diff --git a/src/main/java/org/gcube/informationsystem/resourceregistry/queries/templates/ResourceRegistryQueryTemplateClientImpl.java b/src/main/java/org/gcube/informationsystem/resourceregistry/queries/templates/ResourceRegistryQueryTemplateClientImpl.java
index 0cf781f..df5f6f1 100644
--- a/src/main/java/org/gcube/informationsystem/resourceregistry/queries/templates/ResourceRegistryQueryTemplateClientImpl.java
+++ b/src/main/java/org/gcube/informationsystem/resourceregistry/queries/templates/ResourceRegistryQueryTemplateClientImpl.java
@@ -2,7 +2,9 @@ package org.gcube.informationsystem.resourceregistry.queries.templates;
 
 import java.net.HttpURLConnection;
 import java.util.ArrayList;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 
 import org.gcube.com.fasterxml.jackson.databind.JavaType;
 import org.gcube.com.fasterxml.jackson.databind.JsonNode;
@@ -29,19 +31,37 @@ public class ResourceRegistryQueryTemplateClientImpl implements ResourceRegistry
 	
 	private static final Logger logger = LoggerFactory.getLogger(ResourceRegistryQueryTemplateClientImpl.class);
 	
+	private static final String ACCEPT_HTTP_HEADER_KEY = "Accept";
+	private static final String CONTENT_TYPE_HTTP_HEADER_KEY = "Content-Type";
+	
 	protected final String address;
 	
+	protected Map<String, String> headers;
+	
+	public void addHeader(String name, String value) {
+		headers.put(name, value);
+	}
+	
+	protected GXHTTPStringRequest getGXHTTPStringRequest() {
+		GXHTTPStringRequest gxHTTPStringRequest = GXHTTPUtility.getGXHTTPStringRequest(address);
+		gxHTTPStringRequest.from(this.getClass().getSimpleName());
+		for(String name : headers.keySet()) {
+			gxHTTPStringRequest.header(name, headers.get(name));
+		}
+		return gxHTTPStringRequest;
+	}
+	
 	public ResourceRegistryQueryTemplateClientImpl(String address) {
 		this.address = address;
+		this.headers = new HashMap<>();
 	}
 	
 	@Override
 	public List<QueryTemplate> all() throws ResourceRegistryException {
 		try {
 			logger.trace("Going to list {}s", QueryTemplate.NAME);
-			GXHTTPStringRequest gxHTTPStringRequest = GXHTTPUtility.getGXHTTPStringRequest(address);
-			gxHTTPStringRequest.from(ResourceRegistryQueryTemplateClient.class.getSimpleName());
-			gxHTTPStringRequest.header("Accept", GXConnection.APPLICATION_JSON_CHARSET_UTF_8);
+			GXHTTPStringRequest gxHTTPStringRequest = getGXHTTPStringRequest();
+			gxHTTPStringRequest.header(ACCEPT_HTTP_HEADER_KEY, GXConnection.APPLICATION_JSON_CHARSET_UTF_8);
 			gxHTTPStringRequest.path(QueryTemplatePath.QUERY_TEMPLATES_PATH_PART);
 			
 			HttpURLConnection httpURLConnection = gxHTTPStringRequest.get();
@@ -80,10 +100,9 @@ public class ResourceRegistryQueryTemplateClientImpl implements ResourceRegistry
 			logger.trace("Going to create: {}", queryTemplate);
 			QueryTemplate qt = ElementMapper.unmarshal(QueryTemplate.class, queryTemplate);
 			
-			GXHTTPStringRequest gxHTTPStringRequest = GXHTTPUtility.getGXHTTPStringRequest(address);
-			gxHTTPStringRequest.from(ResourceRegistryQueryTemplateClient.class.getSimpleName());
-			gxHTTPStringRequest.header("Accept", GXConnection.APPLICATION_JSON_CHARSET_UTF_8);
-			gxHTTPStringRequest.header("Content-type", GXConnection.APPLICATION_JSON_CHARSET_UTF_8);
+			GXHTTPStringRequest gxHTTPStringRequest = getGXHTTPStringRequest();
+			gxHTTPStringRequest.header(ACCEPT_HTTP_HEADER_KEY, GXConnection.APPLICATION_JSON_CHARSET_UTF_8);
+			gxHTTPStringRequest.header(CONTENT_TYPE_HTTP_HEADER_KEY, GXConnection.APPLICATION_JSON_CHARSET_UTF_8);
 			gxHTTPStringRequest.path(QueryTemplatePath.QUERY_TEMPLATES_PATH_PART);
 			gxHTTPStringRequest.path(qt.getName());
 			
@@ -104,9 +123,8 @@ public class ResourceRegistryQueryTemplateClientImpl implements ResourceRegistry
 	public boolean exist(String queryTemplateName) throws ResourceRegistryException {
 		try {
 			logger.trace("Going to read {} with name {}", QueryTemplate.NAME, queryTemplateName);
-			GXHTTPStringRequest gxHTTPStringRequest = GXHTTPUtility.getGXHTTPStringRequest(address);
-			gxHTTPStringRequest.from(ResourceRegistryQueryTemplateClient.class.getSimpleName());
-			gxHTTPStringRequest.header("Accept", GXConnection.APPLICATION_JSON_CHARSET_UTF_8);
+			GXHTTPStringRequest gxHTTPStringRequest = getGXHTTPStringRequest();
+			gxHTTPStringRequest.header(ACCEPT_HTTP_HEADER_KEY, GXConnection.APPLICATION_JSON_CHARSET_UTF_8);
 			gxHTTPStringRequest.path(QueryTemplatePath.QUERY_TEMPLATES_PATH_PART);
 			gxHTTPStringRequest.path(queryTemplateName);
 			
