diff --git a/.gitignore b/.gitignore
index 3517dbc..c58fcc7 100755
--- a/.gitignore
+++ b/.gitignore
@@ -8,24 +8,4 @@ hs_err*.log
 application.properties
 usernames.txt
 
-# IDEs and editors
-.idea/
-.project
-.classpath
-.c9/
-*.launch
-.settings/
-*.sublime-workspace
-
-# Visual Studio Code
 .vscode
-.vscode/*
-!.vscode/settings.json
-!.vscode/tasks.json
-!.vscode/launch.json
-!.vscode/extensions.json
-.history/*
-
-# System files
-.DS_Store
-Thumbs.db
\ No newline at end of file
diff --git a/application/pom.xml b/application/pom.xml
index e931b24..93aa76e 100755
--- a/application/pom.xml
+++ b/application/pom.xml
@@ -130,6 +130,16 @@
 				</dependency>
 			</dependencies>
 		</profile>
+		<profile>
+			<id>developer</id>
+			<dependencies>
+				<dependency>
+					<groupId>de.bstly.we</groupId>
+					<artifactId>webstly-developer</artifactId>
+					<version>${revision}</version>
+				</dependency>
+			</dependencies>
+		</profile>
 	</profiles>
 
 	<build>
diff --git a/core/src/main/java/de/bstly/we/controller/support/JsonStringBodyControllerAdvice.java b/core/src/main/java/de/bstly/we/controller/support/JsonStringBodyControllerAdvice.java
index 1a24a6d..2e7ceae 100644
--- a/core/src/main/java/de/bstly/we/controller/support/JsonStringBodyControllerAdvice.java
+++ b/core/src/main/java/de/bstly/we/controller/support/JsonStringBodyControllerAdvice.java
@@ -7,19 +7,19 @@ import java.io.IOException;
 import java.lang.reflect.Type;
 
 import org.springframework.core.MethodParameter;
-import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpInputMessage;
+import org.springframework.http.HttpStatus;
 import org.springframework.http.MediaType;
 import org.springframework.http.converter.HttpMessageConverter;
-import org.springframework.http.converter.StringHttpMessageConverter;
 import org.springframework.http.server.ServerHttpRequest;
 import org.springframework.http.server.ServerHttpResponse;
+import org.springframework.util.MimeType;
 import org.springframework.web.bind.annotation.ControllerAdvice;
 import org.springframework.web.servlet.mvc.method.annotation.RequestBodyAdvice;
 import org.springframework.web.servlet.mvc.method.annotation.ResponseBodyAdvice;
 
-import com.google.gson.Gson;
-import com.google.gson.JsonPrimitive;
+import com.google.gson.JsonElement;
+import com.google.gson.JsonParser;
 
 /**
  * The Class JsonStringBodyControllerAdvice.
@@ -27,8 +27,6 @@ import com.google.gson.JsonPrimitive;
 @ControllerAdvice
 public class JsonStringBodyControllerAdvice implements RequestBodyAdvice, ResponseBodyAdvice<String> {
 
-	private Gson gson = new Gson();
-
 	/*
 	 * @see org.springframework.web.servlet.mvc.method.annotation.RequestBodyAdvice#
 	 * supports(org.springframework.core.MethodParameter, java.lang.reflect.Type,
@@ -49,6 +47,11 @@ public class JsonStringBodyControllerAdvice implements RequestBodyAdvice, Respon
 	@Override
 	public HttpInputMessage beforeBodyRead(HttpInputMessage inputMessage, MethodParameter parameter, Type targetType,
 			Class<? extends HttpMessageConverter<?>> converterType) throws IOException {
+		if (inputMessage.getHeaders() == null || inputMessage.getHeaders().getContentType() == null || !inputMessage
+				.getHeaders().getContentType().equalsTypeAndSubtype(MimeType.valueOf("application/json"))) {
+			throw new EntityResponseStatusException(HttpStatus.UNSUPPORTED_MEDIA_TYPE);
+		}
+
 		return inputMessage;
 	}
 
