[Feature]: Official support for loading extensions in Playwright MCP

[hsm207]

🚀 Feature Request

Support for loading Chrome extensions (e.g., --load-extension) directly and officially through the Playwright MCP configuration.

While Playwright's core chromium.launchPersistentContext fully supports browser extensions, this functionality is currently undocumented and difficult to configure within the Playwright MCP server.

Example

A developer should be able to load an unpacked extension in the Playwright MCP configuration file like this:

{
  "browser": {
    "launchOptions": {
      "args": ["--disable-extensions-except=./dist", "--load-extension=./dist"]
    }
  }
}

Motivation

Playwright is a premier tool for browser automation and testing, and workflows like debugging extension-based tools require loading unpacked extensions.

In my investigation of the source code, I discovered that achieving this currently requires a complex, undocumented set of configurations:

1. Setting allowUnrestrictedFileAccess: true to bypass the _checkUrlAllowed protocol guard for chrome-extension://.
2. Bypassing the default "chrome" channel by passing an empty string (channel: "") to use the hermetic Chromium binary.
3. Manually overriding the forced assistantMode: true (which injects --disable-extensions) by using ignoreDefaultArgs: ['--disable-extensions'].

I am unsure if this is the "official" or intended way to handle extensions in MCP. Making this a first-class, documented feature would bring the MCP server in line with the rest of the Playwright ecosystem.

References: See my original documentation discussion here: #39560

[pavelfeldman]

Does this not work? Would be interesting to see a complete end-to-end example where things don't work.

{
  "browser": {
    "launchOptions": {
      "args": ["--disable-extensions-except=./dist", "--load-extension=./dist"]
    }
  }
}

[hsm207]

It does not work.

I've made a repo to test e2e the config you suggested vs what I found to work here: https://github.com/hsm207/mcp-extension-repro

[pavelfeldman]

• I'll fix allowUnrestrictedFileAccess
• Channel is as designed
• assistantMode: true does not affect --disable-extensions