This guide shows how to generate images using Nano Banana Pro via the Leonardo.AI REST API.

Sample Request

curl --location 'https://cloud.leonardo.ai/api/rest/v2/generations' \
     --header 'authorization: Bearer {api-key}' \
     --header 'Content-Type: application/json' \
     --data '{
       "model": "gemini-image-2",
       "parameters": {
           "width": 1024,
           "height": 1024,
           "prompt": "a portrait-style photograph featuring a koala",
           "quantity": 1,
           "style_ids": [
                "111dc692-d470-4eec-b791-3475abac4c46"
           ],
           "prompt_enhance": "OFF"
        },
        "public": false
      }'

Recipe

API Request Endpoint, Headers, Parameters

Endpoint

https://cloud.leonardo.ai/api/rest/v2/generations

Headers

--header "accept: application/json" \
--header "authorization: Bearer <YOUR_API_KEY>" \
--header "content-type: application/json"

Body Parameters

Parameter	Type	Definition
guidances	`object`	Optional. Object defining image guidance inputs that influence the generated result.
guidances.image_reference	`array`	Optional. Array of up to 6 reference images. Each reference includes image.id, image.type (`GENERATED` or `UPLOADED`), and strength (`LOW`, `MID`, `HIGH`).
height	`integer`	Optional. Height input resolution.
model	`string`	Required. Model identifier. Refer to the table below for a list of models. Set to `gemini-image-2`.
prompt	`string`	Required. Text prompt describing what image you want the model to generate.
prompt_enhance	`string`	Optional. Enables prompt enhancement when set to `"ON"`; disabled when set to `"OFF"`.
public	`boolean`	Optional. Boolean flag that determines whether the generation is public (`true`) or private (`false`).
quantity	`integer`	Optional. Number of images to generate in a single request. Default is 1, maximum is 8.
seed	`integer`	Optional. Apply a fixed seed to maintain consistency across generation sets.
style_ids	`array`	Optional. Array of style UUIDs used to apply preset artistic styles to the output.
width	`integer`	Optional. Width input resolution.

List of Height and Width

Model	Height	Width
Nano Banana Pro	0, 672, 768, 848, 896, 928, 1024, 1152, 1200, 1264, 1376, 1344, 1536, 1696, 1792, 1856, 2048, 2304, 2400, 2528, 2752, 2688, 3072, 3392, 3584, 3712, 4096, 4608, 4800, 5056, 5504	0, 672, 768, 848, 896, 928, 1024, 1152, 1200, 1264, 1376, 1344, 1536, 1696, 1792, 1856, 2048, 2304, 2400, 2528, 2752, 2688, 3072, 3392, 3584, 3712, 4096, 4608, 4800, 5056, 5504

When not specified, default height and width is 1024.

A width and height of 0 and 0 will allow the output to try to match the input image reference.

List of Style IDs

Preset Style	UUID
3D Render	`debdf72a-91a4-467b-bf61-cc02bdeb69c6`
Acrylic	`3cbb655a-7ca4-463f-b697-8a03ad67327c`
Creative	`6fedbf1f-4a17-45ec-84fb-92fe524a29ef`
Dynamic	`111dc692-d470-4eec-b791-3475abac4c46`
Fashion	`594c4a08-a522-4e0e-b7ff-e4dac4b6b622`
Game Concept	`09d2b5b5-d7c5-4c02-905d-9f84051640f4`
Graphic Design 2D	`703d6fe5-7f1c-4a9e-8da0-5331f214d5cf`
Graphic Design 3D	`7d7c2bc5-4b12-4ac3-81a9-630057e9e89f`
Illustration	`645e4195-f63d-4715-a3f2-3fb1e6eb8c70`
None	`556c1ee5-ec38-42e8-955a-1e82dad0ffa1`
Portrait	`8e2bc543-6ee2-45f9-bcd9-594b6ce84dcd`
Portrait Cinematic	`4edb03c9-8a26-4041-9d01-f85b5d4abd71`
Portrait Fashion	`0d34f8e1-46d4-428f-8ddd-4b11811fa7c9`
Pro B&W photography	`22a9a7d2-2166-4d86-80ff-22e2643adbcf`
Pro Color Photography	`7c3f932b-a572-47cb-9b9b-f20211e63b5b`
Pro Film Photography	`581ba6d6-5aac-4492-bebe-54c424a0d46e`
Ray Traced	`b504f83c-3326-4947-82e1-7fe9e839ec0f`
Stock Photo	`5bdc3f2a-1be6-4d1c-8e77-992a30824a2c`
Watercolor	`1db308ce-c7ad-4d10-96fd-592fa6b75cc4`

Image Guidance

Sample Request

curl --location 'https://cloud.leonardo.ai/api/rest/v2/generations' \
     --header 'authorization: Bearer {api-key}' \
     --header 'Content-Type: application/json' \
     --data '{
       "model": "gemini-image-2",
       "parameters": {
           "width": 1024,
           "height": 1024,
           "prompt": "A koala is wearing a colourful Hawaiian shirt",
           "quantity": 1,
           "guidances": {
               "image_reference": [
                   {
                       "image": {
                           "id": "fc6f78c6-e7ac-491b-ad26-01f6843db870",
                           "type": "GENERATED"
                       },
                       "strength": "MID"
                   },
                   {
                       "image": {
                           "id": "a8e374dd-52f8-4236-ad9e-99b1f601fa3a",
                           "type": "UPLOADED"
                       },
                       "strength": "MID"
                   }
               ]
           },
           "style_ids": [
               "111dc692-d470-4eec-b791-3475abac4c46"
           ],
           "prompt_enhance": "OFF"
       },
       "public": false
   }'