test: [OpenAI] E2E Tool Call Execution

pom.xml

@@ -72,6 +72,7 @@
     <mockito.version>5.16.1</mockito.version>
     <javaparser.version>3.26.3</javaparser.version>
     <jsonschema-generator.version>4.38.0</jsonschema-generator.version>
+    <jackson.version>2.18.3</jackson.version>
     <!-- conflicts resolution -->
     <micrometer.version>1.14.2</micrometer.version>
     <json.version>20250107</json.version>
@@ -132,7 +133,12 @@
       <dependency>
         <groupId>com.fasterxml.jackson.module</groupId>
         <artifactId>jackson-module-parameter-names</artifactId>
-        <version>2.18.3</version>
+        <version>${jackson.version}</version>
+      </dependency>
+      <dependency>
+        <groupId>com.fasterxml.jackson.module</groupId>
+        <artifactId>jackson-module-jsonSchema</artifactId>
+        <version>${jackson.version}</version>
       </dependency>
       <dependency>
         <groupId>com.github.victools</groupId>

sample-code/spring-app/pom.xml

@@ -70,6 +70,10 @@
       <groupId>com.sap.cloud.sdk.cloudplatform</groupId>
       <artifactId>cloudplatform-core</artifactId>
     </dependency>
+    <dependency>
+      <groupId>com.sap.cloud.sdk.cloudplatform</groupId>
+      <artifactId>cloudplatform-connectivity</artifactId>
+    </dependency>
     <dependency>
       <groupId>com.sap.cloud.sdk.datamodel</groupId>
       <artifactId>openapi-core</artifactId>
@@ -131,6 +135,14 @@
       <groupId>com.fasterxml.jackson.core</groupId>
       <artifactId>jackson-annotations</artifactId>
     </dependency>
+    <dependency>
+      <groupId>com.fasterxml.jackson.module</groupId>
+      <artifactId>jackson-module-jsonSchema</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>com.fasterxml.jackson.core</groupId>
+      <artifactId>jackson-core</artifactId>
+    </dependency>
     <!-- scope "runtime" -->
     <dependency>
       <groupId>ch.qos.logback</groupId>
@@ -177,10 +189,6 @@
       <artifactId>assertj-core</artifactId>
       <scope>test</scope>
     </dependency>
-    <dependency>
-      <groupId>com.sap.cloud.sdk.cloudplatform</groupId>
-      <artifactId>cloudplatform-connectivity</artifactId>
-    </dependency>
   </dependencies>
 
   <build>

sample-code/spring-app/src/main/java/com/sap/ai/sdk/app/controllers/OpenAiController.java

@@ -120,11 +120,13 @@ Object chatCompletionImage(
     return response.getChoices().get(0).getMessage();
   }
 
-  @GetMapping("/chatCompletionTool")
+  @GetMapping("/chatCompletionToolExecution")
   @Nonnull
-  Object chatCompletionTools(
-      @Nullable @RequestParam(value = "format", required = false) final String format) {
-    final var response = service.chatCompletionTools(12);
+  Object chatCompletionToolExecution(
+      @Nullable @RequestParam(value = "format", required = false) final String format,
+      @Nonnull @RequestParam(value = "location", defaultValue = "Dubai") final String location,
+      @Nonnull @RequestParam(value = "unit", defaultValue = "°C") final String unit) {
+    final var response = service.chatCompletionToolExecution(location, unit);
     if ("json".equals(format)) {
       return response;
     }

sample-code/spring-app/src/main/java/com/sap/ai/sdk/app/services/OpenAiService.java

@@ -5,6 +5,11 @@
 import static com.sap.ai.sdk.foundationmodels.openai.OpenAiModel.TEXT_EMBEDDING_3_SMALL;
 import static com.sap.ai.sdk.foundationmodels.openai.model.OpenAiChatCompletionTool.ToolType.FUNCTION;
 
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.core.type.TypeReference;
+import com.fasterxml.jackson.databind.JsonMappingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.module.jsonSchema.JsonSchemaGenerator;
 import com.sap.ai.sdk.core.AiCoreService;
 import com.sap.ai.sdk.foundationmodels.openai.OpenAiClient;
 import com.sap.ai.sdk.foundationmodels.openai.model.OpenAiChatCompletionDelta;
@@ -13,8 +18,10 @@
 import com.sap.ai.sdk.foundationmodels.openai.model.OpenAiChatCompletionParameters;
 import com.sap.ai.sdk.foundationmodels.openai.model.OpenAiChatCompletionTool;
 import com.sap.ai.sdk.foundationmodels.openai.model.OpenAiChatMessage;
+import com.sap.ai.sdk.foundationmodels.openai.model.OpenAiChatToolCall;
 import com.sap.ai.sdk.foundationmodels.openai.model.OpenAiEmbeddingOutput;
 import com.sap.ai.sdk.foundationmodels.openai.model.OpenAiEmbeddingParameters;
+import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
 import java.util.stream.Stream;
@@ -26,6 +33,7 @@
 @Service
 @Slf4j
 public class OpenAiService {
+  private static final ObjectMapper JACKSON = new ObjectMapper();
 
