curl --request POST \
  --url https://api.evolink.ai/v1/images/generations \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "model": "gemini-nano-banana-2.1",
  "prompt": "A cat playing on the grass",
  "size": "16:9",
  "quality": "2K"
}
'

{
  "created": 1757165031,
  "id": "task-unified-1757165031-uyujaw3d",
  "model": "gemini-nano-banana-2.1",
  "object": "image.generation.task",
  "progress": 0,
  "status": "pending",
  "task_info": {
    "can_cancel": true,
    "estimated_time": 45
  },
  "type": "image",
  "usage": {
    "billing_rule": "per_image",
    "credits_reserved": 3.0845,
    "user_group": "default"
  }
}

{
  "error": {
    "code": "invalid_request",
    "message": "Invalid request parameters",
    "type": "invalid_request_error"
  }
}

{
  "error": {
    "code": "unauthorized",
    "message": "Invalid or expired token",
    "type": "authentication_error"
  }
}

{
  "error": {
    "code": "insufficient_quota",
    "message": "Insufficient quota. Please top up your account.",
    "type": "insufficient_quota"
  }
}

{
  "error": {
    "code": "model_access_denied",
    "message": "Token does not have access to model: gemini-nano-banana-2.1",
    "type": "invalid_request_error"
  }
}

{
  "error": {
    "code": "rate_limit_exceeded",
    "message": "Too many requests, please try again later",
    "type": "rate_limit_error"
  }
}

{
  "error": {
    "code": "internal_error",
    "message": "Internal server error",
    "type": "api_error"
  }
}

Nanobanana 2.1

Nanobanana 2.1 Image Generation

Nano Banana 2.1 (gemini-nano-banana-2.1) supports text to image, image to image, image editing, and multi-image composition, with 1K, 2K, and 4K output resolutions
Asynchronous processing: use the returned task ID to query the task
Generated image links are valid for 24 hours. Please save the images promptly
Billing: output images are billed by resolution, input images per image, and web search and image search by the actual number of searches. Prompt text, text output, and reasoning are billed per token. Actual charges are based on the usage returned by the task query

POST

images

generations

curl --request POST \
  --url https://api.evolink.ai/v1/images/generations \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "model": "gemini-nano-banana-2.1",
  "prompt": "A cat playing on the grass",
  "size": "16:9",
  "quality": "2K"
}
'

{
  "created": 1757165031,
  "id": "task-unified-1757165031-uyujaw3d",
  "model": "gemini-nano-banana-2.1",
  "object": "image.generation.task",
  "progress": 0,
  "status": "pending",
  "task_info": {
    "can_cancel": true,
    "estimated_time": 45
  },
  "type": "image",
  "usage": {
    "billing_rule": "per_image",
    "credits_reserved": 3.0845,
    "user_group": "default"
  }
}

{
  "error": {
    "code": "invalid_request",
    "message": "Invalid request parameters",
    "type": "invalid_request_error"
  }
}

{
  "error": {
    "code": "unauthorized",
    "message": "Invalid or expired token",
    "type": "authentication_error"
  }
}

{
  "error": {
    "code": "insufficient_quota",
    "message": "Insufficient quota. Please top up your account.",
    "type": "insufficient_quota"
  }
}

{
  "error": {
    "code": "model_access_denied",
    "message": "Token does not have access to model: gemini-nano-banana-2.1",
    "type": "invalid_request_error"
  }
}

{
  "error": {
    "code": "rate_limit_exceeded",
    "message": "Too many requests, please try again later",
    "type": "rate_limit_error"
  }
}

{
  "error": {
    "code": "internal_error",
    "message": "Internal server error",
    "type": "api_error"
  }
}

Authorizations

Authorization

string

header

required

##All APIs require Bearer Token authentication##

Get API Key:

Visit API Key Management Page to get your API Key

Add to request header:

Authorization: Bearer YOUR_API_KEY

Body

application/json

model

enum<string>

default:gemini-nano-banana-2.1

required

Image generation model name, official channel, better stability and controllability, suitable for commercial scenarios

Available options:

gemini-nano-banana-2.1

Example:

"gemini-nano-banana-2.1"

prompt

string

required

Prompt describing the image to generate or how to edit an input image, up to 4000 tokens

Example:

"A cat playing in the grass"

size

enum<string>

default:auto

Aspect ratio of the generated image, default is auto

Available options:

auto,

1:1,

1:4,

4:1,

1:8,

8:1,

2:3,

3:2,

3:4,

4:3,

4:5,

5:4,

9:16,

16:9,

21:9

quality

enum<string>

default:2K

Output image resolution, default is 2K

Note:

Prices vary by resolution. Output images are billed at the selected resolution. Setting this parameter explicitly is recommended

Available options:

1K,

2K,

4K

image_urls

string<uri>[]

List of reference image URLs for image to image generation, image editing, and multi-image composition

Note:

Up to 14 input images per request
Image size: no more than 20MB
Supported file formats: .jpeg, .jpg, .png, .webp
Image URLs must be directly accessible by the server or trigger a direct image download when accessed (such URLs typically end in an image extension such as .png or .jpg)
Input images are billed per image

Maximum array length: 14

Example:

[
  "https://example.com/image1.png",
  "https://example.com/image2.png"
]

model_params

object

Model extension parameters

Show child attributes

callback_url

string<uri>

HTTPS callback address after task completion

Callback Timing:

Triggered when task is completed, failed, or cancelled
Sent after billing confirmation is completed

Security Restrictions:

Only HTTPS protocol is supported
Callback to internal IP addresses is prohibited (127.0.0.1, 10.x.x.x, 172.16-31.x.x, 192.168.x.x, etc.)
URL length must not exceed 2048 characters

Callback Mechanism:

Timeout: 10 seconds
Maximum 3 retries on failure (retries after 1 second/2 seconds/4 seconds)
Callback response body format is consistent with the task query API response format
Callback address returning 2xx status code is considered successful, other status codes will trigger retry

Example:

"https://your-domain.com/webhooks/image-task-completed"

Response

Image generation task created successfully

created

integer

Task creation timestamp

Example:

1757165031

string

Task ID

Example:

"task-unified-1757165031-uyujaw3d"

model

string

Actual model name used

Example:

"gemini-nano-banana-2.1"

object

enum<string>

Specific task type

Available options:

image.generation.task

progress

integer

Task progress percentage (0-100)

Required range: 0 <= x <= 100

Example:

0

status

enum<string>

Task status

Available options:

pending,

processing,

completed,

failed

Example:

"pending"

task_info

object

Asynchronous task information

Show child attributes

type

enum<string>

Task output type

Available options:

text,

image,

audio,

video

Example:

"image"

usage

object

Usage and billing information

Show child attributes

Image Series

Video Series

Audio Series

Text Series

Account Management

Task Management

File Management

Nanobanana 2.1 Image Generation

Authorizations

Body

Response