## OpenAI Codex Access Guide

> Now you can use models like `gpt-5.1-codex` via the [UModelverse Platform](https://console.scloudsg.com/modelverse/model-center).

## 🚀 Quick Start

### 1. Installation

1. Please ensure you have npm installed. Refer to the [Node.js official website](https://nodejs.org/en/download).

2. Install OpenAI Codex:

```shell
npm install -g @openai/codex@latest
```

### 2. Configuration

#### 2.1 Configure the Model Provider

Create and configure your `~/.codex/config.toml` file in a Mac or Linux environment:

```toml
model_provider = "ucloud"
model_reasoning_effort = "high"
model = "gpt-5.1-codex"

[model_providers.ucloud]
name = "ucloud"
base_url = "https://api.umodelverse.ai/v1"
wire_api = "responses"
requires_openai_auth = true
```

#### 2.2 Configure the API Key

Create and configure your `~/.codex/auth.json` file:

```json
{
  "OPENAI_API_KEY": "your-umodelverse-api-key"
}
```

> **Note**: Please replace `your-umodelverse-api-key` with the actual API Key you obtained from the UModelverse platform.

### 3. Use Codex

Once configured, you can run Codex directly in the terminal:

```shell
codex
```

You can switch models via `/model`, as shown in the image:
<img src="https://cdn.udelivrs.com/2026/01/529a774b5e66ebbe51c01ba7ba4aa9e3_1767698734512.png" data-origin="https://cdn.udelivrs.com/2026/01/529a774b5e66ebbe51c01ba7ba4aa9e3_1767698734512.png" alt="codex-model" class="medium-zoom-image" style="">
You can also directly install the `codex` VS Code extension after configuring and use it by switching the model and reasoning effort.
<img src="https://cdn.udelivrs.com/2026/01/1d202ecd6faf132f00fb318a921a6186_1767698734510.png" data-origin="https://cdn.udelivrs.com/2026/01/1d202ecd6faf132f00fb318a921a6186_1767698734510.png" alt="codex-model" class="medium-zoom-image" style="">