   /**
    * Chat request to OpenAI
@@ -86,30 +94,79 @@ public OpenAiChatCompletionOutput chatCompletionImage(@Nonnull final String link
   }
 
   /**
-   * Chat request to OpenAI with a tool.
+   * Executes a chat completion request to OpenAI with a tool that calculates the weather.
    *
-   * @param months The number of months to be inferred in the tool
-   * @return the assistant message response
+   * @param location The location to get the weather for.
+   * @param unit The unit of temperature to use.
+   * @return The assistant message response.
    */
   @Nonnull
-  public OpenAiChatCompletionOutput chatCompletionTools(final int months) {
-    final var question =
-        "A pair of rabbits is placed in a field. Each month, every pair produces one new pair, starting from the second month. How many rabbits will there be after %s months?"
-            .formatted(months);
-    final var par = Map.of("type", "object", "properties", Map.of("N", Map.of("type", "integer")));
+  public OpenAiChatCompletionOutput chatCompletionToolExecution(
+      @Nonnull final String location, @Nonnull final String unit) {
+
+    // 1. Define the function
+    final Map<String, Object> schemaMap = generateSchema(WeatherMethod.Request.class);
     final var function =
         new OpenAiChatCompletionFunction()
-            .setName("fibonacci")
-            .setDescription("Calculate the Fibonacci number for given sequence index.")
-            .setParameters(par);
+            .setName("weather")
+            .setDescription("Get the weather for the given location")
+            .setParameters(schemaMap);
     final var tool = new OpenAiChatCompletionTool().setType(FUNCTION).setFunction(function);
+
+    final var messages = new ArrayList<OpenAiChatMessage>();
+    messages.add(
+        new OpenAiChatMessage.OpenAiChatUserMessage()
+            .addText("What's the weather in %s in %s?".formatted(location, unit)));
+
+    // Assistant will call the function
     final var request =
         new OpenAiChatCompletionParameters()
-            .addMessages(new OpenAiChatMessage.OpenAiChatUserMessage().addText(question))
-            .setTools(List.of(tool))
-            .setToolChoiceFunction("fibonacci");
+            .addMessages(messages.toArray(OpenAiChatMessage[]::new))
+            .setTools(List.of(tool));
+
+    final OpenAiChatCompletionOutput response =
+        OpenAiClient.forModel(GPT_4O_MINI).chatCompletion(request);
+
+    // 2. Optionally, execute the function.
+    final OpenAiChatToolCall toolCall =
+        response.getChoices().get(0).getMessage().getToolCalls().get(0);
+    final WeatherMethod.Request arguments =
+        parseJson(toolCall.getFunction().getArguments(), WeatherMethod.Request.class);
+    final WeatherMethod.Response currentWeather = WeatherMethod.getCurrentWeather(arguments);
+
+    final OpenAiChatMessage.OpenAiChatAssistantMessage assistantMessage =
+        response.getChoices().get(0).getMessage();
+    messages.add(assistantMessage);
+
+    final var toolMessage =
+        new OpenAiChatMessage.OpenAiChatToolMessage()
+            .setToolCallId(toolCall.getId())
+            .setContent(currentWeather.toString());
+    messages.add(toolMessage);
+
+    final var finalRequest =
+        new OpenAiChatCompletionParameters()
+            .addMessages(messages.toArray(OpenAiChatMessage[]::new));
+
+    return OpenAiClient.forModel(GPT_4O_MINI).chatCompletion(finalRequest);
+  }
+
+  private static <T> T parseJson(@Nonnull final String rawJson, @Nonnull final Class<T> clazz) {
+    try {
+      return JACKSON.readValue(rawJson, clazz);
+    } catch (JsonProcessingException e) {
+      throw new IllegalArgumentException("Failed to parse tool call arguments: " + rawJson, e);
+    }
+  }
 
-    return OpenAiClient.forModel(GPT_4O_MINI).chatCompletion(request);
+  private static Map<String, Object> generateSchema(@Nonnull final Class<?> clazz) {
+    final var jsonSchemaGenerator = new JsonSchemaGenerator(JACKSON);
+    try {
+      final var schema = jsonSchemaGenerator.generateSchema(clazz);
+      return JACKSON.convertValue(schema, new TypeReference<>() {});
+    } catch (JsonMappingException e) {
+      throw new IllegalArgumentException("Could not generate schema for " + clazz.getName(), e);
+    }
   }
 
