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 df71ef0..a4e07e0 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
@@ -39,7 +39,7 @@ public FunctionController(FunctionService functionService) {
 	
 	@PostMapping(path="/books", produces = MediaType.APPLICATION_JSON_VALUE)
 	public FunctionResult postQuestion(@RequestBody FunctionSearch functionSearch) {
-		return new FunctionResult(this.functionService.functionCall(functionSearch.question()));
+		return this.functionService.functionCall(functionSearch.question(), functionSearch.resultFormat());
 	}
 	
 }
diff --git a/backend/src/main/java/ch/xxx/aidoclibchat/domain/model/dto/FunctionResult.java b/backend/src/main/java/ch/xxx/aidoclibchat/domain/model/dto/FunctionResult.java
index eac7b70..1cbc11a 100644
--- a/backend/src/main/java/ch/xxx/aidoclibchat/domain/model/dto/FunctionResult.java
+++ b/backend/src/main/java/ch/xxx/aidoclibchat/domain/model/dto/FunctionResult.java
@@ -12,4 +12,6 @@
  */
 package ch.xxx.aidoclibchat.domain.model.dto;
 
-public record FunctionResult(String result) { }
+import ch.xxx.aidoclibchat.usecase.service.FunctionService.JsonResult;
+
+public record FunctionResult(String result, JsonResult jsonResult) { }
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 d08846c..7487969 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
@@ -12,6 +12,8 @@
  */
 package ch.xxx.aidoclibchat.usecase.service;
 
+import java.util.List;
+
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.ai.chat.client.ChatClient;
@@ -19,14 +21,28 @@
 import org.springframework.beans.factory.annotation.Value;
 import org.springframework.stereotype.Service;
 
+import com.fasterxml.jackson.annotation.JsonPropertyOrder;
+
+import ch.xxx.aidoclibchat.domain.model.dto.FunctionResult;
+import ch.xxx.aidoclibchat.domain.model.dto.FunctionSearch.ResultFormat;
+
 @Service
 public class FunctionService {
 	private static final Logger LOGGER = LoggerFactory.getLogger(FunctionService.class);
 	private final ChatClient chatClient;
+
+	@JsonPropertyOrder({ "title", "summary" })
+	public record JsonBook(String title, String summary) {
+	}
+
+	@JsonPropertyOrder({ "author", "books" })
+	public record JsonResult(String author, List<JsonBook> books) {
+	}
+
 	private final String promptStr = """
-			Make sure to have a parameter when calling a function. 
+			Make sure to have a parameter when calling a function.
 			If no parameter is provided ask the user for the parameter.
-			Create a summary for each book based on the function response subject.			
+			Create a summary for each book based on the function response subject.
 
 			User Query:
 			%s
@@ -39,13 +55,27 @@ public FunctionService(Builder builder) {
 		this.chatClient = builder.build();
 	}
 
-	public String functionCall(String question) {
+	public FunctionResult functionCall(String question, ResultFormat resultFormat) {
 		if (!this.activeProfile.contains("ollama")) {
-			return "";
+			return new FunctionResult(" ", null);
 		}
 
-		var result = this.chatClient.prompt().user(this.promptStr + question).functions("openLibraryClient").call().content();
+		FunctionResult result = switch (resultFormat) {
+		case ResultFormat.Text -> this.functionCallText(question);
+		case ResultFormat.Json -> this.functionCallJson(question);
+		};
 		return result;
 	}
 
+	private FunctionResult functionCallText(String question) {
+		var result = this.chatClient.prompt().user(this.promptStr + question).functions("openLibraryClient").call()
+				.content();
+		return new FunctionResult(result, null);
+	}
+
+	private FunctionResult functionCallJson(String question) {
+		var result = this.chatClient.prompt().user(this.promptStr + question).functions("openLibraryClient").call()
+				.entity(JsonResult.class);
+		return new FunctionResult(null, result);
+	}
 }
diff --git a/frontend/src/angular/src/app/function-search/function-search.component.html b/frontend/src/angular/src/app/function-search/function-search.component.html
index 5b5dd4a..80b6e6b 100644
--- a/frontend/src/angular/src/app/function-search/function-search.component.html
+++ b/frontend/src/angular/src/app/function-search/function-search.component.html
@@ -60,7 +60,7 @@
   </div>
 </div>
 } @else {
-<p class="result-text">{{response}}</p>
+<p class="result-text">{{responseText}}</p>
 <!-- 
 <mat-tree
   [dataSource]="dataSource"
diff --git a/frontend/src/angular/src/app/function-search/function-search.component.ts b/frontend/src/angular/src/app/function-search/function-search.component.ts
index 361530e..908bcf2 100644
--- a/frontend/src/angular/src/app/function-search/function-search.component.ts
+++ b/frontend/src/angular/src/app/function-search/function-search.component.ts
@@ -70,7 +70,7 @@ export class FunctionSearchComponent {
     (node) => node.children
   );
   protected dataSource = new MatTreeNestedDataSource<TreeNode>();
-  protected response = '';
+  protected responseText = '';
   protected resultFormats = ['text','json'];
   protected resultFormatControl = new FormControl(this.resultFormats[0]);
 
@@ -110,7 +110,7 @@ export class FunctionSearchComponent {
         takeUntilDestroyed(this.destroyRef),
         tap(() => (this.searching = false))
       )
-	  .subscribe(value => this.response = value.result
+	  .subscribe(value => this.responseText = value.result ?? ''
 	  );
       //.subscribe((value) => (this.dataSource.data = this.mapResult(value)));
   }
diff --git a/frontend/src/angular/src/app/model/functions.ts b/frontend/src/angular/src/app/model/functions.ts
index f18705b..be34d9c 100644
--- a/frontend/src/angular/src/app/model/functions.ts
+++ b/frontend/src/angular/src/app/model/functions.ts
@@ -37,5 +37,16 @@ export interface FunctionResponse {
 }
 
 export interface FunctionResult {
-	result: string;
+	result?: string;
+	jsonResult?: JsonResult;
+}
+
+export interface JsonResult {
+	author: string;
+	books: JsonBook[];
+}
+
+export interface JsonBook {
+	title: string;
+	summary: string;
 }
\ No newline at end of file