Desktop: remote MCP startup timeout blocks creating new conversation

Summary

When Codex Desktop starts a new local conversation/thread, a failing remote MCP server can block thread/start until the UI times out. In my case, an enabled remote MCP server caused thread creation to take about 40s. The UI showed timeout errors and the first message could not be sent. Disabling that MCP server and restarting Codex Desktop immediately fixed new conversation creation.

Environment

• Codex Desktop on macOS
• Codex Desktop version: 26.616.51431 (4212)
• Chromium base: 149.0.7827.115
• Local mode with an existing repo selected
• Remote MCP server configured in ~/.codex/config.toml
• The remote MCP URL was https://stitch.googleapis.com/mcp

Steps to reproduce

1. Configure a remote MCP server that is unavailable or slow during auth/discovery/connection.
2. Fully restart Codex Desktop.
3. Open a new conversation in a local repo.
4. Send the first message.

Actual behavior

• The UI shows timeout errors such as:
• Error creating task: Timeout
• Error starting conversation: Timeout
• Local logs show thread startup spending about 40s in the create-thread path before eventually emitting thread/started.
• Representative log characteristics:
• thread_start_create_thread duration_ms=40155
• thread_start_total duration_ms=40161
• session_init.auth_mcp attempts remote MCP OAuth discovery and fails/times out.
• By the time thread/started is emitted, the UI has already timed out and the new conversation is not usable.

Expected behavior

A single optional MCP server should not block the core conversation/thread creation path. If a remote MCP server fails, Codex should degrade gracefully by marking that tool unavailable, loading/retrying it in the background, or using a shorter non-blocking timeout. The thread should still start and the user should still be able to send messages.

Workaround

Commenting out the problematic remote MCP server in ~/.codex/config.toml and restarting Codex Desktop restores new conversation creation.

Why this matters

MCP/connectors are optional extensions. A misconfigured, slow, or unreachable MCP server should not make the main Codex Desktop workflow unusable.