How to set the working directory for Codex

Launching Codex from the wrong folder can load the wrong project files, instructions, and Git context. Use the working-directory flag when the parent shell should stay where it is but the Codex run needs to start inside a specific repository or scratch folder.

The -C and --cd flags select the working root before Codex processes the prompt. Relative paths, project instructions, project-scoped .codex/config.toml layers, and repository context are then discovered from that selected directory.

For codex exec, the repository guard still applies after the working root is selected. A Git repository passed with -C passes that guard, while an intentional scratch directory needs --skip-git-repo-check; use --add-dir only when the session needs an extra writable path beside the main workspace.

1. Choose the absolute path that should own the Codex session.

   $ git -C /home/user/work/example-repo rev-parse --show-toplevel
   /home/user/work/example-repo

   Use a repository root when the task should load project instructions, Git status, and project-scoped Codex config from that tree.

2. Start an interactive Codex session with that directory as the working root.

   $ codex -C /home/user/work/example-repo

   The terminal UI should open with the directory line set to ~/work/example-repo or the absolute target path. -C and --cd are equivalent.

   Related: How to start a Codex interactive session

3. Run a non-interactive Codex task with the same working root.

   $ codex exec -C /home/user/work/example-repo --sandbox read-only "Return OK."
   OpenAI Codex v0.139.0
   --------
   workdir: /home/user/work/example-repo
   sandbox: read-only
   ##### snipped #####

   The workdir line confirms that Codex switched to the chosen directory before processing the prompt. --sandbox read-only keeps the check from writing files.

   Related: How to run a command with Codex exec

4. Add the repository-check override only for an intentional scratch directory.

   $ codex exec -C /home/user/tmp/codex-scratch --skip-git-repo-check --sandbox read-only "Return OK."
   OpenAI Codex v0.139.0
   --------
   workdir: /home/user/tmp/codex-scratch
   sandbox: read-only
   ##### snipped #####

   Without --skip-git-repo-check, codex exec stops outside Git with Not inside a trusted directory and --skip-git-repo-check was not specified. Do not use the override for normal repository work.

   Related: How to skip Codex git repository checks
   Related: How to fix the Codex trusted-directory error

5. Use --add-dir only for extra writable paths.

   $ codex -C /home/user/work/example-repo --sandbox workspace-write --add-dir /home/user/shared-notes

   -C changes the primary workspace. --add-dir adds a separate path that Codex can write alongside it.

   Related: How to add a writable directory for Codex