diff --git a/scm-core/src/main/java/sonia/scm/repository/api/HookException.java b/scm-core/src/main/java/sonia/scm/repository/api/HookException.java
new file mode 100644
index 0000000000..e17ec33621
--- /dev/null
+++ b/scm-core/src/main/java/sonia/scm/repository/api/HookException.java
@@ -0,0 +1,88 @@
+/**
+ * Copyright (c) 2010, Sebastian Sdorra All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer. 2. Redistributions in
+ * binary form must reproduce the above copyright notice, this list of
+ * conditions and the following disclaimer in the documentation and/or other
+ * materials provided with the distribution. 3. Neither the name of SCM-Manager;
+ * nor the names of its contributors may be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * http://bitbucket.org/sdorra/scm-manager
+ *
+ */
+
+
+
+package sonia.scm.repository.api;
+
+/**
+ * Base exception for all exceptions which can occur during the hook
+ * initialization.
+ *
+ * @author Sebastian Sdorra
+ * @since 1.33
+ */
+public class HookException extends RuntimeException
+{
+
+  /** Field description */
+  private static final long serialVersionUID = 2572704247316715734L;
+
+  //~--- constructors ---------------------------------------------------------
+
+  /**
+   * Constructs ...
+   *
+   */
+  public HookException() {}
+
+  /**
+   * Constructs ...
+   *
+   *
+   * @param message
+   */
+  public HookException(String message)
+  {
+    super(message);
+  }
+
+  /**
+   * Constructs ...
+   *
+   *
+   * @param cause
+   */
+  public HookException(Throwable cause)
+  {
+    super(cause);
+  }
+
+  /**
+   * Constructs ...
+   *
+   *
+   * @param message
+   * @param cause
+   */
+  public HookException(String message, Throwable cause)
+  {
+    super(message, cause);
+  }
+}
diff --git a/scm-core/src/main/java/sonia/scm/repository/api/HookFeatureIsNotSupportedException.java b/scm-core/src/main/java/sonia/scm/repository/api/HookFeatureIsNotSupportedException.java
new file mode 100644
index 0000000000..08f8d4bba3
--- /dev/null
+++ b/scm-core/src/main/java/sonia/scm/repository/api/HookFeatureIsNotSupportedException.java
@@ -0,0 +1,92 @@
+/**
+ * Copyright (c) 2010, Sebastian Sdorra All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer. 2. Redistributions in
+ * binary form must reproduce the above copyright notice, this list of
+ * conditions and the following disclaimer in the documentation and/or other
+ * materials provided with the distribution. 3. Neither the name of SCM-Manager;
+ * nor the names of its contributors may be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * http://bitbucket.org/sdorra/scm-manager
+ *
+ */
+
+
+
+package sonia.scm.repository.api;
+
+/**
+ * This exception is thrown if the underlying provider of the 
+ * {@link HookContext} does not support the requested {@link HookFeature}.
+ *
+ * @author Sebastian Sdorra
+ * @since 1.33
+ */
+public class HookFeatureIsNotSupportedException extends HookException
+{
+
+  /** Field description */
+  private static final long serialVersionUID = -7670872902321373610L;
+
+  //~--- constructors ---------------------------------------------------------
+
+  /**
+   * Constructs a new {@link HookFeatureIsNotSupportedException}.
+   *
+   *
+   * @param unsupportedFeature feature which is not supported
+   */
+  public HookFeatureIsNotSupportedException(HookFeature unsupportedFeature)
+  {
+    super(unsupportedFeature.toString().concat(" is not supported"));
+    this.unsupportedFeature = unsupportedFeature;
+  }
+
+  /**
+   * Constructs a new {@link HookFeatureIsNotSupportedException}.
+   *
+   *
+   * @param message message for the exception
+   * @param unsupportedFeature feature which is not supported
+   */
+  public HookFeatureIsNotSupportedException(String message,
+    HookFeature unsupportedFeature)
+  {
+    super(message);
+    this.unsupportedFeature = unsupportedFeature;
+  }
+
+  //~--- get methods ----------------------------------------------------------
+
+  /**
+   * Returns the feature which is not supported.
+   *
+   *
+   * @return unsupported hook feature
+   */
+  public HookFeature getUnsupportedFeature()
+  {
+    return unsupportedFeature;
+  }
+
+  //~--- fields ---------------------------------------------------------------
+
+  /** unsupported hook feature */
+  private HookFeature unsupportedFeature;
+}
diff --git a/scm-core/src/main/java/sonia/scm/repository/spi/HookContextProvider.java b/scm-core/src/main/java/sonia/scm/repository/spi/HookContextProvider.java
index 5d67715cd8..0bc91679b7 100644
--- a/scm-core/src/main/java/sonia/scm/repository/spi/HookContextProvider.java
+++ b/scm-core/src/main/java/sonia/scm/repository/spi/HookContextProvider.java
@@ -33,7 +33,9 @@ package sonia.scm.repository.spi;
 
