OpenAI Codex CLI error
Codex CLI: Error starting conversation
Error starting conversationStatus: Fixed in releaseLast verified 2 documented fixes3 sources
What it means
The Codex VS Code extension failed as soon as a new chat was started, before any code was involved.
Causes
- Bash detection failure in the VS Code Codex extension on Windows under certain conditions (PR #3421).
How to fix it
- Fix 1.
Update: PR #3421 was merged into extension pre-release 0.5.32 and the next mainline release (maintainer dylan-hurd-oai on #2841); the CLI change first shipped in rust-v0.51.0.
- Fix 2.
Maintainers strongly recommended running in WSL2 on Windows for the best sandbox and approvals experience (#2841).
More Codex CLI errors
All 14 Codex CLI errorsstream disconnected before completion: stream closed before response.completedStatus: Workaroundstream disconnected before completion: error sending request for url (https://chatgpt.com/backend-api/codex/responses)Status: OpenError running remote compact task: stream disconnected before completion: error sending request for url (https://chatgpt.com/backend-api/codex/responses/compact)Status: Fixed in releaseSelected model is at capacity. Please try a different model.Status: By designYour access token could not be refreshed because your refresh token was already used. Please log out and sign in again.Status: Fixed in releaseCodex ran out of room in the model's context window. Start a new thread or clear earlier history before retrying.Status: Fixed in releaseError logging in: Port 127.0.0.1:1455 is already in useStatus: WorkaroundToken exchange failed: token endpoint returned status 403 ForbiddenStatus: Workaround
Related reading
- Codex CLI 0.163: Instant Steering Is Now the DefaultCodex CLI 0.163.0 makes mid-response steering the default and adds searchable /config and a leader key. What changed and what to check before upgrading.
- Codex 'gpt-5.5 Model Is Not Supported' Error: The FixCodex says gpt-5.5 is not supported with a ChatGPT account because OpenAI retired it from ChatGPT sign-in on October 14. The fix and what still works.
- Agent Harness Lessons From a 500B-Token Decompile: Give Agents a PASS/FAIL OracleAgent harness lessons from a 500B+ token decompile: a byte-matching PASS/FAIL oracle beat the reviewer agent. How agents cheated it and what to copy.
- Codex CLI Background Daemon: How to Turn It OffCodex CLI starts a persistent, self-updating background daemon since 0.157.0. What it does, why it hit Hacker News and the reported workaround to turn it off.
- Codex CLI 0.162: Managed Worktrees and Pinned TasksCodex CLI 0.162 lets the agent create and list its own Git worktrees, adds pinned tasks and custom provider capability overrides. What to change this week.
- ChatGPT Free vs Go vs Plus After GPT-6: Which Model You GetFree and Go ($8) both get GPT-6 Luna in Chat. Plus ($20) is the cheapest plan with GPT-6 Sol and full Codex. What each ChatGPT plan buys now.
FAQ
What does "Error starting conversation" mean in Codex CLI?
The Codex VS Code extension failed as soon as a new chat was started, before any code was involved.
How do I fix "Error starting conversation"?
There are 2 documented fixes. Start with the first: Update: PR #3421 was merged into extension pre-release 0.5.32 and the next mainline release (maintainer dylan-hurd-oai on #2841); the CLI change first shipped in rust-v0.51.0.
Is this Codex CLI error fixed?
Status: Fixed in release. A release fixed this. The affected versions note says where the fix landed. Affected versions: Reported on Windows 10 with the new VS Code extension, August 2025 (#2841); fixed in extension 0.5.32 and rust-v0.51.0
Sources
Last verified against 3 sources: official docs, maintainer replies and release notes.
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