diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..ea5889f
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,5 @@
+/.classpath
+/.project
+/.buckd
+/buck-cache
+/buck-out
diff --git a/BUCK b/BUCK
new file mode 100644
index 0000000..d77534a
--- /dev/null
+++ b/BUCK
@@ -0,0 +1,9 @@
+gerrit_plugin(
+  name = 'hooks',
+  srcs = glob(['src/main/java/**/*.java']),
+  resources = glob(['src/main/resources/**/*']),
+  manifest_entries = [
+    'Gerrit-PluginName: hooks',
+    'Gerrit-Module: com.googlesource.gerrit.plugins.hooks.Module'
+  ]
+)
diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..11069ed
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,201 @@
+                              Apache License
+                        Version 2.0, January 2004
+                     http://www.apache.org/licenses/
+
+TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+1. Definitions.
+
+   "License" shall mean the terms and conditions for use, reproduction,
+   and distribution as defined by Sections 1 through 9 of this document.
+
+   "Licensor" shall mean the copyright owner or entity authorized by
+   the copyright owner that is granting the License.
+
+   "Legal Entity" shall mean the union of the acting entity and all
+   other entities that control, are controlled by, or are under common
+   control with that entity. For the purposes of this definition,
+   "control" means (i) the power, direct or indirect, to cause the
+   direction or management of such entity, whether by contract or
+   otherwise, or (ii) ownership of fifty percent (50%) or more of the
+   outstanding shares, or (iii) beneficial ownership of such entity.
+
+   "You" (or "Your") shall mean an individual or Legal Entity
+   exercising permissions granted by this License.
+
+   "Source" form shall mean the preferred form for making modifications,
+   including but not limited to software source code, documentation
+   source, and configuration files.
+
+   "Object" form shall mean any form resulting from mechanical
+   transformation or translation of a Source form, including but
+   not limited to compiled object code, generated documentation,
+   and conversions to other media types.
+
+   "Work" shall mean the work of authorship, whether in Source or
+   Object form, made available under the License, as indicated by a
+   copyright notice that is included in or attached to the work
+   (an example is provided in the Appendix below).
+
+   "Derivative Works" shall mean any work, whether in Source or Object
+   form, that is based on (or derived from) the Work and for which the
+   editorial revisions, annotations, elaborations, or other modifications
+   represent, as a whole, an original work of authorship. For the purposes
+   of this License, Derivative Works shall not include works that remain
+   separable from, or merely link (or bind by name) to the interfaces of,
+   the Work and Derivative Works thereof.
+
+   "Contribution" shall mean any work of authorship, including
+   the original version of the Work and any modifications or additions
+   to that Work or Derivative Works thereof, that is intentionally
+   submitted to Licensor for inclusion in the Work by the copyright owner
+   or by an individual or Legal Entity authorized to submit on behalf of
+   the copyright owner. For the purposes of this definition, "submitted"
+   means any form of electronic, verbal, or written communication sent
+   to the Licensor or its representatives, including but not limited to
+   communication on electronic mailing lists, source code control systems,
+   and issue tracking systems that are managed by, or on behalf of, the
+   Licensor for the purpose of discussing and improving the Work, but
+   excluding communication that is conspicuously marked or otherwise
+   designated in writing by the copyright owner as "Not a Contribution."
+
+   "Contributor" shall mean Licensor and any individual or Legal Entity
+   on behalf of whom a Contribution has been received by Licensor and
+   subsequently incorporated within the Work.
+
+2. Grant of Copyright License. Subject to the terms and conditions of
+   this License, each Contributor hereby grants to You a perpetual,
+   worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+   copyright license to reproduce, prepare Derivative Works of,
+   publicly display, publicly perform, sublicense, and distribute the
+   Work and such Derivative Works in Source or Object form.
+
+3. Grant of Patent License. Subject to the terms and conditions of
+   this License, each Contributor hereby grants to You a perpetual,
+   worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+   (except as stated in this section) patent license to make, have made,
+   use, offer to sell, sell, import, and otherwise transfer the Work,
+   where such license applies only to those patent claims licensable
+   by such Contributor that are necessarily infringed by their
+   Contribution(s) alone or by combination of their Contribution(s)
+   with the Work to which such Contribution(s) was submitted. If You
+   institute patent litigation against any entity (including a
+   cross-claim or counterclaim in a lawsuit) alleging that the Work
+   or a Contribution incorporated within the Work constitutes direct
+   or contributory patent infringement, then any patent licenses
+   granted to You under this License for that Work shall terminate
+   as of the date such litigation is filed.
+
+4. Redistribution. You may reproduce and distribute copies of the
+   Work or Derivative Works thereof in any medium, with or without
+   modifications, and in Source or Object form, provided that You
+   meet the following conditions:
+
+   (a) You must give any other recipients of the Work or
+       Derivative Works a copy of this License; and
+
+   (b) You must cause any modified files to carry prominent notices
+       stating that You changed the files; and
+
+   (c) You must retain, in the Source form of any Derivative Works
+       that You distribute, all copyright, patent, trademark, and
+       attribution notices from the Source form of the Work,
+       excluding those notices that do not pertain to any part of
+       the Derivative Works; and
+
+   (d) If the Work includes a "NOTICE" text file as part of its
+       distribution, then any Derivative Works that You distribute must
+       include a readable copy of the attribution notices contained
+       within such NOTICE file, excluding those notices that do not
+       pertain to any part of the Derivative Works, in at least one
+       of the following places: within a NOTICE text file distributed
+       as part of the Derivative Works; within the Source form or
+       documentation, if provided along with the Derivative Works; or,
+       within a display generated by the Derivative Works, if and
+       wherever such third-party notices normally appear. The contents
+       of the NOTICE file are for informational purposes only and
+       do not modify the License. You may add Your own attribution
+       notices within Derivative Works that You distribute, alongside
+       or as an addendum to the NOTICE text from the Work, provided
+       that such additional attribution notices cannot be construed
+       as modifying the License.
+
+   You may add Your own copyright statement to Your modifications and
+   may provide additional or different license terms and conditions
+   for use, reproduction, or distribution of Your modifications, or
+   for any such Derivative Works as a whole, provided Your use,
+   reproduction, and distribution of the Work otherwise complies with
+   the conditions stated in this License.
+
+5. Submission of Contributions. Unless You explicitly state otherwise,
+   any Contribution intentionally submitted for inclusion in the Work
+   by You to the Licensor shall be under the terms and conditions of
+   this License, without any additional terms or conditions.
+   Notwithstanding the above, nothing herein shall supersede or modify
+   the terms of any separate license agreement you may have executed
+   with Licensor regarding such Contributions.
+
+6. Trademarks. This License does not grant permission to use the trade
+   names, trademarks, service marks, or product names of the Licensor,
+   except as required for reasonable and customary use in describing the
+   origin of the Work and reproducing the content of the NOTICE file.
+
+7. Disclaimer of Warranty. Unless required by applicable law or
+   agreed to in writing, Licensor provides the Work (and each
+   Contributor provides its Contributions) on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+   implied, including, without limitation, any warranties or conditions
+   of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+   PARTICULAR PURPOSE. You are solely responsible for determining the
+   appropriateness of using or redistributing the Work and assume any
+   risks associated with Your exercise of permissions under this License.
+
+8. Limitation of Liability. In no event and under no legal theory,
+   whether in tort (including negligence), contract, or otherwise,
+   unless required by applicable law (such as deliberate and grossly
+   negligent acts) or agreed to in writing, shall any Contributor be
+   liable to You for damages, including any direct, indirect, special,
+   incidental, or consequential damages of any character arising as a
+   result of this License or out of the use or inability to use the
+   Work (including but not limited to damages for loss of goodwill,
+   work stoppage, computer failure or malfunction, or any and all
+   other commercial damages or losses), even if such Contributor
+   has been advised of the possibility of such damages.
+
+9. Accepting Warranty or Additional Liability. While redistributing
+   the Work or Derivative Works thereof, You may choose to offer,
+   and charge a fee for, acceptance of support, warranty, indemnity,
+   or other liability obligations and/or rights consistent with this
+   License. However, in accepting such obligations, You may act only
+   on Your own behalf and on Your sole responsibility, not on behalf
+   of any other Contributor, and only if You agree to indemnify,
+   defend, and hold each Contributor harmless for any liability
+   incurred by, or claims asserted against, such Contributor by reason
+   of your accepting any such warranty or additional liability.
