Merge branch 'stable-3.7' into stable-3.8 * stable-3.7: Fix misleading log message when adding reviewers Change-Id: Ie94419ca4e2b3a49a5b88a55b4be020bd0841a61

diff --git a/owners-autoassign/src/main/java/com/googlesource/gerrit/owners/common/GitRefListener.java b/owners-autoassign/src/main/java/com/googlesource/gerrit/owners/common/GitRefListener.java
index 9a8edb6..16c720a 100644
--- a/owners-autoassign/src/main/java/com/googlesource/gerrit/owners/common/GitRefListener.java
+++ b/owners-autoassign/src/main/java/com/googlesource/gerrit/owners/common/GitRefListener.java

@@ -90,6 +90,7 @@
   private final AutoAssignConfig cfg;
 
   private final PathOwnersEntriesCache cache;
+  private final PluginSettings pluginSettings;
 
   @Inject
   public GitRefListener(
@@ -103,7 +104,8 @@
       Provider<CurrentUser> currentUserProvider,
       ChangeNotes.Factory notesFactory,
       AutoAssignConfig cfg,
-      PathOwnersEntriesCache cache) {
+      PathOwnersEntriesCache cache,
+      PluginSettings pluginSettings) {
     this.api = api;
     this.patchListCache = patchListCache;
     this.projectCache = projectCache;
@@ -115,6 +117,7 @@
     this.notesFactory = notesFactory;
     this.cfg = cfg;
     this.cache = cache;
+    this.pluginSettings = pluginSettings;
   }
 
   @Override
@@ -241,7 +244,8 @@
                 patchList,
                 cfg.expandGroups(),
                 projectNameKey.get(),
-                cache);
+                cache,
+                pluginSettings.globalLabel());
         Set<Account.Id> allReviewers = Sets.newHashSet();
         allReviewers.addAll(owners.get().values());
         allReviewers.addAll(owners.getReviewers().values());

diff --git a/owners-autoassign/src/main/resources/Documentation/config.md b/owners-autoassign/src/main/resources/Documentation/config.md
index a99e3b1..1caf92f 100644
--- a/owners-autoassign/src/main/resources/Documentation/config.md
+++ b/owners-autoassign/src/main/resources/Documentation/config.md

@@ -26,10 +26,19 @@
 
 ## Project configuration
 
-The project configuration `autoAssignWip` controls the automatic
-assignment of reviewers based on the OWNERS file on WIP changes.
+There are 2 project specific configurations: `autoAssignWip` and
+`autoAssignField`. `autoAssignWip` controls the automatic assignment of
+reviewers based on the OWNERS file on WIP changes, while `autoAssignField`
+controls which field these OWNERS will be assigned too. It can be one of
+`REVIEWER` or `CC`. e.g.:
 
-The setting can be inherited from the parent project by setting the value
+```
+[plugin "owners-autoassign"]
+  autoAssignField = CC
+  autoAssignWip = TRUE
+```
+
+Both settings can be inherited from the parent project by setting the value
 to `INHERIT`.
 
 By default, all changes are subject to auto-assignment, unless the project

diff --git a/owners-autoassign/src/test/java/com/googlesource/gerrit/owners/common/GitRefListenerTest.java b/owners-autoassign/src/test/java/com/googlesource/gerrit/owners/common/GitRefListenerTest.java
index b651572..846f583 100644
--- a/owners-autoassign/src/test/java/com/googlesource/gerrit/owners/common/GitRefListenerTest.java
+++ b/owners-autoassign/src/test/java/com/googlesource/gerrit/owners/common/GitRefListenerTest.java

@@ -47,7 +47,8 @@
       Provider<CurrentUser> currentUserProvider,
       ChangeNotes.Factory notesFactory,
       AutoAssignConfig cfg,
-      PathOwnersEntriesCache cache) {
+      PathOwnersEntriesCache cache,
+      PluginSettings pluginSettings) {
     super(
         api,
         patchListCache,
@@ -59,7 +60,8 @@
         currentUserProvider,
         notesFactory,
         cfg,
-        cache);
+        cache,
+        pluginSettings);
   }
 
   @Override

diff --git a/owners-common/src/main/java/com/googlesource/gerrit/owners/common/PathOwners.java b/owners-common/src/main/java/com/googlesource/gerrit/owners/common/PathOwners.java
index e7e437a..1e5023b 100644
--- a/owners-common/src/main/java/com/googlesource/gerrit/owners/common/PathOwners.java
+++ b/owners-common/src/main/java/com/googlesource/gerrit/owners/common/PathOwners.java

@@ -103,7 +103,8 @@
       Map<String, FileDiffOutput> fileDiffMap,
       boolean expandGroups,
       String project,
-      PathOwnersEntriesCache cache)
+      PathOwnersEntriesCache cache,
+      Optional<LabelDefinition> globalLabel)
       throws InvalidOwnersFileException {
     this(
         accounts,
@@ -114,7 +115,8 @@
         getModifiedPaths(fileDiffMap),
         expandGroups,
         project,
-        cache);
+        cache,
+        globalLabel);
   }
 
   public PathOwners(
@@ -126,7 +128,8 @@
       DiffSummary diffSummary,
       boolean expandGroups,
       String project,
-      PathOwnersEntriesCache cache)
+      PathOwnersEntriesCache cache,
+      Optional<LabelDefinition> globalLabel)
       throws InvalidOwnersFileException {
     this(
         accounts,
@@ -137,7 +140,8 @@
         ImmutableSet.copyOf(diffSummary.getPaths()),
         expandGroups,
         project,
-        cache);
+        cache,
+        globalLabel);
   }
 
   public PathOwners(
@@ -149,7 +153,8 @@
       Set<String> modifiedPaths,
       boolean expandGroups,
       String project,
-      PathOwnersEntriesCache cache)
+      PathOwnersEntriesCache cache,
+      Optional<LabelDefinition> globalLabel)
       throws InvalidOwnersFileException {
     this.repositoryManager = repositoryManager;
     this.repository = repository;
@@ -170,7 +175,7 @@
     matchers = map.getMatchers();
     fileOwners = map.getFileOwners();
     fileGroupOwners = map.getFileGroupOwners();
-    label = map.getLabel();
+    label = globalLabel.or(map::getLabel);
   }
   /**
    * Returns a read only view of the paths to owners mapping.

diff --git a/owners-common/src/main/java/com/googlesource/gerrit/owners/common/PathOwnersEntriesCacheImpl.java b/owners-common/src/main/java/com/googlesource/gerrit/owners/common/PathOwnersEntriesCacheImpl.java
index 3af7a58..c882414 100644
--- a/owners-common/src/main/java/com/googlesource/gerrit/owners/common/PathOwnersEntriesCacheImpl.java
+++ b/owners-common/src/main/java/com/googlesource/gerrit/owners/common/PathOwnersEntriesCacheImpl.java

@@ -20,6 +20,7 @@
 import com.google.common.cache.LoadingCache;
 import com.google.common.collect.HashMultimap;
 import com.google.common.collect.Multimap;
+import com.google.gerrit.entities.RefNames;
 import com.google.inject.Inject;
 import com.google.inject.Singleton;
 import com.google.inject.name.Named;
@@ -88,6 +89,6 @@
   }
 
   private String indexKey(String project, String branch) {
-    return new StringBuilder(project).append('@').append(branch).toString();
+    return new StringBuilder(project).append('@').append(RefNames.fullName(branch)).toString();
   }
 }

diff --git a/owners-common/src/main/java/com/googlesource/gerrit/owners/common/PluginSettings.java b/owners-common/src/main/java/com/googlesource/gerrit/owners/common/PluginSettings.java
index 26b0f62..1fd7403 100644
--- a/owners-common/src/main/java/com/googlesource/gerrit/owners/common/PluginSettings.java
+++ b/owners-common/src/main/java/com/googlesource/gerrit/owners/common/PluginSettings.java

@@ -15,6 +15,7 @@
 
 package com.googlesource.gerrit.owners.common;
 
+import com.google.common.base.Suppliers;
 import com.google.common.collect.ImmutableSet;
 import com.google.gerrit.entities.Project;
 import com.google.gerrit.extensions.annotations.PluginName;
@@ -23,6 +24,8 @@
 import com.google.gerrit.server.project.NoSuchProjectException;
 import com.google.inject.Inject;
 import com.google.inject.Singleton;
+import java.util.Optional;
+import java.util.function.Supplier;
 import org.eclipse.jgit.lib.Config;
 import org.eclipse.jgit.lib.Constants;
 
@@ -36,6 +39,8 @@
   private final boolean expandGroups;
   private final boolean enableSubmitRequirement;
 
+  private final Supplier<Optional<LabelDefinition>> globalLabel;
+
   @Inject
   public PluginSettings(PluginConfigFactory configFactory, @PluginName String ownersPluginName) {
     this.configFactory = configFactory;
@@ -48,6 +53,10 @@
     this.expandGroups = globalPluginConfig.getBoolean("owners", "expandGroups", true);
     this.enableSubmitRequirement =
         globalPluginConfig.getBoolean("owners", "enableSubmitRequirement", false);
+
+    this.globalLabel =
+        Suppliers.memoize(
+            () -> LabelDefinition.parse(globalPluginConfig.getString("owners", null, "label")));
   }
 
   /**
@@ -95,6 +104,19 @@
     return configFactory.getFromProjectConfigWithInheritance(projectKey, ownersPluginName);
   }
 
+  /**
+   * Global definition of the review label to use for the owners' plugin.
+   *
+   * <p>When the global label is set in the plugin.owners.label settings the value overrides any
+   * label name defined in the OWNERS files of any repository.
+   *
+   * @return the global label definition or {@link Optional#empty()} if there isn't any global label
+   *     definition.
+   */
+  public Optional<LabelDefinition> globalLabel() {
+    return globalLabel.get();
+  }
+
   // Logic copied from JGit's TestRepository
   private static String normalizeRef(String ref) {
     if (Constants.HEAD.equals(ref)) {

diff --git a/owners-common/src/test/java/com/googlesource/gerrit/owners/common/PathOwnersTest.java b/owners-common/src/test/java/com/googlesource/gerrit/owners/common/PathOwnersTest.java
index 542ff6d..7ab294f 100644
--- a/owners-common/src/test/java/com/googlesource/gerrit/owners/common/PathOwnersTest.java
+++ b/owners-common/src/test/java/com/googlesource/gerrit/owners/common/PathOwnersTest.java

@@ -51,7 +51,11 @@
   private static final boolean EXPAND_GROUPS = true;
   private static final boolean DO_NOT_EXPAND_GROUPS = false;
   private static final String EXPECTED_LABEL = "expected-label";
+  private static final Short EXPECTED_LABEL_SCORE = 1;
+  private static final LabelDefinition EXPECTED_LABEL_DEFINITION =
+      new LabelDefinition(EXPECTED_LABEL, EXPECTED_LABEL_SCORE);
   private static final String A_LABEL = "a-label";
+  private static final String B_LABEL = "b-label";
   private static PathOwnersEntriesCache CACHE_MOCK = new PathOwnersEntriesCacheMock();
 
   public static final String CLASSIC_FILE_TXT = "classic/file.txt";
@@ -80,12 +84,33 @@
             Set.of(CLASSIC_FILE_TXT),
             EXPAND_GROUPS,
             "foo",
-            CACHE_MOCK);
+            CACHE_MOCK,
+            Optional.empty());
     Set<Account.Id> ownersSet = owners.get().get(CLASSIC_OWNERS);
     assertEquals(2, ownersSet.size());
     assertTrue(ownersSet.contains(USER_A_ID));
     assertTrue(ownersSet.contains(USER_B_ID));
     assertTrue(owners.expandGroups());
+    assertThat(owners.getLabel()).isEmpty();
+  }
+
+  @Test
+  public void testGlobalLabel() throws Exception {
+    mockOwners(USER_A_EMAIL_COM, USER_B_EMAIL_COM);
+
+    PathOwners owners =
+        new PathOwners(
+            accounts,
+            repositoryManager,
+            repository,
+            emptyList(),
+            branch,
+            Set.of(CLASSIC_FILE_TXT),
+            EXPAND_GROUPS,
+            "foo",
+            CACHE_MOCK,
+            Optional.of(EXPECTED_LABEL_DEFINITION));
+    assertThat(owners.getLabel()).hasValue(EXPECTED_LABEL_DEFINITION);
   }
 
   @Test
@@ -102,7 +127,8 @@
             Set.of(CLASSIC_FILE_TXT),
             DO_NOT_EXPAND_GROUPS,
             "foo",
-            CACHE_MOCK);
+            CACHE_MOCK,
+            Optional.empty());
     Set<String> ownersSet = owners.getFileGroupOwners().get(CLASSIC_FILE_TXT);
     assertEquals(2, ownersSet.size());
     assertTrue(ownersSet.contains(USER_A));
@@ -124,7 +150,8 @@
             Set.of(CLASSIC_FILE_TXT),
             EXPAND_GROUPS,
             "foo",
-            CACHE_MOCK);
+            CACHE_MOCK,
+            Optional.empty());
     Set<Account.Id> ownersSet = owners.get().get(CLASSIC_OWNERS);
     assertEquals(0, ownersSet.size());
   }
@@ -149,7 +176,8 @@
             Set.of("classic/file.txt"),
             EXPAND_GROUPS,
             "foo",
-            CACHE_MOCK);
+            CACHE_MOCK,
+            Optional.empty());
     Set<Account.Id> ownersSet2 = owners2.get().get(CLASSIC_OWNERS);
 
     // in this case we are inheriting the acct3 from /OWNERS
@@ -164,6 +192,50 @@
   }
 
