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POST
/
v1
/
images
/
generations
Nano Banana 2 Interface
curl --request POST \
  --url https://api.evolink.ai/v1/images/generations \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "model": "gemini-3.1-flash-image-preview",
  "prompt": "A cat playing on the grass"
}
'
{
  "created": 1757165031,
  "id": "task-unified-1757165031-uyujaw3d",
  "model": "gemini-3.1-flash-image-preview",
  "progress": 0,
  "status": "pending",
  "task_info": {
    "can_cancel": true,
    "estimated_time": 45
  },
  "type": "image",
  "usage": {
    "billing_rule": "per_call",
    "credits_reserved": 8.7,
    "user_group": "default"
  }
}

Documentation Index

Fetch the complete documentation index at: https://docs.evolink.ai/llms.txt

Use this file to discover all available pages before exploring further.

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-3.1-flash-image-preview
required

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

Available options:
gemini-3.1-flash-image-preview
Example:

"gemini-3.1-flash-image-preview"

​
prompt
string
required

Prompt describing the image to be generated, or describing how to edit the input image, limited to 2000 tokens

Maximum string length: 2000
Example:

"A cat playing in the grass"

​
size
enum<string>

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>

Quality of the generated image, default is 2K

Note:

  • Different quality levels have different pricing
Available options:
0.5K,
1K,
2K,
4K
​
image_urls
string<uri>[]

Reference image URL list for image-to-image and image editing functions

Note:

  • Maximum number of input images per request: 14
  • Image size: not exceeding 20MB
  • Supported file formats: .jpeg, .jpg, .png, .webp
  • Image URLs must be directly accessible by the server, or the image URL should directly download when accessed (typically these URLs end with image file extensions, such as .png, .jpg)
  • Maximum of 4 real person images can be uploaded
Example:
[
  "https://example.com/image1.png",
  "https://example.com/image2.png"
]
​
model_params
object

Model extension parameters

​
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

​
id
string

Task ID

Example:

"task-unified-1757165031-uyujaw3d"

​
model
string

Actual model name used

Example:

"gemini-3.1-flash-image-preview"

​
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

​
type
enum<string>

Task output type

Available options:
text,
image,
audio,
video
Example:

"image"

​
usage
object

Usage and billing information