# How to Configure the Codex Model and Reasoning Effort for the openai/codex-plugin-cc Plugin > Learn to configure the Codex model and reasoning effort for the openai/codex-plugin-cc plugin using config files or command flags. Optimize your plugin's performance today. - Repository: [OpenAI/codex-plugin-cc](https://github.com/openai/codex-plugin-cc) - Tags: how-to-guide - Published: 2026-07-04 --- **You can configure the Codex model and reasoning effort via a [`.codex/config.toml`](https://github.com/openai/codex-plugin-cc/blob/main/.codex/config.toml) file for project-level defaults or override them per-command using `--model` and `--effort` flags.** The openai/codex-plugin-cc repository provides flexible configuration options that let you control which AI model processes your tasks and how much computational effort it applies. You can set these parameters globally for your entire project or adjust them dynamically for individual commands. This guide covers the specific file locations, validation logic, and API propagation paths defined in the source code. ## Project-Level Configuration with [`.codex/config.toml`](https://github.com/openai/codex-plugin-cc/blob/main/.codex/config.toml) Create a [`.codex/config.toml`](https://github.com/openai/codex-plugin-cc/blob/main/.codex/config.toml) file at the root of your repository to establish default settings for all plugin commands. ```toml model = "gpt-5.4-mini" # Default model for all plugin commands model_reasoning_effort = "high" # Default reasoning effort level ``` The plugin recognizes six valid values for `model_reasoning_effort`: `none`, `minimal`, `low`, `medium`, `high`, and `xhigh`. ### Configuration Precedence and Trust Levels The plugin loads configuration files in the following order: 1. User-level config at `~/.codex/config.toml` 2. Project-level config at [`.codex/config.toml`](https://github.com/openai/codex-plugin-cc/blob/main/.codex/config.toml) (loaded only when the project is **trusted**) If you omit command-line flags, the plugin falls back to these configuration values before allowing Codex to use its internal defaults. ## Command-Line Runtime Overrides All task-type commands—including `/codex:review`, `/codex:rescue`, and `/codex:task`—accept two runtime-selection flags that override configuration file settings: - **`--model `** – Selects a specific model. The special value `spark` maps internally to `gpt-5.3-codex-spark`. - **`--effort `** – Sets reasoning effort to `none`, `minimal`, `low`, `medium`, `high`, or `xhigh`. When you invoke a command, the plugin validates the `--effort` flag in **`codex-companion.mjs`** through the `normalizeReasoningEffort` function, which ensures only the six allowed values are accepted. ## How Settings Propagate to the Codex Server After validation, the plugin forwards your selections to the Codex app-server via the `turn/start` API call. The implementation in **`plugins/codex/scripts/lib/codex.mjs`** handles this propagation: - **Model handling** – Line 66 passes the value: `model: options.model ?? null` - **Reasoning effort handling** – Line 1140 passes the value: `effort: options.effort ?? null` If you do not provide `--model` or `--effort` flags, these fields remain `null` and the Codex server applies its own defaults. ## Practical Usage Examples Use the project defaults with `/codex:review`: ```bash /codex:review --background ``` Override the model for a single invocation using the `spark` shorthand: ```bash /codex:review --model spark --background ``` Adjust only the reasoning effort to reduce processing time: ```bash /codex:review --effort low --background ``` Specify both model and effort explicitly for complex rescue operations: ```bash /codex:rescue --model gpt-5.4-mini --effort high ``` As documented in **[`plugins/codex/commands/rescue.md`](https://github.com/openai/codex-plugin-cc/blob/main/plugins/codex/commands/rescue.md)** (line 45), these flags apply consistently across all task commands. ## Summary - **Configure defaults** in [`.codex/config.toml`](https://github.com/openai/codex-plugin-cc/blob/main/.codex/config.toml) using `model` and `model_reasoning_effort` keys. - **Trust requirement** – Project-level configs load only for trusted repositories. - **Override per-command** with `--model` and `--effort` flags available on `/codex:review`, `/codex:rescue`, and `/codex:task`. - **Validation** occurs in `codex-companion.mjs` via `normalizeReasoningEffort`. - **Propagation** happens through `plugins/codex/scripts/lib/codex.mjs` (lines 66 and 1140) to the `turn/start` API endpoint. ## Frequently Asked Questions ### What are the valid values for the reasoning effort setting? The `model_reasoning_effort` configuration key and `--effort` flag accept six values: `none`, `minimal`, `low`, `medium`, `high`, and `xhigh`. These are validated in the `normalizeReasoningEffort` function within `codex-companion.mjs` before being sent to the Codex server. ### Can I use different models for different commands in the same project? Yes. While the [`.codex/config.toml`](https://github.com/openai/codex-plugin-cc/blob/main/.codex/config.toml) file sets project-wide defaults, you can override the model for any single command using the `--model` flag. For example, use `--model spark` (which maps to `gpt-5.3-codex-spark`) for quick tasks and `--model gpt-5.4-mini` for comprehensive reviews. ### Why is my project-level configuration not loading? The plugin only loads [`.codex/config.toml`](https://github.com/openai/codex-plugin-cc/blob/main/.codex/config.toml) when the project is marked as **trusted**. If your configuration values are not applying, verify that the repository has been trusted in your development environment. User-level settings at `~/.codex/config.toml` load regardless of trust status. ### What happens if I do not specify a model or effort? If you omit both configuration file entries and command-line flags, the plugin sends `null` values for these fields to the Codex server via the `turn/start` API call. The Codex backend then applies its own internal defaults, as documented in the repository README.