OpenAI Gateway

Connect directly to the OpenAI API

The OpenAI gateway connects ChatJS directly to the OpenAI API using the @ai-sdk/openai provider SDK. Use this when you only need OpenAI models and want the simplest setup with type-safe model IDs.

Setup

1. Follow the OpenAI quickstart to create an API key
2. Add to .env.local:

OPENAI_API_KEY=sk-...

3. Set the gateway in your config:

const config: ConfigInput = {
  ai: {
    gateway: "openai",
    workflows: {
      chat: "gpt-5-mini",
      title: "gpt-5-nano",
      // ...
    },
    // ...
  },
};

Authentication

Available Models

All models available to your API key (GPT, DALL-E, and embedding models). The full list is fetched at runtime and cached for 1 hour.

Model IDs

Unlike the Vercel and OpenRouter gateways which use provider/model format, the OpenAI gateway uses bare model IDs since all models come from OpenAI:

• gpt-5-mini
• gpt-5-nano
• gpt-4o
• o3-mini

The gateway provides type-safe model IDs extracted from the @ai-sdk/openai SDK, giving you autocomplete in chat.config.ts.

Image Generation

The OpenAI gateway supports dedicated image models through createImageModel():

• gpt-image-1
• gpt-image-1.5
• dall-e-3

This enables the built-in Image Generation feature.

Related

• Gateways Overview for the full gateway comparison
• Vercel Gateway for multi-provider access via a single key