diff --git a/backend/src/main/java/ch/xxx/aidoclibchat/adapter/controller/FunctionController.java b/backend/src/main/java/ch/xxx/aidoclibchat/adapter/controller/FunctionController.java
index 938e8e4..79dce4e 100644
--- a/backend/src/main/java/ch/xxx/aidoclibchat/adapter/controller/FunctionController.java
+++ b/backend/src/main/java/ch/xxx/aidoclibchat/adapter/controller/FunctionController.java
@@ -17,6 +17,7 @@
 import org.springframework.web.bind.annotation.RequestParam;
 import org.springframework.web.bind.annotation.RestController;
 
+import ch.xxx.aidoclibchat.domain.client.OpenLibraryClient;
 import ch.xxx.aidoclibchat.usecase.service.FunctionService;
 
 @RestController
@@ -29,8 +30,8 @@ public FunctionController(FunctionService functionService) {
 	}
 	
 	//example: http://localhost:8080/rest/function/books?question=show+books+of+author+kevin+rudd+with+title+avoidable+war
-	@GetMapping("/books")
-	public String postQuestion(@RequestParam(name="question", defaultValue = "") String question) {
+	@GetMapping(path =  "/books", produces = "application/json")
+	public OpenLibraryClient.Response postQuestion(@RequestParam(name="question", defaultValue = "") String question) {
 		return this.functionService.functionCall(question);
 	}
 	
diff --git a/backend/src/main/java/ch/xxx/aidoclibchat/domain/client/OpenLibraryClient.java b/backend/src/main/java/ch/xxx/aidoclibchat/domain/client/OpenLibraryClient.java
index 232576f..ba88aa0 100644
--- a/backend/src/main/java/ch/xxx/aidoclibchat/domain/client/OpenLibraryClient.java
+++ b/backend/src/main/java/ch/xxx/aidoclibchat/domain/client/OpenLibraryClient.java
@@ -19,7 +19,16 @@
 
 public interface OpenLibraryClient extends Function<OpenLibraryClient.Request, OpenLibraryClient.Response> {
 	@JsonIgnoreProperties(ignoreUnknown = true)
-	record Book(@JsonProperty(value= "author_name", required = false) List<String> authorName) {}
+	record Book(@JsonProperty(value= "author_name", required = false) List<String> authorName,
+			@JsonProperty(value= "language", required = false) List<String> languages,
+			@JsonProperty(value= "publish_date", required = false) List<String> publishDates,
+			@JsonProperty(value= "publisher", required = false) List<String> publishers, 
+			String title, String type,
+			@JsonProperty(value= "subject", required = false) List<String> subjects,
+			@JsonProperty(value= "place", required = false) List<String> places,
+			@JsonProperty(value= "time", required = false) List<String> times,
+			@JsonProperty(value= "person", required = false) List<String> persons,
+			@JsonProperty(value= "ratings_average", required = false) Double ratingsAverage) {}
 	@JsonInclude(Include.NON_NULL)
 	@JsonClassDescription("OpenLibrary API request")
 	record Request(@JsonProperty(required=false, value="author") @JsonPropertyDescription("The book author") String author,
diff --git a/backend/src/main/java/ch/xxx/aidoclibchat/usecase/service/FunctionService.java b/backend/src/main/java/ch/xxx/aidoclibchat/usecase/service/FunctionService.java
index 58b5b4a..6cd967d 100644
--- a/backend/src/main/java/ch/xxx/aidoclibchat/usecase/service/FunctionService.java
+++ b/backend/src/main/java/ch/xxx/aidoclibchat/usecase/service/FunctionService.java
@@ -29,6 +29,7 @@
 
 import ch.xxx.aidoclibchat.domain.client.OpenLibraryClient;
 import ch.xxx.aidoclibchat.domain.client.OpenLibraryClient.FunctionTool.Type;
+import ch.xxx.aidoclibchat.domain.client.OpenLibraryClient.Response;
 
 @Service
 public class FunctionService {
@@ -75,9 +76,9 @@ public FunctionService(ObjectMapper objectMapper, ChatClient chatClient, OpenLib
 		this.openLibraryClient = openLibraryClient;
 	}
 
-	public String functionCall(String question) {
+	public Response functionCall(String question) {
 		if (!this.activeProfile.contains("ollama")) {
-			return "false";
+			return new Response(0L, 0L, false, List.of());
 		}
 		var description = "Search for books by author, title or subject.";
 		var name = "booksearch";
@@ -91,7 +92,7 @@ public String functionCall(String question) {
 		}
 		var query = String.format(this.promptStr, jsonStr, question);
 		int aiCallCounter = 0;
-		var responseRef = new AtomicReference<String>("false");
+		var responseRef = new AtomicReference<Response>(new Response(0L, 0L, false, List.of()));
 		List<Tool> myToolsList = List.of();
 		while (aiCallCounter < 3 && myToolsList.isEmpty()) {
 			aiCallCounter += 1;
@@ -118,12 +119,13 @@ public String functionCall(String question) {
 				LOGGER.error("ChatResponse: {}", response);
 			}
 		}
+		
 		myToolsList.forEach(myTool -> {
 			var myRequest = new OpenLibraryClient.Request((String) myTool.toolInput().get("author"),
 					(String) myTool.toolInput().get("title"), (String) myTool.toolInput().get("subject"));
 			var myResponse = this.openLibraryClient.apply(myRequest);
 			//LOGGER.info(myResponse.toString());
-			responseRef.set(myResponse.toString());
+			responseRef.set(myResponse);
 		});
 		return responseRef.get();
 	}