Playwriter MCP transport can close while the parent agent stays alive

Environment

• macOS
• Chrome 147.0.7727.56
• playwriter npm/CLI: 0.0.105
• Chrome extension manifest: 0.0.79
• /extension/status reports: playwriterVersion=0.0.102
• MCP launch path: npx -y playwriter@latest

Summary

In some Codex runs, the Playwriter MCP connection closes completely while the parent agent is still running.

Facts

• Playwriter works normally at first.
• Later, a Playwriter call fails with:
  • Transport closed
• Right after that, playwriter/reset also fails with:
  • Transport closed
• The parent Codex agent is still alive and continues running.
• Only the Playwriter MCP connection is gone.

Theory

This looks like the Playwriter MCP transport itself has already closed, not just a browser page, tab, or target failing.

I do not yet know which layer closes first:

• the inner playwriter Node process
• the npx wrapper
• the stdio pipe

Scope

This issue is only about the MCP transport closing entirely.

It is not about tab grouping, tab detaches, or extension version reporting.