OpenAI

Invoke supports OpenAI’s image generation models — both the GPT Image family and the older DALL·E models — through the OpenAI API.

Getting an API Key

1. Open the OpenAI API Platform and sign in.
2. Create a new secret API key.
3. Make sure your account has billing set up — image endpoints are paid per request.

Configuration

Add your key to api_keys.yaml in your Invoke root directory:

external_openai_api_key: "sk-..."

# Optional — use this to point at a compatible proxy or Azure OpenAI deployment
external_openai_base_url: "https://api.openai.com"

Restart Invoke for the change to take effect.

Available Models

Model	Modes	Aspect Ratios	Batch	Notes
GPT Image 1.5	txt2img, img2img, inpaint	1:1, 3:2, 2:3	up to 10	Fastest and cheapest GPT Image model.
GPT Image 1	txt2img, img2img, inpaint	1:1, 3:2, 2:3	up to 10	Highest quality of the GPT Image family.
GPT Image 1 Mini	txt2img, img2img, inpaint	1:1, 3:2, 2:3	up to 10	~80% cheaper than GPT Image 1.
DALL·E 3	txt2img only	1:1, 7:4, 4:7	1	No reference-image / edit support.
DALL·E 2	txt2img, img2img, inpaint	1:1	up to 10	Square only.

Provider-Specific Options

For GPT Image models, Invoke surfaces two provider-specific options in the parameters panel:

• Quality — low, medium, high, or auto. Higher quality costs more and takes longer.
• Background — auto, transparent, or opaque. Use transparent for PNG output with an alpha channel.

DALL·E 2 and DALL·E 3 do not expose these options.

How Requests Are Routed

• Pure text-to-image requests hit /v1/images/generations.
• Any request with an init image or reference images is sent to /v1/images/edits instead. This is done transparently — you don’t need to pick an endpoint.

Tips

1. Batching on GPT Image and DALL·E 2 tops out at 10 per request. Larger batches are split into multiple API calls.
2. Costs can climb quickly with high-quality GPT Image generations. Start with GPT Image 1 Mini when iterating on prompts.
3. Rate limits from OpenAI surface as failed invocations — retry after a short wait.