 //~--- non-JDK imports --------------------------------------------------------
 
+import sonia.scm.repository.api.HookException;
 import sonia.scm.repository.api.HookFeature;
+import sonia.scm.repository.api.HookFeatureIsNotSupportedException;
 import sonia.scm.repository.api.HookMessageProvider;
 
 //~--- JDK imports ------------------------------------------------------------
@@ -56,16 +58,28 @@ public abstract class HookContextProvider
    */
   public final HookMessageProvider getMessageProvider()
   {
-    if (clientFinalization)
+    if (clientDisconnected)
     {
-
-      // TODO
-      throw new IllegalArgumentException();
+      throw new HookException(
+        "message provider is only available in a synchronous hook execution.");
     }
 
     return createMessageProvider();
   }
 
+  //~--- methods --------------------------------------------------------------
+
+  /**
+   * Method description
+   *
+   */
+  final void handleClientDisconnect()
+  {
+    clientDisconnected = true;
+  }
+
+  //~--- get methods ----------------------------------------------------------
+
   /**
    * Method description
    *
@@ -82,20 +96,12 @@ public abstract class HookContextProvider
    */
   public HookChangesetProvider getChangesetProvider()
   {
-    return null;
+    throw new HookFeatureIsNotSupportedException(
+      HookFeature.CHANGESET_PROVIDER);
   }
 
   //~--- methods --------------------------------------------------------------
 
-  /**
-   * Method description
-   *
-   */
-  void handleClientFinalization()
-  {
-    clientFinalization = true;
-  }
-
   /**
    * Method description
    *
@@ -104,11 +110,11 @@ public abstract class HookContextProvider
    */
   protected HookMessageProvider createMessageProvider()
   {
-    return null;
+    throw new HookFeatureIsNotSupportedException(HookFeature.MESSAGE_PROVIDER);
   }
 
   //~--- fields ---------------------------------------------------------------
 
   /** Field description */
-  private boolean clientFinalization = false;
+  private boolean clientDisconnected = false;
 }
diff --git a/scm-core/src/main/java/sonia/scm/repository/spi/HookEventFacade.java b/scm-core/src/main/java/sonia/scm/repository/spi/HookEventFacade.java
index 9c2f996786..a620e59882 100644
--- a/scm-core/src/main/java/sonia/scm/repository/spi/HookEventFacade.java
+++ b/scm-core/src/main/java/sonia/scm/repository/spi/HookEventFacade.java
@@ -169,7 +169,7 @@ public final class HookEventFacade
         new ExtendedRepositoryHookEvent(context, repository, type);
 
       repositoryManager.fireHookEvent(repository, event);
-      hookContextProvider.handleClientFinalization();
+      hookContextProvider.handleClientDisconnect();
     }
 
     //~--- fields -------------------------------------------------------------