How to check Codex CLI version

Checking the installed Codex CLI version confirms which local build the current shell will run before troubleshooting command behavior, comparing environments, or deciding whether the CLI still needs an upgrade.

Current OpenAI Codex CLI documentation describes the terminal client as the local Codex interface, and current local help for the installed binary exposes the standard -V and --version flags. The simplest decisive check is codex --version.

The check is complete when the command prints a version string such as codex-cli 0.121.0. If the shell cannot find codex, the current environment is not using a working Codex CLI install yet.

Steps to check Codex CLI version:

Run the version check in the same terminal environment that normally starts Codex.
```
$ codex --version
codex-cli 0.121.0
```
Current local verification on this host returned codex-cli 0.121.0. The numeric value changes as new Codex CLI releases ship, but the command itself stays the same.
Read the returned line to confirm which Codex CLI build the shell resolved first.

The codex-cli x.y.z string is the installed CLI release for the active shell session. Use that exact value when comparing hosts, confirming an upgrade, or reporting a problem against a specific build.
Treat a shell error instead of a version line as an install or PATH problem in the current environment.
```
$ codex --version
zsh: command not found: codex
```
If the command is not found, open a shell that already includes codex on PATH or install Codex CLI before retrying the version check.

Related: How to install Codex CLI with Homebrew
Run the same version check again after upgrading or changing shells and stop when the reported build matches the version you expect to use.
```
$ codex --version
codex-cli 0.121.0
```
Use How to upgrade Codex CLI with Homebrew when the installed build is older than the current packaged Codex CLI release you want to run. After the package change, rerun codex --version to confirm that the new binary is now active.