This guide shows how to generate images using FLUX.2 Pro model 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 '{
       "public": false,
       "model": "flux-pro-2.0",
       "parameters": {
           "prompt": "A cat wearing a hat",
           "quantity": 1,
           "width": 1440,
           "height": 1440,
           "seed": 4294967295,
           "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"
                  }
              ]
           }
        }
      }'

Recipe

API Request Endpoint, Headers, Parameters (FLUX.2 Pro)

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 4 reference images. Each reference includes image.id, image.type (`GENERATED` or `UPLOADED`), and strength (`LOW`, `MID`, `HIGH`).
height	`integer`	Optional. Height input resolution. Supports `256` to `1440`.
model	`string`	Required. Model identifier. Set to `flux-pro-2.0`
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. The maximum seed value is `4294967295` for Flux.
style_ids	`array`	Optional. Array of style UUIDs used to apply preset artistic styles to the output.
width	`integer`	Optional. Width input resolution. Supports `256` to `1440`.

Aspect Ratio Settings

Aspect Ratio	Width	Height
2:3	960	1440
1:1	1440	1440
16:9	1440	810
9:16	810	1440