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

# Configuration guide

> Configure Codex to use DUIAPI

Codex uses two files for configuration: `config.toml` and `auth.json`. `config.toml` sets the model and API endpoint. `auth.json` stores the API key.

<Tabs>
  <Tab title="Windows">
    ## 1. Open the configuration directory

    Press **Win + R**, enter the following path, and press Enter:

    ```text theme={null}
    %userprofile%\.codex
    ```

    If `config.toml` or `auth.json` does not exist, create it.

    ## 2. Write config.toml

    <Tip>
      Replace `<API_KEY>` with your API key, such as `sk-xxxxxx`. Replace `<MODEL>` with the model you use, such as `qwen3.7-max`.
    </Tip>

    ```toml theme={null}
    model_provider = "custom"
    model = "<MODEL>"
    disable_response_storage = true
    model_reasoning_effort = "medium"

    [model_providers]
    [model_providers.custom]
    name = "custom"
    wire_api = "responses"
    requires_openai_auth = true
    base_url = "https://www.duiapi.com/v1"
    ```

    ## 3. Write auth.json

    ```json theme={null}
    {
      "OPENAI_API_KEY": "<API_KEY>"
    }
    ```

    ## 4. Test the configuration

    ```bash theme={null}
    codex
    ```
  </Tab>

  <Tab title="macOS">
    ## 1. Open the configuration directory

    ```bash theme={null}
    mkdir -p ~/.codex
    cd ~/.codex
    touch config.toml auth.json
    open -a TextEdit config.toml
    ```

    ## 2. Write config.toml

    Use the same `config.toml` content shown in the Windows tab.

    ## 3. Write auth.json

    ```bash theme={null}
    open -a TextEdit auth.json
    ```

    Use the same `auth.json` content shown in the Windows tab.

    ## 4. Test the configuration

    ```bash theme={null}
    codex
    ```
  </Tab>

  <Tab title="Linux">
    ## 1. Open the configuration directory

    ```bash theme={null}
    mkdir -p ~/.codex
    cd ~/.codex
    touch config.toml auth.json
    nano config.toml
    ```

    ## 2. Write config.toml

    Use the same `config.toml` content shown in the Windows tab.

    ## 3. Write auth.json

    ```bash theme={null}
    nano auth.json
    ```

    Use the same `auth.json` content shown in the Windows tab.

    ## 4. Test the configuration

    ```bash theme={null}
    codex
    ```
  </Tab>
</Tabs>