Codex extension in Cursor times out on starting a conversation

Codex Codex CLI
1

Codex extension in Cursor times out every time I start a conversation, or open a recent task that I can see from having a chat in the CLI.

Environment:

  • Windows 11 x64 (10.0.26100)

  • Cursor 1.6.45

  • Codex extension 0.4.12

  • Codex CLI: 0.40.0 (npm global); extension is unpinned and should use bundled CLI

  • Auth: “Logged in using ChatGPT” in Codex; Git operations work

Symptom:

  • Opening the Codex sidebar or sending any prompt spins ~30–45s, then “Error starting conversation.”

  • Recent Codex.log shows handshake succeeds, but newConversation times out.

Relevant log snippet:

2025-09-25 17:14:25.973 [info] Activating Codex extension

2025-09-25 17:16:34.603 [info] Received MCP result: … (recent conversations)

2025-09-25 17:16:34.603 [info] Received MCP result: … (auth status)

2025-09-25 17:16:34.932 [info] Received MCP result: … (config)

2025-09-25 17:17:12.537 [warning] Request d094e100-48e4-4998-8c09-3300c6a3789c newConversation {“cwd”:“g:\\projects\\….”,“model”:“gpt-5-codex”, …} timed out

2025-09-25 17:17:12.538 [error] Error creating local task: Error: Timeout

What works:

  • GitHub auth is fixed; git fetch origin succeeds.

  • MCP results appear in the log (recent conversations, auth status, config).

  • Codex CLI on PATH reports codex-cli 0.40.0; basic CLI commands work.

What I already tried:

  • Fixed previous GitHub environment 404 (now gone).

  • Removed Codex CLI path pin (extension should use bundled x86_64 codex.exe).

  • Backed up Codex config (C:\Users\……\.codex\config.toml → .bak) to force defaults.

  • Updated/reinstalled the Codex extension; Reloaded Cursor.

  • Checked globalStorage for Codex (openai.chatgpt) – folder is missing (nothing to clear).

  • Still get timeouts on newConversation.

Questions for the community:

  • Is there a known issue in Codex extension 0.4.12 where newConversation times out despite MCP/auth working?

  • How can I confirm which codex.exe path the extension actually launches on Windows?

  • Any flags to enable verbose logging for the extension→CLI invocation?

  • Has anyone needed to allowlist the extension’s codex.exe separately in Windows Firewall to fix this?

  • Any other ideas?

Repro steps:

  1. Launch Cursor and open g:\projects\my project

  2. Open Codex sidebar or send a prompt

  3. After ~45s: “Error starting conversation,” and log shows newConversation timeout as above

3

Verbose logging helped me figure out Codex was conflicting with another extension. I disabled it and now Codex works. Thanks for the tip!!!

4

I was mistaken… starting a new conversation still doesn’t work as expected… if I try to start one by entering a prompt it hangs… BUT! if I click on the Task History icon while Codex is thinking then it magically works like no problem ever happened…

Also loading an existing conversation works… sometimes…. only when I again click on the Task History icon while Codex is thinking. And when an recent task loads, then I can chat within an existing one with no problem.

But whenever I try to call the newConversation it always hangs… I get this message in the Codex Output

2025-09-26 21:50:35.804 [warning] Request fcc7129a-e0ca-437a-bd01-37bfd4de3b96 newConversation {“cwd”:“g:\\projects\\…..”,“model”:“gpt-5-codex”,“config”:{},“approvalPolicy”:“on-request”,“baseInstructions”:null,“sandbox”:“workspace-write”,“profile”:null,“includePlanTool”:true,“includeApplyPatchTool”:null} timed out

2025-09-26 21:50:35.804 [error] Error creating local task: Error: Timeout

The logs only shows this when the timeout ocurrs

[main 2025-09-27T01:59:17.866Z] Received request for main process info from other instance.

And there are no interesting messages in the Debugger console

Its strange that it works but only sometimes.

5

Same behavior in vs code, and clicking history while it’s thinking works just as you said. Very strange.