OpenAI Codex CLI error
Codex CLI: Error logging in: Port 127.0.0.1:1455 is already in use
Error logging in: Port 127.0.0.1:1455 is already in useStatus: WorkaroundLast verified 3 documented fixes3 sources
What it means
codex login could not start its local OAuth callback server, which listens on localhost:1455 by default, so the browser sign-in cannot return credentials to the CLI. It may be preceded by "Failed to cancel previous login server: connection timed out".
Causes
- Maintainer etraut-openai (#3927): likely related to your local network configuration (firewalls, VPNs, etc.).
How to fix it
- Fix 1.
Use device code authentication (beta), which the docs prefer for headless machines or when local networking blocks the localhost callback; enable device code login in ChatGPT security settings first.
Terminalcodex login --device-auth - Fix 2.
Or sign in on a machine with a browser and copy ~/.codex/auth.json to the target machine (official auth docs).
Snippetssh user@remote 'mkdir -p ~/.codex' scp ~/.codex/auth.json user@remote:~/.codex/auth.json - Fix 3.
Or forward the callback port over SSH, then run codex login in that session (official auth docs).
Snippetssh -L 1455:localhost:1455 user@remote
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 releaseToken exchange failed: token endpoint returned status 403 ForbiddenStatus: WorkaroundMCP client for `playwright` failed to start: program not foundStatus: Fixed in release
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 logging in: Port 127.0.0.1:1455 is already in use" mean in Codex CLI?
codex login could not start its local OAuth callback server, which listens on localhost:1455 by default, so the browser sign-in cannot return credentials to the CLI. It may be preceded by "Failed to cancel previous login server: connection timed out".
How do I fix "Error logging in: Port 127.0.0.1:1455 is already in use"?
There are 3 documented fixes. Start with the first: Use device code authentication (beta), which the docs prefer for headless machines or when local networking blocks the localhost callback; enable device code login in ChatGPT security settings first.
Is this Codex CLI error fixed?
Status: Workaround. No release removes the cause. The documented fixes work around it. Affected versions: Reported on codex-cli 0.39.0 under WSL (#3927)
Sources
Last verified against 3 sources: official docs, maintainer replies and release notes.
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