diff --git a/src/main/java/org/gcube/oidc/rest/OpenIdConnectRESTHelper.java b/src/main/java/org/gcube/oidc/rest/OpenIdConnectRESTHelper.java
index 8c2ba3d..c8d2161 100644
--- a/src/main/java/org/gcube/oidc/rest/OpenIdConnectRESTHelper.java
+++ b/src/main/java/org/gcube/oidc/rest/OpenIdConnectRESTHelper.java
@@ -13,6 +13,7 @@ import java.net.ProtocolException;
 import java.net.URL;
 import java.net.URLEncoder;
 import java.util.Arrays;
+import java.util.Base64;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -58,6 +59,15 @@ public class OpenIdConnectRESTHelper {
         return q;
     }
 
+    /**
+     * Queries from the OIDC server an OIDC access token, by using provided clientId and client secret.
+     * 
+     * @param clientId the client id
+     * @param clientSecret the client secret
+     * @param tokenUrl the token endpoint {@link URL} of the OIDC server
+     * @return the issued token
+     * @throws OpenIdConnectRESTHelperException if an error occurs (also an unauthorized call), inspect the exception for details
+     */
     public static JWTToken queryClientToken(String clientId, String clientSecret, URL tokenURL)
             throws OpenIdConnectRESTHelperException {
 
@@ -88,7 +98,7 @@ public class OpenIdConnectRESTHelper {
         return performQueryTokenWithPOST(tokenURL, null, params);
     }
 
-    public static JWTToken performQueryTokenWithPOST(URL tokenURL, String authorization,
+    protected static JWTToken performQueryTokenWithPOST(URL tokenURL, String authorization,
             Map<String, List<String>> params) throws OpenIdConnectRESTHelperException {
 
         logger.debug("Querying access token from OIDC server with URL: {}", tokenURL);
@@ -154,7 +164,37 @@ public class OpenIdConnectRESTHelper {
         return con;
     }
 
-    public static JWTToken queryUMAToken(URL tokenUrl, String authorizationToken, String audience,
+    /**
+     * Queries from the OIDC server an UMA token, by using provided clientId and client secret for the given audience
+     * (context) in URLEncoded form and optionally a list of permissions.
+     * 
+     * @param tokenUrl the token endpoint {@link URL} of the OIDC server
+     * @param clientId the client id
+     * @param clientSecret the client secret
+     * @param audience the audience (context) where to request the issuing of the ticket
+     * @param permissions a list of permissions, can be <code>null</code>
+     * @return the issued token
+     * @throws OpenIdConnectRESTHelperException if an error occurs (also an unauthorized call), inspect the exception for details
+     */
+    public static JWTToken queryUMAToken(URL tokenUrl, String clientId, String clientSecret, String audience,
+            List<String> permissions) throws OpenIdConnectRESTHelperException {
+
+        return queryUMAToken(tokenUrl, "Basic " + Base64.getEncoder().encodeToString((clientId + ":" + clientSecret).getBytes()),
+                audience, permissions);
+    }
+
+    /**
+     * Queries from the OIDC server an UMA token, by using provided access token, for the given audience (context)
+     * in URLEncoded form and optionally a list of permissions.
+     * 
+     * @param tokenUrl the token endpoint {@link URL} of the OIDC server
+     * @param authorization the auth token (the access token URLEncoded by the "Bearer " string)
+     * @param audience the audience (context) where to request the issuing of the ticket (URLEncoded)
+     * @param permissions a list of permissions, can be <code>null</code>
+     * @return the issued token
+     * @throws OpenIdConnectRESTHelperException if an error occurs (also an unauthorized call), inspect the exception for details
+     */
+    public static JWTToken queryUMAToken(URL tokenUrl, String authorization, String audience,
             List<String> permissions) throws OpenIdConnectRESTHelperException {
 
