> ## Documentation Index
> Fetch the complete documentation index at: https://docs.4096bytes.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Codex

> Configure 4096bytes in Codex CLI

Codex CLI can connect to 4096bytes through an OpenAI compatible Provider. You need to write the dashboard-generated `config.toml` and `auth.json` into the Codex config directory.

Prefer copying the config from the dashboard **Use key** dialog. It shows the correct path for your system and inserts the current API Key automatically.

## Prerequisites

* You have completed [Create an account](/en/quickstart/create-account).
* You have completed [Get an API Key](/en/quickstart/get-api-key).
* Codex CLI is installed and `codex --version` works.
* The **Use key** dialog is open for the API Key you want to use.

<Warning>
  The API Key in `auth.json` is stored as a local plaintext credential. Do not commit `~/.codex/auth.json`, screenshots, or terminal output to a repository or chat.
</Warning>

## Install

If Codex CLI is not installed, check the latest instructions in the [OpenAI Codex GitHub repository](https://github.com/openai/codex).

macOS or Linux:

```bash theme={null}
curl -fsSL https://chatgpt.com/codex/install.sh | sh
```

Windows PowerShell:

```powershell theme={null}
powershell -ExecutionPolicy ByPass -c "irm https://chatgpt.com/codex/install.ps1 | iex"
```

If you use npm for global CLI tools:

```bash theme={null}
npm install -g @openai/codex
```

After installation, reopen the terminal and verify:

```bash theme={null}
codex --version
```

## Copy config from the dashboard

<Steps>
  <Step title="Open API Keys">
    Open the dashboard and go to **API Keys**.
  </Step>

  <Step title="Choose Codex CLI">
    Find the key you want to use for Codex, click **Use key**, then choose **Codex CLI**.
  </Step>

  <Step title="Choose your system">
    Select **macOS / Linux** or **Windows**. The dashboard shows the target config file paths.
  </Step>

  <Step title="Copy config">
    Copy the `config.toml` and `auth.json` snippets. Put `config.toml` at the beginning of the file so old config does not override it.
  </Step>
</Steps>

<img src="https://mintcdn.com/4096bytes/92zL9C5RTBxmIwvG/images/screenshots/clients/codex/codex-api-key-use-dialog-header.png?fit=max&auto=format&n=92zL9C5RTBxmIwvG&q=85&s=f6d96a0558f5b17bdc59dbe157e7c6fe" alt="Copy config" width="720" style={{ maxWidth: "100%", height: "auto" }} data-path="images/screenshots/clients/codex/codex-api-key-use-dialog-header.png" />

## macOS or Linux

### Write `config.toml`

Open or create `~/.codex/config.toml`, then put this block at the beginning.

```toml theme={null}
model_provider = "OpenAI"
model = "gpt-5.5"
review_model = "gpt-5.5"
model_reasoning_effort = "xhigh"
disable_response_storage = true
network_access = "enabled"
windows_wsl_setup_acknowledged = true

[model_providers.OpenAI]
name = "OpenAI"
base_url = "https://api.4096bytes.com"
wire_api = "responses"
requires_openai_auth = true

[features]
goals = true
```

Use the `model` and `review_model` values shown in the dashboard. If your dashboard shows a different model name, use that value.

### Write `auth.json`

Open or create `~/.codex/auth.json`:

```json theme={null}
{
  "OPENAI_API_KEY": "YOUR_4096BYTES_API_KEY"
}
```

Replace `YOUR_4096BYTES_API_KEY` with the API Key you created in the dashboard.

### Start Codex

Save both files, reopen the terminal, and run:

```bash theme={null}
codex
```

You can also start with a low-risk prompt:

```bash theme={null}
codex "Describe the purpose of the current directory in one sentence. Do not modify files."
```

## Windows

### Write `config.toml`

Open or create:

```text theme={null}
%USERPROFILE%\.codex\config.toml
```

Put this block at the beginning.

```toml theme={null}
model_provider = "OpenAI"
model = "gpt-5.5"
review_model = "gpt-5.5"
model_reasoning_effort = "xhigh"
disable_response_storage = true
network_access = "enabled"
windows_wsl_setup_acknowledged = true

[model_providers.OpenAI]
name = "OpenAI"
base_url = "https://api.4096bytes.com"
wire_api = "responses"
requires_openai_auth = true

[features]
goals = true
```

If you run Codex inside WSL, configure `~/.codex/config.toml` inside WSL instead of the Windows user directory.

### Write `auth.json`

Open or create:

```text theme={null}
%USERPROFILE%\.codex\auth.json
```

Write:

```json theme={null}
{
  "OPENAI_API_KEY": "YOUR_4096BYTES_API_KEY"
}
```

If you run Codex inside WSL, write `~/.codex/auth.json` inside WSL.

### Start Codex

Save both files, reopen PowerShell or Windows Terminal, and run:

```powershell theme={null}
codex
```

You can also test with:

```powershell theme={null}
codex "Describe the purpose of the current directory in one sentence. Do not modify files."
```

## Field reference

| Field                  | Meaning                                                                               |
| ---------------------- | ------------------------------------------------------------------------------------- |
| `model_provider`       | Selects the Provider Codex should use. Here it must match `[model_providers.OpenAI]`. |
| `model`                | Default model name. Copy the value shown in the dashboard.                            |
| `review_model`         | Model used by Codex Review. Usually the same as `model`.                              |
| `base_url`             | 4096bytes API address. Use `https://api.4096bytes.com`.                               |
| `wire_api`             | Uses the Responses API route. Set it to `responses`.                                  |
| `requires_openai_auth` | Makes Codex read `OPENAI_API_KEY` from `auth.json`.                                   |
| `OPENAI_API_KEY`       | The 4096bytes API Key created in the dashboard.                                       |

## Common issues

<AccordionGroup>
  <Accordion title="Codex still uses the old model or address">
    Put the new config at the beginning of `config.toml`. Save, close the terminal, and run `codex` again.
  </Accordion>

  <Accordion title="Codex reports authentication failure">
    Check that `auth.json` is valid JSON. Confirm the API Key has no missing characters, newlines, or extra spaces.
  </Accordion>

  <Accordion title="Codex cannot find the model">
    `model` and `review_model` must match the dashboard model name exactly. Do not copy names from someone else's screenshot.
  </Accordion>

  <Accordion title="Windows config does not take effect">
    Confirm where Codex is running. If it runs in WSL, configure WSL's `~/.codex/`, not `%USERPROFILE%\.codex\`.
  </Accordion>

  <Accordion title="The config already has other Providers">
    You can keep them, but make sure `model_provider = "OpenAI"` points to the 4096bytes `[model_providers.OpenAI]` block.
  </Accordion>
</AccordionGroup>