@@ -84,7 +87,7 @@ public class JsonStringBodyControllerAdvice implements RequestBodyAdvice, Respon
 	 */
 	@Override
 	public boolean supports(MethodParameter returnType, Class<? extends HttpMessageConverter<?>> converterType) {
-		return converterType == StringHttpMessageConverter.class;
+		return returnType.getParameterType() == String.class;
 	}
 
 	/*
@@ -99,8 +102,11 @@ public class JsonStringBodyControllerAdvice implements RequestBodyAdvice, Respon
 	public String beforeBodyWrite(String body, MethodParameter returnType, MediaType selectedContentType,
 			Class<? extends HttpMessageConverter<?>> selectedConverterType, ServerHttpRequest request,
 			ServerHttpResponse response) {
-		response.getHeaders().set(HttpHeaders.CONTENT_TYPE, MediaType.APPLICATION_JSON_VALUE);
-		return gson.toJson(new JsonPrimitive(body));
+		if (body == null) {
+			return "";
+		}
+		JsonElement json = JsonParser.parseString(body);
+		return json.toString();
 	}
 
 }
\ No newline at end of file
diff --git a/developer/pom.xml b/developer/pom.xml
new file mode 100755
index 0000000..2020597
--- /dev/null
+++ b/developer/pom.xml
@@ -0,0 +1,31 @@
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	<parent>
+		<groupId>de.bstly.we</groupId>
+		<artifactId>webstly-main</artifactId>
+		<version>${revision}</version>
+	</parent>
+
+	<properties>
+		<springdoc-openapi-ui.version>1.6.9</springdoc-openapi-ui.version>
+	</properties>
+	
+	<name>developer</name>
+	<artifactId>webstly-developer</artifactId>
+
+	<dependencies>
+		<dependency>
+			<groupId>de.bstly.we</groupId>
+			<artifactId>webstly-core</artifactId>
+			<version>${revision}</version>
+		</dependency>
+
+		<dependency>
+			<groupId>org.springdoc</groupId>
+			<artifactId>springdoc-openapi-ui</artifactId>
+			<version>${springdoc-openapi-ui.version}</version>
+		</dependency>
+	</dependencies>
+</project>
diff --git a/developer/src/main/java/de/bstly/we/developer/SpringDocConfig.java b/developer/src/main/java/de/bstly/we/developer/SpringDocConfig.java
new file mode 100644
index 0000000..0500c7a
--- /dev/null
+++ b/developer/src/main/java/de/bstly/we/developer/SpringDocConfig.java
@@ -0,0 +1,51 @@
+/**
+ * 
+ */
+package de.bstly.we.developer;
+
+import org.springdoc.core.GroupedOpenApi;
+import org.springdoc.core.GroupedOpenApi.Builder;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.info.BuildProperties;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+import io.swagger.v3.oas.models.OpenAPI;
+import io.swagger.v3.oas.models.info.Contact;
+import io.swagger.v3.oas.models.info.Info;
+
+/**
+ * The SpringDocConfig Class.
+ */
+@Configuration
+public class SpringDocConfig {
+
+	@Autowired
+	private BuildProperties buildProperties;
+
+	/**
+	 * api.
+	 *
+	 * @return GroupedOpenApi
+	 */
+	@Bean
+	public GroupedOpenApi api() {
+		Builder builder = GroupedOpenApi.builder();
+		builder.group("<ALL MODULES>").packagesToScan("de.bstly.we");
+		return builder.build();
+	}
+
+	/**
+	 * apiInfo.
+	 *
+	 * @return OpenAPI
+	 */
+	@Bean
+	public OpenAPI apiInfo() {
+		return new OpenAPI()
+				.info(new Info()
+						.title("we.bstly - Api").contact(new Contact().name("Bastelei e. V.")
+								.url("https://www.bstly.de").email("api@bstly.de"))
+						.version(buildProperties.getVersion()));
+	}
+}
diff --git a/pom.xml b/pom.xml
index c6fbb1e..c6957b9 100755
--- a/pom.xml
+++ b/pom.xml
@@ -28,6 +28,7 @@
 		<module>application</module>
 		<module>borrow</module>
 		<module>core</module>
+		<module>developer</module>
 		<module>dyndns</module>
 		<module>email</module>
 		<module>i18n</module>