diff --git a/src/main/java/com/taboola/backstage/internal/FieldsValidator.java b/src/main/java/com/taboola/backstage/internal/FieldsValidator.java
index cca1260..4d1d72b 100644
--- a/src/main/java/com/taboola/backstage/internal/FieldsValidator.java
+++ b/src/main/java/com/taboola/backstage/internal/FieldsValidator.java
@@ -60,7 +60,7 @@ private static void validate(Object obj, Map<Class<?>, BiFunction<Object, Field,
                         }
 
                     } catch (IllegalAccessException e) {
-                        logger.error("Failed to pull field data from field [{}] for annotation [{}]", field.getName(), annotation);
+                        logger.error("Failed to pull field data from field [{}] for annotation [{}]", field.getName(), annotation.toString());
                     }
                 }
             }
diff --git a/src/main/java/com/taboola/backstage/internal/factories/BackstageEndpointsRetrofitFactory.java b/src/main/java/com/taboola/backstage/internal/factories/BackstageEndpointsRetrofitFactory.java
index 177feb4..476b0e2 100644
--- a/src/main/java/com/taboola/backstage/internal/factories/BackstageEndpointsRetrofitFactory.java
+++ b/src/main/java/com/taboola/backstage/internal/factories/BackstageEndpointsRetrofitFactory.java
@@ -25,14 +25,14 @@ public BackstageEndpointsRetrofitFactory(CommunicationFactory communicationFacto
     @Override
     public <A> A createAuthEndpoint(Class<A> clazz) {
         Objects.requireNonNull(clazz, "clazz");
-        logger.debug("creating authentication endpoint using retrofit for class [{}]", clazz);
+        logger.debug("creating authentication endpoint using retrofit for class [{}]", clazz::toString);
         return communicationFactory.createRetrofitAuthEndpoint(clazz);
     }
 
     @Override
     public <E> E createEndpoint(Class<E> clazz) {
         Objects.requireNonNull(clazz, "clazz");
-        logger.debug("creating endpoint using retrofit for class [{}]", clazz);
+        logger.debug("creating endpoint using retrofit for class [{}]", clazz::toString);
         return communicationFactory.createRetrofitEndpoint(clazz);
     }
 }
diff --git a/src/main/java/com/taboola/backstage/services/AuthenticationService.java b/src/main/java/com/taboola/backstage/services/AuthenticationService.java
index 337044f..8913dd8 100644
--- a/src/main/java/com/taboola/backstage/services/AuthenticationService.java
+++ b/src/main/java/com/taboola/backstage/services/AuthenticationService.java
@@ -59,6 +59,16 @@ public interface AuthenticationService {
      */
     BackstageAuthentication reAuthenticate(BackstageAuthentication auth) throws BackstageAPIUnauthorizedException, BackstageAPIConnectivityException, BackstageAPIRequestException;
 
+
+    /**
+     * Creates {@link BackstageAuthentication} based on received access token string.
+     * <p>Keep in mind after such authentication it is NOT possible to use {@link #reAuthenticate(BackstageAuthentication) reAuthenticate} method.</p>
+     *
+     * @param accessToken supplied by authentication {@link com.taboola.backstage.model.auth.Token Token}
+     * @return {@link BackstageAuthentication} object which is being required by all services
+     */
+    BackstageAuthentication authenticate(String accessToken);
+
     /**
      * Specific {@link com.taboola.backstage.model.auth.Token Token} metadata
      *
diff --git a/src/main/java/com/taboola/backstage/services/AuthenticationServiceImpl.java b/src/main/java/com/taboola/backstage/services/AuthenticationServiceImpl.java
index cb08406..7619ef1 100644
--- a/src/main/java/com/taboola/backstage/services/AuthenticationServiceImpl.java
+++ b/src/main/java/com/taboola/backstage/services/AuthenticationServiceImpl.java
@@ -6,6 +6,8 @@
 import com.taboola.backstage.model.auth.*;
 import com.taboola.backstage.internal.BackstageAuthenticationEndpoint;
 
+import java.util.Objects;
+
 /**
  * Created by vladi
  * Date: 10/14/2017
@@ -35,8 +37,17 @@ public BackstageAuthentication passwordAuthentication(String clientId, String cl
     @Override
     public BackstageAuthentication reAuthenticate(BackstageAuthentication auth) throws BackstageAPIUnauthorizedException, BackstageAPIConnectivityException, BackstageAPIRequestException {
         AuthenticationDetails details = auth.getDetails();
+        if(details == null) {
+            throw new IllegalStateException("Can't reAuthenticate without authentication details");
+        }
+
+        GrantType grantType = details.getGrantType();
+        if(grantType == null) {
+            throw new IllegalStateException("Unknown grant type");
+        }
+
         //In order to save some usability pain paying here with down cast...
-        switch (details.getGrantType()) {
+        switch (grantType) {
             case CLIENT_CREDENTIALS:
                 if(details instanceof ClientCredentialAuthenticationDetails) {
                     ClientCredentialAuthenticationDetails clientCredentialDetails = (ClientCredentialAuthenticationDetails) details;
@@ -58,6 +69,14 @@ public BackstageAuthentication reAuthenticate(BackstageAuthentication auth) thro
         }
     }
 
+    @Override
+    public BackstageAuthentication authenticate(String accessToken) {
+        Objects.requireNonNull(accessToken, "accessToken");
+        Token token = new Token();
+        token.setAccessToken(accessToken);
+        return new BackstageAuthentication(null, token);
+    }
+
     @Override
     public TokenDetails getTokenDetails(BackstageAuthentication auth) throws BackstageAPIUnauthorizedException, BackstageAPIConnectivityException, BackstageAPIRequestException {
         return endpoint.getTokenDetails(auth.getToken().getAccessTokenForHeader());
diff --git a/src/test/java/com/taboola/backstage/services/AuthenticationServiceImplTest.java b/src/test/java/com/taboola/backstage/services/AuthenticationServiceImplTest.java
index 4bb8dd4..019a7db 100644
--- a/src/test/java/com/taboola/backstage/services/AuthenticationServiceImplTest.java
+++ b/src/test/java/com/taboola/backstage/services/AuthenticationServiceImplTest.java
@@ -148,4 +148,22 @@ public GrantType getGrantType() {
 
         testInstance.reAuthenticate(invalidInstance);
     }
+
+    @Test(expected = IllegalStateException.class)
+    public void testInvalidGrantType_expectingException() {
+        BackstageAuthentication invalidInstance = new BackstageAuthentication(null, new Token());
+        testInstance.reAuthenticate(invalidInstance);
+    }
+
+    @Test(expected = IllegalStateException.class)
+    public void testNullAuthenticationDetails_expectingException() {
+        BackstageAuthentication invalidInstance = new BackstageAuthentication(new AuthenticationDetails(GrantType.CLIENT_CREDENTIALS) {
+            @Override
+            public GrantType getGrantType() {
+               return null;
+            }
+        }, new Token());
+
+        testInstance.reAuthenticate(invalidInstance);
+    }
 }