chore: configure cli args

Author: OrKoN

docs/cli.md

@@ -17,7 +17,7 @@ The CLI acts as a client to a background `chrome-devtools-mcp` daemon (uses Unix
 
 - **Automatic Start**: The first time you call a tool (e.g., `list_pages`), the CLI automatically starts the MCP server and the browser in the background if they aren't already running.
 - **Persistence**: The same background instance is reused for subsequent commands, preserving the browser state (open pages, cookies, etc.).
-- **Manual Control**: You can explicitly manage the background process using `start`, `stop`, and `status`. The `start` command forwards all subsequent arguments to the underlying MCP server (e.g., `--headless`, `--userDataDir`).
+- **Manual Control**: You can explicitly manage the background process using `start`, `stop`, and `status`. The `start` command forwards all subsequent arguments to the underlying MCP server (e.g., `--headless`, `--userDataDir`) but not all args are supported. Run `chrome-devtools start --help` for supported args. Headless and isolated are enabled by default.
 
 ```sh
 # Check if the daemon is running

src/bin/chrome-devtools.ts

@@ -32,6 +32,35 @@ async function start(args: string[]) {
 
 const defaultArgs = ['--viaCli', '--experimentalStructuredContent'];
 
+const startCliOptions = {
+  ...cliOptions,
+} as Partial<typeof cliOptions>;
+
+// Not supported in CLI on purpose.
+delete startCliOptions.autoConnect;
+// Missing CLI serialization.
+delete startCliOptions.viewport;
+// CLI is generated based on the default tool definitions. To enable conditional
+// tools, they needs to be enabled during CLI generation.
+delete startCliOptions.experimentalPageIdRouting;
+delete startCliOptions.experimentalVision;
+delete startCliOptions.experimentalInteropTools;
+delete startCliOptions.experimentalScreencast;
+delete startCliOptions.categoryEmulation;
+delete startCliOptions.categoryPerformance;
+delete startCliOptions.categoryNetwork;
+delete startCliOptions.categoryExtensions;
+// Always on in CLI.
+delete startCliOptions.experimentalStructuredContent;
+// Change the defaults.
+if (!('default' in cliOptions.headless)) {
+  throw new Error('headless cli option unexpectedly does not have a default');
+}
+if ('default' in cliOptions.isolated) {
+  throw new Error('headless cli option unexpectedly does not have a default');
+}
+startCliOptions.headless!.default = true;
+
 const y = yargs(hideBin(process.argv))
   .scriptName('chrome-devtools')
   .showHelpOnFail(true)
@@ -50,7 +79,7 @@ y.command(
   'Start or restart chrome-devtools-mcp',
   y =>
     y
-      .options(cliOptions)
+      .options(startCliOptions)
       .example(
         '$0 start --browserUrl http://localhost:9222',
         'Start the server connecting to an existing browser',
@@ -60,6 +89,13 @@ y.command(
     if (isDaemonRunning()) {
       await stopDaemon();
     }
+    // Defaults but we do not want to affect the yargs conflict resolution.
+    if (argv.isolated === undefined) {
+      argv.isolated = true;
+    }
+    if (argv.headless === undefined) {
+      argv.headless = true;
+    }
     const args = serializeArgs(cliOptions, argv);
     await start(args);
     process.exit(0);

src/browser.ts

@@ -149,6 +149,7 @@ interface McpLaunchOptions {
   ignoreDefaultChromeArgs?: string[];
   devtools: boolean;
   enableExtensions?: boolean;
+  viaCli?: boolean;
 }
 
 export function detectDisplay(): void {
@@ -181,7 +182,7 @@ export async function launch(options: McpLaunchOptions): Promise<Browser> {
     userDataDir = path.join(
