundle.js';
-import { defineTabTool } from './tool.js';
+import { defineTabTool } from './tool';
 
 import type * as playwright from 'playwright';
 
diff --git a/src/tools/pdf.ts b/src/tools/pdf.ts
index 72bee47..d7defb5 100644
--- a/src/tools/pdf.ts
+++ b/src/tools/pdf.ts
@@ -15,7 +15,7 @@
  */
 
 import { z } from '../mcp/bundle.js';
-import { defineTabTool } from './tool.js';
+import { defineTabTool } from './tool';
 import * as javascript from '../utils/codegen.js';
 
 const pdfSchema = z.object({
diff --git a/src/tools/screenshot.ts b/src/tools/screenshot.ts
index 08d7cf1..256e710 100644
--- a/src/tools/screenshot.ts
+++ b/src/tools/screenshot.ts
@@ -15,9 +15,9 @@
  */
 
 import { z } from '../mcp/bundle.js';
-import { defineTabTool } from './tool.js';
+import { defineTabTool } from './tool';
 import * as javascript from '../utils/codegen.js';
-import { generateLocator } from './utils.js';
+import { generateLocator } from './utils';
 
 import type * as playwright from 'playwright';
 
diff --git a/src/tools/snapshot.ts b/src/tools/snapshot.ts
index 523d69e..a68cf20 100644
--- a/src/tools/snapshot.ts
+++ b/src/tools/snapshot.ts
@@ -15,9 +15,9 @@
  */
 
 import { z } from '../mcp/bundle.js';
-import { defineTabTool, defineTool } from './tool.js';
+import { defineTabTool, defineTool } from './tool';
 import * as javascript from '../utils/codegen.js';
-import { generateLocator } from './utils.js';
+import { generateLocator } from './utils';
 
 const snapshot = defineTool({
   capability: 'core',
diff --git a/src/tools/tabs.ts b/src/tools/tabs.ts
index 4cfe7d5..6ee44fe 100644
--- a/src/tools/tabs.ts
+++ b/src/tools/tabs.ts
@@ -15,7 +15,7 @@
  */
 
 import { z } from '../mcp/bundle.js';
-import { defineTool } from './tool.js';
+import { defineTool } from './tool';
 
 const browserTabs = defineTool({
   capability: 'core-tabs',
diff --git a/src/tools/verify.ts b/src/tools/verify.ts
index 3414f97..b28da52 100644
--- a/src/tools/verify.ts
+++ b/src/tools/verify.ts
@@ -15,9 +15,9 @@
  */
 
 import { z } from '../mcp/bundle.js';
-import { defineTabTool } from './tool.js';
+import { defineTabTool } from './tool';
 import * as javascript from '../utils/codegen.js';
-import { generateLocator } from './utils.js';
+import { generateLocator } from './utils';
 
 const verifyElement = defineTabTool({
   capability: 'verify',
diff --git a/src/tools/wait.ts b/src/tools/wait.ts
index 95c5ab6..9338047 100644
--- a/src/tools/wait.ts
+++ b/src/tools/wait.ts
@@ -15,7 +15,7 @@
  */
 
 import { z } from '../mcp/bundle.js';
-import { defineTool } from './tool.js';
+import { defineTool } from './tool';
 
 const wait = defineTool({
   capability: 'core',
diff --git a/src/utils/package.ts b/src/utils/package.ts
index e3c4bba..0c415d6 100644
--- a/src/utils/package.ts
+++ b/src/utils/package.ts
@@ -16,7 +16,5 @@
 
 import fs from 'fs';
 import path from 'path';
-import url from 'url';
 
-const __filename = url.fileURLToPath(import.meta.url);
-export const packageJSON = JSON.parse(fs.readFileSync(path.join(path.dirname(__filename), '..', '..', 'package.json'), 'utf8'));
+export const packageJSON = JSON.parse(fs.readFileSync(path.join(__dirname, '..', '..', 'package.json'), 'utf8'));
diff --git a/src/vscode/host.ts b/src/vscode/host.ts
index f6d3077..e4e729d 100644
--- a/src/vscode/host.ts
+++ b/src/vscode/host.ts
@@ -14,7 +14,6 @@
  * limitations under the License.
  */
 
