Spring AI Evaluation Testing: How to Test LLM Responses Large Language Models (LLMs) like OpenAI GPT, Gemini, Claude, and Llama have transformed how modern applications generate content, answer questions, summarize documents, and even write code. With the introduction of Spring AI, integrating these powerful AI models into Spring Boot applications has become much easier for Java developers. However, there's one important question every developer should ask: How do we know whether an AI-generated response is actually correct, relevant, and reliable? Unlike traditional software, LLMs don't always produce the same output for the same input. Their responses can vary in wording, accuracy, completeness, and even contain incorrect or misleading information (often called hallucinations). Because of this, simply checking whether your API returns a response is