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

# OpenAI

> Set up Coreply with OpenAI to use GPT-4.1 and GPT-4o models.

Coreply supports OpenAI's API directly. You can use GPT-4.1 and GPT-4o model variants for fast, reliable suggestions.

<Warning>
  OpenAI's free tier is very restrictive. You'll likely need to add credits to your account before Coreply can make API calls successfully. Note that a ChatGPT subscription does **not** include API credits — these are separate and must be purchased at [platform.openai.com](https://platform.openai.com).
</Warning>

## Setup

<Steps>
  <Step title="Get your API key">
    Go to [platform.openai.com/api-keys](https://platform.openai.com/api-keys) and create a new secret key.
  </Step>

  <Step title="Enter your credentials in Coreply">
    Open Coreply's settings and fill in the following values:

    | Field      | Value                        |
    | ---------- | ---------------------------- |
    | API URL    | `https://api.openai.com/v1/` |
    | API Key    | Your secret key from OpenAI  |
    | Model Name | See recommended models below |
  </Step>

  <Step title="Choose a model">
    The following models are recommended for use with Coreply:

    ```text theme={null}
    gpt-4.1-mini
    gpt-4.1-nano
    gpt-4.1
    gpt-4o-mini
    gpt-4o
    ```
  </Step>
</Steps>

## Model notes

<Tip>
  `gpt-4.1-mini` offers the best cost-to-performance ratio for Coreply. The `mini` and `nano` variants are faster and cheaper while still producing high-quality suggestions.
</Tip>

<Warning>
  The `gpt-5` family are reasoning models. They work with Coreply but add significant latency before each suggestion, making them a poor fit for real-time texting assistance.
</Warning>