diff --git a/spring-ia-course/src/main/java/br/com/bravox/eval/ReviewService.java b/spring-ia-course/src/main/java/br/com/bravox/eval/ReviewService.java
new file mode 100644
index 0000000..a8b3e12
--- /dev/null
+++ b/spring-ia-course/src/main/java/br/com/bravox/eval/ReviewService.java
@@ -0,0 +1,29 @@
+package br.com.bravox.eval;
+
+import org.springframework.ai.chat.client.ChatClient;
+import org.springframework.ai.openai.OpenAiChatOptions;
+import org.springframework.stereotype.Service;
+
+@Service
+public class ReviewService {
+    private final ChatClient chatClient;
+
+    public ReviewService(ChatClient.Builder builder) {
+        this.chatClient = builder
+                .defaultOptions(OpenAiChatOptions.builder().temperature(0.1d).build())
+                .build();
+    }
+
+    public Sentiment classifySentiment(String review) {
+        String systemPrompt = """
+                Classify the sentiment of the following text as POSITIVE, NEGATIVE, or NEUTRAL. \
+                Your response must be only one of these three words.""";
+        var sentiment = chatClient.prompt()
+                .system(systemPrompt)
+                .user(review)
+                .call().content();
+        return Sentiment.valueOf(sentiment);
+
+    }
+}
+
diff --git a/spring-ia-course/src/main/java/br/com/bravox/eval/Sentiment.java b/spring-ia-course/src/main/java/br/com/bravox/eval/Sentiment.java
new file mode 100644
index 0000000..7e623ca
--- /dev/null
+++ b/spring-ia-course/src/main/java/br/com/bravox/eval/Sentiment.java
@@ -0,0 +1,5 @@
+package br.com.bravox.eval;
+
+public enum Sentiment {
+    POSITIVE, NEGATIVE, NEUTRAL;
+}
diff --git a/spring-ia-course/src/test/java/br/com/bravox/eval/SentimentAnalysisTest.java b/spring-ia-course/src/test/java/br/com/bravox/eval/SentimentAnalysisTest.java
new file mode 100644
index 0000000..3286f98
--- /dev/null
+++ b/spring-ia-course/src/test/java/br/com/bravox/eval/SentimentAnalysisTest.java
@@ -0,0 +1,35 @@
+package br.com.bravox.eval;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+@SpringBootTest
+public class SentimentAnalysisTest {
+
+    @Autowired
+    private ReviewService reviewService;
+
+    @Test
+    void testPositiveSentiment() {
+       var positiveReview = "I absolutely love the hotel, it was amazing";
+       var sentiment = reviewService.classifySentiment(positiveReview);
+       assertEquals(Sentiment.POSITIVE, sentiment, "the sentiment should be classified as positive.");
+    }
+
+    @Test
+    void testNegativeSentiment() {
+        var negativeReview = "This is the worst experience I've ever had. The product is terrible and broke immediately.";
+        var result = reviewService.classifySentiment(negativeReview);
+        assertEquals(Sentiment.NEGATIVE, result, "The sentiment should be classified as NEGATIVE.");
+    }
+
+    @Test
+    void testNeutralSentiment() {
+        var neutralReview = "The product is okay. It does what it says but nothing more.";
+        var result = reviewService.classifySentiment(neutralReview);
+        assertEquals(Sentiment.NEUTRAL, result, "The sentiment should be classified as NEUTRAL.");
+    }
+}
diff --git a/spring-ia-course/src/test/java/br/com/bravox/eval/StructuredOutputTest.java b/spring-ia-course/src/test/java/br/com/bravox/eval/StructuredOutputTest.java
new file mode 100644
index 0000000..4befb17
--- /dev/null
+++ b/spring-ia-course/src/test/java/br/com/bravox/eval/StructuredOutputTest.java
@@ -0,0 +1,4 @@
+package br.com.bravox.eval;
+
+public class StructuredOutputTest {
+}