-import url from 'url';
 import path from 'path';
 
 import * as mcpBundle from '../mcp/bundle.js';
@@ -137,7 +136,7 @@ class VSCodeProxyBackend implements ServerBackend {
           command: process.execPath,
           cwd: process.cwd(),
           args: [
-            path.join(url.fileURLToPath(import.meta.url), '..', 'main.js'),
+            path.join(__dirname, 'main.js'),
             JSON.stringify(this._config),
             params.connectionString,
             params.lib,
diff --git a/src/vscode/main.ts b/src/vscode/main.ts
index e0e73e2..e1905f6 100644
--- a/src/vscode/main.ts
+++ b/src/vscode/main.ts
@@ -69,8 +69,10 @@ async function main(config: FullConfig, connectionString: string, lib: string) {
   );
 }
 
-await main(
-    JSON.parse(process.argv[2]),
-    process.argv[3],
-    process.argv[4]
-);
+void (async () => {
+  await main(
+      JSON.parse(process.argv[2]),
+      process.argv[3],
+      process.argv[4]
+  );
+})();
diff --git a/tests/capabilities.spec.ts b/tests/capabilities.spec.ts
index fe928de..7ec699a 100644
--- a/tests/capabilities.spec.ts
+++ b/tests/capabilities.spec.ts
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-import { test, expect } from './fixtures.js';
+import { test, expect } from './fixtures';
 
 test('test snapshot tool list', async ({ client }) => {
   const { tools } = await client.listTools();
diff --git a/tests/cdp.spec.ts b/tests/cdp.spec.ts
index 4ab9571..77702c4 100644
--- a/tests/cdp.spec.ts
+++ b/tests/cdp.spec.ts
@@ -14,10 +14,9 @@
  * limitations under the License.
  */
 
-import url from 'node:url';
 import path from 'node:path';
 import { spawnSync } from 'node:child_process';
-import { test, expect } from './fixtures.js';
+import { test, expect } from './fixtures';
 
 test('cdp server', async ({ cdpServer, startClient, server }) => {
   await cdpServer.start();
@@ -84,9 +83,6 @@ test('should throw connection error and allow re-connecting', async ({ cdpServer
   });
 });
 
-// NOTE: Can be removed when we drop Node.js 18 support and changed to import.meta.filename.
-const __filename = url.fileURLToPath(import.meta.url);
-
 test('does not support --device', async () => {
   const result = spawnSync('node', [
     path.join(__filename, '../../cli.js'), '--device=Pixel 5', '--cdp-endpoint=http://localhost:1234',
diff --git a/tests/click.spec.ts b/tests/click.spec.ts
index d6b425e..53db231 100644
--- a/tests/click.spec.ts
+++ b/tests/click.spec.ts
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-import { test, expect } from './fixtures.js';
+import { test, expect } from './fixtures';
 
 test('browser_click', async ({ client, server, mcpBrowser }) => {
   server.setContent('/', `
diff --git a/tests/config.spec.ts b/tests/config.spec.ts
index 8dc5083..246d754 100644
--- a/tests/config.spec.ts
+++ b/tests/config.spec.ts
@@ -17,7 +17,7 @@
 import fs from 'node:fs';
 
 import { Config } from '../config.js';
-import { test, expect } from './fixtures.js';
+import { test, expect } from './fixtures';
 
 test('config user data dir', async ({ startClient, server, mcpMode }, testInfo) => {
   server.setContent('/', `
diff --git a/tests/console.spec.ts b/tests/console.spec.ts
index 572623b..835b453 100644
--- a/tests/console.spec.ts
+++ b/tests/console.spec.ts
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-import { test, expect } from './fixtures.js';
+import { test, expect } from './fixtures';
 
