Nano Banana 2 API：原生图像生成与商品参考图

curl --fail-with-body --max-time 180 \
  https://api.apizt.com/v1beta/models/gemini-3.1-flash-image:generateContent \
  -H "Authorization: Bearer $tokenba_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "contents": [
    {
      "role": "user",
      "parts": [
        {
          "text": "生成一张咖啡店周末活动封面：奶油色桌面上有一杯冰拿铁和一小束橙色花，柔和自然光。画面上方只保留中文标题“周末咖啡”，不要价格、品牌标志或额外文字。正方形构图，适合手机阅读。"
        }
      ]
    }
  ],
  "generationConfig": {
    "responseModalities": [
      "TEXT",
      "IMAGE"
    ],
    "imageConfig": {
      "imageSize": "1K",
      "aspectRatio": "1:1"
    }
  }
}' \
  -o nano-banana-2-generation-response.json

python3 - <<'PY'
import base64, json
from pathlib import Path

result = json.loads(Path("nano-banana-2-generation-response.json").read_text())
saved = 0
extensions = {"image/png": "png", "image/jpeg": "jpg", "image/webp": "webp"}
for candidate in result.get("candidates", []):
    for part in candidate.get("content", {}).get("parts", []):
        image = part.get("inlineData")
        if image and not part.get("thought"):
            extension = extensions.get(image.get("mimeType"))
            if not extension:
                raise ValueError("Unexpected image MIME type")
            saved += 1
            path = Path(f"nano-banana-2-generation-{saved}.{extension}")
            path.write_bytes(base64.b64decode(image["data"], validate=True))
            print(path)
if not saved:
    raise RuntimeError("No final image returned; check response JSON and finishReason")
print(result.get("usageMetadata"))
PY

import base64, json, os
from pathlib import Path
from urllib.request import Request, urlopen

reference = base64.b64encode(Path("reference.png").read_bytes()).decode("ascii")
payload = {
    "contents": [{"role": "user", "parts": [
        {"text": "保留参考图中商品的颜色、形状、标签与数量，把背景更换为浅米色室内桌面，并添加柔和侧光。不要新增文字，不改变商品品牌元素。输出一张正方形商品场景图。"},
        {"inlineData": {"mimeType": "image/png", "data": reference}},
    ]}],
    "generationConfig": {
        "responseModalities": ["TEXT", "IMAGE"],
        "imageConfig": {"imageSize": "1K", "aspectRatio": "1:1"},
    },
}
request = Request(
    "https://api.apizt.com/v1beta/models/gemini-3.1-flash-image:generateContent",
    data=json.dumps(payload).encode("utf-8"),
    headers={
        "Authorization": "Bearer " + os.environ["tokenba_API_KEY"],
        "Content-Type": "application/json",
    },
    method="POST",
)
with urlopen(request, timeout=180) as response:
    result = json.load(response)
Path("nano-banana-2-edit-response.json").write_text(json.dumps(result), encoding="utf-8")
saved = 0
extensions = {"image/png": "png", "image/jpeg": "jpg", "image/webp": "webp"}
for candidate in result.get("candidates", []):
    for part in candidate.get("content", {}).get("parts", []):
        image = part.get("inlineData")
        if image and not part.get("thought"):
            extension = extensions.get(image.get("mimeType"))
            if not extension:
                raise ValueError("Unexpected image MIME type")
            saved += 1
            path = Path(f"nano-banana-2-edit-{saved}.{extension}")
            path.write_bytes(base64.b64decode(image["data"], validate=True))
            print(path)
if not saved:
    raise RuntimeError("No final image returned; check response JSON and finishReason")
print(result.get("usageMetadata"))