Add structured output to OpenAI

Author: geoand

model-providers/openai/openai-vanilla/deployment/src/test/java/org/acme/examples/aiservices/StructuredOutputResponseTest.java

@@ -0,0 +1,84 @@
+package org.acme.examples.aiservices;
+
+import static java.time.Month.JULY;
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.InstanceOfAssertFactories.map;
+
+import java.io.IOException;
+import java.time.LocalDate;
+import java.util.Map;
+
+import jakarta.enterprise.context.ApplicationScoped;
+import jakarta.inject.Inject;
+
+import org.jboss.shrinkwrap.api.ShrinkWrap;
+import org.jboss.shrinkwrap.api.spec.JavaArchive;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.RegisterExtension;
+
+import dev.langchain4j.service.UserMessage;
+import io.quarkiverse.langchain4j.RegisterAiService;
+import io.quarkiverse.langchain4j.openai.testing.internal.OpenAiBaseTest;
+import io.quarkiverse.langchain4j.testing.internal.WiremockAware;
+import io.quarkus.test.QuarkusUnitTest;
+
+public class StructuredOutputResponseTest extends OpenAiBaseTest {
+
+    @RegisterExtension
+    static final QuarkusUnitTest unitTest = new QuarkusUnitTest()
+            .setArchiveProducer(
+                    () -> ShrinkWrap.create(JavaArchive.class))
+            .overrideRuntimeConfigKey("quarkus.langchain4j.openai.api-key", "whatever")
+            .overrideRuntimeConfigKey("quarkus.langchain4j.openai.chat-model.response-format", "json_schema")
+            .overrideRuntimeConfigKey("quarkus.langchain4j.openai.chat-model.strict-json-schema", "true")
+            .overrideRuntimeConfigKey("quarkus.langchain4j.openai.base-url",
+                    WiremockAware.wiremockUrlForConfig("/v1"));
+
+    record Person(String firstName, String lastName, LocalDate birthDate) {
+    }
+
+    @RegisterAiService
+    @ApplicationScoped
+    interface PersonExtractor {
+
+        @UserMessage("Extract information about a person from {{it}}")
+        Person extractPersonFrom(String text);
+    }
+
+    @Inject
+    PersonExtractor personExtractor;
+
+    @Test
+    public void testPojo() throws IOException {
+        setChatCompletionMessageContent(
+                // this is supposed to be a string inside a json string hence all the escaping...
+                "{\\n\\\"firstName\\\": \\\"John\\\",\\n\\\"lastName\\\": \\\"Doe\\\",\\n\\\"birthDate\\\": \\\"1968-07-04\\\"\\n}");
+
+        String text = "In 1968, amidst the fading echoes of Independence Day, "
+                + "a child named John arrived under the calm evening sky. "
+                + "This newborn, bearing the surname Doe, marked the start of a new journey.";
+
+        Person result = personExtractor.extractPersonFrom(text);
+
+        assertThat(result.firstName).isEqualTo("John");
+        assertThat(result.lastName).isEqualTo("Doe");
+        assertThat(result.birthDate).isEqualTo(LocalDate.of(1968, JULY, 4));
+
+        Map<String, Object> requestAsMap = getRequestAsMap();
+        assertSingleRequestMessage(requestAsMap,
+                "Extract information about a person from In 1968, amidst the fading echoes of Independence Day, " +
+                        "a child named John arrived under the calm evening sky. This newborn, bearing the surname Doe, " +
+                        "marked the start of a new journey.");
+        assertThat(requestAsMap).hasEntrySatisfying("response_format", (v) -> {
+            assertThat(v).asInstanceOf(map(String.class, Object.class)).satisfies(responseFormatMap -> {
+                assertThat(responseFormatMap).containsEntry("type", "json_schema");
+                assertThat(responseFormatMap).extracting("json_schema").satisfies(js -> {
+                    assertThat(js).asInstanceOf(map(String.class, Object.class)).satisfies(jsonSchemaMap -> {
+                        assertThat(jsonSchemaMap).containsEntry("name", "Person").containsKey("schema");
+                    });
+                });
+            });
+        });
+
+    }
+}

model-providers/openai/openai-vanilla/runtime/src/main/java/io/quarkiverse/langchain4j/openai/runtime/OpenAiRecorder.java

@@ -85,6 +85,7 @@ public Function<SyntheticCreationalContext<ChatLanguageModel>, ChatLanguageModel
                     .presencePenalty(chatModelConfig.presencePenalty())
                     .frequencyPenalty(chatModelConfig.frequencyPenalty())
                     .responseFormat(chatModelConfig.responseFormat().orElse(null))
+                    .strictJsonSchema(chatModelConfig.strictJsonSchema().orElse(null))
                     .stop(chatModelConfig.stop().orElse(null));
 
             openAiConfig.organizationId().ifPresent(builder::organizationId);

model-providers/openai/openai-vanilla/runtime/src/main/java/io/quarkiverse/langchain4j/openai/runtime/config/ChatModelConfig.java

@@ -76,6 +76,11 @@ public interface ChatModelConfig {
      */
     Optional<String> responseFormat();
 
+    /**
+     * Whether responses follow JSON Schema for Structured Outputs
+     */
+    Optional<Boolean> strictJsonSchema();
+
     /**
      * The list of stop words to use.
      *