       os.homedir(),
       '.cache',
-      'chrome-devtools-mcp',
+      options.viaCli ? 'chrome-devtools-mcp-cli' : 'chrome-devtools-mcp',
       profileDirName,
     );
     await fs.promises.mkdir(userDataDir, {

src/daemon/client.ts

@@ -79,7 +79,7 @@ export async function startDaemon(mcpArgs: string[] = []) {
     fs.unlinkSync(pidFilePath);
   }
 
-  logger('Starting daemon...');
+  logger('Starting daemon...', ...mcpArgs);
   const child = spawn(process.execPath, [DAEMON_SCRIPT_PATH, ...mcpArgs], {
     detached: true,
     stdio: 'ignore',

src/daemon/utils.ts

@@ -9,7 +9,6 @@ import os from 'node:os';
 import path from 'node:path';
 import process from 'node:process';
 
-import type {ParsedArguments} from '../cli.js';
 import {logger} from '../logger.js';
 import type {YargsOptions} from '../third_party/index.js';
 
@@ -102,7 +101,7 @@ export function isDaemonRunning(pid = getDaemonPid()): pid is number {
 
 export function serializeArgs(
   options: Record<string, YargsOptions>,
-  argv: ParsedArguments,
+  argv: Record<string, unknown>,
 ): string[] {
   const args: string[] = [];
   for (const key of Object.keys(options)) {

src/server.ts

@@ -93,6 +93,7 @@ export async function createMcpServer(
             acceptInsecureCerts: serverArgs.acceptInsecureCerts,
             devtools,
             enableExtensions: serverArgs.categoryExtensions,
+            viaCli: serverArgs.viaCli,
           });
 
     if (context?.browser !== browser) {

tests/e2e/chrome-devtools.test.ts

@@ -12,8 +12,6 @@ import {describe, it, afterEach, beforeEach} from 'node:test';
 const CLI_PATH = path.resolve('build/src/bin/chrome-devtools.js');
 
 describe('chrome-devtools', () => {
-  const START_ARGS = ['--headless', '--isolated'];
-
   function assertDaemonIsNotRunning() {
     const result = spawnSync('node', [CLI_PATH, 'status']);
     assert.strictEqual(
@@ -45,7 +43,7 @@ describe('chrome-devtools', () => {
   it('reports daemon status correctly', () => {
     assertDaemonIsNotRunning();
 
-    const startResult = spawnSync('node', [CLI_PATH, 'start', ...START_ARGS]);
+    const startResult = spawnSync('node', [CLI_PATH, 'start']);
     assert.strictEqual(
       startResult.status,
       0,
@@ -58,7 +56,7 @@ describe('chrome-devtools', () => {
   it('can start and stop the daemon', () => {
     assertDaemonIsNotRunning();
 
-    const startResult = spawnSync('node', [CLI_PATH, 'start', ...START_ARGS]);
+    const startResult = spawnSync('node', [CLI_PATH, 'start']);
     assert.strictEqual(
       startResult.status,
       0,
@@ -80,7 +78,7 @@ describe('chrome-devtools', () => {
   it('can invoke list_pages', async () => {
     assertDaemonIsNotRunning();
 
-    const startResult = spawnSync('node', [CLI_PATH, 'start', ...START_ARGS]);
+    const startResult = spawnSync('node', [CLI_PATH, 'start']);
     assert.strictEqual(
       startResult.status,
       0,
@@ -102,7 +100,7 @@ describe('chrome-devtools', () => {
   });
 
   it('can take screenshot', async () => {
-    const startResult = spawnSync('node', [CLI_PATH, 'start', ...START_ARGS]);
+    const startResult = spawnSync('node', [CLI_PATH, 'start']);
     assert.strictEqual(
       startResult.status,
       0,
@@ -122,7 +120,7 @@ describe('chrome-devtools', () => {
   });
 
   it('forwards disclaimers to stderr on start', () => {
-    const result = spawnSync('node', [CLI_PATH, 'start', ...START_ARGS]);
+    const result = spawnSync('node', [CLI_PATH, 'start']);
     assert.strictEqual(
       result.status,
       0,