Agent IDE — Codex fork for AI-native development environment
Find a file
Robby He f3989f6092
fix(unified_exec): use platform default shell when unified_exec shell… (#7486)
# Unified Exec Shell Selection on Windows

## Problem

reference issue #7466

The `unified_exec` handler currently deserializes model-provided tool
calls into the `ExecCommandArgs` struct:

```rust
#[derive(Debug, Deserialize)]
struct ExecCommandArgs {
    cmd: String,
    #[serde(default)]
    workdir: Option<String>,
    #[serde(default = "default_shell")]
    shell: String,
    #[serde(default = "default_login")]
    login: bool,
    #[serde(default = "default_exec_yield_time_ms")]
    yield_time_ms: u64,
    #[serde(default)]
    max_output_tokens: Option<usize>,
    #[serde(default)]
    with_escalated_permissions: Option<bool>,
    #[serde(default)]
    justification: Option<String>,
}
```

The `shell` field uses a hard-coded default:

```rust
fn default_shell() -> String {
    "/bin/bash".to_string()
}
```

When the model returns a tool call JSON that only contains `cmd` (which
is the common case), Serde fills in `shell` with this default value.
Later, `get_command` uses that value as if it were a model-provided
shell path:

```rust
fn get_command(args: &ExecCommandArgs) -> Vec<String> {
    let shell = get_shell_by_model_provided_path(&PathBuf::from(args.shell.clone()));
    shell.derive_exec_args(&args.cmd, args.login)
}
```

On Unix, this usually resolves to `/bin/bash` and works as expected.
However, on Windows this behavior is problematic:

- The hard-coded `"/bin/bash"` is not a valid Windows path.
- `get_shell_by_model_provided_path` treats this as a model-specified
shell, and tries to resolve it (e.g. via `which::which("bash")`), which
may or may not exist and may not behave as intended.
- In practice, this leads to commands being executed under a non-default
or non-existent shell on Windows (for example, WSL bash), instead of the
expected Windows PowerShell or `cmd.exe`.

The core of the issue is that **"model did not specify `shell`" is
currently interpreted as "the model explicitly requested `/bin/bash`"**,
which is both Unix-specific and wrong on Windows.

## Proposed Solution

Instead of hard-coding `"/bin/bash"` into `ExecCommandArgs`, we should
distinguish between:

1. **The model explicitly specifying a shell**, e.g.:

   ```json
   {
     "cmd": "echo hello",
     "shell": "pwsh"
   }
   ```

In this case, we *do* want to respect the model’s choice and use
`get_shell_by_model_provided_path`.

2. **The model omitting the `shell` field entirely**, e.g.:

   ```json
   {
     "cmd": "echo hello"
   }
   ```

In this case, we should *not* assume `/bin/bash`. Instead, we should use
`default_user_shell()` and let the platform decide.

To express this distinction, we can:

1. Change `shell` to be optional in `ExecCommandArgs`:

   ```rust
   #[derive(Debug, Deserialize)]
   struct ExecCommandArgs {
       cmd: String,
       #[serde(default)]
       workdir: Option<String>,
       #[serde(default)]
       shell: Option<String>,
       #[serde(default = "default_login")]
       login: bool,
       #[serde(default = "default_exec_yield_time_ms")]
       yield_time_ms: u64,
       #[serde(default)]
       max_output_tokens: Option<usize>,
       #[serde(default)]
       with_escalated_permissions: Option<bool>,
       #[serde(default)]
       justification: Option<String>,
   }
   ```