+
+END OF TERMS AND CONDITIONS
+
+APPENDIX: How to apply the Apache License to your work.
+
+   To apply the Apache License to your work, attach the following
+   boilerplate notice, with the fields enclosed by brackets "[]"
+   replaced with your own identifying information. (Don't include
+   the brackets!)  The text should be enclosed in the appropriate
+   comment syntax for the file format. We also recommend that a
+   file or class name and description of purpose be included on the
+   same "printed page" as the copyright notice for easier
+   identification within third-party archives.
+
+Copyright [yyyy] [name of copyright owner]
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
diff --git a/src/main/java/com/googlesource/gerrit/plugins/hooks/AgreementSignup.java b/src/main/java/com/googlesource/gerrit/plugins/hooks/AgreementSignup.java
new file mode 100644
index 0000000..3953bf6
--- /dev/null
+++ b/src/main/java/com/googlesource/gerrit/plugins/hooks/AgreementSignup.java
@@ -0,0 +1,46 @@
+// Copyright (C) 2016 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.googlesource.gerrit.plugins.hooks;
+
+import com.google.gerrit.extensions.common.AccountInfo;
+import com.google.gerrit.extensions.events.AgreementSignupListener;
+import com.google.inject.Inject;
+import com.google.inject.Singleton;
+
+@Singleton
+class AgreementSignup implements AgreementSignupListener {
+  private final AsynchronousHook hook;
+  private final HookFactory hookFactory;
+
+  @Inject
+  AgreementSignup(HookFactory hookFactory) {
+    this.hook = hookFactory.createAsync("claSignedHook", "cla-signed");
+    this.hookFactory = hookFactory;
+  }
+
+  @Override
+  public void onAgreementSignup(AgreementSignupListener.Event event) {
+    AccountInfo submitter = event.getAccount();
+    if (submitter != null) {
+      HookArgs args = hookFactory.createArgs();
+
+      args.add("--submitter", submitter);
+      args.add("--user-id", submitter._accountId);
+      args.add("--cla-name", event.getAgreementName());
+
+      hook.submit(args);
+    }
+  }
+}
diff --git a/src/main/java/com/googlesource/gerrit/plugins/hooks/AsynchronousHook.java b/src/main/java/com/googlesource/gerrit/plugins/hooks/AsynchronousHook.java
new file mode 100644
index 0000000..c581642
--- /dev/null
+++ b/src/main/java/com/googlesource/gerrit/plugins/hooks/AsynchronousHook.java
@@ -0,0 +1,34 @@
+// Copyright (C) 2016 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.googlesource.gerrit.plugins.hooks;
+
+import java.nio.file.Path;
+
+public class AsynchronousHook extends Hook {
+  private final HookQueue queue;
+
+  AsynchronousHook(HookQueue queue, Path path) {
+    super(path);
+    this.queue = queue;
+  }
+
+  void submit(HookArgs args) {
+    queue.submit(path, args);
+  }
+
+  void submit(String projectName, HookArgs args) {
+    queue.submit(projectName, path, args);
+  }
+}
diff --git a/src/main/java/com/googlesource/gerrit/plugins/hooks/ChangeAbandoned.java b/src/main/java/com/googlesource/gerrit/plugins/hooks/ChangeAbandoned.java
new file mode 100644
index 0000000..03a9f0b
--- /dev/null
+++ b/src/main/java/com/googlesource/gerrit/plugins/hooks/ChangeAbandoned.java
@@ -0,0 +1,50 @@
+// Copyright (C) 2016 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.googlesource.gerrit.plugins.hooks;
+
+import com.google.gerrit.extensions.common.ChangeInfo;
+import com.google.gerrit.extensions.events.ChangeAbandonedListener;
+import com.google.inject.Inject;
+import com.google.inject.Singleton;
+
+@Singleton
+class ChangeAbandoned implements ChangeAbandonedListener {
+  private final AsynchronousHook hook;
+  private final HookFactory hookFactory;
+
+  @Inject
+  ChangeAbandoned(HookFactory hookFactory) {
+    this.hook = hookFactory.createAsync("changeAbandonedHook", "change-abandoned");
+    this.hookFactory = hookFactory;
+  }
+
+  @Override
+  public void onChangeAbandoned(ChangeAbandonedListener.Event event) {
+    HookArgs args = hookFactory.createArgs();
+
+    ChangeInfo c = event.getChange();
+    args.add("--change", c.id);
+    args.addUrl(c);
+    args.add("--change-owner", c.owner);
+    args.add("--project", c.project);
+    args.add("--branch", c.branch);
+    args.add("--topic", c.topic);
+    args.add("--abandoner", event.getAbandoner());
+    args.add("--commit", c.currentRevision);
+    args.add("--reason", event.getReason());
+
+    hook.submit(c.project, args);
+  }
+}
diff --git a/src/main/java/com/googlesource/gerrit/plugins/hooks/ChangeMerged.java b/src/main/java/com/googlesource/gerrit/plugins/hooks/ChangeMerged.java
new file mode 100644
index 0000000..a31ba97
--- /dev/null
+++ b/src/main/java/com/googlesource/gerrit/plugins/hooks/ChangeMerged.java
@@ -0,0 +1,50 @@
+// Copyright (C) 2016 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.googlesource.gerrit.plugins.hooks;
+
+import com.google.gerrit.extensions.common.ChangeInfo;
+import com.google.gerrit.extensions.events.ChangeMergedListener;
+import com.google.inject.Inject;
+import com.google.inject.Singleton;
+
+@Singleton
+class ChangeMerged implements ChangeMergedListener {
+  private final AsynchronousHook hook;
+  private final HookFactory hookFactory;
+
+  @Inject
+  ChangeMerged(HookFactory hookFactory) {
+    this.hook = hookFactory.createAsync("changeMergedHook", "change-merged");
+    this.hookFactory = hookFactory;
+  }
+
+  @Override
+  public void onChangeMerged(ChangeMergedListener.Event event) {
+    HookArgs args = hookFactory.createArgs();
+
+    ChangeInfo c = event.getChange();
+    args.add("--change", c.id);
+    args.addUrl(c);
+    args.add("--change-owner", c.owner);
+    args.add("--project", c.project);
+    args.add("--branch", c.branch);
+    args.add("--topic", c.topic);
+    args.add("--submitter", event.getMerger());
+    args.add("--commit", c.currentRevision);
+    args.add("--newrev", event.getNewRevisionId());
+
+    hook.submit(c.project, args);
+  }
+}
diff --git a/src/main/java/com/googlesource/gerrit/plugins/hooks/ChangeRestored.java b/src/main/java/com/googlesource/gerrit/plugins/hooks/ChangeRestored.java
new file mode 100644
index 0000000..3b717cb
--- /dev/null
+++ b/src/main/java/com/googlesource/gerrit/plugins/hooks/ChangeRestored.java
@@ -0,0 +1,50 @@
+// Copyright (C) 2016 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.googlesource.gerrit.plugins.hooks;
+
+import com.google.gerrit.extensions.common.ChangeInfo;
+import com.google.gerrit.extensions.events.ChangeRestoredListener;
+import com.google.inject.Inject;
+import com.google.inject.Singleton;
+
+@Singleton
+class ChangeRestored implements ChangeRestoredListener {
+  private final AsynchronousHook hook;
+  private final HookFactory hookFactory;
+
+  @Inject
+  ChangeRestored(HookFactory hookFactory) {
+    this.hook = hookFactory.createAsync("changeRestoredHook", "change-restored");
+    this.hookFactory = hookFactory;
+  }
+
+  @Override
+  public void onChangeRestored(ChangeRestoredListener.Event event) {
+    HookArgs args = hookFactory.createArgs();
+
+    ChangeInfo c = event.getChange();
+    args.add("--change", c.id);
+    args.addUrl(c);
+    args.add("--change-owner", c.owner);
+    args.add("--project", c.project);
+    args.add("--branch", c.branch);
+    args.add("--topic", c.topic);
+    args.add("--restorer", event.getRestorer());
+    args.add("--commit", c.currentRevision);
+    args.add("--reason", event.getReason());
+
+    hook.submit(c.project, args);
+  }
+}
diff --git a/src/main/java/com/googlesource/gerrit/plugins/hooks/CommentAdded.java b/src/main/java/com/googlesource/gerrit/plugins/hooks/CommentAdded.java
new file mode 100644