 test('browser_console_messages', async ({ client, server }) => {
   server.setContent('/', `
diff --git a/tests/core.spec.ts b/tests/core.spec.ts
index cdf1f03..f5bd171 100644
--- a/tests/core.spec.ts
+++ b/tests/core.spec.ts
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-import { test, expect } from './fixtures.js';
+import { test, expect } from './fixtures';
 
 test('browser_navigate', async ({ client, server }) => {
   expect(await client.callTool({
diff --git a/tests/device.spec.ts b/tests/device.spec.ts
index 51f75c1..986d321 100644
--- a/tests/device.spec.ts
+++ b/tests/device.spec.ts
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-import { test, expect } from './fixtures.js';
+import { test, expect } from './fixtures';
 
 test('--device should work', async ({ startClient, server, mcpMode }) => {
   const { client } = await startClient({
diff --git a/tests/dialogs.spec.ts b/tests/dialogs.spec.ts
index 6739825..0b57714 100644
--- a/tests/dialogs.spec.ts
+++ b/tests/dialogs.spec.ts
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-import { test, expect } from './fixtures.js';
+import { test, expect } from './fixtures';
 
 test('alert dialog', async ({ client, server }) => {
   server.setContent('/', `<button onclick="alert('Alert')">Button</button>`, 'text/html');
diff --git a/tests/evaluate.spec.ts b/tests/evaluate.spec.ts
index 8457fca..68c8a39 100644
--- a/tests/evaluate.spec.ts
+++ b/tests/evaluate.spec.ts
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-import { test, expect } from './fixtures.js';
+import { test, expect } from './fixtures';
 
 test('browser_evaluate', async ({ client, server }) => {
   expect(await client.callTool({
diff --git a/tests/files.spec.ts b/tests/files.spec.ts
index 160686a..b3ac198 100644
--- a/tests/files.spec.ts
+++ b/tests/files.spec.ts
@@ -15,7 +15,7 @@
  */
 
 import fs from 'fs/promises';
-import { test, expect } from './fixtures.js';
+import { test, expect } from './fixtures';
 
 test('browser_file_upload', async ({ client, server }, testInfo) => {
   server.setContent('/', `
diff --git a/tests/fixtures.ts b/tests/fixtures.ts
index d6368e8..80d03b9 100644
--- a/tests/fixtures.ts
+++ b/tests/fixtures.ts
@@ -15,7 +15,6 @@
  */
 
 import fs from 'fs';
-import url from 'url';
 import path from 'path';
 import { chromium } from 'playwright';
 
@@ -23,7 +22,7 @@ import { test as baseTest, expect as baseExpect } from '@playwright/test';
 import { StdioClientTransport } from '@modelcontextprotocol/sdk/client/stdio.js';
 import { Client } from '@modelcontextprotocol/sdk/client/index.js';
 import { ListRootsRequestSchema } from '@modelcontextprotocol/sdk/types.js';
-import { TestServer } from './testserver/index.ts';
+import { TestServer } from './testserver/index';
 
 import type { Config } from '../config';
 import type { BrowserContext } from 'playwright';
@@ -186,8 +185,6 @@ async function createTransport(args: string[], mcpMode: TestOptions['mcpMode'],
   transport: Transport,
   stderr: Stream | null,
 }> {
-  // NOTE: Can be removed when we drop Node.js 18 support and changed to import.meta.filename.
-  const __filename = url.fileURLToPath(import.meta.url);
   if (mcpMode === 'docker') {
     const dockerArgs = ['run', '--rm', '-i', '--network=host', '-v', `${test.info().project.outputDir}:/app/test-results`];
     const transport = new StdioClientTransport({
@@ -202,7 +199,7 @@ async function createTransport(args: string[], mcpMode: TestOptions['mcpMode'],
 