   @Test
+  public void testClassicWithInheritanceAndGlobalLabel() throws Exception {
+    expectConfig("OWNERS", createConfig(true, Optional.of(A_LABEL), owners()));
+    expectConfig(CLASSIC_OWNERS, createConfig(true, Optional.of(B_LABEL), owners()));
+
+    replayAll();
+
+    PathOwners owners2 =
+        new PathOwners(
+            accounts,
+            repositoryManager,
+            repository,
+            emptyList(),
+            branch,
+            Set.of("classic/file.txt"),
+            EXPAND_GROUPS,
+            "foo",
+            CACHE_MOCK,
+            Optional.of(EXPECTED_LABEL_DEFINITION));
+    assertThat(owners2.getLabel()).hasValue(EXPECTED_LABEL_DEFINITION);
+  }
+
+  @Test
+  public void testClassicWithoutInheritanceAndGlobalLabel() throws Exception {
+    expectConfig("OWNERS", createConfig(false, Optional.of(A_LABEL), owners()));
+    expectConfig(CLASSIC_OWNERS, createConfig(false, Optional.of(B_LABEL), owners()));
+
+    replayAll();
+
+    PathOwners owners2 =
+        new PathOwners(
+            accounts,
+            repositoryManager,
+            repository,
+            emptyList(),
+            branch,
+            Set.of("classic/file.txt"),
+            EXPAND_GROUPS,
+            "foo",
+            CACHE_MOCK,
+            Optional.of(EXPECTED_LABEL_DEFINITION));
+    assertThat(owners2.getLabel()).hasValue(EXPECTED_LABEL_DEFINITION);
+  }
+
+  @Test
   public void testRootInheritFromProject() throws Exception {
     expectConfig("OWNERS", "master", createConfig(true, owners()));
     expectConfig(
@@ -188,7 +260,8 @@
             Set.of(fileName),
             EXPAND_GROUPS,
             "foo",
-            CACHE_MOCK);
+            CACHE_MOCK,
+            Optional.empty());
 
     Map<String, Set<Account.Id>> fileOwners = owners.getFileOwners();
     assertEquals(1, fileOwners.size());
@@ -233,7 +306,8 @@
             Set.of(fileName),
             EXPAND_GROUPS,
             "foo",
-            CACHE_MOCK);
+            CACHE_MOCK,
+            Optional.empty());
 
     Map<String, Set<Account.Id>> fileOwners = owners.getFileOwners();
     assertEquals(fileOwners.size(), 1);
@@ -282,7 +356,8 @@
             Set.of(sqlFileName, javaFileName),
             EXPAND_GROUPS,
             "foo",
-            CACHE_MOCK);
+            CACHE_MOCK,
+            Optional.empty());
 
     Map<String, Set<Account.Id>> fileOwners = owners.getFileOwners();
     assertEquals(fileOwners.size(), 2);
@@ -326,7 +401,8 @@
             Set.of("dir/subdir/file.txt"),
             EXPAND_GROUPS,
             "foo",
-            CACHE_MOCK);
+            CACHE_MOCK,
+            Optional.empty());
     Set<Account.Id> ownersSet = owners.get().get("dir/subdir/OWNERS");
 
     assertEquals(3, ownersSet.size());
@@ -406,7 +482,8 @@
             Set.of("dir/subdir/file.txt"),
             EXPAND_GROUPS,
             "foo",
-            cacheMock);
+            cacheMock,
+            Optional.empty());
 
     assertThat(owners.getFileOwners()).isNotEmpty();
     int expectedCacheCalls =

diff --git a/owners-common/src/test/java/com/googlesource/gerrit/owners/common/PluginSettingsTest.java b/owners-common/src/test/java/com/googlesource/gerrit/owners/common/PluginSettingsTest.java
index c4c75d4..2aecd88 100644
--- a/owners-common/src/test/java/com/googlesource/gerrit/owners/common/PluginSettingsTest.java
+++ b/owners-common/src/test/java/com/googlesource/gerrit/owners/common/PluginSettingsTest.java

@@ -18,6 +18,7 @@
 import static org.mockito.Mockito.when;
 
 import com.google.gerrit.server.config.PluginConfigFactory;
+import java.util.Optional;
 import org.eclipse.jgit.lib.Config;
 import org.eclipse.jgit.lib.Constants;
 import org.junit.Test;
@@ -81,4 +82,21 @@
     assertThat(pluginSettings.isBranchDisabled(branchName1)).isTrue();
     assertThat(pluginSettings.isBranchDisabled(branchName2)).isTrue();
   }
+
+  @Test
+  public void globalLabelIsEmptyByDefault() {
+    setupMocks(new Config());
+
+    assertThat(pluginSettings.globalLabel()).isEqualTo(Optional.empty());
+  }
+
+  @Test
+  public void globalLabelSetByConfig() {
+    LabelDefinition globalLabelName = new LabelDefinition("Custom-Label", (short) 2);
+    Config pluginConfig = new Config();
+    pluginConfig.setString("owners", null, "label", "Custom-Label,2");
+    setupMocks(pluginConfig);
+
+    assertThat(pluginSettings.globalLabel()).isEqualTo(Optional.of(globalLabelName));
+  }
 }

diff --git a/owners-common/src/test/java/com/googlesource/gerrit/owners/common/RegexTest.java b/owners-common/src/test/java/com/googlesource/gerrit/owners/common/RegexTest.java
index a035d93..821db6a 100644
--- a/owners-common/src/test/java/com/googlesource/gerrit/owners/common/RegexTest.java
+++ b/owners-common/src/test/java/com/googlesource/gerrit/owners/common/RegexTest.java

@@ -31,6 +31,7 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
+import java.util.Optional;
 import java.util.Set;
 import java.util.stream.Collectors;
 import org.junit.Before;
@@ -156,7 +157,8 @@
                 "project/file.sql"), // only .sql matching b,c
             EXPAND_GROUPS,
             "foo",
-            new PathOwnersEntriesCacheMock());
+            new PathOwnersEntriesCacheMock(),
+            Optional.empty());
 
     // assertions on classic owners
     Set<Account.Id> ownersSet = owners.get().get("project/OWNERS");
@@ -263,7 +265,8 @@
             Set.of("project/file.sql", "another.txt"),
             EXPAND_GROUPS,
             "foo",
-            new PathOwnersEntriesCacheMock());
+            new PathOwnersEntriesCacheMock(),
+            Optional.empty());
 
     Set<String> ownedFiles = owners.getFileOwners().keySet();
     assertThat(ownedFiles).containsExactly("project/file.sql");

diff --git a/owners/BUILD b/owners/BUILD
index f08ec84..c1dac46 100644
--- a/owners/BUILD
+++ b/owners/BUILD

@@ -38,7 +38,9 @@
         "Implementation-URL: https://gerrit.googlesource.com/plugins/owners",
         "Gerrit-PluginName: owners",
         "Gerrit-Module: com.googlesource.gerrit.owners.OwnersModule",
+        "Gerrit-HttpModule: com.googlesource.gerrit.owners.HttpModule",
     ],
+    resource_jars = ["//plugins/owners/web:gr-owners"],
     resources = glob(["src/main/resources/**/*"]),
     deps = [
         ":gerrit-owners-predicates",

diff --git a/owners/src/main/java/com/googlesource/gerrit/owners/HttpModule.java b/owners/src/main/java/com/googlesource/gerrit/owners/HttpModule.java
new file mode 100644
index 0000000..10759c0
--- /dev/null
+++ b/owners/src/main/java/com/googlesource/gerrit/owners/HttpModule.java

@@ -0,0 +1,26 @@
+// Copyright (C) 2024 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.owners;
+
+import com.google.gerrit.extensions.registration.DynamicSet;
+import com.google.gerrit.extensions.webui.JavaScriptPlugin;
+import com.google.gerrit.extensions.webui.WebUiPlugin;
+import com.google.inject.servlet.ServletModule;
+
+public class HttpModule extends ServletModule {
+  @Override
+  protected void configureServlets() {
+    DynamicSet.bind(binder(), WebUiPlugin.class).toInstance(new JavaScriptPlugin("gr-owners.js"));
+  }
+}

diff --git a/owners/src/main/java/com/googlesource/gerrit/owners/OwnersStoredValues.java b/owners/src/main/java/com/googlesource/gerrit/owners/OwnersStoredValues.java
index c077bb3..ff8bc18 100644
--- a/owners/src/main/java/com/googlesource/gerrit/owners/OwnersStoredValues.java
+++ b/owners/src/main/java/com/googlesource/gerrit/owners/OwnersStoredValues.java

@@ -73,7 +73,8 @@
                   patchList,
                   settings.expandGroups(),
                   projectState.getName(),
-                  cache);
+                  cache,
+                  settings.globalLabel());
             } catch (InvalidOwnersFileException e) {
               // re-throw exception as it is already logged but more importantly it is nicely
               // handled by the prolog rules evaluator and results in prolog rule error

diff --git a/owners/src/main/java/com/googlesource/gerrit/owners/OwnersSubmitRequirement.java b/owners/src/main/java/com/googlesource/gerrit/owners/OwnersSubmitRequirement.java
index 0d8dac4..64638bc 100644
--- a/owners/src/main/java/com/googlesource/gerrit/owners/OwnersSubmitRequirement.java
+++ b/owners/src/main/java/com/googlesource/gerrit/owners/OwnersSubmitRequirement.java

@@ -216,7 +216,8 @@
                 getDiff(nameKey, cd.currentPatchSet().commitId()),
                 pluginSettings.expandGroups(),
                 nameKey.get(),
-                cache);
+                cache,
+                pluginSettings.globalLabel());
 
         return pathOwners;
       }

diff --git a/owners/src/main/java/com/googlesource/gerrit/owners/entities/FilesOwnersResponse.java b/owners/src/main/java/com/googlesource/gerrit/owners/entities/FilesOwnersResponse.java
index 30c9c73..3f6c937 100644
--- a/owners/src/main/java/com/googlesource/gerrit/owners/entities/FilesOwnersResponse.java
+++ b/owners/src/main/java/com/googlesource/gerrit/owners/entities/FilesOwnersResponse.java

@@ -24,11 +24,15 @@
 
   public final Map<String, Set<GroupOwner>> files;
   public final Map<Integer, Map<String, Integer>> ownersLabels;
+  public final Map<String, Set<GroupOwner>> filesApproved;
 
   public FilesOwnersResponse(
-      Map<Integer, Map<String, Integer>> ownersLabels, Map<String, Set<GroupOwner>> files) {
+      Map<Integer, Map<String, Integer>> ownersLabels,
+      Map<String, Set<GroupOwner>> files,
+      Map<String, Set<GroupOwner>> filesApproved) {
     this.ownersLabels = ownersLabels;
     this.files = files;
+    this.filesApproved = filesApproved;
   }
 
   @Override
@@ -36,16 +40,25 @@
     if (this == o) return true;
     if (o == null || getClass() != o.getClass()) return false;
     FilesOwnersResponse that = (FilesOwnersResponse) o;
-    return Objects.equal(files, that.files) && Objects.equal(ownersLabels, that.ownersLabels);
+    return Objects.equal(files, that.files)
+        && Objects.equal(ownersLabels, that.ownersLabels)
+        && Objects.equal(filesApproved, that.filesApproved);
   }
 
   @Override
   public int hashCode() {
-    return Objects.hashCode(files, ownersLabels);
+    return Objects.hashCode(files, ownersLabels, filesApproved);
   }
 
   @Override
   public String toString() {
-    return "FilesOwnersResponse{" + "files=" + files + ", ownersLabels=" + ownersLabels + '}';
+    return "FilesOwnersResponse{"
+        + "files="
+        + files
+        + ", ownersLabels="
+        + ownersLabels
+        + ", filesApproved="
+        + filesApproved
+        + '}';
   }
 }

diff --git a/owners/src/main/java/com/googlesource/gerrit/owners/restapi/GetFilesOwners.java b/owners/src/main/java/com/googlesource/gerrit/owners/restapi/GetFilesOwners.java
index a724239..005e83f 100644
--- a/owners/src/main/java/com/googlesource/gerrit/owners/restapi/GetFilesOwners.java
+++ b/owners/src/main/java/com/googlesource/gerrit/owners/restapi/GetFilesOwners.java

@@ -114,7 +114,8 @@
               changePaths,
               pluginSettings.expandGroups(),
               project.get(),
-              cache);
+              cache,
+              pluginSettings.globalLabel());
 
       Map<String, Set<GroupOwner>> fileExpandedOwners =
           Maps.transformValues(
@@ -144,7 +145,14 @@
                   !isApprovedByOwner(
                       fileExpandedOwners.get(fileOwnerEntry.getKey()), ownersLabels, label));
 
-      return Response.ok(new FilesOwnersResponse(ownersLabels, filesWithPendingOwners));
+      Map<String, Set<GroupOwner>> filesApprovedByOwners =
+              Maps.filterEntries(
+                      fileToOwners,
+                      (fileOwnerEntry) ->
+                              isApprovedByOwner(
+                                      fileExpandedOwners.get(fileOwnerEntry.getKey()), ownersLabels, label));
+
+      return Response.ok(new FilesOwnersResponse(ownersLabels, filesWithPendingOwners, filesApprovedByOwners));
     } catch (InvalidOwnersFileException e) {
       logger.atSevere().withCause(e).log("Reading/parsing OWNERS file error.");
       throw new ResourceConflictException(e.getMessage(), e);

diff --git a/owners/src/main/resources/Documentation/config.md b/owners/src/main/resources/Documentation/config.md
index 1d157c6..811325b 100644
--- a/owners/src/main/resources/Documentation/config.md
+++ b/owners/src/main/resources/Documentation/config.md

@@ -28,6 +28,18 @@
       expandGroups = false
     ```
 
+owners.label
+:   Global override for the label and score, separated by a comma, to use by
+    the owners of changes for approving them. When defined, it overrides any
+    other label definition set by the OWNERS at any level in any project.
+
+    Example:
+
+    ```
+    [owners]
+      label = Code-Review, 1
+    ```
+
 <a name="owners.enableSubmitRequirement">owners.enableSubmitRequirement</a>
 :   If set to `true` the approvals are evaluated through the owners plugin
     provided submit rule without a need of prolog predicate being added to a

diff --git a/owners/src/main/resources/Documentation/rest-api.md b/owners/src/main/resources/Documentation/rest-api.md
index 68fb463..3505d6c 100644
--- a/owners/src/main/resources/Documentation/rest-api.md
+++ b/owners/src/main/resources/Documentation/rest-api.md