index 0000000..9e1e6ed
--- /dev/null
+++ b/src/main/java/com/googlesource/gerrit/plugins/hooks/CommentAdded.java
@@ -0,0 +1,52 @@
+// Copyright (C) 2016 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.googlesource.gerrit.plugins.hooks;
+
+import com.google.gerrit.extensions.common.ChangeInfo;
+import com.google.gerrit.extensions.events.CommentAddedListener;
+import com.google.inject.Inject;
+import com.google.inject.Singleton;
+
+@Singleton
+class CommentAdded implements CommentAddedListener {
+  private final AsynchronousHook hook;
+  private final HookFactory hookFactory;
+
+  @Inject
+  CommentAdded(HookFactory hookFactory) {
+    this.hook = hookFactory.createAsync("commentAddedHook", "comment-added");
+    this.hookFactory = hookFactory;
+  }
+
+  @Override
+  public void onCommentAdded(CommentAddedListener.Event event) {
+    HookArgs args = hookFactory.createArgs();
+
+    ChangeInfo c = event.getChange();
+    args.add("--change", c.id);
+    args.add("--is-draft", event.getRevision().draft);
+    args.addUrl(c);
+    args.add("--change-owner", c.owner);
+    args.add("--project", c.project);
+    args.add("--branch", c.branch);
+    args.add("--topic", c.topic);
+    args.add("--author", event.getAuthor());
+    args.add("--commit", event.getRevision().commit.commit);
+    args.add("--comment", event.getComment());
+    args.addApprovals(event.getApprovals(), event.getOldApprovals());
+
+    hook.submit(c.project, args);
+  }
+}
diff --git a/src/main/java/com/googlesource/gerrit/plugins/hooks/CommitReceived.java b/src/main/java/com/googlesource/gerrit/plugins/hooks/CommitReceived.java
new file mode 100644
index 0000000..8f8ea57
--- /dev/null
+++ b/src/main/java/com/googlesource/gerrit/plugins/hooks/CommitReceived.java
@@ -0,0 +1,79 @@
+// Copyright (C) 2016 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.googlesource.gerrit.plugins.hooks;
+
+import static com.google.gerrit.reviewdb.client.RefNames.REFS_CHANGES;
+import static org.eclipse.jgit.lib.Constants.R_HEADS;
+
+import com.google.gerrit.server.IdentifiedUser;
+import com.google.gerrit.server.events.CommitReceivedEvent;
+import com.google.gerrit.server.git.validators.CommitValidationException;
+import com.google.gerrit.server.git.validators.CommitValidationListener;
+import com.google.gerrit.server.git.validators.CommitValidationMessage;
+import com.google.inject.Inject;
+
+import org.eclipse.jgit.lib.ObjectId;
+
+import java.util.Collections;
+import java.util.List;
+
+public class CommitReceived implements CommitValidationListener {
+  private final SynchronousHook hook;
+  private final HookFactory hookFactory;
+
+  @Inject
+  CommitReceived(HookFactory hookFactory) {
+    this.hook = hookFactory.createSync("refUpdateHook", "ref-update");
+    this.hookFactory = hookFactory;
+  }
+
+  @Override
+  public List<CommitValidationMessage> onCommitReceived(
+      CommitReceivedEvent receiveEvent) throws CommitValidationException {
+    IdentifiedUser user = receiveEvent.user;
+    String refname = receiveEvent.refName;
+    ObjectId old = ObjectId.zeroId();
+    if (receiveEvent.commit.getParentCount() > 0) {
+      old = receiveEvent.commit.getParent(0);
+    }
+
+    if (receiveEvent.command.getRefName().startsWith(REFS_CHANGES)) {
+      /*
+      * If the ref-update hook tries to distinguish behavior between pushes to
+      * refs/heads/... and refs/for/..., make sure we send it the correct
+      * refname.
+      * Also, if this is targetting refs/for/, make sure we behave the same as
+      * what a push to refs/for/ would behave; in particular, setting oldrev
+      * to 0000000000000000000000000000000000000000.
+      */
+      refname = refname.replace(R_HEADS, "refs/for/refs/heads/");
+      old = ObjectId.zeroId();
+    }
+
+    HookArgs args = hookFactory.createArgs();
+    args.add("--project", receiveEvent.project.getName());
+    args.add("--refname", refname);
+    args.add("--uploader", user.getNameEmail());
+    args.add("--oldrev", old.name());
+    args.add("--newrev", receiveEvent.commit.name());
+
+    HookResult result = hook.run(args);
+    if (result != null && result.getExitValue() != 0) {
+      throw new CommitValidationException(result.toString().trim());
+    }
+
+    return Collections.emptyList();
+  }
+}
diff --git a/src/main/java/com/googlesource/gerrit/plugins/hooks/DraftPublished.java b/src/main/java/com/googlesource/gerrit/plugins/hooks/DraftPublished.java
new file mode 100644
index 0000000..f948dcc
--- /dev/null
+++ b/src/main/java/com/googlesource/gerrit/plugins/hooks/DraftPublished.java
@@ -0,0 +1,50 @@
+// Copyright (C) 2016 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.googlesource.gerrit.plugins.hooks;
+
+import com.google.gerrit.extensions.common.ChangeInfo;
+import com.google.gerrit.extensions.events.DraftPublishedListener;
+import com.google.inject.Inject;
+import com.google.inject.Singleton;
+
+@Singleton
+class DraftPublished implements DraftPublishedListener {
+  private final AsynchronousHook hook;
+  private final HookFactory hookFactory;
+
+  @Inject
+  DraftPublished(HookFactory hookFactory) {
+    this.hook = hookFactory.createAsync("draftPublishedHook", "draft-published");
+    this.hookFactory = hookFactory;
+  }
+
+  @Override
+  public void onDraftPublished(DraftPublishedListener.Event event) {
+    HookArgs args = hookFactory.createArgs();
+
+    ChangeInfo c = event.getChange();
+    args.add("--change", c.id);
+    args.addUrl(c);
+    args.add("--change-owner", c.owner);
+    args.add("--project", c.project);
+    args.add("--branch", c.branch);
+    args.add("--topic", c.topic);
+    args.add("--uploader", event.getPublisher());
+    args.add("--commit", event.getRevision().commit.commit);
+    args.add("--patchset", event.getRevision()._number);
+
+    hook.submit(c.project, args);
+  }
+}
diff --git a/src/main/java/com/googlesource/gerrit/plugins/hooks/GitReferenceUpdated.java b/src/main/java/com/googlesource/gerrit/plugins/hooks/GitReferenceUpdated.java
new file mode 100644
index 0000000..cf1a10d
--- /dev/null
+++ b/src/main/java/com/googlesource/gerrit/plugins/hooks/GitReferenceUpdated.java
@@ -0,0 +1,44 @@
+// Copyright (C) 2016 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.googlesource.gerrit.plugins.hooks;
+
+import com.google.gerrit.extensions.events.GitReferenceUpdatedListener;
+import com.google.inject.Inject;
+import com.google.inject.Singleton;
+
+@Singleton
+class GitReferenceUpdated implements GitReferenceUpdatedListener {
+  private final AsynchronousHook hook;
+  private final HookFactory hookFactory;
+
+  @Inject
+  GitReferenceUpdated(HookFactory hookFactory) {
+    this.hook = hookFactory.createAsync("refUpdatedHook", "ref-updated");
+    this.hookFactory = hookFactory;
+  }
+
+  @Override
+  public void onGitReferenceUpdated(GitReferenceUpdatedListener.Event event) {
+    HookArgs args = hookFactory.createArgs();
+
+    args.add("--oldrev", event.getOldObjectId());
+    args.add("--newrev", event.getNewObjectId());
+    args.add("--refname", event.getRefName());
+    args.add("--project", event.getProjectName());
+    args.add("--submitter", event.getUpdater());
+
+    hook.submit(event.getProjectName(), args);
+  }
+}
diff --git a/src/main/java/com/googlesource/gerrit/plugins/hooks/HashtagsEdited.java b/src/main/java/com/googlesource/gerrit/plugins/hooks/HashtagsEdited.java
new file mode 100644
index 0000000..401c5d6
--- /dev/null
+++ b/src/main/java/com/googlesource/gerrit/plugins/hooks/HashtagsEdited.java
@@ -0,0 +1,57 @@
+// Copyright (C) 2016 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.googlesource.gerrit.plugins.hooks;
