Image Generation

Multi-provider image generation with an OpenAI-canonical API surface. All providers are normalized to the same request/response schema.

Supported Providers

Provider	Models	Key Features
OpenAI	`openai/gpt-image-1`, `openai/dall-e-3`	Transparency, high quality
Gemini	`gemini/imagen-3`	Negative prompts, seeds
Stability AI	`stability/sdxl`, `stability/sd3`	ControlNet, CFG scale, steps
Flux	`flux/pro`, `flux/dev`, `flux/schnell`	LoRA support, seeds
xAI	`xai/aurora`	Fast generation

Basic Request

POST /v1/images/generations


{
  "prompt": "A majestic lion in a savanna at sunset",
  "model": "openai/gpt-image-1",
  "n": 1,
  "size": "1024x1024",
  "quality": "high"
}

Response


{
  "code": 200,
  "type": "SUCCESS",
  "data": {
    "created": 1735500000,
    "data": [{
      "url": "https://provider-url.com/...",
      "file_id": "file_abc123",
      "file_url": "https://cdn.picklayer.com/...",
      "revised_prompt": "A majestic African lion..."
    }],
    "model": "openai/gpt-image-1"
  }
}

Core Parameters

Parameter	Type	Default	Description
`prompt`	string	required	Text prompt (max 32000 chars)
`model`	string	required	Provider-prefixed model ID
`n`	number	1	Number of images (1-10)
`size`	string	”1024x1024”	Output size
`quality`	string	”auto”	`low`, `medium`, `high`, `hd`
`response_format`	string	”url”	`url` or `b64_json`

Provider-Specific Parameters

Stability AI / Flux


{
  "prompt": "A futuristic city skyline",
  "model": "stability/sdxl",
  "negative_prompt": "blurry, low quality",
  "cfg_scale": 7.5,
  "steps": 30,
  "seed": 12345
}

Stability AI with ControlNet


{
  "prompt": "A futuristic city skyline",
  "model": "stability/sdxl",
  "control_image": "file_abc123",
  "control_type": "depth"
}

Flux with LoRA


{
  "prompt": "Portrait photo in anime style",
  "model": "flux/pro",
  "lora": "anime-portrait-v1",
  "cfg_scale": 3.5
}

OpenAI GPT-Image-1


{
  "prompt": "A logo for a tech company",
  "model": "openai/gpt-image-1",
  "background": "transparent",
  "output_format": "png"
}

Provider Capability Comparison

Provider	Negative Prompt	Seed	CFG Scale	Steps	Transparency	ControlNet
OpenAI	-	-	-	-	Yes	-
Gemini	Yes	Yes	-	-	-	-
Stability	Yes	Yes	Yes	Yes	-	Yes
Flux	-	Yes	Yes	Yes	-	-
xAI	-	-	-	-	-	-

CDN Storage

Generated images are automatically stored to PickLayer’s CDN:

file_id: PickLayer file ID for permanent storage
file_url: CDN URL for permanent access
Provider URLs may expire; use CDN URLs for long-term access

Billing

Charged by output megapixels (width x height x n). Guard reserves before provider call and finalizes with actuals.

Usage is recorded internally and available via /usage/summary, but it is not returned in image generation responses.

Unsupported Parameter Warnings

When sending parameters not supported by the target provider, they’re filtered and returned in metadata.warnings:


{
  "metadata": {
    "warnings": [
      { "field": "negative_prompt", "message": "not supported by OpenAI, ignored" }
    ]
  }
}