@@ -1,7 +1,8 @@
 # Rest API
 
-The @PLUGIN@ exposes a Rest API endpoint to list the owners associated to each file that
-needs a review, and, for each owner, its current labels and votes:
+The @PLUGIN@ exposes a Rest API endpoint to list the owners associated with each file that
+needs approval (`file` field), is approved (`files_approved`) and, for each owner,
+its current labels and votes (`owners_labels`):
 
 ```bash
 GET /changes/{change-id}/revisions/{revision-id}/owners~files-owners
@@ -18,6 +19,12 @@
       { "name":"Jack", "id": 1000003 }
     ]
   },
+  "files_approved": {
+    "NewBuild.build":[
+      { "name":"John", "id": 1000004 },
+      { "name":"Release Engineer", "id": 1000001 }
+    ]
+  },
   "owners_labels" : {
     "1000002": {
       "Verified": 1,

diff --git a/owners/src/test/java/com/googlesource/gerrit/owners/restapi/GetFilesOwnersITAbstract.java b/owners/src/test/java/com/googlesource/gerrit/owners/restapi/GetFilesOwnersITAbstract.java
index c39974c..1633783 100644
--- a/owners/src/test/java/com/googlesource/gerrit/owners/restapi/GetFilesOwnersITAbstract.java
+++ b/owners/src/test/java/com/googlesource/gerrit/owners/restapi/GetFilesOwnersITAbstract.java

@@ -42,6 +42,7 @@
 import com.googlesource.gerrit.owners.entities.Owner;
 import com.googlesource.gerrit.owners.restapi.GetFilesOwners.LabelNotFoundException;
 import java.util.Arrays;
+import java.util.Map;
 import javax.servlet.http.HttpServletResponse;
 import org.apache.commons.compress.utils.Sets;
 import org.eclipse.jgit.internal.storage.dfs.DfsRepositoryDescription;
@@ -102,7 +103,7 @@
   }
 
   @Test
-  public void shouldReturnOwnersLabelsWhenNotApprovedByOwners() throws Exception {
+  public void shouldReturnEmptyOwnersLabelsWhenNotApprovedByOwners() throws Exception {
     addOwnerFileToRoot(true);
     String changeId = createChange().getChangeId();
 
@@ -116,7 +117,21 @@
   }
 
   @Test
-  public void shouldReturnEmptyResponseWhenApprovedByOwners() throws Exception {
+  public void shouldReturnNonEmptyOwnersLabelsWhenApprovedByOwners() throws Exception {
+    addOwnerFileToRoot(true);
+    String changeId = createChange().getChangeId();
+    approve(changeId);
+
+    Response<FilesOwnersResponse> resp =
+        assertResponseOk(ownersApi.apply(parseCurrentRevisionResource(changeId)));
+
+    assertThat(resp.value().ownersLabels)
+        .containsExactly(admin.id().get(), Map.of(LabelId.CODE_REVIEW, 2));
+  }
+
+  @Test
+  public void shouldReturnEmptyFilesAndNonEmptyFilesApprovedResponseWhenApprovedByOwners()
+      throws Exception {
     addOwnerFileToRoot(true);
     String changeId = createChange().getChangeId();
     approve(changeId);
@@ -125,6 +140,8 @@
         assertResponseOk(ownersApi.apply(parseCurrentRevisionResource(changeId)));
 
     assertThat(resp.value().files).isEmpty();
+    assertThat(resp.value().filesApproved)
+        .containsExactly("a.txt", Sets.newHashSet(new Owner(admin.fullName(), admin.id().get())));
   }
 
   @Test
@@ -138,12 +155,14 @@
 
     assertThat(resp.value().files)
         .containsExactly("a.txt", Sets.newHashSet(new GroupOwner(admin.username())));
+    assertThat(resp.value().filesApproved).isEmpty();
   }
 
   @Test
   @GlobalPluginConfig(pluginName = "owners", name = "owners.expandGroups", value = "false")
-  public void shouldReturnEmptyResponseWhenApprovedByOwnersWithUnexpandedFileOwners()
-      throws Exception {
+  public void
+      shouldReturnEmptyFilesAndNonEmptyFilesApprovedResponseWhenApprovedByOwnersWithUnexpandedFileOwners()
+          throws Exception {
     addOwnerFileToRoot(true);
     String changeId = createChange().getChangeId();
     approve(changeId);
@@ -152,6 +171,8 @@
         assertResponseOk(ownersApi.apply(parseCurrentRevisionResource(changeId)));
 
     assertThat(resp.value().files).isEmpty();
+    assertThat(resp.value().filesApproved)
+        .containsExactly("a.txt", Sets.newHashSet(new GroupOwner(admin.username())));
   }
 
   @Test
@@ -165,6 +186,7 @@
 
     assertThat(resp.value().files)
         .containsExactly("a.txt", Sets.newHashSet(new GroupOwner(admin.username())));
+    assertThat(resp.value().filesApproved).isEmpty();
   }
 
   @Test
@@ -192,6 +214,7 @@
     addOwnerFileToProjectConfig(allProjects, true, user);
     resp = assertResponseOk(ownersApi.apply(parseCurrentRevisionResource(changeId)));
     assertThat(resp.value().files).containsExactly("a.txt", Sets.newHashSet(projectOwner));
+    assertThat(resp.value().filesApproved).isEmpty();
   }
 
   @Test
@@ -265,6 +288,7 @@
         assertResponseOk(ownersApi.apply(parseCurrentRevisionResource(changeId)));
 
     assertThat(resp.value().files).containsExactly("a.txt", Sets.newHashSet(rootOwner));
+    assertThat(resp.value().filesApproved).isEmpty();
   }
 
   private void assertInheritFromProject(Project.NameKey projectNameKey) throws Exception {
@@ -277,6 +301,7 @@
 
     assertThat(resp.value().files)
         .containsExactly("a.txt", Sets.newHashSet(rootOwner, projectOwner));
+    assertThat(resp.value().filesApproved).isEmpty();
   }
 
   private void addBrokenOwnersFileToRoot() throws Exception {

diff --git a/owners/src/test/java/com/googlesource/gerrit/owners/restapi/GetFilesOwnersSubmitRequirementsIT.java b/owners/src/test/java/com/googlesource/gerrit/owners/restapi/GetFilesOwnersSubmitRequirementsIT.java
index 8172611..f5c80b7 100644
--- a/owners/src/test/java/com/googlesource/gerrit/owners/restapi/GetFilesOwnersSubmitRequirementsIT.java
+++ b/owners/src/test/java/com/googlesource/gerrit/owners/restapi/GetFilesOwnersSubmitRequirementsIT.java

@@ -72,6 +72,7 @@
     assertThat(resp.value().files)
         .containsExactly("foo", Sets.newHashSet(new Owner(admin.fullName(), admin.id().get())));
     assertThat(resp.value().ownersLabels).isEmpty();
+    assertThat(resp.value().filesApproved).isEmpty();
 
     // give CR+1 as requested
     recommend(changeId);
@@ -80,6 +81,8 @@
     assertThat(resp.value().files).isEmpty();
     assertThat(resp.value().ownersLabels)
         .containsExactly(admin.id().get(), Map.of(LabelId.CODE_REVIEW, 1));
+    assertThat(resp.value().filesApproved)
+        .containsExactly("foo", Sets.newHashSet(new Owner(admin.fullName(), admin.id().get())));
   }
 
   @Test
@@ -96,6 +99,7 @@
     assertThat(resp.value().files)
         .containsExactly("foo", Sets.newHashSet(new Owner(admin.fullName(), admin.id().get())));
     assertThat(resp.value().ownersLabels).isEmpty();
+    assertThat(resp.value().filesApproved).isEmpty();
 
     // give LabelFoo+1 as requested
     gApi.changes().id(changeId).current().review(new ReviewInput().label(label, 1));
@@ -103,6 +107,8 @@
     resp = assertResponseOk(ownersApi.apply(parseCurrentRevisionResource(changeId)));
     assertThat(resp.value().files).isEmpty();
     assertThat(resp.value().ownersLabels).containsEntry(admin.id().get(), Map.of(label, 1));
+    assertThat(resp.value().filesApproved)
+        .containsExactly("foo", Sets.newHashSet(new Owner(admin.fullName(), admin.id().get())));
   }
 
   private void addOwnerFileToRoot(LabelDefinition label, TestAccount u) throws Exception {

diff --git a/owners/web/.eslintrc.js b/owners/web/.eslintrc.js
new file mode 100644
index 0000000..776d84e
--- /dev/null
+++ b/owners/web/.eslintrc.js

@@ -0,0 +1,20 @@
+/**
+ * @license
+ * Copyright (C) 2024 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.
+ */
+__plugindir = 'owners/web';
+module.exports = {
+  extends: '../../.eslintrc.js',
+};
\ No newline at end of file

diff --git a/owners/web/BUILD b/owners/web/BUILD
new file mode 100644
index 0000000..56ab697
--- /dev/null
+++ b/owners/web/BUILD

@@ -0,0 +1,68 @@
+load("@npm//@bazel/typescript:index.bzl", "ts_config", "ts_project")
+load("//tools/bzl:js.bzl", "gerrit_js_bundle", "karma_test")
+load("//tools/js:eslint.bzl", "plugin_eslint")
+
+package_group(
+    name = "visibility",
+    packages = ["//plugins/owners/..."],
+)
+
+package(default_visibility = [":visibility"])
+
+ts_config(
+    name = "tsconfig",
+    src = "tsconfig.json",
+    deps = [
+        "//plugins:tsconfig-plugins-base.json",
+    ],
+)
+
+ts_project(
+    name = "owners-ts",
+    srcs = glob(
+        ["**/*.ts"],
+        exclude = [
+            "**/*test*",
+            "**/test-utils.ts",
+        ],
+    ),
+    incremental = True,
+    out_dir = "_bazel_ts_out",
+    tsc = "//tools/node_tools:tsc-bin",
+    tsconfig = ":tsconfig",
+    deps = [
+        "@plugins_npm//@gerritcodereview/typescript-api",
+        "@plugins_npm//lit",
+        "@plugins_npm//rxjs",
+    ],
+)
+
+ts_project(
+    name = "owners-ts-tests",
+    srcs = glob([
+        "**/*.ts",
+        "**/test-utils.ts",
+    ]),
+    incremental = True,
+    out_dir = "_bazel_ts_out_tests",
+    tsc = "//tools/node_tools:tsc-bin",
+    tsconfig = ":tsconfig",
+    deps = [
+        "@plugins_npm//:node_modules",
+        "@ui_dev_npm//:node_modules",
+    ],
+)
+
+gerrit_js_bundle(
+    name = "gr-owners",
+    srcs = [":owners-ts"],
+    entry_point = "_bazel_ts_out/plugin.js",
+)
+
+karma_test(
+    name = "karma_test",
+    srcs = ["karma_test.sh"],
+    data = [":owners-ts-tests"],
+)
+
+plugin_eslint()

diff --git a/owners/web/gerrit-model.ts b/owners/web/gerrit-model.ts
new file mode 100644
index 0000000..da0d42c
--- /dev/null
+++ b/owners/web/gerrit-model.ts

@@ -0,0 +1,54 @@
+/**
+ * @license
+ * Copyright (C) 2024 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.
+ */
+
+import {AccountInfo} from '@gerritcodereview/typescript-api/rest-api';
+
+/**
+ * A provider for a value. Copied from Gerrit core.
+ */
+export type Provider<T> = () => T;
+
+/**
+ * Partial Gerrit's `AccountsModel` interface that defines functions needed in the owners plugin
+ */
+export interface AccountsModel {
+  fillDetails(account: AccountInfo): AccountInfo;
+}
+
+/**
+ * Parital Gerrit's `GrAccountLabel` interface that provides access to the `AccountsModel`
+ */
+export interface GrAccountLabel extends Element {
+  getAccountsModel: Provider<AccountsModel>;
+}
+
+/**
+ * Partial Gerrit's `SpecialFilePath` enum
+ */
+export enum SpecialFilePath {
+  COMMIT_MESSAGE = '/COMMIT_MSG',
+  MERGE_LIST = '/MERGE_LIST',
+}
+
+/**
+ * Partial Gerrit's `Window` interface defintion so that `getBaseUrl` function can work.
+ */
+declare global {
+  interface Window {
+    CANONICAL_PATH?: string;
+  }
+}

diff --git a/owners/web/gr-files.ts b/owners/web/gr-files.ts
new file mode 100644
index 0000000..d0fe189
--- /dev/null
+++ b/owners/web/gr-files.ts

@@ -0,0 +1,569 @@
+/**
+ * @license
+ * Copyright (C) 2024 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.
+ */
+
+import {css, html, LitElement, nothing, PropertyValues, CSSResult} from 'lit';
+import {customElement, property} from 'lit/decorators';
+import {
+  AccountInfo,
+  ApprovalInfo,
+  ChangeInfo,
+  ChangeStatus,
+  GroupInfo,
+  LabelInfo,
+  isDetailedLabelInfo,
+  EmailAddress,
+  ReviewerState,
+} from '@gerritcodereview/typescript-api/rest-api';
+import {
+  FilesOwners,
+  isOwner,
+  OwnersLabels,
+  hasOwnersSubmitRequirement,
+} from './owners-service';
+import {
+  FileOwnership,
+  FileStatus,
+  OwnerOrGroupOwner,
+  PatchRange,
+  UserRole,
+} from './owners-model';
+import {query} from './utils';
+import {GrAccountLabel} from './gerrit-model';
+import {OwnersMixin} from './owners-mixin';
+
+const STATUS_CODE = {
+  MISSING: 'missing',
+  APPROVED: 'approved',
+};
+
+const STATUS_ICON = {
+  [STATUS_CODE.MISSING]: 'schedule',
+  [STATUS_CODE.APPROVED]: 'check',
+};
+
+const FILE_STATUS = {
+  [FileStatus.NEEDS_APPROVAL]: STATUS_CODE.MISSING,
+  [FileStatus.APPROVED]: STATUS_CODE.APPROVED,
+};
+
+const HOVER_HEADING = {
+  [STATUS_CODE.MISSING]: "Needs Owners' Approval",
+  [STATUS_CODE.APPROVED]: 'Approved by Owners',
+};
+
+const DISPLAY_OWNERS_FOR_FILE_LIMIT = 5;
+const LIMITED_FILES_OWNERS_TOOLTIP = `File owners limited to first ${DISPLAY_OWNERS_FOR_FILE_LIMIT} accounts.`;
+
+const common = OwnersMixin(LitElement);
+
+class FilesCommon extends common {
+  protected override willUpdate(changedProperties: PropertyValues): void {
+    super.willUpdate(changedProperties);
+
+    this.hidden = shouldHide(
+      this.change,
+      this.patchRange,
+      this.filesOwners,
+      this.user?.role
+    );
+  }
+
+  protected static commonStyles(): CSSResult[] {
+    return [window?.Gerrit?.styles.font as CSSResult];
+  }
+}
+
+export const FILES_OWNERS_COLUMN_HEADER = 'files-owners-column-header';
+@customElement(FILES_OWNERS_COLUMN_HEADER)
+export class FilesColumnHeader extends FilesCommon {
+  static override get styles() {
+    return [
+      ...FilesCommon.commonStyles(),
+      css`
+        :host() {
+          display: block;
+          padding-right: var(--spacing-m);
+          width: 4em;
+        }
+        :host[hidden] {
+          display: none;
+        }
+      `,
+    ];
+  }
+
+  override render() {
+    if (this.hidden) return nothing;
+    return html`<div>Status</div>`;
+  }
+}
+
+/**
+ * It has to be part of this file as components defined in dedicated files are not visible
+ */
+@customElement('gr-owner')
+export class GrOwner extends LitElement {
+  @property({type: Object})
+  owner?: AccountInfo;
+
+  @property({type: Object})
+  groupOwner?: GroupInfo;
+
+  @property({type: Object})
+  approval?: ApprovalInfo;
+
+  @property({type: Object})
+  info?: LabelInfo;
+
+  @property({type: String})
+  email?: EmailAddress;
+
+  static override get styles() {
+    return [
+      css`
+        .container {
+          display: flex;