@@ -148,9 +166,8 @@ public class ResourceRegistryQueryTemplateClientImpl implements ResourceRegistry
 	public String readAsString(String queryTemplateName) throws QueryTemplateNotFoundException, ResourceRegistryException {
 		try {
 			logger.trace("Going to read {} with name {}", QueryTemplate.NAME, queryTemplateName);
-			GXHTTPStringRequest gxHTTPStringRequest = GXHTTPUtility.getGXHTTPStringRequest(address);
-			gxHTTPStringRequest.from(ResourceRegistryQueryTemplateClient.class.getSimpleName());
-			gxHTTPStringRequest.header("Accept", GXConnection.APPLICATION_JSON_CHARSET_UTF_8);
+			GXHTTPStringRequest gxHTTPStringRequest = getGXHTTPStringRequest();
+			gxHTTPStringRequest.header(ACCEPT_HTTP_HEADER_KEY, GXConnection.APPLICATION_JSON_CHARSET_UTF_8);
 			gxHTTPStringRequest.path(QueryTemplatePath.QUERY_TEMPLATES_PATH_PART);
 			gxHTTPStringRequest.path(queryTemplateName);
 			
@@ -185,10 +202,9 @@ public class ResourceRegistryQueryTemplateClientImpl implements ResourceRegistry
 			logger.trace("Going to update: {}", queryTemplate);
 			QueryTemplate qt = ElementMapper.unmarshal(QueryTemplate.class, queryTemplate);
 			
-			GXHTTPStringRequest gxHTTPStringRequest = GXHTTPUtility.getGXHTTPStringRequest(address);
-			gxHTTPStringRequest.from(ResourceRegistryQueryTemplateClient.class.getSimpleName());
-			gxHTTPStringRequest.header("Accept", GXConnection.APPLICATION_JSON_CHARSET_UTF_8);
-			gxHTTPStringRequest.header("Content-type", GXConnection.APPLICATION_JSON_CHARSET_UTF_8);
+			GXHTTPStringRequest gxHTTPStringRequest = getGXHTTPStringRequest();
+			gxHTTPStringRequest.header(ACCEPT_HTTP_HEADER_KEY, GXConnection.APPLICATION_JSON_CHARSET_UTF_8);
+			gxHTTPStringRequest.header(CONTENT_TYPE_HTTP_HEADER_KEY, GXConnection.APPLICATION_JSON_CHARSET_UTF_8);
 			gxHTTPStringRequest.path(QueryTemplatePath.QUERY_TEMPLATES_PATH_PART);
 			gxHTTPStringRequest.path(qt.getName());
 			
@@ -238,10 +254,9 @@ public class ResourceRegistryQueryTemplateClientImpl implements ResourceRegistry
 				logger.trace("Going to run {} with the following parameters {}", QueryTemplate.NAME, params);
 			}
 			
-			GXHTTPStringRequest gxHTTPStringRequest = GXHTTPUtility.getGXHTTPStringRequest(address);
-			gxHTTPStringRequest.from(ResourceRegistryQueryTemplateClient.class.getSimpleName());
-			gxHTTPStringRequest.header("Accept", GXConnection.APPLICATION_JSON_CHARSET_UTF_8);
-			gxHTTPStringRequest.header("Content-type", GXConnection.APPLICATION_JSON_CHARSET_UTF_8);
+			GXHTTPStringRequest gxHTTPStringRequest = getGXHTTPStringRequest();
+			gxHTTPStringRequest.header(ACCEPT_HTTP_HEADER_KEY, GXConnection.APPLICATION_JSON_CHARSET_UTF_8);
+			gxHTTPStringRequest.header(CONTENT_TYPE_HTTP_HEADER_KEY, GXConnection.APPLICATION_JSON_CHARSET_UTF_8);
 			gxHTTPStringRequest.path(QueryTemplatePath.QUERY_TEMPLATES_PATH_PART);
 			gxHTTPStringRequest.path(name);
 			
@@ -285,9 +300,8 @@ public class ResourceRegistryQueryTemplateClientImpl implements ResourceRegistry
 	public boolean delete(String queryTemplateName) throws QueryTemplateNotFoundException, ResourceRegistryException {
 		try {
 			logger.trace("Going to delete {} with name {}", QueryTemplate.NAME, queryTemplateName);
-			GXHTTPStringRequest gxHTTPStringRequest = GXHTTPUtility.getGXHTTPStringRequest(address);
-			gxHTTPStringRequest.from(ResourceRegistryQueryTemplateClient.class.getSimpleName());
-			gxHTTPStringRequest.header("Accept", GXConnection.APPLICATION_JSON_CHARSET_UTF_8);
+			GXHTTPStringRequest gxHTTPStringRequest = getGXHTTPStringRequest();
+			gxHTTPStringRequest.header(ACCEPT_HTTP_HEADER_KEY, GXConnection.APPLICATION_JSON_CHARSET_UTF_8);
 			gxHTTPStringRequest.path(QueryTemplatePath.QUERY_TEMPLATES_PATH_PART);
 			gxHTTPStringRequest.path(queryTemplateName);