   const transport = new StdioClientTransport({
     command: 'node',
-    args: [path.join(path.dirname(__filename), '../cli.js'), ...args],
+    args: [path.join(__dirname, '../cli.js'), ...args],
     cwd: path.dirname(test.info().config.configFile!),
     stderr: 'pipe',
     env: {
diff --git a/tests/form.spec.ts b/tests/form.spec.ts
index 458cc4c..339d79d 100644
--- a/tests/form.spec.ts
+++ b/tests/form.spec.ts
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-import { test, expect } from './fixtures.js';
+import { test, expect } from './fixtures';
 
 test('browser_fill_form (textbox)', async ({ client, server }) => {
   server.setContent('/', `
diff --git a/tests/headed.spec.ts b/tests/headed.spec.ts
index 7274657..af3be37 100644
--- a/tests/headed.spec.ts
+++ b/tests/headed.spec.ts
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-import { test, expect } from './fixtures.js';
+import { test, expect } from './fixtures';
 
 for (const mcpHeadless of [false, true]) {
   test.describe(`mcpHeadless: ${mcpHeadless}`, () => {
diff --git a/tests/http.spec.ts b/tests/http.spec.ts
index 4ff9ac9..6558451 100644
--- a/tests/http.spec.ts
+++ b/tests/http.spec.ts
@@ -14,20 +14,16 @@
  * limitations under the License.
  */
 
-import fs from 'node:fs';
-import url from 'node:url';
+import fs from 'fs';
 
-import { ChildProcess, spawn } from 'node:child_process';
-import path from 'node:path';
+import { ChildProcess, spawn } from 'child_process';
+import path from 'path';
 import { StreamableHTTPClientTransport } from '@modelcontextprotocol/sdk/client/streamableHttp.js';
 import { Client } from '@modelcontextprotocol/sdk/client/index.js';
 
-import { test as baseTest, expect } from './fixtures.js';
+import { test as baseTest, expect } from './fixtures';
 import type { Config } from '../config.d.ts';
 
-// NOTE: Can be removed when we drop Node.js 18 support and changed to import.meta.filename.
-const __filename = url.fileURLToPath(import.meta.url);
-
 const test = baseTest.extend<{ serverEndpoint: (options?: { args?: string[], noPort?: boolean }) => Promise<{ url: URL, stderr: () => string }> }>({
   serverEndpoint: async ({ mcpHeadless }, use, testInfo) => {
     let cp: ChildProcess | undefined;
diff --git a/tests/iframes.spec.ts b/tests/iframes.spec.ts
index 69d9863..3c53de1 100644
--- a/tests/iframes.spec.ts
+++ b/tests/iframes.spec.ts
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-import { test, expect } from './fixtures.js';
+import { test, expect } from './fixtures';
 
 test('stitched aria frames', async ({ client }) => {
   expect(await client.callTool({
diff --git a/tests/install.spec.ts b/tests/install.spec.ts
index e8c1b42..70fde07 100644
--- a/tests/install.spec.ts
+++ b/tests/install.spec.ts
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-import { test, expect } from './fixtures.js';
+import { test, expect } from './fixtures';
 
 test('browser_install', async ({ client, mcpBrowser }) => {
   test.skip(mcpBrowser !== 'chromium', 'Test only chromium');
diff --git a/tests/launch.spec.ts b/tests/launch.spec.ts
index 37fa264..f7f0171 100644
--- a/tests/launch.spec.ts
+++ b/tests/launch.spec.ts
@@ -16,7 +16,7 @@
 
 import fs from 'fs';
 
-import { test, expect, formatOutput } from './fixtures.js';
+import { test, expect, formatOutput } from './fixtures';
 
 test('test reopen browser', async ({ startClient, server, mcpMode }) => {
   const { client, stderr } = await startClient();
diff --git a/tests/library.spec.ts b/tests/library.spec.ts
index 2029b3d..754df89 100644
--- a/tests/library.spec.ts
+++ b/tests/library.spec.ts
@@ -15,7 +15,7 @@
  */
 import child_process from 'child_process';
 import fs from 'fs/promises';
-import { test, expect } from './fixtures.js';
+import { test, expect } from './fixtures';
 