+        }
+        gr-vote-chip {
+          margin-left: 5px;
+          --gr-vote-chip-width: 14px;
+          --gr-vote-chip-height: 14px;
+        }
+        gr-tooltip-content {
+          display: inline-block;
+        }
+      `,
+    ];
+  }
+
+  override render() {
+    if (!this.owner && !this.groupOwner) {
+      return nothing;
+    }
+
+    const isAccountOwner = this.owner !== undefined;
+    const ownerLabel = isAccountOwner
+      ? this.owner?._account_id
+        ? html`<gr-account-label .account=${this.owner}></gr-account-label>`
+        : html`<span>${this.owner?.display_name}</span>`
+      : html`<span>Group: ${this.groupOwner?.name}</span>`;
+
+    const voteChip =
+      isAccountOwner && this.approval
+        ? html` <gr-vote-chip
+            .vote=${this.approval}
+            .label=${this.info}
+          ></gr-vote-chip>`
+        : nothing;
+
+    // allow user to copy what is available:
+    // * email or name (if available) for AccountInfo owner type
+    // * group name for GroupInfo owner type
+    const [copyText, copyTooltip] = isAccountOwner
+      ? this.email || this.owner?.display_name
+        ? [
+            this.email ?? this.owner?.display_name,
+            this.email ? 'email' : 'name',
+          ]
+        : [nothing, nothing]
+      : [this.groupOwner?.name, 'group name'];
+    const copy = copyText
+      ? html` <gr-copy-clipboard
+          .text=${copyText}
+          hasTooltip
+          hideinput
+          buttonTitle="Copy owner's ${copyTooltip} to clipboard"
+        ></gr-copy-clipboard>`
+      : nothing;
+
+    return html`
+      <div class="container">${ownerLabel} ${voteChip} ${copy}</div>
+    `;
+  }
+
+  override async updated(changedProperties: PropertyValues) {
+    super.updated(changedProperties);
+
+    if (changedProperties.has('owner')) {
+      if (this.owner && !this.email) {
+        const accountLabel = query<GrAccountLabel>(this, 'gr-account-label');
+        if (!accountLabel) {
+          return;
+        }
+
+        const updateOwner = await accountLabel
+          ?.getAccountsModel()
+          ?.fillDetails(this.owner);
+        this.email = updateOwner?.email;
+      }
+    }
+  }
+}
+
+export const FILES_OWNERS_COLUMN_CONTENT = 'files-owners-column-content';
+@customElement(FILES_OWNERS_COLUMN_CONTENT)
+export class FilesColumnContent extends FilesCommon {
+  @property({type: String})
+  path?: string;
+
+  @property({type: String})
+  oldPath?: string;
+
+  @property({type: String, reflect: true, attribute: 'file-status'})
+  fileStatus?: string;
+
+  private owners?: OwnerOrGroupOwner[];
+
+  // taken from Gerrit's common-util.ts
+  private uniqueId = Math.random().toString(36).substring(2);
+
+  static override get styles() {
+    return [
+      ...FilesCommon.commonStyles(),
+      css`
+        :host {
+          display: flex;
+          padding-right: var(--spacing-m);
+          width: 4em;
+          text-align: center;
+        }
+        :host[hidden] {
+          display: none;
+        }
+        gr-icon {
+          padding: var(--spacing-xs) 0px;
+          margin-left: 9px;
+        }
+        :host([file-status='approved']) gr-icon.status {
+          color: var(--positive-green-text-color);
+        }
+        :host([file-status='missing']) gr-icon.status {
+          color: #ffa62f;
+        }
+      `,
+    ];
+  }
+
+  override render() {
+    if (this.hidden || !this.fileStatus) {
+      return nothing;
+    }
+
+    const icon = STATUS_ICON[this.fileStatus];
+    return html`
+      <gr-icon
+        id="${this.pathId()}"
+        class="status"
+        icon=${icon}
+        aria-hidden="true"
+      ></gr-icon>
+      ${this.renderFileOwners()}
+    `;
+  }
+
+  private pathId(): string {
+    return `path-${this.uniqueId}`;
+  }
+
+  private renderFileOwners() {
+    const owners = this.owners ?? [];
+    const splicedOwners = owners.splice(0, DISPLAY_OWNERS_FOR_FILE_LIMIT);
+    const showEllipsis = owners.length > DISPLAY_OWNERS_FOR_FILE_LIMIT;
+    const heading = HOVER_HEADING[this.fileStatus ?? STATUS_CODE.MISSING];
+    // inlining <style> here is ugly but an alternative would be to copy the `HovercardMixin` from Gerrit and implement hoover from scratch
+    return html`<gr-hovercard for="${this.pathId()}">
+      <style>
+        #file-owners-hoovercard {
+          min-width: 256px;
+          max-width: 256px;
+          margin: -10px;
+          padding: var(--spacing-xl) 0 var(--spacing-m) 0;
+        }
+        h3 {
+          font: inherit;
+        }
+        .heading-3 {
+          margin-left: -2px;
+          font-family: var(--header-font-family);
+          font-size: var(--font-size-h3);
+          font-weight: var(--font-weight-h3);
+          line-height: var(--line-height-h3);
+        }
+        .row {
+          display: flex;
+        }
+        div.section {
+          margin: 0 var(--spacing-xl) var(--spacing-m) var(--spacing-xl);
+          display: flex;
+          align-items: center;
+        }
+        div.sectionIcon {
+          flex: 0 0 30px;
+        }
+        div.sectionIcon gr-icon {
+          position: relative;
+        }
+        div.sectionContent .row {
+          margin-left: 2px;
+        }
+        div.sectionContent .notLast {
+          margin-bottom: 2px;
+        }
+        div.sectionContent .ellipsis {
+          margin-left: 5px;
+        }
+      </style>
+      <div id="file-owners-hoovercard">
+        <div class="section">
+          <div class="sectionIcon">
+            <gr-icon class="status" icon="info" aria-hidden="true"></gr-icon>
+          </div>
+          <div class="sectionContent">
+            <h3 class="name heading-3">
+              <span>${heading}</span>
+            </h3>
+          </div>
+        </div>
+        <div class="section">
+          <div class="sectionContent">
+            ${splicedOwners.map((owner, idx) => {
+              const [approval, info] =
+                computeApprovalAndInfo(
+                  owner,
+                  this.filesOwners?.owners_labels ?? {},
+                  this.change
+                ) ?? [];
+              return html`
+                <div
+                  class="row ${showEllipsis || idx + 1 < splicedOwners.length
+                    ? 'notLast'
+                    : ''}"
+                >
+                  <gr-owner
+                    .owner=${owner.owner}
+                    .groupOwner=${owner.groupOwner}
+                    .approval=${approval}
+                    .info=${info}
+                    .email=${owner.owner ? owner.owner.email : nothing}
+                  ></gr-owner>
+                </div>
+              `;
+            })}
+            ${showEllipsis
+              ? html`
+                <gr-tooltip-content
+                  title=${LIMITED_FILES_OWNERS_TOOLTIP}
+                  aria-label="limited-file-onwers"
+                  aria-description=${LIMITED_FILES_OWNERS_TOOLTIP}
+                  has-tooltip
+                >
+                  <div class="row ellipsis">...</div>
+                </gt-tooltip-content>`
+              : nothing}
+          </div>
+        </div>
+      </div>
+    </gr-hovercard>`;
+  }
+
+  protected override willUpdate(changedProperties: PropertyValues): void {
+    super.willUpdate(changedProperties);
+    this.computeFileState();
+  }
+
+  private computeFileState(): void {
+    const fileOwnership = getFileOwnership(this.path, this.filesOwners);
+    if (!fileOwnership || fileOwnership.fileStatus === FileStatus.NOT_OWNED) {
+      this.fileStatus = undefined;
+      this.owners = undefined;
+      return;
+    }
+
+    this.fileStatus = FILE_STATUS[fileOwnership.fileStatus];
+    const accounts = getChangeAccounts(this.change);
+
+    this.owners = (fileOwnership.owners ?? []).map(owner => {
+      if (isOwner(owner)) {
+        return {
+          owner:
+            accounts.byAccountId.get(owner.id) ??
+            ({_account_id: owner.id} as unknown as AccountInfo),
+        } as unknown as OwnerOrGroupOwner;
+      }
+
+      const groupPrefix = 'group/';
+      if (owner.name.startsWith(groupPrefix)) {
+        return {
+          groupOwner: {
+            name: owner.name.substring(groupPrefix.length),
+          } as unknown as GroupInfo,
+        } as unknown as OwnerOrGroupOwner;
+      }
+
+      // when `owners.expandGroups = false` then neither group nor account
+      // will be expanded therefore try to match account with change's available
+      // accounts through email without domain or by full name
+      // finally construct `AccountInfo` just with a `name` property
+      const accountOwner =
+        accounts.byEmailWithoutDomain.get(owner.name) ??
+        accounts.byFullName.get(owner.name) ??
+        ({display_name: owner.name} as unknown as AccountInfo);
+      return {owner: accountOwner} as unknown as OwnerOrGroupOwner;
+    });
+  }
+}
+
+export function shouldHide(
+  change?: ChangeInfo,
+  patchRange?: PatchRange,
+  filesOwners?: FilesOwners,
+  userRole?: UserRole
+): boolean {
+  // don't show owners when no change or change is merged
+  if (change === undefined || patchRange === undefined) {
+    return true;
+  }
+  if (
+    change.status === ChangeStatus.ABANDONED ||
+    change.status === ChangeStatus.MERGED
+  ) {
+    return true;
+  }
+
+  // Note: in some special cases, patchNum is undefined on latest patchset
+  // like after publishing the edit, still show for them
+  // TODO: this should be fixed in Gerrit
+  if (patchRange?.patchNum === undefined) return false;
+
+  // only show if its latest patchset
+  const latestPatchset = change.revisions![change.current_revision!];
+  if (`${patchRange.patchNum}` !== `${latestPatchset._number}`) {
+    return true;
+  }
+
+  // show owners when they apply to the change and for logged in user
+  if (
+    hasOwnersSubmitRequirement(change) &&
+    filesOwners &&
+    (filesOwners.files || filesOwners.files_approved)
+  ) {
+    return !userRole || userRole === UserRole.ANONYMOUS;
+  }
+  return true;
+}
+
+export function getFileOwnership(
+  path?: string,
+  filesOwners?: FilesOwners
+): FileOwnership | undefined {
+  if (path === undefined || filesOwners === undefined) {
+    return undefined;
+  }
+
+  const fileOwners = (filesOwners.files ?? {})[path];
+  const fileApprovers = (filesOwners.files_approved ?? {})[path];
+  if (fileApprovers) {
+    return {
+      fileStatus: FileStatus.APPROVED,
+      owners: fileApprovers,
+    };
+  } else if (fileOwners) {
+    return {
+      fileStatus: FileStatus.NEEDS_APPROVAL,
+      owners: fileOwners,
+    };
+  } else {
+    return {fileStatus: FileStatus.NOT_OWNED};
+  }
+}
+
+export function computeApprovalAndInfo(
+  fileOwner: OwnerOrGroupOwner,
+  labels: OwnersLabels,
+  change?: ChangeInfo
+): [ApprovalInfo, LabelInfo] | undefined {
+  if (!change?.labels || !fileOwner?.owner) {
+    return;
+  }
+  const accountId = fileOwner.owner._account_id;
+  const ownersLabel = labels[`${accountId}`];
+  if (!ownersLabel) {
+    return;
+  }
+
+  for (const label of Object.keys(ownersLabel)) {
+    const info = change.labels[label];
+    if (!info || !isDetailedLabelInfo(info)) {
+      return;
+    }
+
+    const vote = ownersLabel[label];
+    if ((info.default_value && info.default_value === vote) || vote === 0) {
+      // ignore default value
+      return;
+    }
+
+    const approval = info.all?.filter(x => x._account_id === accountId)[0];
+    return approval ? [approval, info] : undefined;
+  }
+
+  return;
+}
+
+export interface ChangeAccounts {
+  byAccountId: Map<number, AccountInfo>;
+  byEmailWithoutDomain: Map<string, AccountInfo>;
+  byFullName: Map<string, AccountInfo>;
+}
+
+export function getChangeAccounts(change?: ChangeInfo): ChangeAccounts {
+  const accounts = {
+    byAccountId: new Map(),
+    byEmailWithoutDomain: new Map(),
+    byFullName: new Map(),
+  } as unknown as ChangeAccounts;
+
+  if (!change) {
+    return accounts;
+  }
+
+  [
+    change.owner,
+    ...(change.submitter ? [change.submitter] : []),
+    ...(change.reviewers[ReviewerState.REVIEWER] ?? []),
+    ...(change.reviewers[ReviewerState.CC] ?? []),
+  ].forEach(account => {
+    if (account._account_id) {
+      accounts.byAccountId.set(account._account_id, account);
+    }
+
+    if (account.email && account.email.indexOf('@') > 0) {
+      accounts.byEmailWithoutDomain.set(
+        account.email.substring(
+          0,
+          account.email.indexOf('@')
+        ) as unknown as string,
+        account
+      );
+    }
+
+    if (account.name) {
+      accounts.byFullName.set(account.name, account);
+    }
+  });
+  return accounts;
+}

diff --git a/owners/web/gr-files_test.ts b/owners/web/gr-files_test.ts
new file mode 100644
index 0000000..d05f6e7
--- /dev/null
+++ b/owners/web/gr-files_test.ts

@@ -0,0 +1,475 @@
+/**
+ * @license
+ * Copyright (C) 2024 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.
+ */
+
+import {assert} from '@open-wc/testing';
+
+import {
+  computeApprovalAndInfo,
+  getChangeAccounts,
+  getFileOwnership,
+  shouldHide,
+} from './gr-files';
+import {
+  FileOwnership,
+  FileStatus,
+  OwnerOrGroupOwner,
+  PatchRange,
+  UserRole,
+} from './owners-model';
+import {
+  AccountInfo,
+  ApprovalInfo,
+  ChangeInfo,
+  ChangeStatus,
+  DetailedLabelInfo,
+  SubmitRequirementResultInfo,
+  ReviewerState,
+} from '@gerritcodereview/typescript-api/rest-api';
+import {FilesOwners, OwnersLabels} from './owners-service';