+
+import com.google.gerrit.extensions.common.ChangeInfo;
+import com.google.gerrit.extensions.events.HashtagsEditedListener;
+import com.google.inject.Inject;
+import com.google.inject.Singleton;
+
+import java.util.Collection;
+
+@Singleton
+class HashtagsEdited implements HashtagsEditedListener {
+  private final AsynchronousHook hook;
+  private final HookFactory hookFactory;
+
+  @Inject
+  HashtagsEdited(HookFactory hookFactory) {
+    this.hook = hookFactory.createAsync("hashtagsChanged", "hashtags-changed");
+    this.hookFactory = hookFactory;
+  }
+
+  @Override
+  public void onHashtagsEdited(HashtagsEditedListener.Event event) {
+    HookArgs args = hookFactory.createArgs();
+
+    ChangeInfo c = event.getChange();
+    args.add("--change", c.id);
+    args.add("--change-owner", c.owner);
+    args.add("--project", c.project);
+    args.add("--branch", c.branch);
+    args.add("--editor", event.getEditor());
+    add(args, "--hashtag", event.getHashtags());
+    add(args, "--added", event.getAddedHashtags());
+    add(args, "--removed", event.getRemovedHashtags());
+
+    hook.submit(c.project, args);
+  }
+
+  private void add(HookArgs args, String name, Collection<String> hashtags) {
+    for (String hashtag : hashtags) {
+      args.add(name, hashtag);
+    }
+  }
+}
diff --git a/src/main/java/com/googlesource/gerrit/plugins/hooks/Hook.java b/src/main/java/com/googlesource/gerrit/plugins/hooks/Hook.java
new file mode 100644
index 0000000..87fb4f4
--- /dev/null
+++ b/src/main/java/com/googlesource/gerrit/plugins/hooks/Hook.java
@@ -0,0 +1,25 @@
+// Copyright (C) 2016 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.googlesource.gerrit.plugins.hooks;
+
+import java.nio.file.Path;
+
+public class Hook {
+  protected final Path path;
+
+  Hook(Path path) {
+    this.path = path;
+  }
+}
diff --git a/src/main/java/com/googlesource/gerrit/plugins/hooks/HookArgs.java b/src/main/java/com/googlesource/gerrit/plugins/hooks/HookArgs.java
new file mode 100644
index 0000000..fe9bf20
--- /dev/null
+++ b/src/main/java/com/googlesource/gerrit/plugins/hooks/HookArgs.java
@@ -0,0 +1,109 @@
+// Copyright (C) 2016 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.googlesource.gerrit.plugins.hooks;
+
+import static com.google.common.base.MoreObjects.firstNonNull;
+
+import com.google.common.base.Strings;
+import com.google.common.collect.ImmutableList;
+import com.google.gerrit.extensions.common.AccountInfo;
+import com.google.gerrit.extensions.common.ApprovalInfo;
+import com.google.gerrit.extensions.common.ChangeInfo;
+import com.google.inject.Provider;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+
+class HookArgs {
+  private final String anonymousCowardName;
+  private final Provider<String> urlProvider;
+  private final List<String> args;
+
+  HookArgs(String anonymousCowardName, Provider<String> urlProvider) {
+    this.anonymousCowardName = anonymousCowardName;
+    this.urlProvider = urlProvider;
+    this.args = new ArrayList<>();
+  }
+
+  public ImmutableList<String> get() {
+    return ImmutableList.copyOf(args);
+  }
+
+  public void add(String name, String value) {
+    args.add(name);
+    args.add(Strings.nullToEmpty(value));
+  }
+
+  public void add(String name, int value) {
+    args.add(name);
+    args.add(String.valueOf(value));
+  }
+
+  public void add(String name, Integer value) {
+    args.add(name);
+    args.add(value.toString());
+  }
+
+  public void add(String name, Boolean value) {
+    args.add(name);
+    args.add(firstNonNull(value, false).toString());
+  }
+
+  public void add(String name, AccountInfo account) {
+    if (account != null) {
+      args.add(name);
+      args.add(format(account));
+    }
+  }
+
+  public void addUrl(ChangeInfo change) {
+    args.add("--change-url");
+    String url = urlProvider.get();
+    if (change != null && url != null) {
+      args.add(url + change.changeId);
+    } else {
+      args.add("");
+    }
+  }
+
+  public void addApprovals(Map<String, ApprovalInfo> approvals,
+      Map<String, ApprovalInfo> oldApprovals) {
+    for (Map.Entry<String, ApprovalInfo> approval : approvals.entrySet()) {
+      if (approval.getValue() != null) {
+        args.add("--" + approval.getKey());
+        args.add(approval.getValue().value.toString());
+        if (oldApprovals != null && !oldApprovals.isEmpty()) {
+          ApprovalInfo oldValue = oldApprovals.get(approval.getKey());
+          if (oldValue != null && oldValue.value != null) {
+            args.add("--" + approval.getKey() + "-oldValue");
+            args.add(oldValue.value.toString());
+          }
+        }
+      }
+    }
+  }
+
+  private String format(AccountInfo account) {
+    StringBuilder who = new StringBuilder(
+        firstNonNull(account.name, anonymousCowardName));
+    if (account.email != null) {
+      who.append(" (")
+        .append(account.email)
+        .append(")");
+    }
+    return who.toString();
+  }
+}
diff --git a/src/main/java/com/googlesource/gerrit/plugins/hooks/HookExecutor.java b/src/main/java/com/googlesource/gerrit/plugins/hooks/HookExecutor.java
new file mode 100644
index 0000000..ba5ee70
--- /dev/null
+++ b/src/main/java/com/googlesource/gerrit/plugins/hooks/HookExecutor.java
@@ -0,0 +1,100 @@
+package com.googlesource.gerrit.plugins.hooks;
+
+import com.google.common.util.concurrent.ThreadFactoryBuilder;
+import com.google.gerrit.extensions.events.LifecycleListener;
+import com.google.gerrit.server.config.GerritServerConfig;
+import com.google.gerrit.server.config.SitePaths;
+import com.google.gerrit.server.git.GitRepositoryManager;
+import com.google.inject.Inject;
+
+import org.eclipse.jgit.lib.Config;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.lang.Thread.UncaughtExceptionHandler;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.FutureTask;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
+
+public class HookExecutor implements LifecycleListener {
+  private static final Logger log =
+      LoggerFactory.getLogger(HookExecutor.class);
+  private static final UncaughtExceptionHandler LOG_UNCAUGHT_EXCEPTION =
+      new UncaughtExceptionHandler() {
+        @Override
+        public void uncaughtException(Thread t, Throwable e) {
+          log.error("HookExecutor thread " + t.getName()
+            + " threw exception", e);
+        }
+      };
+
+  private final SitePaths sitePaths;
+  private final GitRepositoryManager gitManager;
+  private final ExecutorService threadPool;
+  private final int timeout;
+
+  @Inject
+  HookExecutor(@GerritServerConfig Config config,
+      SitePaths sitePaths,
+      GitRepositoryManager gitManager) {
+    this.sitePaths = sitePaths;
+    this.gitManager = gitManager;
+
+    this.timeout = config.getInt("hooks", "syncHookTimeout", 30);
+    this.threadPool = Executors.newCachedThreadPool(
+        new ThreadFactoryBuilder()
+          .setNameFormat("SyncHook-%d")
+          .setUncaughtExceptionHandler(LOG_UNCAUGHT_EXCEPTION)
+          .build());
+  }
+
+  HookResult submit(Path hook, HookArgs args) {
+    return submit(null, hook, args);
+  }
+
+  HookResult submit(String projectName, Path hook, HookArgs args) {
+    if (!Files.exists(hook)) {
+      return null;
+    }
+    HookTask.Sync hookTask = new HookTask.Sync(
+        gitManager, sitePaths.site_path, projectName, hook, args);
+    FutureTask<HookResult> task = new FutureTask<>(hookTask);
+    threadPool.execute(task);
+    String message;
+
+    try {
+      return task.get(timeout, TimeUnit.SECONDS);
+    } catch (TimeoutException e) {
