Codex CLI installation and CodeNodex one-click configuration

Codex CLI is a coding agent that runs in your local terminal. Before installing it, confirm that the current user can write to the target directory and prefer an installation method the team can update consistently.

The official installation script is suitable for a quick start, while npm and Homebrew are more suitable for environments that already use corresponding package managers. Do not maintain multiple installations at the same time, otherwise older executables in the PATH may be hit first.

Installation and configuration are separate steps. Check the version, help and local diagnostics first so PATH issues remain distinct from authentication failures. The following read-only checks do not modify project files.

If the codex command is unavailable, restart the terminal and try again. If it still fails, confirm that the package manager's bin directory is on PATH and check for an older executable with the same name.

The CodeNodex installer downloads the release for the current operating system and architecture and verifies its SHA256 checksum. The CLI validates the API key before writing configuration and never writes login passwords or API keys into the project repository.

The Unix installer preferentially installs to /usr/local/bin; if there is no permission, it will fall back to the user directory. Windows installs to the local application data directory by default.

The login path is suitable for users who already have a CodeNodex account. The CLI will list the Keys under the account, and write $CODEX_HOME/config.toml and auth.json after verification; if CODEX_HOME is not set, ~/.codex/ will be used by default.

The merge retains existing providers, project settings, and fields not managed by the CLI; it stops and rolls back if the target file cannot be parsed, is a symbolic link, or fails to be written midway.

Automated environments or sites with their own user authentication can supply an API key directly. Silent input keeps the key out of shell history, but --key still places the value in the process arguments, where privileged processes on the same machine may observe it. Prefer account login and interactive key selection for long-term use.

The platform must match the API key's protocol; CodeNodex configures Codex with the openai platform. The CLI does not write any files if validation fails.

Finally, check CLI diagnostics, login status and one read-only task. Ask that task to inspect the repository and propose a plan so you can verify the model, provider and working directory without changing code.

Move to a write-enabled workflow only after the read-only task succeeds. This sequence makes it easier to distinguish connection failures from permission-policy failures.