+import {deepEqual} from './utils';
+import {getRandom} from './test-utils';
+
+suite('owners status tests', () => {
+  const path = 'readme.md';
+  const approvedPath = 'db.sql';
+  const filesOwners = {
+    files: {[path]: [{name: 'John', id: 1}]},
+    files_approved: {[approvedPath]: [{name: 'Merry', id: 2}]},
+  } as unknown as FilesOwners;
+
+  suite('shouldHide tests', () => {
+    const loggedIn = getRandom(UserRole.CHANGE_OWNER, UserRole.OTHER);
+
+    test('shouldHide - should be `true` when change is not defined', () => {
+      const undefinedChange = undefined;
+      const definedPatchRange = {} as unknown as PatchRange;
+      assert.equal(
+        shouldHide(undefinedChange, definedPatchRange, filesOwners, loggedIn),
+        true
+      );
+    });
+
+    test('shouldHide - should be `true` when patch range is not defined', () => {
+      const definedChange = {} as unknown as ChangeInfo;
+      const undefinedPatchRange = undefined;
+      assert.equal(
+        shouldHide(definedChange, undefinedPatchRange, filesOwners, loggedIn),
+        true
+      );
+    });
+
+    test('shouldHide - should be `true` when change is abandoned', () => {
+      const abandonedChange = {
+        status: ChangeStatus.ABANDONED,
+      } as unknown as ChangeInfo;
+      const definedPatchRange = {} as unknown as PatchRange;
+      assert.equal(
+        shouldHide(abandonedChange, definedPatchRange, filesOwners, loggedIn),
+        true
+      );
+    });
+
+    test('shouldHide - should be `true` when change is merged', () => {
+      const mergedChange = {
+        status: ChangeStatus.MERGED,
+      } as unknown as ChangeInfo;
+      const definedPatchRange = {} as unknown as PatchRange;
+      assert.equal(
+        shouldHide(mergedChange, definedPatchRange, filesOwners, loggedIn),
+        true
+      );
+    });
+
+    test('shouldHide - should be `true` if not on the latest PS', () => {
+      const changeWithPs2 = {
+        status: ChangeStatus.NEW,
+        revisions: {
+          current_rev: {_number: 2},
+        },
+        current_revision: 'current_rev',
+      } as unknown as ChangeInfo;
+      const patchRangeOnPs1 = {patchNum: 1} as unknown as PatchRange;
+      assert.equal(
+        shouldHide(changeWithPs2, patchRangeOnPs1, filesOwners, loggedIn),
+        true
+      );
+    });
+
+    const change = {
+      status: ChangeStatus.NEW,
+      revisions: {
+        current_rev: {_number: 1},
+      },
+      current_revision: 'current_rev',
+    } as unknown as ChangeInfo;
+    const patchRange = {patchNum: 1} as unknown as PatchRange;
+
+    test('shouldHide - should be `true` when change has no submit requirements', () => {
+      assert.equal(shouldHide(change, patchRange, filesOwners, loggedIn), true);
+    });
+
+    test('shouldHide - should be `true` when change has no `Owner-Approval` submit requirements', () => {
+      const changeWithDifferentSubmitReqs = {
+        ...change,
+        submit_requirements: [
+          {submittability_expression_result: {expression: 'other'}},
+        ] as unknown as SubmitRequirementResultInfo[],
+      };
+      assert.equal(
+        shouldHide(
+          changeWithDifferentSubmitReqs,
+          patchRange,
+          filesOwners,
+          loggedIn
+        ),
+        true
+      );
+    });
+
+    const submitRequirements = getRandom({
+      submit_requirements: [
+        {submittability_expression_result: {expression: 'has:approval_owners'}},
+        {
+          submittability_expression_result: {
+            expression: 'rule:owners~OwnersSubmitRequirement',
+          },
+        },
+      ] as unknown as SubmitRequirementResultInfo[],
+    });
+    const changeWithSubmitRequirementOrRecord = {
+      ...change,
+      ...submitRequirements,
+    };
+
+    test('shouldHide - should be `true` when user is anonymous', () => {
+      const anonymous = UserRole.ANONYMOUS;
+      assert.equal(
+        shouldHide(
+          changeWithSubmitRequirementOrRecord,
+          patchRange,
+          filesOwners,
+          anonymous
+        ),
+        true
+      );
+    });
+
+    test('shouldHide - should be `true` when files owners are `undefined`', () => {
+      const undefinedFilesOwners = getRandom(
+        undefined,
+        {}
+      ) as unknown as FilesOwners;
+      assert.equal(
+        shouldHide(
+          changeWithSubmitRequirementOrRecord,
+          patchRange,
+          undefinedFilesOwners,
+          loggedIn
+        ),
+        true
+      );
+    });
+
+    test('shouldHide - should be `false` when change has all files approved', () => {
+      const allFilesApproved = {
+        approved_files: {[approvedPath]: [{name: 'Merry', id: 2}]},
+      } as unknown as FilesOwners;
+      assert.equal(
+        shouldHide(
+          changeWithSubmitRequirementOrRecord,
+          patchRange,
+          allFilesApproved,
+          loggedIn
+        ),
+        true
+      );
+    });
+
+    test('shouldHide - should be `false` when change has no files approved', () => {
+      const noApprovedFiles = {
+        files: {[path]: [{name: 'John', id: 1}]},
+      } as unknown as FilesOwners;
+      assert.equal(
+        shouldHide(
+          changeWithSubmitRequirementOrRecord,
+          patchRange,
+          noApprovedFiles,
+          loggedIn
+        ),
+        false
+      );
+    });
+
+    test('shouldHide - should be `false` when change has both approved and not approved files', () => {
+      assert.equal(
+        shouldHide(
+          changeWithSubmitRequirementOrRecord,
+          patchRange,
+          filesOwners,
+          loggedIn
+        ),
+        false
+      );
+    });
+
+    test('shouldHide - should be `false` when in edit mode', () => {
+      const patchRangeWithoutPatchNum = {} as unknown as PatchRange;
+      assert.equal(
+        shouldHide(change, patchRangeWithoutPatchNum, filesOwners, loggedIn),
+        false
+      );
+    });
+  });
+
+  suite('getFileOwnership tests', () => {
+    const emptyFilesOwners = {} as unknown as FilesOwners;
+
+    test('getFileOwnership - should be `undefined` when path is `undefined', () => {
+      const undefinedPath = undefined;
+      assert.equal(
+        getFileOwnership(undefinedPath, emptyFilesOwners),
+        undefined
+      );
+    });
+
+    test('getFileOwnership - should be `undefined` when file owners are `undefined', () => {
+      const undefinedFileOwners = undefined;
+      assert.equal(getFileOwnership(path, undefinedFileOwners), undefined);
+    });
+
+    test('getFileOwnership - should return `FileOwnership` with `APPROVED` fileStatus when file is approved', () => {
+      assert.equal(
+        deepEqual(getFileOwnership(approvedPath, filesOwners), {
+          fileStatus: FileStatus.APPROVED,
+          owners: [{name: 'Merry', id: 2}],
+        } as FileOwnership),
+        true
+      );
+    });
+
+    test('getFileOwnership - should return `FileOwnership` with `NOT_OWNED` fileStatus when file has no owner', () => {
+      assert.equal(
+        deepEqual(getFileOwnership(path, emptyFilesOwners), {
+          fileStatus: FileStatus.NOT_OWNED,
+        } as FileOwnership),
+        true
+      );
+    });
+
+    test('getFileOwnership - should return `FileOwnership` with `NEEDS_APPROVAL` fileStatus when file has owner', () => {
+      const fileOwnersWithPathOwner = {
+        files: {[path]: [{name: 'John', id: 1}]},
+      } as unknown as FilesOwners;
+
+      assert.equal(
+        deepEqual(getFileOwnership(path, fileOwnersWithPathOwner), {
+          fileStatus: FileStatus.NEEDS_APPROVAL,
+          owners: [{name: 'John', id: 1}],
+        } as FileOwnership),
+        true
+      );
+    });
+  });
+
+  suite('computeApprovalAndInfo tests', () => {
+    const account = 1;
+    const fileOwner = {
+      owner: {_account_id: account} as unknown as AccountInfo,
+    } as unknown as OwnerOrGroupOwner;
+    const label = 'Code-Review';
+    const crPlus1OwnersVote = {
+      [`${account}`]: {[label]: 1},
+    } as unknown as OwnersLabels;
+    const changeWithLabels = {
+      labels: {
+        [label]: {
+          all: [
+            {
+              value: 1,
+              date: '2024-10-22 17:26:21.000000000',
+              permitted_voting_range: {
+                min: -2,
+                max: 2,
+              },
+              _account_id: account,
+            },
+          ],
+          values: {
+            '-2': 'This shall not be submitted',
+            '-1': 'I would prefer this is not submitted as is',
+            ' 0': 'No score',
+            '+1': 'Looks good to me, but someone else must approve',
+            '+2': 'Looks good to me, approved',
+          },
+          description: '',
+          default_value: 0,
+        },
+      },
+    } as unknown as ChangeInfo;
+
+    test('computeApprovalAndInfo - should be `undefined` when change is `undefined', () => {
+      const undefinedChange = undefined;
+      assert.equal(
+        computeApprovalAndInfo(fileOwner, crPlus1OwnersVote, undefinedChange),
+        undefined
+      );
+    });
+
+    test('computeApprovalAndInfo - should be `undefined` when there is no owners vote', () => {
+      const emptyOwnersVote = {};
+      assert.equal(
+        computeApprovalAndInfo(fileOwner, emptyOwnersVote, changeWithLabels),
+        undefined
+      );
+    });
+
+    test('computeApprovalAndInfo - should be `undefined` for default owners vote', () => {
+      const defaultOwnersVote = {[label]: 0} as unknown as OwnersLabels;
+      assert.equal(
+        computeApprovalAndInfo(fileOwner, defaultOwnersVote, changeWithLabels),
+        undefined
+      );
+    });
+
+    test('computeApprovalAndInfo - should be computed for CR+1 owners vote', () => {
+      const expectedApproval = {
+        value: 1,
+        date: '2024-10-22 17:26:21.000000000',
+        permitted_voting_range: {
+          min: -2,
+          max: 2,
+        },
+        _account_id: account,
+      } as unknown as ApprovalInfo;
+      const expectedInfo = {
+        all: [expectedApproval],
+        values: {
+          '-2': 'This shall not be submitted',
+          '-1': 'I would prefer this is not submitted as is',
+          ' 0': 'No score',
+          '+1': 'Looks good to me, but someone else must approve',
+          '+2': 'Looks good to me, approved',
+        },
+        description: '',
+        default_value: 0,
+      } as unknown as DetailedLabelInfo;
+
+      assert.equal(
+        deepEqual(
+          computeApprovalAndInfo(
+            fileOwner,
+            crPlus1OwnersVote,
+            changeWithLabels
+          ),
+          [expectedApproval, expectedInfo]
+        ),
+        true
+      );
+    });
+  });
+
+  suite('getChangeAccounts tests', () => {
+    test('getChangeAccounts - should return empty map when change is `undefined', () => {
+      const undefinedChange = undefined;
+      const accounts = getChangeAccounts(undefinedChange);
+      assert.equal(accounts.byAccountId.size, 0);
+      assert.equal(accounts.byEmailWithoutDomain.size, 0);
+      assert.equal(accounts.byFullName.size, 0);
+    });
+
+    test('getChangeAccounts - should return map with owner when change has only owner and empty reviewers defined', () => {
+      const owner = account(1);
+      const changeWithOwner = {
+        owner,
+        reviewers: {},
+      } as unknown as ChangeInfo;
+      const accounts = getChangeAccounts(changeWithOwner);
+      assert.equal(
+        deepEqual(accounts.byAccountId, new Map([[1, owner]])),
+        true
+      );
+      assert.equal(
+        deepEqual(accounts.byEmailWithoutDomain, new Map([['1_email', owner]])),
+        true
+      );
+      assert.equal(
+        deepEqual(accounts.byFullName, new Map([['1_name', owner]])),
+        true
+      );
+    });
+
+    test('getChangeAccounts - should return map with owner, submitter and reviewers', () => {
+      const owner = account(1);
+      const submitter = account(2);
+      const reviewer = account(3);
+      const ccReviewer = account(4);
+      const change = {
+        owner,
+        submitter,
+        reviewers: {
+          [ReviewerState.REVIEWER]: [reviewer],
+          [ReviewerState.CC]: [ccReviewer],
+        },
+      } as unknown as ChangeInfo;
+      const accounts = getChangeAccounts(change);
+      assert.equal(
+        deepEqual(
+          accounts.byAccountId,
+          new Map([
+            [1, owner],
+            [2, submitter],
+            [3, reviewer],
+            [4, ccReviewer],
+          ])
+        ),
+        true
+      );
+      assert.equal(
+        deepEqual(
+          accounts.byEmailWithoutDomain,
+          new Map([
+            ['1_email', owner],
+            ['2_email', submitter],
+            ['3_email', reviewer],
+            ['4_email', ccReviewer],
+          ])
+        ),
+        true
+      );
+      assert.equal(
+        deepEqual(
+          accounts.byFullName,
+          new Map([
+            ['1_name', owner],
+            ['2_name', submitter],
+            ['3_name', reviewer],
+            ['4_name', ccReviewer],
+          ])
+        ),
+        true
+      );
+    });
+  });
+});
+
+function account(id: number) {
+  return {
+    _account_id: id,
+    email: `${id}_email@example.com`,
+    name: `${id}_name`,
+  } as unknown as AccountInfo;
+}

diff --git a/owners/web/gr-owned-files.ts b/owners/web/gr-owned-files.ts
new file mode 100644