+      message = "Synchronous hook timed out "  + hook.toAbsolutePath();
+      log.error(message);
+    } catch (Exception e) {
+      message = "Error running hook " + hook.toAbsolutePath();
+      log.error(message, e);
+    }
+    task.cancel(true);
+    hookTask.cancel();
+
+    return new HookResult(hookTask.getOutput(), message);
+  }
+
+  @Override
+  public void start() {
+  }
+
+  @Override
+  public void stop() {
+    threadPool.shutdown();
+    boolean isTerminated;
+    do {
+      try {
+        isTerminated = threadPool.awaitTermination(10, TimeUnit.SECONDS);
+      } catch (InterruptedException ie) {
+        isTerminated = false;
+      }
+    } while (!isTerminated);
+  }
+}
diff --git a/src/main/java/com/googlesource/gerrit/plugins/hooks/HookFactory.java b/src/main/java/com/googlesource/gerrit/plugins/hooks/HookFactory.java
new file mode 100644
index 0000000..3ec1d8c
--- /dev/null
+++ b/src/main/java/com/googlesource/gerrit/plugins/hooks/HookFactory.java
@@ -0,0 +1,80 @@
+// Copyright (C) 2016 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.googlesource.gerrit.plugins.hooks;
+
+import static com.google.common.base.MoreObjects.firstNonNull;
+
+import com.google.gerrit.common.Nullable;
+import com.google.gerrit.server.config.AnonymousCowardName;
+import com.google.gerrit.server.config.CanonicalWebUrl;
+import com.google.gerrit.server.config.GerritServerConfig;
+import com.google.gerrit.server.config.SitePaths;
+import com.google.inject.Inject;
+import com.google.inject.Provider;
+import com.google.inject.Singleton;
+
+import org.eclipse.jgit.lib.Config;
+
+import java.nio.file.Path;
+import java.nio.file.Paths;
+
+@Singleton
+public class HookFactory {
+  private final HookQueue queue;
+  private final HookExecutor syncHookExecutor;
+  private final Config config;
+  private final String anonymousCowardName;
+  private final Provider<String> urlProvider;
+  private final Path hooksPath;
+
+  @Inject
+  HookFactory(HookQueue queue,
+      HookExecutor syncHookExecutor,
+      @GerritServerConfig Config config,
+      @AnonymousCowardName String anonymousCowardName,
+      @CanonicalWebUrl @Nullable Provider<String> urlProvider,
+      SitePaths sitePaths) {
+    this.queue = queue;
+    this.syncHookExecutor = syncHookExecutor;
+    this.config = config;
+    this.anonymousCowardName = anonymousCowardName;
+    this.urlProvider = urlProvider;
+
+    String v = config.getString("hooks", null, "path");
+    if (v != null) {
+      this.hooksPath = Paths.get(v);
+    } else {
+      this.hooksPath = sitePaths.hooks_dir;
+    }
+  }
+
+  private Path getHookPath(String configName, String defaultName) {
+    String v = config.getString("hooks", null, configName);
+    return hooksPath.resolve(firstNonNull(v, defaultName));
+  }
+
+  public AsynchronousHook createAsync(String configName, String defaultName) {
+    return new AsynchronousHook(queue, getHookPath(configName, defaultName));
+  }
+
+  public SynchronousHook createSync(String configName, String defaultName) {
+    return new SynchronousHook(
+        syncHookExecutor, getHookPath(configName, defaultName));
+  }
+
+  public HookArgs createArgs() {
+    return new HookArgs(anonymousCowardName, urlProvider);
+  }
+}
diff --git a/src/main/java/com/googlesource/gerrit/plugins/hooks/HookQueue.java b/src/main/java/com/googlesource/gerrit/plugins/hooks/HookQueue.java
new file mode 100644
index 0000000..0b9c387
--- /dev/null
+++ b/src/main/java/com/googlesource/gerrit/plugins/hooks/HookQueue.java
@@ -0,0 +1,70 @@
+// Copyright (C) 2016 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.googlesource.gerrit.plugins.hooks;
+
+import com.google.gerrit.extensions.events.LifecycleListener;
+import com.google.gerrit.server.config.SitePaths;
+import com.google.gerrit.server.git.GitRepositoryManager;
+import com.google.gerrit.server.git.WorkQueue;
+import com.google.inject.Inject;
+
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+class HookQueue implements LifecycleListener {
+  private final GitRepositoryManager gitManager;
+  private final WorkQueue workQueue;
+  private final SitePaths sitePaths;
+
+  private WorkQueue.Executor queue;
+
+  @Inject
+  HookQueue(GitRepositoryManager m,
+      WorkQueue q,
+      SitePaths s) {
+    gitManager = m;
+    workQueue = q;
+    sitePaths = s;
+  }
+
+  void submit(Path hook, HookArgs args) {
+    submit(null, hook, args);
+  }
+
+  void submit(String projectName, Path hook, HookArgs args) {
+    if (Files.exists(hook)) {
+      queue.submit(new HookTask.Async(
+          gitManager,
+          sitePaths.site_path,
+          projectName,
+          hook,
+          args));
+    }
+  }
+
+  @Override
+  public void start() {
+    queue = workQueue.createQueue(1, "HookQueue");
+  }
+
+  @Override
+  public void stop() {
+    if (queue != null) {
+      queue.unregisterWorkQueue();
+      queue.shutdownNow();
+      queue = null;
+    }
+  }
+}
diff --git a/src/main/java/com/googlesource/gerrit/plugins/hooks/HookResult.java b/src/main/java/com/googlesource/gerrit/plugins/hooks/HookResult.java
new file mode 100644
index 0000000..c9711db
--- /dev/null
+++ b/src/main/java/com/googlesource/gerrit/plugins/hooks/HookResult.java
@@ -0,0 +1,62 @@
+// Copyright (C) 2016 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.googlesource.gerrit.plugins.hooks;
+
+import com.google.common.base.Strings;
+
+public class HookResult {
+  private final int exitValue;
+  private final String output;
+  private final String executionError;
+
+  HookResult(int exitValue, String output) {
+    this.exitValue = exitValue;
+    this.output = output;
+    this.executionError = null;
+  }
+
+  HookResult(String output, String executionError) {
+    this.exitValue = -1;
+    this.output = output;
+    this.executionError = executionError;
+  }
+
+  public int getExitValue() {
+    return exitValue;
+  }
+
+  public String getOutput() {
+    return output;
+  }
+
+  @Override
+  public String toString() {
+    StringBuilder sb = new StringBuilder();
+
+    if (!Strings.isNullOrEmpty(output)) {
+      sb.append(output);
+
+      if (executionError != null) {
+        sb.append(" - ");
+      }
+    }
+
+    if (executionError != null) {
+      sb.append(executionError);
+    }
+
+    return sb.toString();
+  }
+}
diff --git a/src/main/java/com/googlesource/gerrit/plugins/hooks/HookTask.java b/src/main/java/com/googlesource/gerrit/plugins/hooks/HookTask.java
new file mode 100644
index 0000000..f722034
--- /dev/null
+++ b/src/main/java/com/googlesource/gerrit/plugins/hooks/HookTask.java
@@ -0,0 +1,157 @@
+// Copyright (C) 2016 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.googlesource.gerrit.plugins.hooks;
+
+import static java.nio.charset.StandardCharsets.UTF_8;
+
+import com.google.common.io.ByteStreams;
+import com.google.gerrit.reviewdb.client.Project;
+import com.google.gerrit.server.git.GitRepositoryManager;
+
+import org.eclipse.jgit.lib.Repository;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.StringReader;
+import java.io.StringWriter;
+import java.nio.file.Path;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.Callable;
+
+class HookTask {
+  private static final Logger log = LoggerFactory.getLogger(HookTask.class);
+
+  private final GitRepositoryManager gitManager;
+  private final Path sitePath;
+  private final String projectName;
+  private final Path hook;
+  private final List<String> args;
+  private StringWriter output;
+  private Process ps;
+
+  public static class Async extends HookTask implements Runnable {
+    Async(GitRepositoryManager gitManager, Path sitePath, String projectName,
