GPT Image 2 在线生图：不用 ChatGPT Plus，单张 $0.03，30 种精确尺寸

import base64
import mimetypes
import os
import sys

import requests

API_KEY = os.environ.get("LAOZHANG_API_KEY")
if not API_KEY:
    raise RuntimeError("Set the LAOZHANG_API_KEY environment variable before running this example.")

REQUEST_TIMEOUT_SECONDS = 500
headers = {"Authorization": f"Bearer {API_KEY}"}

def extension_for_mime(mime_type):
    return {
        "image/jpeg": "jpg",
        "image/png": "png",
        "image/webp": "webp",
        "image/gif": "gif",
    }.get(mime_type, "bin")


def decode_base64_image(value, fallback_mime="image/png"):
    mime_type = fallback_mime
    encoded = value
    if value.startswith("data:"):
        header, encoded = value.split(",", 1)
        mime_type = header[5:].split(";", 1)[0] or fallback_mime
    return base64.b64decode(encoded, validate=True), mime_type


def parse_json_response(response):
    try:
        result = response.json()
    except ValueError as error:
        print("API returned a non-JSON response.", file=sys.stderr)
        raise SystemExit(1) from error
    if not isinstance(result, dict):
        print("API returned an unexpected JSON shape.", file=sys.stderr)
        raise SystemExit(1)
    return result


def extract_image(result):
    if not isinstance(result, dict):
        return None
    images = result.get("data") or []
    first_image = images[0] if images and isinstance(images[0], dict) else {}
    encoded = first_image.get("b64_json")
    if isinstance(encoded, str) and encoded:
        return decode_base64_image(encoded)

    image_url = first_image.get("url")
    if isinstance(image_url, str) and image_url:
        image_response = requests.get(image_url, timeout=REQUEST_TIMEOUT_SECONDS)
        image_response.raise_for_status()
        mime_type = image_response.headers.get("Content-Type", "image/png").split(";", 1)[0]
        return image_response.content, mime_type

    return None


def save_result_image(result):
    extracted = extract_image(result)
    if not extracted:
        keys = sorted(result.keys()) if isinstance(result, dict) else []
        print(f"No image data in response. Top-level keys: {keys}", file=sys.stderr)
        raise SystemExit(1)

    image_bytes, mime_type = extracted
    output_path = f"output.{extension_for_mime(mime_type)}"
    with open(output_path, "wb") as output_file:
        output_file.write(image_bytes)
    print(f"Image saved: {output_path} ({mime_type})")


API_URL = "https://api2.laozhang.ai/v1/images/generations"
headers["Content-Type"] = "application/json"

payload = {
    "model": "gpt-image-2-vip",
    "prompt": "极简咖啡海报，准确显示标题“COFFEE MADE SIMPLE”，高对比排版，温暖自然光，干净商业版式。",
    "size": "2048x2048",
    "quality": "high"
}

try:
    response = requests.post(
        API_URL,
        headers=headers,
        json=payload,
        timeout=REQUEST_TIMEOUT_SECONDS,
    )
except requests.Timeout as error:
    print(
        "Request timed out after 500 seconds. The result status may be unknown; "
        "check call and billing logs before retrying.",
        file=sys.stderr,
    )
    raise SystemExit(1) from error

if response.status_code != 200:
    print(f"API error {response.status_code}: {response.text}", file=sys.stderr)
    raise SystemExit(1)

save_result_image(parse_json_response(response))