Codex desktop: universal setup

This tutorial is for the Codex desktop app, not the command-line terminal version. You need to modify the configuration file.

OpenOx API site:

https://api.openoxai.com/v1

1. Prerequisites

Before you begin, prepare the following:

1. The Codex desktop app installed
2. An OpenOx account
3. An OpenOx API key:How to Create an API Token

An OpenOx API key generally looks like this:

YOUR_OPENOX_API_KEY

2. Downloading the Codex Desktop App

Steps:

Official download link: https://get.microsoft.com/installer/download/9PLM9XGG6VKS?cid=website_cta_psi

Mac installer

3. Opening the Codex Desktop App

After installation is complete, open the Codex desktop app.

On first launch, you will usually see a sign-in page. There are two common sign-in methods:

1. Sign in with a ChatGPT account
2. Sign in with an API key

Here, select:

API Key Sign-in

Then enter the OpenOx API key you created.

Note:

• Do not include spaces when copying the API key.
• Do not copy line breaks.
• If an error occurs after pasting, first check for spaces before or after the key.
• If you previously signed in with a personal ChatGPT account, sign out first.

4. If You Have Already Signed In with a Personal Account

If Codex is already signed in with a ChatGPT account, sign out first, then sign in again using an API key.

Steps:

1. Open the Codex Desktop App
2. Click File in the upper-left corner
3. Click:

Sign out

4. Return to the sign-in page
5. Select:

API Key

6. Enter the API key provided to you by OpenOx

If you are using Codex for the first time, you do not need to sign out; simply choose API key sign-in.

5. Setting the OpenOx API Site

To make the Codex desktop app send requests to the OpenOx API, you need to modify the Codex configuration file:config.toml

This is the most important step in the entire tutorial.

Opening the Configuration File

1. Open the Codex Desktop App
2. Click in the lower-left corner:

Settings

3. Find the configuration entry
4. Open config.toml

If you cannot find the Settings button, click ① 【File】 ②【Settings…】 ③【Configuration】④【Open config.toml】

Mac Configuration Content

Mac users should copy the following content into config.toml. Make sure the entire configuration file contains only the following content.

model_provider = "openox"
model = "gpt-5.6-sol"
model_reasoning_effort = "high"
disable_response_storage = true

approval_policy = "on-request"
sandbox_mode = "workspace-write"

[model_providers.openox]
name = "OpenOx"
base_url = "https://api.openoxai.com/v1"
wire_api = "responses"
requires_openai_auth = true

[sandbox_workspace_write]
network_access = true

On Mac, you do not need to add the [windows] configuration.

8. Save and Restart Codex

After completing the configuration:

1. Save config.toml
2. Exit the Codex desktop app completely
3. Reopen Codex
4. Open your project
5. Create a new task to test it

You can enter:

Hello, please help me review the structure of the current project

If Codex responds normally without any API key, model, or network errors, OpenOx has been connected successfully.