+        Path hook, HookArgs args) {
+      super(gitManager, sitePath, projectName, hook, args);
+    }
+
+    @Override
+    public void run() {
+      super.runHook();
+    }
+  }
+
+  public static class Sync extends HookTask implements Callable<HookResult> {
+    Sync(GitRepositoryManager gitManager, Path sitePath, String projectName,
+        Path hook, HookArgs args) {
+      super(gitManager, sitePath, projectName, hook, args);
+    }
+
+    @Override
+    public HookResult call() throws Exception {
+      return super.runHook();
+    }
+  }
+
+  HookTask(GitRepositoryManager gitManager,
+      Path sitePath,
+      String projectName,
+      Path hook,
+      HookArgs args) {
+    this.gitManager = gitManager;
+    this.sitePath = sitePath;
+    this.projectName = projectName;
+    this.hook = hook;
+    this.args = args.get();
+  }
+
+  public void cancel() {
+    ps.destroy();
+  }
+
+  protected String getName() {
+    return hook.getFileName().toString();
+  }
+
+  public String getOutput() {
+    return output != null ? output.toString() : null;
+  }
+
+  public HookResult runHook() {
+    HookResult result = null;
+    try {
+      List<String> argv = new ArrayList<>(1 + args.size());
+      argv.add(hook.toAbsolutePath().toString());
+      argv.addAll(args);
+
+      ProcessBuilder pb = new ProcessBuilder(argv);
+      pb.redirectErrorStream(true);
+
+      Map<String, String> env = pb.environment();
+      env.put("GERRIT_SITE", sitePath.toAbsolutePath().toString());
+
+      if (projectName != null) {
+        try (Repository git = gitManager.openRepository(
+              new Project.NameKey(projectName))) {
+          pb.directory(git.getDirectory());
+          env.put("GIT_DIR", git.getDirectory().getAbsolutePath());
+        }
+      }
+
+      ps = pb.start();
+      ps.getOutputStream().close();
+      String output =
+          new String(ByteStreams.toByteArray(ps.getInputStream()), UTF_8);
+      ps.waitFor();
+      result = new HookResult(ps.exitValue(), output);
+    } catch (InterruptedException iex) {
+      // InterruptedException - timeout or cancel
+    } catch (Throwable err) {
+      log.error("Error running hook " + hook.toAbsolutePath(), err);
+    }
+
+    if (result != null) {
+      int exitValue = result.getExitValue();
+      if (exitValue == 0) {
+        log.debug("hook[" + getName() + "] exitValue:" + exitValue);
+      } else {
+        log.info("hook[" + getName() + "] exitValue:" + exitValue);
+      }
+
+      BufferedReader br =
+          new BufferedReader(new StringReader(result.getOutput()));
+      try {
+        String line;
+        while ((line = br.readLine()) != null) {
+          log.info("hook[" + getName() + "] output: " + line);
+        }
+      } catch (IOException iox) {
+        log.error("Error writing hook output", iox);
+      }
+    }
+
+    return result;
+  }
+
+  @Override
+  public String toString() {
+    return "hook " + hook.getFileName();
+  }
+}
+
diff --git a/src/main/java/com/googlesource/gerrit/plugins/hooks/Module.java b/src/main/java/com/googlesource/gerrit/plugins/hooks/Module.java
new file mode 100644
index 0000000..b75fc34
--- /dev/null
+++ b/src/main/java/com/googlesource/gerrit/plugins/hooks/Module.java
@@ -0,0 +1,79 @@
+// Copyright (C) 2016 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.googlesource.gerrit.plugins.hooks;
+
+import com.google.gerrit.extensions.events.AgreementSignupListener;
+import com.google.gerrit.extensions.events.ChangeAbandonedListener;
+import com.google.gerrit.extensions.events.ChangeMergedListener;
+import com.google.gerrit.extensions.events.ChangeRestoredListener;
+import com.google.gerrit.extensions.events.CommentAddedListener;
+import com.google.gerrit.extensions.events.DraftPublishedListener;
+import com.google.gerrit.extensions.events.GitReferenceUpdatedListener;
+import com.google.gerrit.extensions.events.HashtagsEditedListener;
+import com.google.gerrit.extensions.events.LifecycleListener;
+import com.google.gerrit.extensions.events.NewProjectCreatedListener;
+import com.google.gerrit.extensions.events.ReviewerAddedListener;
+import com.google.gerrit.extensions.events.ReviewerDeletedListener;
+import com.google.gerrit.extensions.events.RevisionCreatedListener;
+import com.google.gerrit.extensions.events.TopicEditedListener;
+import com.google.gerrit.extensions.registration.DynamicSet;
+import com.google.gerrit.server.git.validators.CommitValidationListener;
+import com.google.inject.AbstractModule;
+import com.google.inject.Scopes;
+import com.google.inject.internal.UniqueAnnotations;
+
+class Module extends AbstractModule {
+  @Override
+  protected void configure() {
+    bind(HookQueue.class).in(Scopes.SINGLETON);
+    bind(LifecycleListener.class)
+        .annotatedWith(UniqueAnnotations.create())
+        .to(HookQueue.class);
+    bind(HookExecutor.class).in(Scopes.SINGLETON);
+    bind(LifecycleListener.class)
+        .annotatedWith(UniqueAnnotations.create())
+        .to(HookExecutor.class);
+
+    DynamicSet.bind(binder(), AgreementSignupListener.class)
+        .to(AgreementSignup.class);
+    DynamicSet.bind(binder(), ChangeAbandonedListener.class)
+        .to(ChangeAbandoned.class);
+    DynamicSet.bind(binder(), ChangeMergedListener.class)
+        .to(ChangeMerged.class);
+    DynamicSet.bind(binder(), ChangeRestoredListener.class)
+        .to(ChangeRestored.class);
+    DynamicSet.bind(binder(), CommentAddedListener.class)
+        .to(CommentAdded.class);
+    DynamicSet.bind(binder(), DraftPublishedListener.class)
+        .to(DraftPublished.class);
+    DynamicSet.bind(binder(), GitReferenceUpdatedListener.class)
+        .to(GitReferenceUpdated.class);
+    DynamicSet.bind(binder(), HashtagsEditedListener.class)
+        .to(HashtagsEdited.class);
+    DynamicSet.bind(binder(), NewProjectCreatedListener.class)
+        .to(NewProjectCreated.class);
+    DynamicSet.bind(binder(), ReviewerAddedListener.class)
+        .to(ReviewerAdded.class);
+    DynamicSet.bind(binder(), ReviewerDeletedListener.class)
+        .to(ReviewerDeleted.class);
+    DynamicSet.bind(binder(), RevisionCreatedListener.class)
+        .to(RevisionCreated.class);
+    DynamicSet.bind(binder(), TopicEditedListener.class)
+        .to(TopicEdited.class);
+
+    DynamicSet.bind(binder(), CommitValidationListener.class)
+        .to(CommitReceived.class);
+  }
+}
diff --git a/src/main/java/com/googlesource/gerrit/plugins/hooks/NewProjectCreated.java b/src/main/java/com/googlesource/gerrit/plugins/hooks/NewProjectCreated.java
new file mode 100644
index 0000000..eb566f8
--- /dev/null
+++ b/src/main/java/com/googlesource/gerrit/plugins/hooks/NewProjectCreated.java
@@ -0,0 +1,39 @@
+// Copyright (C) 2016 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.googlesource.gerrit.plugins.hooks;
+
+import com.google.gerrit.extensions.events.NewProjectCreatedListener;
+import com.google.inject.Inject;
+import com.google.inject.Singleton;
+
+@Singleton
+class NewProjectCreated implements NewProjectCreatedListener {
+  private final AsynchronousHook hook;
+  private final HookFactory hookFactory;
+
+  @Inject
+  NewProjectCreated(HookFactory hookFactory) {
+    this.hook = hookFactory.createAsync("projectCreated", "project-created");
+    this.hookFactory = hookFactory;
+  }
+
+  @Override
+  public void onNewProjectCreated(NewProjectCreatedListener.Event event) {
+    HookArgs args = hookFactory.createArgs();
+    args.add("--project", event.getProjectName());
+    args.add("--head", event.getHeadName());
+    hook.submit(event.getProjectName(), args);
+  }
+}