   /**

sample-code/spring-app/src/test/java/com/sap/ai/sdk/app/services/OpenAiServiceV2.java → sample-code/spring-app/src/main/java/com/sap/ai/sdk/app/services/OpenAiServiceV2.java

@@ -5,18 +5,26 @@
 import static com.sap.ai.sdk.foundationmodels.openai.OpenAiModel.TEXT_EMBEDDING_3_SMALL;
 import static com.sap.ai.sdk.foundationmodels.openai.generated.model.ChatCompletionTool.TypeEnum.FUNCTION;
 
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.core.type.TypeReference;
+import com.fasterxml.jackson.databind.JsonMappingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.module.jsonSchema.JsonSchemaGenerator;
 import com.sap.ai.sdk.core.AiCoreService;
+import com.sap.ai.sdk.foundationmodels.openai.OpenAiAssistantMessage;
 import com.sap.ai.sdk.foundationmodels.openai.OpenAiChatCompletionDelta;
 import com.sap.ai.sdk.foundationmodels.openai.OpenAiChatCompletionRequest;
 import com.sap.ai.sdk.foundationmodels.openai.OpenAiChatCompletionResponse;
 import com.sap.ai.sdk.foundationmodels.openai.OpenAiClient;
 import com.sap.ai.sdk.foundationmodels.openai.OpenAiEmbeddingRequest;
 import com.sap.ai.sdk.foundationmodels.openai.OpenAiEmbeddingResponse;
+import com.sap.ai.sdk.foundationmodels.openai.OpenAiFunctionCall;
 import com.sap.ai.sdk.foundationmodels.openai.OpenAiImageItem;
 import com.sap.ai.sdk.foundationmodels.openai.OpenAiMessage;
-import com.sap.ai.sdk.foundationmodels.openai.OpenAiToolChoice;
+import com.sap.ai.sdk.foundationmodels.openai.OpenAiToolCall;
 import com.sap.ai.sdk.foundationmodels.openai.generated.model.ChatCompletionTool;
 import com.sap.ai.sdk.foundationmodels.openai.generated.model.FunctionObject;
+import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
 import java.util.stream.Stream;
@@ -28,6 +36,7 @@
 @Service
 @Slf4j
 public class OpenAiServiceV2 {
+  private static final ObjectMapper JACKSON = new ObjectMapper();
 
   /**
    * Chat request to OpenAI
@@ -84,30 +93,71 @@ public OpenAiChatCompletionResponse chatCompletionImage(@Nonnull final String li
   }
 
   /**
-   * Chat request to OpenAI with a tool.
+   * Executes a chat completion request to OpenAI with a tool that calculates the weather.
    *
-   * @param months The number of months to be inferred in the tool
-   * @return the assistant message response
+   * @param location The location to get the weather for.
+   * @param unit The unit of temperature to use.
+   * @return The assistant message response.
    */
   @Nonnull
-  public OpenAiChatCompletionResponse chatCompletionTools(final int months) {
+  public OpenAiChatCompletionResponse chatCompletionToolExecution(
+      @Nonnull final String location, @Nonnull final String unit) {
+
+    // 1. Define the function
+    final Map<String, Object> schemaMap = generateSchema(WeatherMethod.Request.class);
     final var function =
         new FunctionObject()
-            .name("fibonacci")
-            .description("Calculate the Fibonacci number for given sequence index.")
-            .parameters(
-                Map.of("type", "object", "properties", Map.of("N", Map.of("type", "integer"))));
-
+            .name("weather")
+            .description("Get the weather for the given location")
+            .parameters(schemaMap);
     final var tool = new ChatCompletionTool().type(FUNCTION).function(function);
 