 test('library can be used from CommonJS', { annotation: { type: 'issue', description: 'https://github.com/microsoft/playwright-mcp/issues/456' } }, async ({}, testInfo) => {
   const file = testInfo.outputPath('main.cjs');
diff --git a/tests/mdb.spec.ts b/tests/mdb.spec.ts
index d694b58..8b98414 100644
--- a/tests/mdb.spec.ts
+++ b/tests/mdb.spec.ts
@@ -21,7 +21,7 @@ import { StreamableHTTPClientTransport } from '@modelcontextprotocol/sdk/client/
 
 import { runMainBackend, runOnPauseBackendLoop } from '../src/mcp/mdb.js';
 
-import { test, expect } from './fixtures.js';
+import { test, expect } from './fixtures';
 
 import type * as mcpServer from '../src/mcp/server.js';
 import type { ServerBackendOnPause } from '../src/mcp/mdb.js';
diff --git a/tests/network.spec.ts b/tests/network.spec.ts
index 96ee98c..40b3852 100644
--- a/tests/network.spec.ts
+++ b/tests/network.spec.ts
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-import { test, expect } from './fixtures.js';
+import { test, expect } from './fixtures';
 
 test('browser_network_requests', async ({ client, server }) => {
   server.setContent('/', `
diff --git a/tests/pdf.spec.ts b/tests/pdf.spec.ts
index 3d72e75..937eb16 100644
--- a/tests/pdf.spec.ts
+++ b/tests/pdf.spec.ts
@@ -16,7 +16,7 @@
 
 import fs from 'fs';
 
-import { test, expect } from './fixtures.js';
+import { test, expect } from './fixtures';
 
 test('save as pdf unavailable', async ({ startClient, server }) => {
   const { client } = await startClient();
diff --git a/tests/roots.spec.ts b/tests/roots.spec.ts
index ad5170b..94c1e9e 100644
--- a/tests/roots.spec.ts
+++ b/tests/roots.spec.ts
@@ -18,7 +18,7 @@ import fs from 'fs';
 import path from 'path';
 import { pathToFileURL } from 'url';
 
-import { test, expect } from './fixtures.js';
+import { test, expect } from './fixtures';
 import { createHash } from '../src/utils/guid.js';
 
 const p = process.platform === 'win32' ? 'c:\\non\\existent\\folder' : '/non/existent/folder';
diff --git a/tests/screenshot.spec.ts b/tests/screenshot.spec.ts
index 294a43f..50b2eae 100644
--- a/tests/screenshot.spec.ts
+++ b/tests/screenshot.spec.ts
@@ -16,7 +16,7 @@
 
 import fs from 'fs';
 
-import { test, expect } from './fixtures.js';
+import { test, expect } from './fixtures';
 
 test('browser_take_screenshot (viewport)', async ({ startClient, server }, testInfo) => {
   const { client } = await startClient({
diff --git a/tests/session-log.spec.ts b/tests/session-log.spec.ts
index 2654c2d..364723d 100644
--- a/tests/session-log.spec.ts
+++ b/tests/session-log.spec.ts
@@ -17,7 +17,7 @@
 import fs from 'fs';
 import path from 'path';
 
-import { test, expect } from './fixtures.js';
+import { test, expect } from './fixtures';
 
 test('session log should record tool calls', async ({ startClient, server }, testInfo) => {
   const { client, stderr } = await startClient({
diff --git a/tests/sse.spec.ts b/tests/sse.spec.ts
index 60cc740..62183d9 100644
--- a/tests/sse.spec.ts
+++ b/tests/sse.spec.ts
@@ -14,20 +14,16 @@
  * limitations under the License.
  */
 
-import fs from 'node:fs';
-import url from 'node:url';
+import fs from 'fs';
 
-import { ChildProcess, spawn } from 'node:child_process';
-import path from 'node:path';
+import { ChildProcess, spawn } from 'child_process';
+import path from 'path';
 import { SSEClientTransport } from '@modelcontextprotocol/sdk/client/sse.js';
 import { Client } from '@modelcontextprotocol/sdk/client/index.js';
 
