# Codex

[Codex](https://developers.openai.com/codex) is a coding agent developed by
OpenAI that you can run locally from your terminal and that can read, modify,
and run code on your machine, in the chosen directory. It’s open-source, and
built in Rust for speed and efficiency.

## Prerequisites

In order to use the AI Gateway with Codex you will need to complete these steps
first:

<Stepper>

1. Create a [new provider](/ai-gateway/managing-providers) in the AI Gateway for
   the provider you want to use with Codex

2. [Set up a new team](/ai-gateway/managing-teams)

3. Create a [new app](/ai-gateway/managing-apps) to use specifically with Codex
   and assign it to the team you created

4. Copy the API Key for the app you created, as well as the Gateway URL

</Stepper>

## Configure Codex CLI

There are two approaches you can take to using Codex with Zuplo's AI Gateway.

1. **Route OpenAI through AI Gateway** - This would configure your OpenAI
   provider in Codex to route requests through the AI Gateway rather than
   directly to OpenAI

2. **Create a Zuplo specific provider** - Use Zuplo as a provider that be
   selected in the Codex configuration and work with any OpenAI compatible
   models

Configuration steps for both options are below:

### Route OpenAI through AI Gateway

Open the [Codex configuration](https://developers.openai.com/codex/local-config)
`~/.codex/config.toml` and modify the `model_providers.openai-chat-completions`
entry so that the `base_url` points to your AI Gateway URL, and your `env_key`
is set to the API Key of the app you created to use with Codex.

```toml
[model_providers.openai-chat-completions]
name = "OpenAI using Chat Completions"
base_url = "https://<your-ai-gateway-url>/v1"
env_key = "ZUPLO_AI_GATEWAY_API_KEY"
```

Save the file and reload Codex. Your OpenAI requests will now be routed through
the Zuplo AI Gateway.

### Zuplo AI Gateway provider

To add a specific provider for the AI Gateway you can add an additional entry to
the Codex `config.toml` file.

```toml
[model_providers.zuplo]
name = "Zuplo AI Gateway"
base_url = "https://<your-ai-gateway-url>/v1"
env_key = "ZUPLO_AI_GATEWAY_API_KEY"
```

Save the file and reload Codex. Your Zuplo AI Gateway provider will now be
available and you can switch Codex over to use it at any time by running:

```bash
codex --config model_provider="zuplo"
```