feat: support passing args to Chrome (#338)

Drive-by: removes custom devtools frontend as a dedicated argument.

Closes #261

Author: OrKoN

README.md

@@ -291,6 +291,10 @@ The Chrome DevTools MCP server supports the following configuration option:
   If enabled, ignores errors relative to self-signed and expired certificates. Use with caution.
   - **Type:** boolean
 
+- **`--chromeArg`**
+  Additional arguments for Chrome. Only applies when Chrome is launched by chrome-devtools-mcp.
+  - **Type:** array
+
 <!-- END AUTO GENERATED OPTIONS -->
 
 Pass them via the `args` property in the JSON configuration. For example:

src/browser.ts

@@ -60,7 +60,6 @@ export async function ensureBrowserConnected(options: {
 interface McpLaunchOptions {
   acceptInsecureCerts?: boolean;
   executablePath?: string;
-  customDevTools?: string;
   channel?: Channel;
   userDataDir?: string;
   headless: boolean;
@@ -75,7 +74,7 @@ interface McpLaunchOptions {
 }
 
 export async function launch(options: McpLaunchOptions): Promise<Browser> {
-  const {channel, executablePath, customDevTools, headless, isolated} = options;
+  const {channel, executablePath, headless, isolated} = options;
   const profileDirName =
     channel && channel !== 'stable'
       ? `chrome-profile-${channel}`
@@ -98,9 +97,6 @@ export async function launch(options: McpLaunchOptions): Promise<Browser> {
     ...(options.args ?? []),
     '--hide-crash-restore-bubble',
   ];
-  if (customDevTools) {
-    args.push(`--custom-devtools-frontend=file://${customDevTools}`);
-  }
   if (headless) {
     args.push('--screen-info={3840x2160}');
   }

src/cli.ts

@@ -43,13 +43,6 @@ export const cliOptions = {
       'If specified, creates a temporary user-data-dir that is automatically cleaned up after the browser is closed.',
     default: false,
   },
-  customDevtools: {
-    type: 'string',
-    description: 'Path to custom DevTools.',
-    hidden: true,
-    conflicts: 'browserUrl',
-    alias: 'd',
-  },
   channel: {
     type: 'string',
     description:
@@ -89,10 +82,15 @@ export const cliOptions = {
     description: `If enabled, ignores errors relative to self-signed and expired certificates. Use with caution.`,
   },
   experimentalDevtools: {
-    type: 'boolean' as const,
+    type: 'boolean',
     describe: 'Whether to enable automation over DevTools targets',
     hidden: true,
   },
+  chromeArg: {
+    type: 'array',
+    describe:
+      'Additional arguments for Chrome. Only applies when Chrome is launched by chrome-devtools-mcp.',
+  },
 } satisfies Record<string, YargsOptions>;
 
 export function parseArguments(version: string, argv = process.argv) {
@@ -122,6 +120,10 @@ export function parseArguments(version: string, argv = process.argv) {
         '$0 --viewport 1280x720',
         'Launch Chrome with the initial viewport size of 1280x720px',
       ],
+      [
+        `$0 --chrome-arg='--no-sandbox' --chrome-arg='--disable-setuid-sandbox'`,
+        'Launch Chrome without sandboxes. Use with caution.',
+      ],
     ]);
 
   return yargsInstance

src/main.ts

@@ -69,7 +69,7 @@ server.server.setRequestHandler(SetLevelRequestSchema, () => {
 
 let context: McpContext;
 async function getContext(): Promise<McpContext> {
-  const extraArgs: string[] = [];
+  const extraArgs: string[] = (args.chromeArg ?? []).map(String);
   if (args.proxyServer) {
     extraArgs.push(`--proxy-server=${args.proxyServer}`);
   }
@@ -82,7 +82,6 @@ async function getContext(): Promise<McpContext> {
     : await ensureBrowserLaunched({
         headless: args.headless,
         executablePath: args.executablePath,
-        customDevTools: args.customDevtools,
         channel: args.channel as Channel,
         isolated: args.isolated,
         logFile,

tests/cli.test.ts

@@ -94,4 +94,22 @@ describe('cli args parsing', () => {
       },
     });
   });
+
+  it('parses viewport', async () => {
+    const args = parseArguments('1.0.0', [
+      'node',
+      'main.js',
+      `--chrome-arg='--no-sandbox'`,
+      `--chrome-arg='--disable-setuid-sandbox'`,
+    ]);
+    assert.deepStrictEqual(args, {
+      _: [],
+      headless: false,
+      isolated: false,
+      $0: 'npx chrome-devtools-mcp@latest',
+      channel: 'stable',
+      'chrome-arg': ['--no-sandbox', '--disable-setuid-sandbox'],
+      chromeArg: ['--no-sandbox', '--disable-setuid-sandbox'],
+    });
+  });
 });