-import { test as baseTest, expect } from './fixtures.js';
+import { test as baseTest, expect } from './fixtures';
 import type { Config } from '../config.d.ts';
 
-// NOTE: Can be removed when we drop Node.js 18 support and changed to import.meta.filename.
-const __filename = url.fileURLToPath(import.meta.url);
-
 const test = baseTest.extend<{ serverEndpoint: (options?: { args?: string[], noPort?: boolean }) => Promise<{ url: URL, stderr: () => string }> }>({
   serverEndpoint: async ({ mcpHeadless }, use, testInfo) => {
     let cp: ChildProcess | undefined;
diff --git a/tests/tabs.spec.ts b/tests/tabs.spec.ts
index ddd873d..a0b40d8 100644
--- a/tests/tabs.spec.ts
+++ b/tests/tabs.spec.ts
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-import { test, expect } from './fixtures.js';
+import { test, expect } from './fixtures';
 
 import type { Client } from '@modelcontextprotocol/sdk/client/index.js';
 
diff --git a/tests/testserver/index.ts b/tests/testserver/index.ts
index b40f7f4..da77cb5 100644
--- a/tests/testserver/index.ts
+++ b/tests/testserver/index.ts
@@ -16,7 +16,6 @@
  */
 
 import fs from 'fs';
-import url from 'node:url';
 import http from 'http';
 import https from 'https';
 import path from 'path';
@@ -25,9 +24,6 @@ import debug from 'debug';
 const fulfillSymbol = Symbol('fulfil callback');
 const rejectSymbol = Symbol('reject callback');
 
-// NOTE: Can be removed when we drop Node.js 18 support and changed to import.meta.filename.
-const __filename = url.fileURLToPath(import.meta.url);
-
 export class TestServer {
   private _server: http.Server;
   readonly debugServer: any;
diff --git a/tests/trace.spec.ts b/tests/trace.spec.ts
index 6cfe12e..927f23a 100644
--- a/tests/trace.spec.ts
+++ b/tests/trace.spec.ts
@@ -16,7 +16,7 @@
 
 import fs from 'fs';
 
-import { test, expect } from './fixtures.js';
+import { test, expect } from './fixtures';
 
 test('check that trace is saved', async ({ startClient, server, mcpMode }, testInfo) => {
   const outputDir = testInfo.outputPath('output');
diff --git a/tests/type.spec.ts b/tests/type.spec.ts
index ffcc6c6..7ac2314 100644
--- a/tests/type.spec.ts
+++ b/tests/type.spec.ts
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-import { test, expect } from './fixtures.js';
+import { test, expect } from './fixtures';
 
 test('browser_type', async ({ client, server }) => {
   server.setContent('/', `
diff --git a/tests/verify.spec.ts b/tests/verify.spec.ts
index 91366e1..58c9b36 100644
--- a/tests/verify.spec.ts
+++ b/tests/verify.spec.ts
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-import { test, expect } from './fixtures.js';
+import { test, expect } from './fixtures';
 
 test.use({ mcpArgs: ['--caps=verify'] });
 
diff --git a/tests/vscode.spec.ts b/tests/vscode.spec.ts
index 3582ca3..7f1c3d2 100644
--- a/tests/vscode.spec.ts
+++ b/tests/vscode.spec.ts
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-import { test, expect } from './fixtures.js';
+import { test, expect } from './fixtures';
 
 test('browser_connect(vscode) works', async ({ startClient, playwright, browserName }) => {
   const { client } = await startClient({
@@ -27,7 +27,7 @@ test('browser_connect(vscode) works', async ({ startClient, playwright, browserN
     name: 'browser_connect',
     arguments: {
       connectionString: server.wsEndpoint(),
-      lib: import.meta.resolve('playwright'),
+      lib: require.resolve('playwright'),
     }
   })).toHaveResponse({
     result: 'Successfully connected.'
diff --git a/tests/wait.spec.ts b/tests/wait.spec.ts
index a75c955..0388faf 100644
--- a/tests/wait.spec.ts
+++ b/tests/wait.spec.ts
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-import { test, expect } from './fixtures.js';
+import { test, expect } from './fixtures';
 