index 0000000..96ea373
--- /dev/null
+++ b/owners/web/gr-owned-files.ts

@@ -0,0 +1,504 @@
+/**
+ * @license
+ * Copyright (C) 2024 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.
+ */
+
+import {css, html, LitElement, PropertyValues, nothing, CSSResult} from 'lit';
+import {ifDefined} from 'lit/directives/if-defined.js';
+import {OwnersMixin} from './owners-mixin';
+import {customElement, property} from 'lit/decorators';
+import {
+  AccountInfo,
+  ChangeInfo,
+  ChangeStatus,
+  EmailAddress,
+  RevisionInfo,
+  EDIT,
+} from '@gerritcodereview/typescript-api/rest-api';
+import {User, UserRole} from './owners-model';
+import {
+  FilesOwners,
+  hasOwnersSubmitRequirement,
+  isOwner,
+  OwnedFiles,
+} from './owners-service';
+import {
+  computeDisplayPath,
+  diffFilePaths,
+  encodeURL,
+  getBaseUrl,
+  truncatePath,
+} from './utils';
+
+const STATUS_CODE = {
+  MISSING: 'missing',
+  APPROVED: 'approved',
+};
+
+const STATUS_ICON = {
+  [STATUS_CODE.MISSING]: 'schedule',
+  [STATUS_CODE.APPROVED]: 'check',
+};
+
+export interface OwnedFilesInfo {
+  ownedFiles: string[];
+  numberOfPending: number;
+  numberOfApproved: number;
+}
+
+const common = OwnersMixin(LitElement);
+
+class OwnedFilesCommon extends common {
+  @property({type: Object})
+  revision?: RevisionInfo;
+
+  protected ownedFilesInfo?: OwnedFilesInfo;
+
+  protected override willUpdate(changedProperties: PropertyValues): void {
+    super.willUpdate(changedProperties);
+    this.computeOwnedFiles();
+
+    this.hidden = shouldHide(
+      this.change,
+      this.revision,
+      this.user,
+      this.ownedFilesInfo?.ownedFiles
+    );
+  }
+
+  static commonStyles(): CSSResult[] {
+    return [window?.Gerrit?.styles.font as CSSResult];
+  }
+
+  private computeOwnedFiles() {
+    this.ownedFilesInfo = ownedFiles(this.user?.account, this.filesOwners);
+  }
+}
+
+export const OWNED_FILES_TAB_HEADER = 'owned-files-tab-header';
+@customElement(OWNED_FILES_TAB_HEADER)
+export class OwnedFilesTabHeader extends OwnedFilesCommon {
+  @property({type: String, reflect: true, attribute: 'files-status'})
+  filesStatus?: string;
+
+  private ownedFiles: number | undefined;
+
+  static override get styles() {
+    return [
+      ...OwnedFilesCommon.commonStyles(),
+      css`
+        [hidden] {
+          display: none;
+        }
+        gr-icon {
+          padding: var(--spacing-xs) 0px;
+          margin-left: 3px;
+        }
+        :host([files-status='approved']) gr-icon.status {
+          color: var(--positive-green-text-color);
+        }
+        :host([files-status='missing']) gr-icon.status {
+          color: #ffa62f;
+        }
+      `,
+    ];
+  }
+
+  protected override willUpdate(changedProperties: PropertyValues): void {
+    super.willUpdate(changedProperties);
+
+    if (this.hidden || this.ownedFilesInfo === undefined) {
+      this.filesStatus = undefined;
+      this.ownedFiles = undefined;
+    } else {
+      [this.filesStatus, this.ownedFiles] =
+        this.ownedFilesInfo.numberOfPending > 0
+          ? [STATUS_CODE.MISSING, this.ownedFilesInfo.numberOfPending]
+          : [STATUS_CODE.APPROVED, this.ownedFilesInfo.numberOfApproved];
+    }
+  }
+
+  override render() {
+    // even if `nothing` is returned Gerrit still shows the pointer and allows
+    // clicking at it, redirecting to the empty tab when done; traverse through
+    // the shadowRoots down to the tab and disable/enable it when needed
+    const tabParent = document
+      .querySelector('#pg-app')
+      ?.shadowRoot?.querySelector('#app-element')
+      ?.shadowRoot?.querySelector('main > gr-change-view')
+      ?.shadowRoot?.querySelector(
+        '#tabs > paper-tab[data-name="change-view-tab-header-owners"]'
+      );
+    if (this.hidden) {
+      if (tabParent && !tabParent.getAttribute('disabled')) {
+        tabParent.setAttribute('disabled', 'disabled');
+      }
+      return nothing;
+    }
+    if (tabParent && tabParent.getAttribute('disabled')) {
+      tabParent.removeAttribute('disabled');
+    }
+
+    if (
+      this.ownedFilesInfo === undefined ||
+      this.filesStatus === undefined ||
+      this.ownedFiles === undefined
+    ) {
+      return html`<div>Owned Files</div>`;
+    }
+
+    const icon = STATUS_ICON[this.filesStatus];
+    const [info, summary] = this.buildInfoAndSummary(
+      this.filesStatus,
+      this.ownedFilesInfo.numberOfApproved,
+      this.ownedFilesInfo.numberOfPending
+    );
+    return html` <div>
+      Owned Files
+      <gr-tooltip-content
+        title=${info}
+        aria-label=${summary}
+        aria-description=${info}
+        has-tooltip
+      >
+        <gr-icon
+          id="owned-files-status"
+          class="status"
+          icon=${icon}
+          aria-hidden="true"
+        ></gr-icon>
+      </gr-tooltip-content>
+    </div>`;
+  }
+
+  private buildInfoAndSummary(
+    filesStatus: string,
+    filesApproved: number,
+    filesPending: number
+  ): [string, string] {
+    const pendingInfo =
+      filesPending > 0
+        ? `Missing approval for ${filesPending} file${
+            filesPending > 1 ? 's' : ''
+          }`
+        : '';
+    const approvedInfo =
+      filesApproved > 0
+        ? `${filesApproved} file${
+            filesApproved > 1 ? 's' : ''
+          } already approved.`
+        : '';
+    const info = `${
+      STATUS_CODE.APPROVED === filesStatus
+        ? approvedInfo
+        : `${pendingInfo}${filesApproved > 0 ? ` and ${approvedInfo}` : '.'}`
+    }`;
+    const summary = `${
+      STATUS_CODE.APPROVED === filesStatus ? 'Approved' : 'Missing'
+    }`;
+    return [info, summary];
+  }
+}
+
+@customElement('gr-owned-files-list')
+export class GrOwnedFilesList extends LitElement {
+  @property({type: Object})
+  change?: ChangeInfo;
+
+  @property({type: Object})
+  revision?: RevisionInfo;
+
+  @property({type: Array})
+  ownedFiles?: string[];
+
+  static override get styles() {
+    return [
+      ...OwnedFilesCommon.commonStyles(),
+      css`
+        :host {
+          display: block;
+        }
+        .row {
+          align-items: center;
+          border-top: 1px solid var(--border-color);
+          display: flex;
+          min-height: calc(var(--line-height-normal) + 2 * var(--spacing-s));
+          padding: var(--spacing-xs) var(--spacing-l);
+        }
+        .header-row {
+          background-color: var(--background-color-secondary);
+        }
+        .file-row {
+          cursor: pointer;
+        }
+        .file-row:hover {
+          background-color: var(--hover-background-color);
+        }
+        .file-row.selected {
+          background-color: var(--selection-background-color);
+        }
+        .path {
+          cursor: pointer;
+          flex: 1;
+          /* Wrap it into multiple lines if too long. */
+          white-space: normal;
+          word-break: break-word;
+        }
+        .matchingFilePath {
+          color: var(--deemphasized-text-color);
+        }
+        .newFilePath {
+          color: var(--primary-text-color);
+        }
+        .fileName {
+          color: var(--link-color);
+        }
+        .truncatedFileName {
+          display: none;
+        }
+        .row:focus {
+          outline: none;
+        }
+        .row:hover {
+          opacity: 100;
+        }
+        .pathLink {
+          display: inline-block;
+          margin: -2px 0;
+          padding: var(--spacing-s) 0;
+          text-decoration: none;
+        }
+        .pathLink:hover span.fullFileName,
+        .pathLink:hover span.truncatedFileName {
+          text-decoration: underline;
+        }
+      `,
+    ];
+  }
+
+  override render() {
+    if (!this.change || !this.revision || !this.ownedFiles) return nothing;
+
+    return html`
+      <div id="container" role="grid" aria-label="Owned files list">
+        ${this.renderOwnedFilesHeaderRow()}
+        ${this.ownedFiles?.map((ownedFile, index) =>
+          this.renderOwnedFileRow(ownedFile, index)
+        )}
+      </div>
+    `;
+  }
+
+  private renderOwnedFilesHeaderRow() {
+    return html`
+      <div class="header-row row" role="row">
+        <div class="path" role="columnheader">File</div>
+      </div>
+    `;
+  }
+
+  private renderOwnedFileRow(ownedFile: string, index: number) {
+    return html`
+      <div
+        class="file-row row"
+        tabindex="-1"
+        role="row"
+        aria-label=${ownedFile}
+      >
+        ${this.renderFilePath(ownedFile, index)}
+      </div>
+    `;
+  }
+
+  private renderFilePath(file: string, index: number) {
+    const displayPath = computeDisplayPath(file);
+    const previousFile = (this.ownedFiles ?? [])[index - 1];
+    return html`
+      <span class="path" role="gridcell">
+        <a
+          class="pathLink"
+          href=${ifDefined(computeDiffUrl(file, this.change, this.revision))}
+        >
+          <span title=${displayPath} class="fullFileName">
+            ${this.renderStyledPath(file, previousFile)}
+          </span>
+          <span title=${displayPath} class="truncatedFileName">
+            ${truncatePath(displayPath)}
+          </span>
+        </a>
+      </span>
+    `;
+  }
+
+  private renderStyledPath(filePath: string, previousFilePath?: string) {
+    const {matchingFolders, newFolders, fileName} = diffFilePaths(
+      filePath,
+      previousFilePath
+    );
+    return [
+      matchingFolders.length > 0
+        ? html`<span class="matchingFilePath">${matchingFolders}</span>`
+        : nothing,
+      newFolders.length > 0
+        ? html`<span class="newFilePath">${newFolders}</span>`
+        : nothing,
+      html`<span class="fileName">${fileName}</span>`,
+    ];
+  }
+}
+
+export const OWNED_FILES_TAB_CONTENT = 'owned-files-tab-content';
+@customElement(OWNED_FILES_TAB_CONTENT)
+export class OwnedFilesTabContent extends OwnedFilesCommon {
+  static override get styles() {
+    return [
+      ...OwnedFilesCommon.commonStyles(),
+      css`
+        :host {
+          display: block;
+        }
+      `,
+    ];
+  }
+
+  override render() {
+    if (this.hidden) return nothing;
+
+    return html`
+      <gr-owned-files-list
+        id="ownedFilesList"
+        .change=${this.change}
+        .revision=${this.revision}
+        .ownedFiles=${this.ownedFilesInfo?.ownedFiles}
+      >
+      </gr-owned-files-list>
+    `;
+  }
+}
+
+export function shouldHide(
+  change?: ChangeInfo,
+  revision?: RevisionInfo,
+  user?: User,
+  ownedFiles?: string[]
+) {
+  // don't show owned files when no change or change is abandoned/merged or being edited or viewing not current PS
+  if (
+    change === undefined ||
+    change.status === ChangeStatus.ABANDONED ||
+    change.status === ChangeStatus.MERGED ||
+    revision === undefined ||
+    revision._number === EDIT ||
+    change.current_revision !== revision.commit?.commit
+  ) {
+    return true;
+  }
+
+  // show owned files if user owns anything
+  if (hasOwnersSubmitRequirement(change)) {
+    return (
+      !user ||
+      user.role === UserRole.ANONYMOUS ||
+      (ownedFiles ?? []).length === 0
+    );
+  }
+  return true;
+}
+
+function collectOwnedFiles(
+  owner: AccountInfo,
+  groupPrefix: string,
+  files: OwnedFiles,
+  emailWithoutDomain?: string
+): string[] {
+  const ownedFiles = [];
+  for (const file of Object.keys(files ?? [])) {
+    if (
+      files[file].find(fileOwner => {
+        if (isOwner(fileOwner)) {
+          return fileOwner.id === owner._account_id;
+        }
+
+        return (
+          !fileOwner.name?.startsWith(groupPrefix) &&
+          (fileOwner.name === emailWithoutDomain ||
+            fileOwner.name === owner.name)
+        );
+      })
+    ) {
+      ownedFiles.push(file);
+    }
+  }
+
+  return ownedFiles;
+}
+
+export function ownedFiles(
+  owner?: AccountInfo,
+  filesOwners?: FilesOwners
+): OwnedFilesInfo | undefined {
+  if (
+    !owner ||
+    !filesOwners ||
+    (!filesOwners.files && !filesOwners.files_approved)
+  ) {
+    return;
+  }
+
+  const groupPrefix = 'group/';
+  const emailWithoutDomain = toEmailWithoutDomain(owner.email);
+  const pendingFiles = collectOwnedFiles(
+    owner,
+    groupPrefix,
+    filesOwners.files,
+    emailWithoutDomain
+  );
+  const approvedFiles = collectOwnedFiles(
+    owner,
+    groupPrefix,
+    filesOwners.files_approved,
+    emailWithoutDomain
+  );
+  return {
+    ownedFiles: [...pendingFiles, ...approvedFiles],
+    numberOfPending: pendingFiles.length,
+    numberOfApproved: approvedFiles.length,
+  } as OwnedFilesInfo;
+}
+
+export function computeDiffUrl(
+  file: string,
+  change?: ChangeInfo,
+  revision?: RevisionInfo
+) {
+  if (change === undefined || revision?._number === undefined) {
+    return;
+  }
+
+  let repo = '';
+  if (change.project) repo = `${encodeURL(change.project)}/+/`;
+
+  // TODO it can be a range of patchsets but `PatchRange` is not passed to the `change-view-tab-content` :/ fix in Gerrit?
+  const range = `/${revision._number}`;
+
+  const path = `/${encodeURL(file)}`;
+
+  return `${getBaseUrl()}/c/${repo}${change._number}${range}${path}`;
+}
+
+function toEmailWithoutDomain(email?: EmailAddress): string | undefined {
+  const startDomainIndex = email?.indexOf('@');
+  return startDomainIndex ? email?.substring(0, startDomainIndex) : undefined;
+}

diff --git a/owners/web/gr-owned-files_test.ts b/owners/web/gr-owned-files_test.ts
new file mode 100644
index 0000000..d7bef24
--- /dev/null
+++ b/owners/web/gr-owned-files_test.ts

