Using OpenVeer in Codex CLI

Introduction

Codex CLI is OpenAI's open-source terminal coding agent that can read and write files, run commands, fix bugs, and complete full coding tasks directly in the command line.
By connecting through OpenVeer, you can freely use multiple models — including GPT and Claude — in Codex CLI, with more flexible and competitive pricing.

Prerequisites

Before you begin, make sure you have:

1. Installed Node.js
   Download and install from the Node.js website (latest LTS, v20 or newer recommended) to install Codex CLI via npm

2. Obtained an OpenVeer API Key
   Log in to the OpenVeer Console to get your API key (starts with sk-)

Step 1: Install Codex CLI

Choose any of the following methods to install:

npm (Recommended)

Install globally with npm — works on all operating systems:

npm install -g @openai/codex

Homebrew (macOS)

macOS users can also install with Homebrew:

brew install codex

Verify the installation

After installing, run the following command to confirm:

codex --version

If a version number is printed, the installation succeeded.

Step 2: Configure the OpenVeer API

Codex CLI manages model providers via configuration files under the ~/.codex/ directory. All we need to do is add a custom provider pointing to OpenVeer.

2.1 Locate the config directory

• macOS / Linux: ~/.codex/
• Windows: C:\Users\<username>\.codex\

2.2 Configure the API key

In the config directory, create or edit the auth.json file and fill in your OpenVeer key:

{
  "OPENAI_API_KEY": "sk-xxxxxxxxxxxx"
}

2.3 Configure the model provider

In the config directory, create or edit the config.toml file and add the OpenVeer provider:

# Default model
model = "gpt-5.5"
# Default provider — matches [model_providers.openveer] below
model_provider = "openveer"

# OpenVeer provider configuration
[model_providers.openveer]
name = "OpenVeer"
base_url = "https://api.openveer.com/v1"
wire_api = "responses"
requires_openai_auth = true

After saving both files, restart Codex CLI for the changes to take effect.

Step 3: Get Started

Verify the configuration

In any project directory, run the following command to confirm everything is wired up:

codex "Introduce yourself in one sentence"

If you get an AI reply, the configuration is working. If you see a sign-in screen, or 401 / 403 errors, refer to the FAQ section below.

Interactive mode

Run codex directly to enter the interactive UI — ideal for full coding tasks:

codex

Once inside, describe what you need in natural language, e.g.:

Create an Express.js server with a JSON-returning health check endpoint

Codex will analyze your project, generate code, run commands, and ask for confirmation before performing sensitive operations.

Approval modes

On first run, Codex will ask you to pick an approval level:

We recommend starting with Auto mode. Type /approvals in the interactive UI to change it anytime.

Switch models

In the interactive UI, type /model to switch quickly, or change the model field in config.toml and restart.

Supported Models

For Codex CLI, the following GPT-5 series models are recommended:

Common Commands

Frequently used commands and shortcuts in Codex CLI:

FAQ

Q1: A ChatGPT sign-in screen appears after launch?

If you see "Sign in with ChatGPT" or similar after launch, the configuration didn't take effect.

Troubleshooting:

1. Make sure both config.toml and auth.json are inside ~/.codex/
2. Check that model_provider in config.toml is set to openveer
3. Check that auth.json is valid JSON and the key is filled in completely

Q2: Getting 401 / 403 errors?

Also make sure base_url is set to https://api.openveer.com/v1, not the official OpenAI URL.

Q3: Connection failed?

1. Check your network connection
2. Make sure base_url in config.toml is correct
3. If you're behind a proxy, ensure it allows access to api.openveer.com

Q4: wire_api = "chat" is no longer supported?

Recent Codex CLI versions (0.84.0 and later) have removed the chat protocol. Update wire_api in config.toml to responses:

wire_api = "responses"

OpenVeer supports the Responses API — just restart Codex after the change.

Q5: Tool calls or runs are failing?

Make sure wire_api in config.toml is set to responses. If you still hit compatibility issues, switch to a recommended GPT-5 series model (e.g. gpt-5.5, gpt-5.3-codex) — they pair more reliably with Codex CLI.

Q6: Use environment variables instead of auth.json?

You can also configure the key via an environment variable. Change the provider block in config.toml to:

[model_providers.openveer]
name = "OpenVeer"
base_url = "https://api.openveer.com/v1"
wire_api = "responses"
env_key = "APIMART_API_KEY"

Then set the environment variable APIMART_API_KEY to your OpenVeer key. auth.json is no longer required in this setup.

Q7: How do I switch models?

Two ways:

1. In the interactive UI: Type /model to switch
2. Edit the config: Change the model field in config.toml and restart Codex CLI

Q8: How do I check usage and billing?

Log in to the OpenVeer Console to view API call statistics, token consumption details, and cost trends.

Support and Help

If you run into any issues while using Codex CLI:

• 📚 OpenVeer Documentation Center
• 💬 Discord Community
• 🐦 Twitter @AIOpenVeer
• 📧 Technical support: zhihong@openveer.com

This documentation is built and hosted on Mintlify, a developer documentation platform.