if (model === 'gemini-2.0-flash-exp-image-generation') {
    apiKey = process.env.GEMINI_FLASH_API_KEY;
    if (!apiKey) throw new Error('GEMINI_FLASH_API_KEY environment variable not set.');
    apiUrl = 'https://generativelanguage.googleapis.com/v1beta/models/gemini-pro-vision:generateContent';
    // Construct Gemini request body
    const imageParts = imageFiles.map(file => ({
        inline_data: {
            mime_type: file.mimetype,
            data: file.buffer.toString('base64')
        }
    }));
    
    requestBody = {
        contents: [
            {
                parts: [
                    { text: prompt },
                    ...imageParts
                ]
            }
        ]
    };
    console.log('Using Gemini Flash API Key');
}