OpenAI Codex CLI Setup Guide

Overview

Codex CLI is OpenAI's terminal coding agent. It reads, writes, and runs code through sandboxed, reviewable patches. Point its custom provider at UnoRouter's base URL to use any model in the catalog.

Quick Config

Paste these into the client. Your key auto-fills when signed in.

Base URL: https://api.unorouter.com/v1
API Key: YOUR_API_KEY

Compatibility

Step-by-step setup

1. 1
   Install Codex CLI

   Install Codex CLI globally with npm.

   bash

   npm install -g @openai/codex

   Sign in to auto-fill your API key

2. 2
   Configure the model provider

   Edit `~/.codex/config.toml`. Set your model id and add a custom provider with UnoRouter's base URL using the responses wire API.

   toml

   # ~/.codex/config.toml
   model = "YOUR_MODEL_ID"
   model_provider = "unorouter"
   
   [model_providers.unorouter]
   name = "UnoRouter"
   base_url = "https://api.unorouter.com/v1"
   wire_api = "responses"

   Sign in to auto-fill your API key

3. 3
   Add your API key

   Write your UnoRouter API key into `~/.codex/auth.json`.

   json

   // ~/.codex/auth.json
   {
     "OPENAI_API_KEY": "YOUR_API_KEY"
   }

   Sign in to auto-fill your API key

4. 4
   Start Codex

   Run `codex` in your project directory.

   bash

   codex

   Sign in to auto-fill your API key

$env:OPENAI_BASE_URL="https://api.unorouter.com/v1"
$env:OPENAI_API_KEY="YOUR_API_KEY"

codex

Recommended models

Free models that work here. Paste any model id into the client.

Gotchas

• !On an unsupported endpoint error, confirm `wire_api` is `responses` and the base URL ends in `/v1`.
• !A 401 means the key in `~/.codex/auth.json` is missing or stale. Paste a fresh key from your UnoRouter dashboard.
• !If Codex ignores your provider, check the table name in `config.toml`. Provider IDs allow underscores, not hyphens (`model_providers.my_provider`, never `my-provider`). `openai` is reserved and cannot be overridden.