 test('browser_wait_for(text)', async ({ client, server }) => {
   server.setContent('/', `
diff --git a/tests/webdriver.spec.ts b/tests/webdriver.spec.ts
index bd96925..ef742d7 100644
--- a/tests/webdriver.spec.ts
+++ b/tests/webdriver.spec.ts
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-import { test, expect } from './fixtures.js';
+import { test, expect } from './fixtures';
 
 test('do not falsely advertise user agent as a test driver', async ({ client, server, mcpBrowser }) => {
   test.skip(mcpBrowser === 'firefox');
diff --git a/tsconfig.json b/tsconfig.json
index 114ce8b..c9424f8 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -1,10 +1,9 @@
 {
   "compilerOptions": {
-    "target": "ESNext",
+    "target": "ES2019",
     "esModuleInterop": true,
-    "moduleResolution": "nodenext",
     "strict": true,
-    "module": "NodeNext",
+    "module": "commonjs",
     "rootDir": "src",
     "outDir": "./lib",
     "resolveJsonModule": true
diff --git a/utils/check-deps.js b/utils/check-deps.js
index 60d545c..adbdde8 100644
--- a/utils/check-deps.js
+++ b/utils/check-deps.js
@@ -18,13 +18,10 @@
 
 // @ts-check
 
-import fs from 'fs';
-import ts from 'typescript';
-import path from 'path';
-import Module from 'module';
-
-const __dirname = path.dirname(new URL(import.meta.url).pathname);
-const require = Module.createRequire(import.meta.url);
+const fs = require('fs');
+const ts = require('typescript');
+const path = require('path');
+const Module = require('module');
 
 const builtins = new Set(Module.builtinModules);
 
diff --git a/utils/set-version.js b/utils/set-version.js
index b0d7b34..ec0e2da 100644
--- a/utils/set-version.js
+++ b/utils/set-version.js
@@ -22,8 +22,6 @@ import path from 'path';
 import child_process from 'child_process';
 import { argv } from 'process';
 
-const __dirname = path.dirname(new URL(import.meta.url).pathname);
-
 const readJSON = async (filePath) => JSON.parse(await fs.promises.readFile(filePath, 'utf8'));
 const writeJSON = async (filePath, json) => {
   await fs.promises.writeFile(filePath, JSON.stringify(json, null, 2) + '\n');
diff --git a/utils/update-readme.js b/utils/update-readme.js
index 4e0648b..f5855bb 100644
--- a/utils/update-readme.js
+++ b/utils/update-readme.js
@@ -16,13 +16,12 @@
  */
 // @ts-check
 
-import fs from 'node:fs'
-import path from 'node:path'
-import url from 'node:url'
-import zodToJsonSchema from 'zod-to-json-schema'
-import { execSync } from 'node:child_process';
+const fs = require('fs')
+const path = require('path')
+const { zodToJsonSchema } = require('zod-to-json-schema')
+const { execSync } = require('child_process');
 
-import { allTools } from '../lib/tools.js';
+const { allTools } = require('../lib/tools.js');
 
 const capabilities = {
   'core': 'Core automation',
@@ -35,11 +34,8 @@ const capabilities = {
 
 const toolsByCapability = Object.fromEntries(Object.entries(capabilities).map(([capability, title]) => [title, allTools.filter(tool => tool.capability === capability).sort((a, b) => a.schema.name.localeCompare(b.schema.name))]));
 
-// NOTE: Can be removed when we drop Node.js 18 support and changed to import.meta.filename.
-const __filename = url.fileURLToPath(import.meta.url);
-
 /**
- * @param {import('../src/tools/tool.js').ToolSchema<any>} tool 
+ * @param {import('../src/mcp/tool.js').ToolSchema<any>} tool 
  * @returns {string[]}
  */
 function formatToolForReadme(tool) {