diff --git a/src/main/java/com/googlesource/gerrit/plugins/hooks/ReviewerAdded.java b/src/main/java/com/googlesource/gerrit/plugins/hooks/ReviewerAdded.java
new file mode 100644
index 0000000..8575a45
--- /dev/null
+++ b/src/main/java/com/googlesource/gerrit/plugins/hooks/ReviewerAdded.java
@@ -0,0 +1,47 @@
+// Copyright (C) 2016 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.googlesource.gerrit.plugins.hooks;
+
+import com.google.gerrit.extensions.common.ChangeInfo;
+import com.google.gerrit.extensions.events.ReviewerAddedListener;
+import com.google.inject.Inject;
+import com.google.inject.Singleton;
+
+@Singleton
+class ReviewerAdded implements ReviewerAddedListener {
+  private final AsynchronousHook hook;
+  private final HookFactory hookFactory;
+
+  @Inject
+  ReviewerAdded(HookFactory hookFactory) {
+    this.hook = hookFactory.createAsync("reviewerAdded", "reviewer-added");
+    this.hookFactory = hookFactory;
+  }
+
+  @Override
+  public void onReviewerAdded(ReviewerAddedListener.Event event) {
+    HookArgs args = hookFactory.createArgs();
+
+    ChangeInfo c = event.getChange();
+    args.add("--change", c.id);
+    args.addUrl(c);
+    args.add("--change-owner", c.owner);
+    args.add("--project", c.project);
+    args.add("--branch", c.branch);
+    args.add("--reviewer", event.getReviewer());
+
+    hook.submit(c.project, args);
+  }
+}
diff --git a/src/main/java/com/googlesource/gerrit/plugins/hooks/ReviewerDeleted.java b/src/main/java/com/googlesource/gerrit/plugins/hooks/ReviewerDeleted.java
new file mode 100644
index 0000000..5830e56
--- /dev/null
+++ b/src/main/java/com/googlesource/gerrit/plugins/hooks/ReviewerDeleted.java
@@ -0,0 +1,48 @@
+// Copyright (C) 2016 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.googlesource.gerrit.plugins.hooks;
+
+import com.google.gerrit.extensions.common.ChangeInfo;
+import com.google.gerrit.extensions.events.ReviewerDeletedListener;
+import com.google.inject.Inject;
+import com.google.inject.Singleton;
+
+@Singleton
+class ReviewerDeleted implements ReviewerDeletedListener {
+  private final AsynchronousHook hook;
+  private final HookFactory hookFactory;
+
+  @Inject
+  ReviewerDeleted(HookFactory hookFactory) {
+    this.hook = hookFactory.createAsync("reviewerDeleted", "reviewer-deleted");
+    this.hookFactory = hookFactory;
+  }
+
+  @Override
+  public void onReviewerDeleted(ReviewerDeletedListener.Event event) {
+    HookArgs args = hookFactory.createArgs();
+
+    ChangeInfo c = event.getChange();
+    args.add("--change", c.id);
+    args.addUrl(c);
+    args.add("--change-owner", c.owner);
+    args.add("--project", c.project);
+    args.add("--branch", c.branch);
+    args.add("--reviewer", event.getReviewer());
+    args.addApprovals(event.getNewApprovals(), event.getOldApprovals());
+
+    hook.submit(c.project, args);
+  }
+}
diff --git a/src/main/java/com/googlesource/gerrit/plugins/hooks/RevisionCreated.java b/src/main/java/com/googlesource/gerrit/plugins/hooks/RevisionCreated.java
new file mode 100644
index 0000000..ea772ae
--- /dev/null
+++ b/src/main/java/com/googlesource/gerrit/plugins/hooks/RevisionCreated.java
@@ -0,0 +1,52 @@
+// Copyright (C) 2016 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.googlesource.gerrit.plugins.hooks;
+
+import com.google.gerrit.extensions.common.ChangeInfo;
+import com.google.gerrit.extensions.events.RevisionCreatedListener;
+import com.google.inject.Inject;
+import com.google.inject.Singleton;
+
+@Singleton
+public class RevisionCreated implements RevisionCreatedListener {
+  private final AsynchronousHook hook;
+  private final HookFactory hookFactory;
+
+  @Inject
+  RevisionCreated(HookFactory hookFactory) {
+    this.hook = hookFactory.createAsync("patchsetCreated", "patchset-created");
+    this.hookFactory = hookFactory;
+  }
+
+  @Override
+  public void onRevisionCreated(Event event) {
+    HookArgs args = hookFactory.createArgs();
+
+    ChangeInfo c = event.getChange();
+    args.add("--change", c.id);
+    args.add("--is-draft", event.getRevision().draft);
+    args.add("--kind", String.valueOf(event.getRevision().kind));
+    args.addUrl(c);
+    args.add("--change-owner", c.owner);
+    args.add("--project", c.project);
+    args.add("--branch", c.branch);
+    args.add("--topic", c.topic);
+    args.add("--uploader", event.getUploader());
+    args.add("--commit", event.getRevision().commit.commit);
+    args.add("--patchset", event.getRevision()._number);
+
+    hook.submit(c.project, args);
+  }
+}
diff --git a/src/main/java/com/googlesource/gerrit/plugins/hooks/SynchronousHook.java b/src/main/java/com/googlesource/gerrit/plugins/hooks/SynchronousHook.java
new file mode 100644
index 0000000..03cbc40
--- /dev/null
+++ b/src/main/java/com/googlesource/gerrit/plugins/hooks/SynchronousHook.java
@@ -0,0 +1,34 @@
+// Copyright (C) 2016 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.googlesource.gerrit.plugins.hooks;
+
+import java.nio.file.Path;
+
+class SynchronousHook extends Hook {
+  private final HookExecutor executor;
+
+  SynchronousHook(HookExecutor executor, Path path) {
+    super(path);
+    this.executor = executor;
+  }
+
+  HookResult run(HookArgs args) {
+    return executor.submit(path, args);
+  }
+
+  HookResult run(String projectName, HookArgs args) {
+    return executor.submit(projectName, path, args);
+  }
+}
diff --git a/src/main/java/com/googlesource/gerrit/plugins/hooks/TopicEdited.java b/src/main/java/com/googlesource/gerrit/plugins/hooks/TopicEdited.java
new file mode 100644
index 0000000..7fbe6a4
--- /dev/null
+++ b/src/main/java/com/googlesource/gerrit/plugins/hooks/TopicEdited.java
@@ -0,0 +1,48 @@
+// Copyright (C) 2016 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.googlesource.gerrit.plugins.hooks;
+
+import com.google.gerrit.extensions.common.ChangeInfo;
+import com.google.gerrit.extensions.events.TopicEditedListener;
+import com.google.inject.Inject;
+import com.google.inject.Singleton;
+
+@Singleton
+class TopicEdited implements TopicEditedListener {
+  private final AsynchronousHook hook;
+  private final HookFactory hookFactory;
+
+  @Inject
+  TopicEdited(HookFactory hookFactory) {
+    this.hook = hookFactory.createAsync("topicChanged", "topic-changed");
+    this.hookFactory = hookFactory;
+  }
+
+  @Override
+  public void onTopicEdited(TopicEditedListener.Event event) {
+    HookArgs args = hookFactory.createArgs();
+
+    ChangeInfo c = event.getChange();
+    args.add("--change", c.id);
+    args.add("--change-owner", c.owner);
+    args.add("--project", c.project);
+    args.add("--branch", c.branch);
+    args.add("--changer", event.getEditor());
+    args.add("--old-topic", event.getOldTopic());
+    args.add("--new-topic", event.getChange().topic);
+
+    hook.submit(c.project, args);
+  }
+}
diff --git a/src/main/resources/Documentation/about.md b/src/main/resources/Documentation/about.md
new file mode 100644
index 0000000..17c7998
--- /dev/null
+++ b/src/main/resources/Documentation/about.md
@@ -0,0 +1,2 @@
+Gerrit does not run any of the standard git hooks in the repositories
+it works with, but this plugin implements its own hook mechanism.
diff --git a/src/main/resources/Documentation/config.md b/src/main/resources/Documentation/config.md
new file mode 100644
index 0000000..ccd1aa6
--- /dev/null
+++ b/src/main/resources/Documentation/config.md
@@ -0,0 +1,83 @@
+Configuration
+=============
+
+Environment
+-----------
+
+When a project is given to a hook, the environment will have `GIT_DIR` set to
+the full path of the affected git repository so that git commands can be easily
+run.
