Gregory Bastianelli | Software Engineer

How to install with curl

ls 
curl -fsSL https://chatgpt.com/codex/install.sh | sh

This downloads an installation script and immediately runs it.

curl retrieves data from a URL:

curl https://chatgpt.com/codex/install.sh

Without the other pieces, this would print the script’s contents in your terminal.

-fsSL

These are four combined options:

  • -f — fail on HTTP errors such as 404 or 500.
  • -s — silent mode; hides the progress meter.
  • -S — still show an error message when -s is active.
  • -L — follow redirects if the URL points elsewhere.

The same options could be written as:

curl --fail --silent --show-error --location

The URL

https://chatgpt.com/codex/install.sh

This is the shell script being downloaded.

|

The pipe sends the output of the command on its left into the command on its right:

downloaded script → sh

sh

sh executes the downloaded text as a shell script.

So the complete command effectively means:

Download the Codex installer quietly, follow redirects, report errors, and immediately execute the result.

A safer approach is to download and inspect it first:

curl -fsSL https://chatgpt.com/codex/install.sh -o codex-install.sh
less codex-install.sh
sh codex-install.sh

This avoids blindly executing whatever the server returns. Also, the backslash shown before -fsSL in some formatted text is just escaping; type -fsSL, not \-fsSL.