7. Image Generation

Image Generation creates still images from text prompts. Use it for thumbnails, reference frames, product concepts, style exploration, or as input context for Video Generation.

How It Works

Write a prompt, choose a model, format, aspect ratio, and quality setting, and optionally attach image references. Mosaic stores the generated image as a workspace asset so it can be reused by downstream tiles or API runs. Nano Banana Lite is the default image model. Nano Banana and Nano Banana Pro add selectable output resolution. GPT Image 2 remains available with its low, medium, and high quality settings. Image context accepts selected upstream image assets only. Nano Banana models can use up to 14 selected images. GPT Image 2 can use up to 3 selected images. Video and audio inputs are not sent to Image Generation.

API Usage

Create an agent shell:

curl -X POST "https://api.mosaic.so/agent/create" \
  -H "Authorization: Bearer mk_your_api_key" \
  -H "Content-Type: application/json" \
  -d '{
    "name": "Hero frame generator",
    "visibility": "private"
  }'

Add an Image Generation node:

curl -X POST "https://api.mosaic.so/agent/AGENT_ID/update" \
  -H "Authorization: Bearer mk_your_api_key" \
  -H "Content-Type: application/json" \
  -d '{
    "operations": [
      {
        "op": "create_node",
        "node_type_id": "18b998a0-2ea7-4676-a5d3-3ae6c8ac0b72",
        "params_used": {
          "prompt": "A premium studio product photo of a chrome espresso machine on a marble counter",
          "model": "nano-banana-lite",
          "aspect_ratio": "auto",
          "output_format": "png"
        }
      }
    ]
  }'

Run the agent:

curl -X POST "https://api.mosaic.so/agent/AGENT_ID/run" \
  -H "Authorization: Bearer mk_your_api_key" \
  -H "Content-Type: application/json" \
  -d '{
    "callback_url": "https://your-webhook.com/mosaic"
  }'

API Info

Node Params & API Details

Node ID: 18b998a0-2ea7-4676-a5d3-3ae6c8ac0b72

Node params

Param	Type	Required	Default	Notes
`prompt`	`string`	Yes	`""`	Image prompt.
`model`	`"nano-banana-lite" \| "nano-banana" \| "nano-banana-pro" \| "gpt-image-2"`	No	`"nano-banana-lite"`	Image model.
`image_size`	`"square_hd" \| "square" \| "portrait_4_3" \| "portrait_16_9" \| "landscape_4_3" \| "landscape_16_9" \| "auto" \| "custom"`	No	`"landscape_4_3"`	GPT Image 2 output size preset.
`custom_width`	`number`	Conditional	`1280`	GPT Image 2 only. Required when `image_size` is `custom`; multiple of 16, 256-3840.
`custom_height`	`number`	Conditional	`960`	GPT Image 2 only. Required when `image_size` is `custom`; multiple of 16, 256-3840.
`quality`	`"low" \| "medium" \| "high"`	No	`"high"`	GPT Image 2 generation quality.
`aspect_ratio`	`"auto" \| "21:9" \| "16:9" \| "3:2" \| "4:3" \| "5:4" \| "1:1" \| "4:5" \| "3:4" \| "2:3" \| "9:16" \| "4:1" \| "1:4" \| "8:1" \| "1:8"`	No	`"auto"`	Nano Banana image aspect ratio. Nano Banana Pro supports up to `21:9` through `9:16`.
`resolution`	`"0.5K" \| "1K" \| "2K" \| "4K"`	No	`"1K"`	Nano Banana output resolution. Nano Banana Pro supports `1K`, `2K`, and `4K`. Nano Banana Lite uses standard output.
`output_format`	`"jpeg" \| "png" \| "webp"`	No	`"png"`	Generated image format.
`selected_context`	`{images:string[]}`	No	empty list	Selected upstream image references. Nano Banana models support up to 14; GPT Image 2 supports up to 3.

Example

{
  "prompt": "A clean ecommerce hero image of white running shoes on blue acrylic",
  "model": "nano-banana",
  "aspect_ratio": "16:9",
  "resolution": "1K",
  "output_format": "png"
}

⌘I

Getting Started

2. Quickstart

3. Mosaic Philosophy

4. Tiles

5. Canvas

6. Models

7. How To

8. More

How It Works

API Usage

API Info

Node params

Example

​How It Works

​API Usage

​API Info

​Node params

​Example

How It Works

API Usage

API Info

Node params

Example