Cat Breed finder

cat-breed-llama.ts

export interface Env {
	AI: Ai;
}

export default {
	async fetch(request: Request, env: Env): Promise<Response> {
		const res = await fetch('https://cataas.com/cat');
		const blob = await res.arrayBuffer();

		// Convert array buffer to base64 data URL (in chunks to avoid stack overflow)
		const uint8Array = new Uint8Array(blob);
		let binaryString = '';
		const chunkSize = 8192;
		for (let i = 0; i < uint8Array.length; i += chunkSize) {
			const chunk = uint8Array.slice(i, i + chunkSize);
			binaryString += String.fromCharCode(...chunk);
		}
		const base64 = btoa(binaryString);
		const dataUrl = `data:image/jpeg;base64,${base64}`;

		const messages = [
			{
				role: 'system',
				content: 'You are a cat breed expert assistant. You must respond with valid JSON only, matching the provided schema exactly.',
			},
			{
				role: 'user',
				content: [
					{
						type: 'text',
						text: 'Analyze this image and identify the cat breed. Respond with a JSON object containing: breed (string), confidence (one of: high, medium, low).',
					},
					{ type: 'image_url', image_url: { url: dataUrl } },
				],
			},
		];

		const response = await env.AI.run('@cf/meta/llama-3.2-11b-vision-instruct', {
			messages,
			max_tokens: 512,
			response_format: {
				type: 'json_schema',
				json_schema: {
					name: 'cat_breed_analysis',
					strict: true,
					schema: {
						type: 'object',
						properties: {
							breed: {
								type: 'string',
								description: 'The cat breed identified in the image',
							},
							confidence: {
								type: 'string',
								enum: ['high', 'medium', 'low'],
								description: 'Confidence level of the breed identification',
							},
						},
						required: ['breed', 'confidence'],
						additionalProperties: false,
					},
				},
			},
		});

		return Response.json(response);
	},
} satisfies ExportedHandler<Env>;