Codex Windows App fails in WSL with "invalid transport in `mcp_servers.codex_app`"

Resolved 💬 3 comments Opened Aug 26, 2026 by FANGOD Closed Aug 26, 2026

💡 Likely answer: A maintainer (github-actions[bot], contributor) responded on this thread — see the highlighted reply below.

What version of the Codex App are you using (From “About Codex” dialog)?

26.820.60940

os

win11 + wsl 26.04

Description

Codex Windows App fails to start a local task when using a WSL workspace.

The error is:

failed to load configuration: invalid transport
in `mcp_servers.codex_app`

[electron-message-handler] Request failed
error={
  "code": -32600,
  "message": "failed to load configuration: invalid transport\nin `mcp_servers.codex_app`\n"
}
failureReason=invalid_config
method=thread/start



invalid transport in `mcp_servers.codex_app`

View original on GitHub ↗

3 Comments

github-actions[bot] contributor · 2 days ago

Potential duplicates detected. Please review them and close your issue if it is a duplicate.

#40819
#40732
#40715

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taobaibais · 1 day ago

I can confirm the same regression on Windows 11 + WSL2 with Codex Desktop 26.820.x. Both creating new chats and resuming existing chats fail with invalid transport in mcp_servers.codex_app, while my user config.toml has no mcp_servers.codex_app entry. WSL is my required development environment, so switching the agent to Windows-native is not a viable workaround for me. This is a complete work blocker.

taobaibais · 1 day ago

Given that this regression completely blocks a supported development workflow for paying users, OpenAI should also consider compensation for affected accounts. At minimum, users impacted by the WSL outage should receive additional/banked usage resets (or equivalent credits) for the period in which Codex Desktop was unusable in their required environment. We are paying for access to this service, and a release regression that prevents all new/resumed WSL chats from working should not consume users' paid usage window without remedy.