+
+Make sure your hook scripts are executable if running on *nix.
+
+With the exception of the `ref-update` hook, hooks are run in the background
+after the relevant change has taken place so are unable to affect the outcome
+of any given change. Because of the fact the hooks are run in the background
+after the activity, a hook might not be notified about an event if
+the server is shutdown before the hook can be invoked.
+
+Configuration
+-------------
+
+It is possible to change where this plugin looks for hooks, and what
+filenames it looks for by adding a `[hooks]` section to `gerrit.config`.
+
+hooks.path
+:	Location of hook executables. If not set, defaults to `$site_path/hooks`
+
+hooks.syncHookTimeout
+:	Timeout value in seconds for synchronous hooks. If not set, defaults
+to 30 seconds.
+
+hooks.changeAbandonedHook
+:	Filename for the change abandoned hook. If not set, defaults to `change-abandoned`.
+
+hooks.changeMergedHook
+:	Filename for the change merged hook. If not set, defaults to `change-merged`.
+
+hooks.changeRestoredHook
+:	Filename for the change restored hook. If not set, defaults to `change-restored`.
+
+hooks.claSignedHook
+:	Filename for the CLA signed hook. If not set, defaults to `cla-signed`.
+
+hooks.commentAddedHook
+:	Filename for the comment added hook. If not set, defaults to `comment-added`.
+
+hooks.draftPublishedHook
+:	Filename for the draft published hook. If not set, defaults to `draft-published`.
+
+hooks.hashtagsChangedHook
+:	Filename for the hashtags changed hook. If not set, defaults to `hashtags-changed`.
+
+hooks.patchsetCreatedHook
+:	Filename for the patchset created hook. If not set, defaults to `patchset-created`.
+
+hooks.projectCreatedHook
+:	Filename for the project created hook. If not set, defaults to `project-created`.
+
+hooks.refUpdate
+:	Filename for the ref update hook. If not set, defaults to `ref-update`.
+
+hooks.refUpdatedHook
+:	Filename for the ref updated hook. If not set, defaults to `ref-updated`.
+
+hooks.reviewerAddedHook
+:	Filename for the reviewer added hook. If not set, defaults to `reviewer-added`.
+
+hooks.reviewerDeletedHook
+:	Filename for the reviewer update hook. If not set, defaults to `reviewer-deleted`.
+
+hooks.topicChangedHook
+:	Filename for the topic changed hook. If not set, defaults to `topic-changed`.
+
+
+Missing Change URLs
+-------------------
+
+If [gerrit.canonicalWebUrl][1] is not set in `gerrit.config` the
+`--change-url` flag may not be passed to all hooks.  Hooks started out
+of an SSH context (for example the patchset-created hook) don't know
+the server's web URL, unless this variable is configured.
+
+[1]: ../../../Documentation/config-gerrit.html#gerrit.canonicalWebUrl
diff --git a/src/main/resources/Documentation/hooks.md b/src/main/resources/Documentation/hooks.md
new file mode 100644
index 0000000..6b0e0ea
--- /dev/null
+++ b/src/main/resources/Documentation/hooks.md
@@ -0,0 +1,152 @@
+Supported Hooks
+===============
+
+ref-update
+----------
+
+This is called when a push request is received by Gerrit. It allows a push to be
+rejected before it is committed to the Gerrit repository. If the script exits
+with non-zero return code the push will be rejected. Any output from the script
+will be returned to the user, regardless of the return code.
+
+This hook is called synchronously so it is recommended that it not block. A
+default timeout on the hook is set to 30 seconds to avoid "runaway" hooks using
+up server threads.  See [`hooks.syncHookTimeout`][1] for configuration details.
+
+```
+  ref-update --project <project name> --refname <refname> --uploader <uploader> --oldrev <sha1> --newrev <sha1>
+```
+
+patchset-created
+----------------
+
+Called whenever a patchset is created (this includes new changes and drafts).
+
+```
+  patchset-created --change <change id> --is-draft <boolean> --kind <change kind> --change-url <change url> --change-owner <change owner> --project <project name> --branch <branch> --topic <topic> --uploader <uploader> --commit <sha1> --patchset <patchset id>
+```
+
+The `--kind` parameter represents the kind of change uploaded. See documentation
+of [`patchSet`][2] for details.
+
+draft-published
+---------------
+
+Called whenever a draft change is published.
+
+```
+  draft-published --change <change id> --change-url <change url> --change-owner <change owner> --project <project name> --branch <branch> --topic <topic> --uploader <uploader> --commit <sha1> --patchset <patchset id>
+```
+
+comment-added
+-------------
+
+Called whenever a comment is added to a change.
+
+```
+  comment-added --change <change id> --is-draft <boolean> --change-url <change url> --change-owner <change owner> --project <project name> --branch <branch> --topic <topic> --author <comment author> --commit <commit> --comment <comment> [--<approval category id> <score> --<approval category id> <score> --<approval category id>-oldValue <score> ...]
+```
+
+change-merged
+-------------
+
+Called whenever a change has been merged.
+
+```
+  change-merged --change <change id> --change-url <change url> --change-owner <change owner> --project <project name> --branch <branch> --topic <topic> --submitter <submitter> --commit <sha1> --newrev <sha1>
+```
+
+change-abandoned
+----------------
+
+Called whenever a change has been abandoned.
+
+```
+  change-abandoned --change <change id> --change-url <change url> --change-owner <change owner> --project <project name> --branch <branch> --topic <topic> --abandoner <abandoner> --commit <sha1> --reason <reason>
+```
+
+change-restored
+---------------
+
+Called whenever a change has been restored.
+
+```
+  change-restored --change <change id> --change-url <change url> --change-owner <change owner> --project <project name> --branch <branch> --topic <topic> --restorer <restorer> --commit <sha1> --reason <reason>
+```
+
+ref-updated
+-----------
+
+Called whenever a ref has been updated.
+
+```
+  ref-updated --oldrev <old rev> --newrev <new rev> --refname <ref name> --project <project name> --submitter <submitter>
+```
+
+project-created
+---------------
+
+Called whenever a project has been created.
+
+```
+  project-created --project <project name> --head <head name>
+```
+
+reviewer-added
+--------------
+
+Called whenever a reviewer is added to a change.
+
+```
+  reviewer-added --change <change id> --change-url <change url> --change-owner <change owner> --project <project name> --branch <branch> --reviewer <reviewer>
+```
+
+reviewer-deleted
+----------------
+
+Called whenever a reviewer (with a vote) is removed from a change.
+
+```
+  reviewer-deleted --change <change id> --change-url <change url> --change-owner <change owner> --project <project name> --branch <branch> --reviewer <reviewer> [--<approval category id> <score> --<approval category id> <score> ...]
+```
+
+topic-changed
+-------------
+
+Called whenever a change's topic is changed from the Web UI or via the REST API.
+
+```
+  topic-changed --change <change id> --change-owner <change owner> --project <project name> --branch <branch> --changer <changer> --old-topic <old topic> --new-topic <new topic>
+```
+
+hashtags-changed
+----------------
+
+Called whenever hashtags are added to or removed from a change from the Web UI
+or via the REST API.
+
+```
+  hashtags-changed --change <change id>  --change-owner <change owner> --project <project name> --branch <branch> --editor <editor> --added <hashtag> --removed <hashtag> --hashtag <hashtag>
+```
+
+The `--added` parameter may be passed multiple times, once for each
+hashtag that was added to the change.
+
+The `--removed` parameter may be passed multiple times, once for each
+hashtag that was removed from the change.
+
+The `--hashtag` parameter may be passed multiple times, once for each
+hashtag remaining on the change after the add or remove operation has
+been performed.
+
+cla-signed
+----------
+
+Called whenever a user signs a contributor license agreement.
+
+```
+  cla-signed --submitter <submitter> --user-id <user_id> --cla-id <cla_id>
+```
+
+[1]: config.html#hooks.syncHookTimeout
+[2]: ../../../Documentation/json.html#patchSet