-    final var request =
-        new OpenAiChatCompletionRequest(
-                "A pair of rabbits is placed in a field. Each month, every pair produces one new pair, starting from the second month. How many rabbits will there be after %s months?"
-                    .formatted(months))
-            .withTools(List.of(tool))
-            .withToolChoice(OpenAiToolChoice.function("fibonacci"));
+    final var messages = new ArrayList<OpenAiMessage>();
+    messages.add(OpenAiMessage.user("What's the weather in %s in %s?".formatted(location, unit)));
+
+    // Assistant will call the function
+    final var request = new OpenAiChatCompletionRequest(messages).withTools(List.of(tool));
+    final OpenAiChatCompletionResponse response =
+        OpenAiClient.forModel(GPT_4O_MINI).chatCompletion(request);
+
+    // 2. Optionally, execute the function.
+    final OpenAiAssistantMessage assistantMessage = response.getMessage();
+    messages.add(assistantMessage);
+
+    final OpenAiToolCall toolCall = assistantMessage.toolCalls().get(0);
+    if (!(toolCall instanceof OpenAiFunctionCall functionCall)) {
+      throw new IllegalArgumentException(
+          "Expected a function call, but got: %s".formatted(assistantMessage));
+    }
+
+    final WeatherMethod.Request arguments =
+        parseJson(functionCall.getArguments(), WeatherMethod.Request.class);
+    final WeatherMethod.Response weatherMethod = WeatherMethod.getCurrentWeather(arguments);
 
-    return OpenAiClient.forModel(GPT_4O_MINI).chatCompletion(request);
+    messages.add(OpenAiMessage.tool(weatherMethod.toString(), functionCall.getId()));
+
+    // Send back the results, and the model will incorporate them into its final response.
+    return OpenAiClient.forModel(GPT_4O_MINI).chatCompletion(request.withMessages(messages));
+  }
+
+  @Nonnull
+  private static <T> T parseJson(@Nonnull final String rawJson, @Nonnull final Class<T> clazz) {
+    try {
+      return JACKSON.readValue(rawJson, clazz);
+    } catch (JsonProcessingException e) {
+      throw new IllegalArgumentException("Failed to parse tool call arguments: " + rawJson, e);
+    }
+  }
+
+  @Nonnull
+  private static Map<String, Object> generateSchema(@Nonnull final Class<?> clazz) {
+    final var jsonSchemaGenerator = new JsonSchemaGenerator(JACKSON);
+    try {
+      final var schema = jsonSchemaGenerator.generateSchema(clazz);
+      return JACKSON.convertValue(schema, new TypeReference<>() {});
+    } catch (JsonMappingException e) {
+      throw new IllegalArgumentException("Could not generate schema for " + clazz.getName(), e);
+    }
   }
 
   /**

sample-code/spring-app/src/main/java/com/sap/ai/sdk/app/services/WeatherMethod.java

@@ -35,7 +35,7 @@ record Response(double temp, Unit unit) {}
   @Nonnull
   @SuppressWarnings("unused")
   @Tool(description = "Get the weather in location")
-  Response getCurrentWeather(@ToolParam @Nonnull final Request request) {
+  static Response getCurrentWeather(@ToolParam @Nonnull final Request request) {
     final int temperature = request.location.hashCode() % 30;
     return new Response(temperature, request.unit);
   }

sample-code/spring-app/src/main/resources/static/index.html

@@ -569,12 +569,12 @@ <h5 class="mb-1">OpenAI</h5>
                             </li>
                             <li class="list-group-item">
                                 <div class="info-tooltip">
-                                    <button type="submit" formaction="/chatCompletionTool"
+                                    <button type="submit" formaction="/chatCompletionToolExecution"
                                             class="link-offset-2-hover link-underline link-underline-opacity-0 link-underline-opacity-75-hover endpoint">
-                                        <code>/chatCompletionTool</code>
+                                        <code>/chatCompletionToolExecution</code>
                                     </button>
                                     <div class="tooltip-content">
-                                        Chat request to OpenAI with a tool.
+                                        Chat request to OpenAI with an executed tool call.
                                     </div>
                                 </div>
                             </li>

sample-code/spring-app/src/test/java/com/sap/ai/sdk/app/controllers/OpenAiTest.java

@@ -73,16 +73,6 @@ void streamChatCompletion() {
     assertThat(totalOutput.getChoices().get(0).getContentFilterResults()).isNotNull();
   }
 
-  @Test
-  void chatCompletionTools() {
-    final var completion = service.chatCompletionTools(12);
-
-    final var message = completion.getChoices().get(0).getMessage();
-    assertThat(message.getRole()).isEqualTo("assistant");
-    assertThat(message.getToolCalls()).isNotNull();
-    assertThat(message.getToolCalls().get(0).getFunction().getName()).isEqualTo("fibonacci");
-  }
-
   @Test
   void embedding() {
     final var embedding = service.embedding("Hello world");
@@ -101,4 +91,13 @@ void chatCompletionWithResource() {
     assertThat(message.getRole()).isEqualTo("assistant");
     assertThat(message.getContent()).isNotEmpty();
   }
+
+  @Test
+  void chatCompletionToolExecution() {
+    final var completion = service.chatCompletionToolExecution("Dubai", "°C");
+
+    String content = completion.getContent();
+
+    assertThat(content).contains("°C");
+  }
 }