Here, the absence of `shell` in the JSON is represented as `shell:
None`, rather than a hard-coded string value.
2025-12-02 21:49:25 -08:00
.devcontainer chore: install an extension for TOML syntax highlighting in the devcontainer (#1650) 2025-07-22 10:58:09 -07:00
.github Fixed CLA action to properly exempt dependabot (#7429) 2025-11-30 20:45:17 -08:00
.vscode Move rust analyzer target dir (#5328) 2025-10-18 17:31:46 -07:00
codex-cli detect Bun installs in CLI update banner (#5074) 2025-10-14 17:49:44 +00:00
codex-rs fix(unified_exec): use platform default shell when unified_exec shell… (#7486) 2025-12-02 21:49:25 -08:00
docs Trim history.jsonl when history.max_bytes is set (#6242) 2025-12-02 14:01:05 -08:00
scripts fix: ToC so it doesn’t include itself or duplicate the end marker (#4388) 2025-11-05 14:52:51 -08:00
sdk/typescript feat(ts-sdk): allow overriding CLI environment (#6648) 2025-11-14 19:44:19 +00:00
shell-tool-mcp fix: path resolution bug in npx (#7134) 2025-12-02 16:37:14 -08:00
.codespellignore feat: make it possible to toggle mouse mode in the Rust TUI (#971) 2025-05-16 16:16:50 -07:00
.codespellrc TypeScript SDK scaffold (#4455) 2025-09-29 13:27:13 -07:00
.gitignore nit: personal git ignore (#6787) 2025-11-17 17:45:52 +00:00
.npmrc chore: migrate to pnpm for improved monorepo management (#287) 2025-04-18 16:25:15 -07:00
.prettierignore [apply-patch] Clean up apply-patch tool definitions (#2539) 2025-08-21 20:07:41 -07:00
.prettierrc.toml Initial commit 2025-04-16 12:56:08 -04:00
AGENTS.md tests: replace mount_sse_once_match with mount_sse_once for SSE mocking (#6640) 2025-11-13 18:04:05 -08:00
CHANGELOG.md Documentation improvement: add missing period (#3754) 2025-10-30 13:01:33 -07:00
cliff.toml docs(changelog): update install command to @openai/codex@<version> (#2073) 2025-10-18 11:02:22 -07:00
flake.lock Fix nix build (#4048) 2025-10-17 12:19:08 -07:00
flake.nix Fix nix build (#4048) 2025-10-17 12:19:08 -07:00
LICENSE Initial commit 2025-04-16 12:56:08 -04:00
NOTICE resizable viewport (#1732) 2025-07-31 00:06:55 +00:00
package.json chore: subject docs/*.md to Prettier checks (#4645) 2025-10-03 11:35:48 -07:00
pnpm-lock.yaml feat: codex-shell-tool-mcp (#7005) 2025-11-21 08:16:36 -08:00
pnpm-workspace.yaml feat: codex-shell-tool-mcp (#7005) 2025-11-21 08:16:36 -08:00
PNPM.md fix: include pnpm lock file (#377) 2025-04-18 17:01:11 -07:00
README.md move execpolicy quickstart (#7127) 2025-11-21 19:13:51 -05:00

npm i -g @openai/codex
or brew install --cask codex

Codex CLI is a coding agent from OpenAI that runs locally on your computer.

If you want Codex in your code editor (VS Code, Cursor, Windsurf), install in your IDE
If you are looking for the cloud-based agent from OpenAI, Codex Web, go to chatgpt.com/codex

Codex CLI splash


Quickstart

Installing and running Codex CLI

Install globally with your preferred package manager. If you use npm:

npm install -g @openai/codex

Alternatively, if you use Homebrew:

brew install --cask codex

Then simply run codex to get started:

codex

If you're running into upgrade issues with Homebrew, see the FAQ entry on brew upgrade codex.

You can also go to the latest GitHub Release and download the appropriate binary for your platform.

Each GitHub Release contains many executables, but in practice, you likely want one of these:

  • macOS
    • Apple Silicon/arm64: codex-aarch64-apple-darwin.tar.gz
    • x86_64 (older Mac hardware): codex-x86_64-apple-darwin.tar.gz
  • Linux
    • x86_64: codex-x86_64-unknown-linux-musl.tar.gz
    • arm64: codex-aarch64-unknown-linux-musl.tar.gz

Each archive contains a single entry with the platform baked into the name (e.g., codex-x86_64-unknown-linux-musl), so you likely want to rename it to codex after extracting it.

Using Codex with your ChatGPT plan

Codex CLI login

Run codex and select Sign in with ChatGPT. We recommend signing into your ChatGPT account to use Codex as part of your Plus, Pro, Team, Edu, or Enterprise plan. Learn more about what's included in your ChatGPT plan.

You can also use Codex with an API key, but this requires additional setup. If you previously used an API key for usage-based billing, see the migration steps. If you're having trouble with login, please comment on this issue.

Model Context Protocol (MCP)

Codex can access MCP servers. To configure them, refer to the config docs.

Configuration

Codex CLI supports a rich set of configuration options, with preferences stored in ~/.codex/config.toml. For full configuration options, see Configuration.

Execpolicy

See the Execpolicy quickstart to set up rules that govern what commands Codex can execute.

Docs & FAQ


License

This repository is licensed under the Apache-2.0 License.