# Copyright 2025 Google LLC
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# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
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# limitations under the License.
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# SPDX-License-Identifier: Apache-2.0
"""This sample demonstrates how to use Gemini to describe and draw images."""
import asyncio
import base64
import os
from io import BytesIO
from PIL import Image
from genkit.ai import Genkit
from genkit.plugins.google_genai import GoogleAI, googleai_name
from genkit.types import Media, MediaPart, Message, Role, TextPart
ai = Genkit(plugins=[GoogleAI()])
@ai.flow()
async def draw_image_with_gemini(prompt: str = '') -> str:
"""Draw an image.
Args:
prompt: The prompt to draw.
Returns:
The image.
"""
if not prompt:
prompt = 'Draw a cat in a hat.'
return await ai.generate(
prompt=prompt,
config={'response_modalities': ['Text', 'Image']},
model=googleai_name('gemini-2.5-flash-image'),
)
@ai.flow()
async def describe_image_with_gemini(data: str = '') -> str:
"""Describe an image.
Args:
data: The image data as a data URI (e.g., 'data:image/jpeg;base64,...').
Returns:
The description of the image.
"""
if not data:
try:
current_dir = os.path.dirname(os.path.abspath(__file__))
image_path = os.path.join(current_dir, '..', 'image.jpg')
with open(image_path, 'rb') as image_file:
buffer = image_file.read()
img_base64 = base64.b64encode(buffer).decode('utf-8')
data = f'data:image/jpeg;base64,{img_base64}'
except FileNotFoundError as e:
raise ValueError("Default image 'image.jpg' not found. Please provide image data.") from e
if not (data.startswith('data:') and ',' in data):
raise ValueError(f'Expected a data URI (e.g., "data:image/jpeg;base64,..."), but got: {data[:50]}...')
result = await ai.generate(
messages=[
Message(
role=Role.USER,
content=[
TextPart(text='What is shown in this image?'),
MediaPart(media=Media(content_type='image/jpeg', url=data)),
],
),
],
model=googleai_name('gemini-3-flash-preview'),
)
return result.text
async def main() -> None:
"""Main function."""
# Example run logic can go here or be empty for pure flow server
pass
if __name__ == '__main__':
ai.run_main(main())
