Authentication
Usage-based billing alternative: Use an OpenAI API key
If you prefer to pay-as-you-go, you can still authenticate with your OpenAI API key:
printenv OPENAI_API_KEY | codex login --with-api-key
Alternatively, read from a file:
codex login --with-api-key < my_key.txt
The legacy --api-key
flag now exits with an error instructing you to use --with-api-key
so that the key never appears in shell history or process listings.
This key must, at minimum, have write access to the Responses API.
Migrating to ChatGPT login from API key
If you've used the Codex CLI before with usage-based billing via an API key and want to switch to using your ChatGPT plan, follow these steps:
- Update the CLI and ensure
codex --version
is0.20.0
or later - Delete
~/.codex/auth.json
(on Windows:C:\\Users\\USERNAME\\.codex\\auth.json
) - Run
codex login
again
Connecting on a "Headless" Machine
Today, the login process entails running a server on localhost:1455
. If you are on a "headless" server, such as a Docker container or are ssh
'd into a remote machine, loading localhost:1455
in the browser on your local machine will not automatically connect to the webserver running on the headless machine, so you must use one of the following workarounds:
Authenticate locally and copy your credentials to the "headless" machine
The easiest solution is likely to run through the codex login
process on your local machine such that localhost:1455
is accessible in your web browser. When you complete the authentication process, an auth.json
file should be available at $CODEX_HOME/auth.json
(on Mac/Linux, $CODEX_HOME
defaults to ~/.codex
whereas on Windows, it defaults to %USERPROFILE%\\.codex
).
Because the auth.json
file is not tied to a specific host, once you complete the authentication flow locally, you can copy the $CODEX_HOME/auth.json
file to the headless machine and then codex
should "just work" on that machine. Note to copy a file to a Docker container, you can do:
# substitute MY_CONTAINER with the name or id of your Docker container:
CONTAINER_HOME=$(docker exec MY_CONTAINER printenv HOME)
docker exec MY_CONTAINER mkdir -p "$CONTAINER_HOME/.codex"
docker cp auth.json MY_CONTAINER:"$CONTAINER_HOME/.codex/auth.json"
whereas if you are ssh
'd into a remote machine, you likely want to use scp
:
ssh user@remote 'mkdir -p ~/.codex'
scp ~/.codex/auth.json user@remote:~/.codex/auth.json
or try this one-liner:
ssh user@remote 'mkdir -p ~/.codex && cat > ~/.codex/auth.json' < ~/.codex/auth.json
Connecting through VPS or remote
If you run Codex on a remote machine (VPS/server) without a local browser, the login helper starts a server on localhost:1455
on the remote host. To complete login in your local browser, forward that port to your machine before starting the login flow:
# From your local machine
ssh -L 1455:localhost:1455 <user>@<remote-host>
Then, in that SSH session, run codex
and select "Sign in with ChatGPT". When prompted, open the printed URL (it will be http://localhost:1455/...
) in your local browser. The traffic will be tunneled to the remote server.