Choose your Codex setup
There are three ways to use Codex with Lumoswitch. Choose by where you plan to work; you do not need to understand every Codex surface first.
| I want to use | Choose | Available lifecycle | What the setup changes |
|---|---|---|---|
| Only the Codex workspace in the ChatGPT desktop app | ChatGPT Desktop (Codex) | Persistent and removal; no one-time mode | Adds the shared provider, credential, and Lumoswitch model catalog to ~/.codex |
Only codex in a terminal | Codex CLI | One-time, persistent, and removal | Uses a dedicated native CODEX_HOME; plain codex works and shared settings stay unchanged |
Both ChatGPT desktop and codex in a terminal | ChatGPT Desktop + Codex CLI | Shared persistent and removal; no one-time mode | Configures both surfaces once through the shared settings, credential, and model catalog |
Before you start
Have these Lumoswitch values ready:
- API base URL: normally
https://api.lumoswitch.com/v1 - Access Key: the Lumoswitch Access Key shown after you create or rotate it
- Client-facing model name: the model name shown by the API configuration
The Lumoswitch API configuration must enable the Responses output protocol. The model name must match exactly, including capitalization and punctuation.
Open the matching setup page above to find its complete commands and launch instructions. Each path is maintained on one page, so you do not need to assemble configuration from several guides.
Important distinction
The desktop instructions configure the Codex developer workspace inside the ChatGPT desktop app. They do not route ordinary ChatGPT conversations through Lumoswitch and do not replace your normal ChatGPT sign-in.
Codex CLI, the Codex IDE extension, and the Codex workspace in ChatGPT desktop can read the same user-level ~/.codex configuration. The desktop-only and combined guides also create a dedicated model catalog so the picker exposes the API configuration's client-facing model instead of only built-in GPT models. The CLI-only guide intentionally avoids shared files so terminal use can stay isolated.
References: Codex CLI, Codex configuration basics, and custom model providers.