Codex CLI

Set up OpenAI Codex CLI with CometAPI: configure openai_base_url or a custom provider in config.toml, store your API key in auth.json, and start coding with a current model.

Use this guide to run Codex CLI with CometAPI as a model provider.

Official references:

• Codex CLI README
• Codex Authentication
• Codex Advanced Configuration

Model availability changes frequently. The examples below use your-model-id — replace it with a current coding-friendly model ID from the CometAPI Models page.

Prerequisites

Requirement	Details
OS	macOS 12+, Linux (Ubuntu 20.04+ / Debian 10+), or Windows 11 via WSL2
Node.js	22+ (LTS recommended)
Git	2.23+ recommended
CometAPI key	Get one from CometAPI Dashboard (starts with sk-)

Install Codex CLI

npm i -g @openai/codex

Or via Homebrew:

brew install --cask codex

Verify the installation:

codex --version

Configure CometAPI

There are two ways to point Codex at CometAPI. Choose whichever fits your workflow.

Simple: openai_base_url

The easiest option — redirect the built-in OpenAI provider to CometAPI with a single line. No need to define a custom provider.

Create ~/.codex/config.toml:

model = "your-model-id"
openai_base_url = "https://api.cometapi.com/v1"

Named provider

Define a named cometapi provider. Useful when you want to switch between multiple providers using --profile or model_provider.

Create ~/.codex/config.toml:

model = "your-model-id"
model_provider = "cometapi"

[model_providers.cometapi]
name = "CometAPI"
base_url = "https://api.cometapi.com/v1"
env_key = "OPENAI_API_KEY"

env_key tells Codex which environment variable holds your API key. Codex reads the value of OPENAI_API_KEY at runtime — this is not your actual key.

Store your API key

Create ~/.codex/auth.json:

{
  "OPENAI_API_KEY": "sk-your-cometapi-key"
}

Replace sk-your-cometapi-key with your actual CometAPI key.

This file is mandatory. Without a valid OPENAI_API_KEY entry in auth.json, Codex exits with API key auth is missing a key.

Start Codex

cd your-project
codex

On first launch, Codex prompts you to choose a theme and confirm safety settings.

Override model per session

Switch to a different model for a single run without editing config.toml:

codex --model your-model-id

Alternative: environment variable

Instead of auth.json, export the key directly:

export OPENAI_API_KEY="sk-your-cometapi-key"
codex

This sets the key for the current terminal session only. For persistence, add the export line to ~/.zshrc or ~/.bashrc.

Troubleshooting

Symptom	Fix
API key auth is missing a key	Ensure ~/.codex/auth.json contains "OPENAI_API_KEY": "sk-..."
Login prompt appears unexpectedly	Delete stale ~/.codex/auth.json and recreate it with your CometAPI key
Model not found	Check the Models page for currently available models
Connection timeout	Confirm openai_base_url or base_url is https://api.cometapi.com/v1 in config.toml
Windows issues	Codex requires WSL2 on Windows — native CMD/PowerShell is not supported