Image Generation (OpenAI-compatible API)

1. Overview

OpenAI-compatible interface for the Nano Banana image model.

2. Request

• Method:POST

• Endpoint:

  https://gateway.serevixai.ai/v1/images/generations
  

---

3. Parameters

3.1 Header Parameters

Parameter	Type	Required	Description	Example
Content-Type	string	Yes	Sets the request content type. It must be application/json.	application/json
Accept	string	Yes	Sets the response content type. The recommended value is application/json.	application/json
Authorization	string	Yes	API key required for authentication, in the format Bearer $YOUR_API_KEY.	Bearer $YOUR_API_KEY

3.2 Body Parameters (application/json)

Parameter	Type	Required	Description	Example (default)
model	string	Yes	The model ID to use, for example gemini-2.5-flash-image.	gemini-2.5-flash-image
prompt	string	Yes	A text prompt describing the image to generate. Because this is a multimodal model, the prompt should clearly describe the desired image or explicitly request image creation; very short phrases may not produce an image.	A cute baby sea otter
aspect_ratio	string	No	Target image aspect ratio. Supported values: 1:1, 2:3, 3:2, 3:4, 4:3, 4:5, 5:4, 9:16, 16:9, and 21:9.
image_size	string	No	Image size to generate. Supported values: 1K, 2K, and 4K.	1K

4. Request Examples

HTTPShellGoPython

POST /v1/images/generations
Content-Type: application/json
Accept: application/json
Authorization: Bearer $YOUR_API_KEY

{
    "model": "gemini-2.5-flash-image",
    "prompt": "A cute baby sea otter",
    "aspect_ratio": "1:1"
}

curl https://gateway.serevixai.ai/v1/images/generations \
    -H "Content-Type: application/json" \
    -H "Accept: application/json" \
    -H "Authorization: Bearer $YOUR_API_KEY" \
    -d '{
    "model": "gemini-2.5-flash-image",
    "prompt": "A cute baby sea otter",
    "aspect_ratio": "1:1"
}'

package main

import (
    "context"
    "encoding/base64"
    "fmt"
    "os"

    "github.com/openai/openai-go"
    "github.com/openai/openai-go/option"
)

func main() {

    apiKey := "sk-123456789012345678901234567890123456789012345678"
    exampleFilePath := "example.png"

    client := openai.NewClient(
        option.WithAPIKey(apiKey),
        option.WithBaseURL("https://gateway.serevixai.ai/v1"),
    )

    resp, err := client.Images.Generate(
        context.Background(),
        openai.ImageGenerateParams{
            Model:          "gemini-2.5-flash-image",
            Prompt:         "A cute baby sea otter",
            ResponseFormat: "b64_json",
        },
        option.WithJSONSet("aspect_ratio", "1:1"),
    )

    if err != nil {
        fmt.Println("error:", err)
        return
    }

    if len(resp.Data) == 0 || resp.Data[0].B64JSON == "" {
        fmt.Println("error: empty b64_json")
        return
    }

    imageData, err := base64.StdEncoding.DecodeString(resp.Data[0].B64JSON)
    if err != nil {
        fmt.Println("error:", err)
        return
    }

    if err := os.WriteFile(exampleFilePath, imageData, 0644); err != nil {
        fmt.Println("error:", err)
        return
    }

    fmt.Println("success to write to file", exampleFilePath)
}

#!/usr/bin/env python3

import base64
from openai import OpenAI

def main():
    api_key = "sk-123456789012345678901234567890123456789012345678"
    example_file_path = "example.png"

    client = OpenAI(
        api_key=api_key,
        base_url="https://gateway.serevixai.ai/v1"
    )

    response = client.images.generate(
        model="gemini-2.5-flash-image",
        prompt="A cute baby sea otter",
        response_format="b64_json",
        extra_body={"aspect_ratio": "1:1"}
    )

    if not response.data or not response.data[0].b64_json:
        print("error: empty b64_json")
        return

    image_data = base64.b64decode(response.data[0].b64_json)

    with open(example_file_path, "wb") as f:
        f.write(image_data)

    print("success to write to file", example_file_path)

if __name__ == "__main__":
    main()

5. Response Example

{
    "created": 1589478378,
    "data": [
        {
            "b64_json": "..."
        }
    ]
}