BrowserOS MCP server binds to random ports, settings show wrong port

[mmmikko]

Issue Type

Browser Issue

Operating System

Linux

Description of the bug

Environment:

• OS: Ubuntu 25.10
• BrowserOS version: 137.0.7229.69
  Issue:
• MCP settings show port 9100
• Server actually listens on random ports (9063, 9076, 9080, 9081, 9309, 9312, etc.)
• Port changes randomly even after fresh restart
• Test button always fails with "Failed to fetch"
• Issue persists even with CUPS printing service stopped (which I presumed to reserve the port 9100)

Expected:

• Server should bind to configured port (or port shown in settings)
• Test button should work

Steps to Reproduce

Steps to reproduce (Ubuntu 25.10):

1. Enable MCP server in BrowserOS settings
2. Note the port shown (e.g., 9100)
3. Check actual listening port: ss -tlnp | grep browseros
4. Ports don't match

Screenshots / Videos

No response

BrowserOS Version

137.0.7229.69

Additional Context

No response

[mmmikko]

This issue was probably due issue 202, i will check with newer computer soon.

[shadowfax92]

Hi @mmmikko, we have fixed this issue in the latest release 0.30.0. Please let me know if it works for you. Thanks for reporting!

For context: to ensure it works seamlessly across any OS (Windows, Linux, and macOS) and with other applications, we check if the MCP port is available before exposing it. With multiple profiles, there was an issue where it started multiple servers. That should now be fixed.