@@ -0,0 +1,242 @@
+/**
+ * @license
+ * Copyright (C) 2024 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.
+ */
+
+import {assert} from '@open-wc/testing';
+import {
+  AccountId,
+  AccountInfo,
+  ChangeInfo,
+  ChangeStatus,
+  CommitId,
+  RevisionInfo,
+  EDIT,
+  SubmitRequirementResultInfo,
+} from '@gerritcodereview/typescript-api/rest-api';
+import {ownedFiles, OwnedFilesInfo, shouldHide} from './gr-owned-files';
+import {FilesOwners, GroupOwner, Owner} from './owners-service';
+import {deepEqual} from './utils';
+import {User, UserRole} from './owners-model';
+import {getRandom} from './test-utils';
+
+suite('owned files tests', () => {
+  suite('ownedFiles tests', () => {
+    const ownerAccountId = 1;
+    const owner = account(ownerAccountId);
+
+    const ownedFile = 'README.md';
+    const ownedApprovedFile = 'db.sql';
+    const files = {
+      [ownedFile]: [fileOwner(1)],
+      'some.text': [fileOwner(6)],
+    };
+    const files_approved = {
+      [ownedApprovedFile]: [fileOwner(1)],
+    };
+    const filesOwners = {
+      files,
+      files_approved,
+    } as unknown as FilesOwners;
+    const emptyOwnerFilesInfo = {
+      ownedFiles: [],
+      numberOfApproved: 0,
+      numberOfPending: 0,
+    } as unknown as OwnedFilesInfo;
+
+    test('ownedFiles - should be `undefined` when owner is `undefined`', () => {
+      const undefinedOwner = undefined;
+      assert.equal(ownedFiles(undefinedOwner, filesOwners), undefined);
+    });
+
+    test('ownedFiles - should be `undefined` when filesOwners are `undefined`', () => {
+      const undefinedFilesOwners = undefined;
+      assert.equal(ownedFiles(owner, undefinedFilesOwners), undefined);
+    });
+
+    test('ownedFiles - should return empty owned file when no files are owned by user', () => {
+      const user = account(2);
+      assert.equal(
+        deepEqual(ownedFiles(user, filesOwners), emptyOwnerFilesInfo),
+        true
+      );
+    });
+
+    test('ownedFiles - should return owned files', () => {
+      assert.equal(
+        deepEqual(ownedFiles(owner, filesOwners), {
+          ownedFiles: [ownedFile, ownedApprovedFile],
+          numberOfApproved: 1,
+          numberOfPending: 1,
+        }),
+        true
+      );
+    });
+
+    test('ownedFiles - should match file owner through email without domain name', () => {
+      const filesOwners = {
+        files: {
+          [ownedFile]: [fileOwnerWithNameOnly(`${ownerAccountId}_email`)],
+          'some.text': [fileOwnerWithNameOnly('random_joe')],
+        },
+      } as unknown as FilesOwners;
+      assert.equal(
+        deepEqual(ownedFiles(owner, filesOwners), {
+          ownedFiles: [ownedFile],
+          numberOfApproved: 0,
+          numberOfPending: 1,
+        }),
+        true
+      );
+    });
+
+    test('ownedFiles - should match file owner through full name', () => {
+      const filesOwners = {
+        files_approved: {
+          [ownedFile]: [fileOwnerWithNameOnly(`${ownerAccountId}_name`)],
+          'some.text': [fileOwnerWithNameOnly('random_joe')],
+        },
+      } as unknown as FilesOwners;
+      assert.equal(
+        deepEqual(ownedFiles(owner, filesOwners), {
+          ownedFiles: [ownedFile],
+          numberOfApproved: 1,
+          numberOfPending: 0,
+        }),
+        true
+      );
+    });
+
+    test('ownedFiles - should NOT match file owner over email without domain or full name when account id is different', () => {
+      const notFileOwner = {...owner, _account_id: 2 as unknown as AccountId};
+      assert.equal(
+        deepEqual(ownedFiles(notFileOwner, filesOwners), emptyOwnerFilesInfo),
+        true
+      );
+    });
+  });
+
+  suite('shouldHide tests', () => {
+    const current_revision = 'commit-1' as unknown as CommitId;
+    const change = {
+      status: ChangeStatus.NEW,
+      submit_requirements: [
+        {submittability_expression_result: {expression: 'has:approval_owners'}},
+      ] as unknown as SubmitRequirementResultInfo[],
+      current_revision,
+    } as unknown as ChangeInfo;
+    const revisionInfo = {
+      _number: 1,
+      commit: {commit: current_revision},
+    } as unknown as RevisionInfo;
+    const user = {account: account(1), role: UserRole.OTHER};
+    const ownedFiles = ['README.md'];
+
+    test('shouldHide - should be `true` when change is `undefined`', () => {
+      const undefinedChange = undefined;
+      assert.equal(
+        shouldHide(undefinedChange, revisionInfo, user, ownedFiles),
+        true
+      );
+    });
+
+    test('shouldHide - should be `true` when change is `ABANDONED` or `MERGED`', () => {
+      const abandonedOrMergedChange = {
+        ...change,
+        status: getRandom(ChangeStatus.ABANDONED, ChangeStatus.MERGED),
+      };
+      assert.equal(
+        shouldHide(abandonedOrMergedChange, revisionInfo, user, ownedFiles),
+        true
+      );
+    });
+
+    test('shouldHide - should be `true` when revisionInfo is `undefined` or in `EDIT` mode', () => {
+      const undefinedOrEditRevisionInfo = getRandom(undefined, {
+        _number: EDIT,
+      } as unknown as RevisionInfo);
+      assert.equal(
+        shouldHide(change, undefinedOrEditRevisionInfo, user, ownedFiles),
+        true
+      );
+    });
+
+    test('shouldHide - should be `true` when NOT current_revision is viewed', () => {
+      const notCurrentRevisionInfo = {
+        _number: 0,
+        commit: {commit: 'not-current' as unknown as CommitId},
+      } as unknown as RevisionInfo;
+      assert.equal(
+        shouldHide(change, notCurrentRevisionInfo, user, ownedFiles),
+        true
+      );
+    });
+
+    test('shouldHide - should be `true` when change has different submit requirements', () => {
+      const changeWithOtherSubmitRequirements = {
+        ...change,
+        submit_requirements: [
+          {
+            submittability_expression_result: {
+              expression: 'has:other_predicate',
+            },
+          },
+        ] as unknown as SubmitRequirementResultInfo[],
+      };
+      assert.equal(
+        shouldHide(
+          changeWithOtherSubmitRequirements,
+          revisionInfo,
+          user,
+          ownedFiles
+        ),
+        true
+      );
+    });
+
+    test('shouldHide - should be `true` when user is `undefined` or `ANONYMOUS`', () => {
+      const undefinedOrAnonymousUser = getRandom(undefined, {
+        role: UserRole.ANONYMOUS,
+      } as unknown as User);
+      assert.equal(
+        shouldHide(change, revisionInfo, undefinedOrAnonymousUser, ownedFiles),
+        true
+      );
+    });
+
+    test('shouldHide - should be `false` when user owns files', () => {
+      assert.equal(shouldHide(change, revisionInfo, user, ownedFiles), false);
+    });
+  });
+});
+
+function account(id: number): AccountInfo {
+  return {
+    _account_id: id,
+    email: `${id}_email@example.com`,
+    name: `${id}_name`,
+  } as unknown as AccountInfo;
+}
+
+function fileOwner(id: number): Owner {
+  return {
+    id,
+    name: `${id}_name`,
+  } as unknown as Owner;
+}
+
+function fileOwnerWithNameOnly(name: string): GroupOwner {
+  return {name} as unknown as GroupOwner;
+}

diff --git a/owners/web/karma_test.sh b/owners/web/karma_test.sh
new file mode 100755
index 0000000..7cecdae
--- /dev/null
+++ b/owners/web/karma_test.sh

@@ -0,0 +1,6 @@
+#!/bin/bash
+set -euo pipefail
+./$1 start $2 --single-run \
+  --root 'plugins/owners/web/_bazel_ts_out_tests/' \
+  --test-files '*_test.js' \
+  --browsers ${3:-ChromeHeadless}

diff --git a/owners/web/owners-mixin.ts b/owners/web/owners-mixin.ts
new file mode 100644
index 0000000..cd9217a
--- /dev/null
+++ b/owners/web/owners-mixin.ts

@@ -0,0 +1,124 @@
+/**
+ * @license
+ * Copyright (C) 2024 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.
+ */
+
+import {Subscription} from 'rxjs';
+import {LitElement, PropertyValues} from 'lit';
+import {property, state} from 'lit/decorators';
+import {ChangeInfo} from '@gerritcodereview/typescript-api/rest-api';
+import {FilesOwners, OwnersService} from './owners-service';
+import {RestPluginApi} from '@gerritcodereview/typescript-api/rest';
+import {ModelLoader, OwnersModel, PatchRange, User} from './owners-model';
+
+// Lit mixin definition as described in https://lit.dev/docs/composition/mixins/
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
+export type Constructor<T> = new (...args: any[]) => T;
+
+export interface OwnersInterface extends LitElement {
+  change?: ChangeInfo;
+  patchRange?: PatchRange;
+  restApi?: RestPluginApi;
+  user?: User;
+  filesOwners?: FilesOwners;
+
+  onModelUpdate(): void;
+}
+
+export const OwnersMixin = <T extends Constructor<LitElement>>(
+  superClass: T
+) => {
+  class Mixin extends superClass {
+    @property({type: Object})
+    change?: ChangeInfo;
+
+    @property({type: Object})
+    patchRange?: PatchRange;
+
+    @property({type: Object})
+    restApi?: RestPluginApi;
+
+    @state()
+    user?: User;
+
+    @state()
+    filesOwners?: FilesOwners;
+
+    private _model?: OwnersModel;
+
+    modelLoader?: ModelLoader;
+
+    private subscriptions: Array<Subscription> = [];
+
+    get model() {
+      return this._model;
+    }
+
+    set model(model: OwnersModel | undefined) {
+      if (this._model === model) return;
+      for (const s of this.subscriptions) {
+        s.unsubscribe();
+      }
+      this.subscriptions = [];
+      this._model = model;
+      if (!model) return;
+
+      this.subscriptions.push(
+        model.state$.subscribe(s => {
+          this.user = s.user;
+        })
+      );
+
+      this.subscriptions.push(
+        model.state$.subscribe(s => {
+          this.filesOwners = s.filesOwners;
+        })
+      );
+
+      this.onModelUpdate();
+    }
+
+    protected override willUpdate(changedProperties: PropertyValues): void {
+      super.willUpdate(changedProperties);
+
+      if (changedProperties.has('change') || changedProperties.has('restApi')) {
+        if (!this.restApi || !this.change) {
+          this.model = undefined;
+          this.modelLoader = undefined;
+          return;
+        }
+        const service = OwnersService.getOwnersService(
+          this.restApi,
+          this.change
+        );
+        const model = OwnersModel.getModel(this.change);
+        this.modelLoader = new ModelLoader(service, model);
+        this.model = model;
+      }
+    }
+
+    protected onModelUpdate() {
+      this.modelLoader?.loadUser();
+      this.modelLoader?.loadFilesOwners();
+    }
+
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    constructor(...args: any[]) {
+      super(...args);
+    }
+  }
+
+  return Mixin as unknown as T & Constructor<OwnersInterface>;
+};

diff --git a/owners/web/owners-model.ts b/owners/web/owners-model.ts
new file mode 100644
index 0000000..48e7e08
--- /dev/null
+++ b/owners/web/owners-model.ts

@@ -0,0 +1,148 @@
+/**
+ * @license
+ * Copyright (C) 2024 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.
+ */
+
+import {BehaviorSubject, Observable} from 'rxjs';
+import {
+  AccountInfo,
+  BasePatchSetNum,
+  ChangeInfo,
+  GroupInfo,
+  RevisionPatchSetNum,
+} from '@gerritcodereview/typescript-api/rest-api';
+import {FileOwner, FilesOwners, OwnersService} from './owners-service';
+import {deepEqual} from './utils';
+
+export interface PatchRange {
+  patchNum: RevisionPatchSetNum;
+  basePatchNum: BasePatchSetNum;
+}
+
+export enum UserRole {
+  ANONYMOUS = 'ANONYMOUS',
+  CHANGE_OWNER = 'CHANGE_OWNER',
+  OTHER = 'OTHER',
+}
+
+export interface User {
+  account?: AccountInfo;
+  role: UserRole;
+}
+
+export interface OwnersState {
+  user?: User;
+  filesOwners?: FilesOwners;
+}
+
+export enum FileStatus {
+  NEEDS_APPROVAL = 'NEEDS_APPROVAL',
+  APPROVED = 'APPROVED',
+  NOT_OWNED = 'NOT_OWNED',
+}
+
+export interface FileOwnership {
+  fileStatus: FileStatus;
+  owners?: FileOwner[];
+}
+
+export interface OwnerOrGroupOwner {
+  owner?: AccountInfo;
+  groupOwner?: GroupInfo;
+}
+
+let ownersModel: OwnersModel | undefined;
+
+export class OwnersModel extends EventTarget {
+  private subject$: BehaviorSubject<OwnersState> = new BehaviorSubject(
+    {} as OwnersState
+  );
+
+  public state$: Observable<OwnersState> = this.subject$.asObservable();
+
+  constructor(readonly change: ChangeInfo) {
+    super();
+  }
+
+  get state() {
+    return this.subject$.getValue();
+  }
+
+  private setState(state: OwnersState) {
+    this.subject$.next(Object.freeze(state));
+  }
+
+  setUser(user: User) {
+    const current = this.subject$.getValue();
+    if (current.user === user) return;
+    this.setState({...current, user});
+  }
+
+  setFilesOwners(filesOwners: FilesOwners | undefined) {
+    const current = this.subject$.getValue();
+    if (deepEqual(current.filesOwners, filesOwners)) return;
+    this.setState({...current, filesOwners});
+  }
+
+  static getModel(change: ChangeInfo) {
+    if (!ownersModel || ownersModel.change !== change) {
+      ownersModel = new OwnersModel(change);
+    }
+    return ownersModel;
+  }
+}
+
+export class ModelLoader {
+  constructor(
+    private readonly service: OwnersService,
+    private readonly model: OwnersModel
+  ) {}
+
+  async loadUser() {
+    await this._loadProperty(
+      'user',
+      () => this.service.getLoggedInUser(),
+      value => this.model.setUser(value)
+    );
+  }
+
+  async loadFilesOwners() {
+    await this._loadProperty(
+      'filesOwners',
+      () => this.service.getFilesOwners(),
