> ## Documentation Index
> Fetch the complete documentation index at: https://mintlify.com/openai/codex-plugin-cc/llms.txt
> Use this file to discover all available pages before exploring further.

# Codex configuration

> Configure the default model, reasoning effort, and other Codex settings used by the plugin.

## How configuration works

The plugin uses your local Codex CLI, which reads configuration from standard Codex config files. There are two levels:

* **User-level**: `~/.codex/config.toml` — applies to all repositories on this machine
* **Project-level**: `.codex/config.toml` at the root of the directory you started Claude in — applies only to that project

Project-level config only loads when the project is trusted.

<Tip>
  If you already use Codex directly, the plugin uses the same config you already have — nothing new to set up.
</Tip>

## Setting the default model

Set the `model` key in your config file to control which model all plugin commands use by default:

```toml theme={null}
model = "gpt-5.4-mini"
```

This model is used by all plugin commands (`/codex:review`, `/codex:adversarial-review`, `/codex:rescue`) unless overridden per-command.

## Setting reasoning effort

Set `model_reasoning_effort` to control how much reasoning the model applies:

```toml theme={null}
model_reasoning_effort = "xhigh"
```

Valid values are: `none`, `minimal`, `low`, `medium`, `high`, `xhigh`.

## Example project-level config

Place this file at `.codex/config.toml` in the root of your project:

```toml theme={null}
model = "gpt-5.4-mini"
model_reasoning_effort = "xhigh"
```

## Config file locations

| Location                            | Scope                                      |
| ----------------------------------- | ------------------------------------------ |
| `~/.codex/config.toml`              | All repositories on this machine           |
| `.codex/config.toml` (project root) | The current project only (must be trusted) |

## Per-command overrides

`/codex:rescue` supports `--model` and `--effort` flags to override config for a single run:

```bash theme={null}
/codex:rescue --model gpt-5.4-mini --effort medium investigate the flaky test
```

The `spark` model alias maps to `gpt-5.3-codex-spark`:

```bash theme={null}
/codex:rescue --model spark fix the issue quickly
```

## Custom API base URL

If you need to point the OpenAI provider at a different endpoint, set `openai_base_url` in your Codex config:

```toml theme={null}
openai_base_url = "https://your-custom-endpoint.example.com/v1"
```

This is useful if you use an API key tied to a custom base URL. Because the plugin delegates through your local Codex CLI, your existing sign-in method and authentication state still apply — no additional setup is needed.

<Note>
  The full Codex configuration reference is available in the [Codex docs](https://developers.openai.com/codex/config-reference).
</Note>