POST/api/v1/imagine4 creditsSynchronous

Nano Banana 2

Provider · GoogleType · T2I / I2IModel ID · nano-banana-2Upstream ID · nano-banana-2

Google Imagen — the latest and most capable Nano Banana model. Supports up to 4K resolution, up to 14 reference images simultaneously, and extreme aspect ratios. Exceptional for character consistency across multiple reference images.

Request Parameters

Parameter	Type	Required	Description
prompt	`string`	Required	The text prompt describing the image to generate.
model	`string`	Optional	Set to `nano-banana-2` to use this model.Default: `nano-banana-2`
image_url	`string`	Optional	Reference image URL for image-to-image generation. Optional — omit for pure text-to-image.
aspect_ratio	`string`	Optional	Output aspect ratio. Allowed: 1:1 · 16:9 · 9:16 · 4:3 · 3:4 · 3:2 · 2:3.Default: `1:1`
resolution	`string`	Optional	Output resolution. Allowed: 1K · 2K · 4K. Only supported by this model.
webhook_url	`string`	Optional	URL where we POST the completed task result.
webhook_secret	`string`	Optional	Sent as x-webhook-secret header in webhook delivery for verification.

Example Request

cURL

curl -X POST https://api.journeyapi.com/api/v1/imagine \
  -H "Authorization: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "nano-banana-2",
    "prompt": "the character in a cozy coffee shop, watercolor style",
    "image_url": "https://example.com/character-ref.jpg",
    "resolution": "2K",
    "aspect_ratio": "3:4"
  }'

Response

This model is synchronous — the response includes the finished image_url directly. No polling required.

200 OK

{
  "task_id": "550e8400-e29b-41d4-a716-446655440000",
  "status": "finished",
  "image_url": "https://cdn.example.com/output.png"
}

Tips

1Supply up to 10 object reference images + 4 character reference images for best consistency.
2Use `resolution: "4K"` for maximum detail — only this model supports 4K.
3More reference images increase generation latency noticeably.

Quirks & Gotchas

With 14 reference images, expect noticeably longer response times (30–60s).