{
  "contents": [
    {
      "role": "user",
      "parts": [
        {
          "text": "图片生成提示词"
        },
        {
          "inline_data": {
            "mime_type": "image/png",
            "data": "参考图 base64，不包含 data:image/png;base64, 前缀"
          }
        }
      ]
    }
  ],
  "generationConfig": {
    "responseModalities": ["IMAGE"],
    "imageConfig": {
      "aspectRatio": "1:1",
      "imageSize": "1K"
    }
  }
}

{
  "candidates": [
    {
      "content": {
        "role": "model",
        "parts": [
          {
            "text": "https://abd.wellapi.xin/api/generations/3cfb9eeb-b1af-4376-970d-5e1a7c224744/image?token=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJwdXJwb3NlIjoib3BlbmFwaS1nZW5lcmF0aW9uLWltYWdlIiwiZ2VuZXJhdGlvbklkIjoiM2NmYjllZWItYjFhZi00Mzc2LTk3MGQtNWUxYTdjMjI0NzQ0IiwiYWN0b3JJZCI6ImNtcTdtc2llajA2NHh6NDl4a3ZhcGZla20iLCJhY3RvclR5cGUiOiJhcGlLZXkiLCJpYXQiOjE3ODI4MzM5MzUsImV4cCI6MTc4Mjg0MTEzNX0.XWFfq9rUase1NFVqW27wshxNKuA5WjfbzH6oRuUINO4"
          }
        ]
      },
      "finishReason": "STOP",
      "index": 0
    }
  ],
  "modelVersion": "Nano_Banana_Pro",
  "usageMetadata": {
    "promptTokenCount": 96,
    "candidatesTokenCount": 1548,
    "totalTokenCount": 1644
  }
}

{
  "candidates": [
    {
      "content": {
        "role": "model",
        "parts": [
          {
            "text": "https://file1.aitohumanize.com/file/52032f4491534bbca42ebef18ddd1ae5.png"
          }
        ]
      },
      "finishReason": "STOP",
      "index": 0
    }
  ],
  "modelVersion": "gemini-3.1-flash-image-preview",
  "usageMetadata": {
    "promptTokenCount": 16,
    "candidatesTokenCount": 11145,
    "totalTokenCount": 11161
  }
}

1. 解析 JSON 根对象。
2. 取 candidates[0].content.parts[0].text。
3. 判断该字段值是否以 http:// 或 https:// 开头。
   - 是 → 即为图片 URL，直接使用或转存。
   - 否 → 记录完整返回体，上报异常。
4. 对 gemini-3-pro-image-preview 返回的 URL，建议立即下载/转存，
   避免 JWT token 过期后无法访问。

{
  "error": {
    "code": 400,
    "message": "Invalid request body",
    "status": "INVALID_ARGUMENT"
  }
}

{
  "error": {
    "code": 401,
    "message": "API key not valid",
    "status": "UNAUTHENTICATED"
  }
}