         Map<String, List<String>> params = new HashMap<>();
@@ -174,18 +214,45 @@ public class OpenIdConnectRESTHelper {
                         }
                     }).collect(Collectors.toList()));
         }
-        return performQueryTokenWithPOST(tokenUrl, authorizationToken, params);
+        return performQueryTokenWithPOST(tokenUrl, authorization, params);
     }
 
+    /**
+     * Refreshes the token from the OIDC server.
+     * 
+     * @param tokenUrl the token endpoint {@link URL} of the OIDC server
+     * @param token the token to be refreshed
+     * @return a new token refreshed from the previous one
+     * @throws OpenIdConnectRESTHelperException if an error occurs (also an unauthorized call), inspect the exception for details
+     */
     public static JWTToken refreshToken(URL tokenURL, JWTToken token) throws OpenIdConnectRESTHelperException {
         return refreshToken(tokenURL, null, null, token);
     }
 
+    /**
+     * Refreshes the token from the OIDC server for a specific client represented by the client id.
+     * 
+     * @param tokenUrl the token endpoint {@link URL} of the OIDC server
+     * @param clientId the client id
+     * @param token the token to be refreshed
+     * @return a new token refreshed from the previous one
+     * @throws OpenIdConnectRESTHelperException if an error occurs (also an unauthorized call), inspect the exception for details
+     */
     public static JWTToken refreshToken(URL tokenURL, String clientId, JWTToken token)
             throws OpenIdConnectRESTHelperException {
         return refreshToken(tokenURL, clientId, null, token);
     }
 
+    /**
+     * Refreshes the token from the OIDC server for a specific client represented by the client id.
+     * 
+     * @param tokenUrl the token endpoint {@link URL} of the OIDC server
+     * @param clientId the client id
+     * @param clientSecret the client secret
+     * @param token the token to be refreshed
+     * @return a new token refreshed from the previous one
+     * @throws OpenIdConnectRESTHelperException if an error occurs (also an unauthorized call), inspect the exception for details
+     */
     public static JWTToken refreshToken(URL tokenURL, String clientId, String clientSecret, JWTToken token)
             throws OpenIdConnectRESTHelperException {
 
@@ -233,10 +300,27 @@ public class OpenIdConnectRESTHelper {
         }
     }
 
+    /**
+     * Performs the logout (SSOut) from all the sessions opened in the OIDC server.
+     * 
+     * @param logoutUrl the logut endpoint {@link URL} of the OIDC server
+     * @param token the token used to take info from
+     * @return <code>true</code> if the logout is performed correctly, <code>false</code> otherwise
+     * @throws IOException if an I/O error occurs during the communication with the server
+     */
     public static boolean logout(URL logoutUrl, JWTToken token) throws IOException {
         return logout(logoutUrl, null, token);
     }
 
+    /**
+     * Performs the logout from the session related to the provided client id in the OIDC server.
+     * 
+     * @param logoutUrl the logut endpoint {@link URL} of the OIDC server
+     * @param clientId the client id
+     * @param token the token used to take info from
+     * @return <code>true</code> if the logout is performed correctly, <code>false</code> otherwise
+     * @throws IOException if an I/O error occurs during the communication with the server
+     */
     public static boolean logout(URL logoutUrl, String clientId, JWTToken token) throws IOException {
         Map<String, List<String>> params = new HashMap<>();
         if (clientId == null) {
@@ -276,9 +360,9 @@ public class OpenIdConnectRESTHelper {
             }
             if (conn.getResponseCode() == 200) {
                 String contentType = conn.getContentType();
-    
+
                 logger.debug("Getting the stream to the avatar resource with MIME: {}", contentType);
-    
+
                 InputStream is = conn.getInputStream();
                 buffer = new ByteArrayOutputStream();
                 int nRead;
@@ -286,7 +370,7 @@ public class OpenIdConnectRESTHelper {
                 while ((nRead = is.read(data, 0, data.length)) != -1) {
                     buffer.write(data, 0, nRead);
                 }
-    
+
                 buffer.flush();
                 return buffer.toByteArray();
             } else {