Configure Codex CLI

This page explains how to use Codex CLI with Cubicspaces through the OpenAI-compatible API.

Prerequisites

• Codex CLI is installed.
• You have created a Cubicspaces API key.
• Your account can access a model suitable for coding tasks.

Set the API Key

PowerShell

$env:OPENAI_API_KEY="YOUR_API_KEY"

macOS / Linux

export OPENAI_API_KEY="YOUR_API_KEY"

For long-term use, save this variable in your shell profile or system environment variables.

Configure Codex

Edit the Codex config file:

~/.codex/config.toml

Add a Cubicspaces model provider and set it as the default provider:

model_provider = "cubicspaces"
model = "gpt-5.5"

[model_providers.cubicspaces]
name = "Cubicspaces"
base_url = "https://cubicspaces.cloud/v1"
env_key = "OPENAI_API_KEY"
wire_api = "responses"

Replace model with a model available to your account and suitable for coding tasks.

Verify the Setup

Run this in any project directory:

codex "Read the current project structure and summarize the main directories."

If Codex returns a project summary, the Cubicspaces connection is working.

Troubleshooting

401 or authentication failed

Check that OPENAI_API_KEY is set to your Cubicspaces API key and is available in the current terminal session.

404 or wrong request path

Codex needs /v1 in base_url when using the OpenAI-compatible API:

https://cubicspaces.cloud/v1