+      value => this.model.setFilesOwners(value)
+    );
+  }
+
+  private async _loadProperty<K extends keyof OwnersState, T>(
+    propertyName: K,
+    propertyLoader: () => Promise<T>,
+    propertySetter: (value: T) => void
+  ) {
+    if (this.model.state[propertyName] !== undefined) return;
+    let newValue: T;
+    try {
+      newValue = await propertyLoader();
+    } catch (e) {
+      console.error(e);
+      return;
+    }
+    // It is possible, that several requests is made in parallel.
+    // Store only the first result and discard all other results.
+    // (also, due to the CodeOwnersCacheApi all result must be identical)
+    if (this.model.state[propertyName] !== undefined) return;
+    propertySetter(newValue);
+  }
+}

diff --git a/owners/web/owners-service.ts b/owners/web/owners-service.ts
new file mode 100644
index 0000000..0a57362
--- /dev/null
+++ b/owners/web/owners-service.ts

@@ -0,0 +1,206 @@
+/**
+ * @license
+ * Copyright (C) 2024 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.
+ */
+
+import {HttpMethod, RestPluginApi} from '@gerritcodereview/typescript-api/rest';
+import {
+  AccountDetailInfo,
+  ChangeInfo,
+  NumericChangeId,
+  RepoName,
+} from '@gerritcodereview/typescript-api/rest-api';
+import {User, UserRole} from './owners-model';
+
+export interface GroupOwner {
+  name: string;
+}
+
+export interface Owner extends GroupOwner {
+  id: number;
+}
+
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
+export function isOwner(o: any): o is Owner {
+  return o && typeof o.id === 'number' && typeof o.name === 'string';
+}
+
+export type FileOwner = Owner | GroupOwner;
+
+export interface OwnedFiles {
+  [fileName: string]: FileOwner[];
+}
+
+export interface OwnersLabels {
+  [id: string]: {
+    [label: string]: number;
+  };
+}
+
+export interface FilesOwners {
+  files: OwnedFiles;
+  files_approved: OwnedFiles;
+  owners_labels: OwnersLabels;
+}
+
+const OWNERS_SUBMIT_REQUIREMENT = 'has:approval_owners';
+const OWNERS_SUBMIT_RULE = 'owners~OwnersSubmitRequirement';
+
+export function hasOwnersSubmitRequirement(change: ChangeInfo): boolean {
+  return (
+    change.submit_requirements !== undefined &&
+    change.submit_requirements.find(r => {
+      const expression = r.submittability_expression_result.expression;
+      return (
+        expression.includes(OWNERS_SUBMIT_REQUIREMENT) ||
+        expression.includes(OWNERS_SUBMIT_RULE)
+      );
+    }) !== undefined
+  );
+}
+
+class ResponseError extends Error {
+  constructor(readonly response: Response) {
+    super();
+  }
+}
+
+async function getErrorMessage(response: Response) {
+  const text = await response.text();
+  return text ? `${response.status}: ${text}` : `${response.status}`;
+}
+
+class OwnersApi {
+  constructor(readonly restApi: RestPluginApi) {}
+
+  async getAccount(): Promise<AccountDetailInfo | undefined> {
+    const loggedIn = await this.restApi.getLoggedIn();
+    if (!loggedIn) return undefined;
+    return await this.restApi.getAccount();
+  }
+
+  /**
+   * Returns the list of owners associated to each file that needs a review or were approved,
+   * and, for each owner, its current labels and votes.
+   *
+   * @doc
+   * https://gerrit.googlesource.com/plugins/owners/+/refs/heads/master/owners/src/main/resources/Documentation/rest-api.md
+   */
+  getFilesOwners(
+    repoName: RepoName,
+    changeId: NumericChangeId,
+    revision: String
+  ): Promise<FilesOwners> {
+    return this.get(
+      `/changes/${encodeURIComponent(
+        repoName
+      )}~${changeId}/revisions/${revision}/owners~files-owners`
+    ) as Promise<FilesOwners>;
+  }
+
+  private async get(url: string): Promise<unknown> {
+    const errFn = (response?: Response | null, error?: Error) => {
+      if (error) throw error;
+      if (response) throw new ResponseError(response);
+      throw new Error('Generic REST API error');
+    };
+    try {
+      return await this.restApi.send(HttpMethod.GET, url, undefined, errFn);
+    } catch (err) {
+      if (err instanceof ResponseError && err.response.status === 409) {
+        getErrorMessage(err.response).then(msg => {
+          // TODO handle 409 in UI - show banner with error
+          console.error(`Plugin configuration errot: ${msg}`);
+        });
+      }
+      throw err;
+    }
+  }
+}
+
+/**
+ * Calls to REST API can be safely cached cuz:
+ * 1. Gerrit doesn't update the existing change object but obtains and passes new instead
+ * 2. `OwnersService.getOwnersService` guarantees that whenever new change object is retrieved the new service instance is created (and cache is created with it)
+ */
+class OwnersApiCache {
+  private loggedInUser?: Promise<User>;
+
+  private filesOwners?: Promise<FilesOwners | undefined>;
+
+  constructor(
+    private readonly api: OwnersApi,
+    private readonly change: ChangeInfo
+  ) {}
+
+  getLoggedInUser(): Promise<User> {
+    if (this.loggedInUser === undefined) {
+      this.loggedInUser = this.getLoggedInUserImpl();
+    }
+    return this.loggedInUser;
+  }
+
+  getFilesOwners(): Promise<FilesOwners | undefined> {
+    if (this.filesOwners === undefined) {
+      this.filesOwners = this.getFilesOwnersImpl();
+    }
+    return this.filesOwners;
+  }
+
+  private async getLoggedInUserImpl(): Promise<User> {
+    const account = await this.api.getAccount();
+    if (!account) {
+      return {role: UserRole.ANONYMOUS} as unknown as User;
+    }
+    const role =
+      this.change.owner._account_id === account._account_id
+        ? UserRole.CHANGE_OWNER
+        : UserRole.OTHER;
+    return {account, role} as unknown as User;
+  }
+
+  private async getFilesOwnersImpl(): Promise<FilesOwners | undefined> {
+    return this.api.getFilesOwners(
+      this.change.project,
+      this.change._number,
+      this.change.current_revision ?? 'current'
+    );
+  }
+}
+
+let service: OwnersService | undefined;
+
+export class OwnersService {
+  private apiCache: OwnersApiCache;
+
+  constructor(readonly restApi: RestPluginApi, readonly change: ChangeInfo) {
+    this.apiCache = new OwnersApiCache(new OwnersApi(restApi), change);
+  }
+
+  getLoggedInUser(): Promise<User> {
+    return this.apiCache.getLoggedInUser();
+  }
+
+  getFilesOwners(): Promise<FilesOwners | undefined> {
+    return this.apiCache.getFilesOwners();
+  }
+
+  static getOwnersService(restApi: RestPluginApi, change: ChangeInfo) {
+    if (!service || service.change !== change) {
+      service = new OwnersService(restApi, change);
+    }
+    return service;
+  }
+}

diff --git a/owners/web/owners-service_test.ts b/owners/web/owners-service_test.ts
new file mode 100644
index 0000000..fbb9dc7
--- /dev/null
+++ b/owners/web/owners-service_test.ts

@@ -0,0 +1,298 @@
+/**
+ * @license
+ * Copyright (C) 2024 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.
+ */
+
+import {
+  FilesOwners,
+  hasOwnersSubmitRequirement,
+  OwnersService,
+} from './owners-service';
+import {
+  RequestPayload,
+  RestPluginApi,
+} from '@gerritcodereview/typescript-api/rest';
+import {
+  AccountInfo,
+  ChangeInfo,
+  ChangeStatus,
+  HttpMethod,
+} from '@gerritcodereview/typescript-api/rest-api';
+import {assert} from '@open-wc/testing';
+import {UserRole} from './owners-model';
+import {deepEqual} from './utils';
+
+suite('owners service tests', () => {
+  const fakeRestApi = {} as unknown as RestPluginApi;
+  const fakeChange = {} as unknown as ChangeInfo;
+
+  suite('basic api request tests', () => {
+    test('getOwnersService - same change returns the same instance', () => {
+      assert.equal(
+        OwnersService.getOwnersService(fakeRestApi, fakeChange),
+        OwnersService.getOwnersService(fakeRestApi, fakeChange)
+      );
+    });
+
+    test('getOwnersService - modified change returns new instance', () => {
+      assert.notEqual(
+        OwnersService.getOwnersService(fakeRestApi, {...fakeChange}),
+        OwnersService.getOwnersService(fakeRestApi, {...fakeChange})
+      );
+    });
+  });
+
+  suite('user role tests', () => {
+    test('getLoggedInUser - returns ANONYMOUS when user not logged in', async () => {
+      const notLoggedInApi = {
+        getLoggedIn() {
+          return Promise.resolve(false);
+        },
+      } as unknown as RestPluginApi;
+
+      const service = OwnersService.getOwnersService(
+        notLoggedInApi,
+        fakeChange
+      );
+      const user = await service.getLoggedInUser();
+      assert.equal(user.role, UserRole.ANONYMOUS);
+      assert.equal(user.account, undefined);
+    });
+
+    test('getLoggedInUser - returns OTHER for logged in user that is NOT change owner', async () => {
+      const loggedUser = account(2);
+      const userLoggedInApi = {
+        getLoggedIn() {
+          return Promise.resolve(true);
+        },
+        getAccount() {
+          return Promise.resolve(loggedUser);
+        },
+      } as unknown as RestPluginApi;
+      const change = {owner: account(1)} as unknown as ChangeInfo;
+
+      const service = OwnersService.getOwnersService(userLoggedInApi, change);
+      const user = await service.getLoggedInUser();
+      assert.equal(user.role, UserRole.OTHER);
+      assert.equal(user.account, loggedUser);
+    });
+
+    test('getLoggedInUser - returns CHANGE_OWNER for logged in user that is a change owner', async () => {
+      const owner = account(1);
+      const changeOwnerLoggedInApi = {
+        getLoggedIn() {
+          return Promise.resolve(true);
+        },
+        getAccount() {
+          return Promise.resolve(owner);
+        },
+      } as unknown as RestPluginApi;
+      const change = {owner} as unknown as ChangeInfo;
+
+      const service = OwnersService.getOwnersService(
+        changeOwnerLoggedInApi,
+        change
+      );
+      const user = await service.getLoggedInUser();
+      assert.equal(user.role, UserRole.CHANGE_OWNER);
+      assert.equal(user.account, owner);
+    });
+
+    test('getLoggedInUser - should fetch response from plugin only once', async () => {
+      let calls = 0;
+      const notLoggedInApi = {
+        getLoggedIn() {
+          calls++;
+          return Promise.resolve(false);
+        },
+      } as unknown as RestPluginApi;
+
+      const service = OwnersService.getOwnersService(
+        notLoggedInApi,
+        fakeChange
+      );
+
+      await service.getLoggedInUser();
+      await service.getLoggedInUser();
+      assert.equal(calls, 1);
+    });
+  });
+
+  suite('files owners tests', () => {
+    teardown(() => {
+      sinon.restore();
+    });
+
+    function setupRestApiForLoggedIn(loggedIn: boolean): RestPluginApi {
+      return {
+        getLoggedIn() {
+          return Promise.resolve(loggedIn);
+        },
+        send(
+          _method: HttpMethod,
+          _url: string,
+          _payload?: RequestPayload,
+          _errFn?: ErrorCallback,
+          _contentType?: string
+        ) {
+          return Promise.resolve({});
+        },
+      } as unknown as RestPluginApi;
+    }
+
+    function loggedInRestApiService(acc: number): RestPluginApi {
+      return {
+        ...setupRestApiForLoggedIn(true),
+        getAccount() {
+          return Promise.resolve(account(acc));
+        },
+      } as unknown as RestPluginApi;
+    }
+
+    let service: OwnersService;
+    let getApiStub: sinon.SinonStub;
+
+    function setup(response = {}) {
+      const acc = account(1);
+      const base_change = {
+        ...fakeChange,
+        _number: 1,
+        status: ChangeStatus.NEW,
+        project: 'test_repo',
+        owner: acc,
+      } as unknown as ChangeInfo;
+      const restApi = loggedInRestApiService(1);
+
+      getApiStub = sinon.stub(restApi, 'send');
+      getApiStub
+        .withArgs(
+          sinon.match.any,
+          `/changes/${base_change.project}~${base_change._number}/revisions/current/owners~files-owners`,
+          sinon.match.any,
+          sinon.match.any
+        )
+        .returns(Promise.resolve(response));
+      service = OwnersService.getOwnersService(restApi, base_change);
+    }
+
+    test('should call getFilesOwners', async () => {
+      const expected = {
+        files: {
+          'AJavaFile.java': [{name: 'Bob', id: 1000001}],
+          'Aptyhonfileroot.py': [
+            {name: 'John', id: 1000002},
+            {name: 'Bob', id: 1000001},
+            {name: 'Jack', id: 1000003},
+          ],
+        },
+        owners_labels: {
+          '1000002': {
+            Verified: 1,
+            'Code-Review': 0,
+          },
+          '1000001': {
+            'Code-Review': 2,
+          },
+        },
+      };
+      setup(expected);
+
+      const response = await service.getFilesOwners();
+      await flush();
+      assert.equal(getApiStub.callCount, 1);
+      assert.equal(
+        deepEqual(response, {...expected} as unknown as FilesOwners),
+        true
+      );
+    });
+
+    test('should fetch response from plugin only once', async () => {
+      setup();
+
+      await service.getFilesOwners();
+      await flush();
+
+      await service.getFilesOwners();
+      await flush();
+
+      assert.equal(getApiStub.callCount, 1);
+    });
+  });
+
+  suite('hasOwnersSubmitRequirement tests', () => {
+    test('hasOwnersSubmitRequirement - should be `false` when change has no owners submit requirement', () => {
+      const noSubmitRequirementOrRecordChange = {} as unknown as ChangeInfo;
+      assert.equal(
+        hasOwnersSubmitRequirement(noSubmitRequirementOrRecordChange),
+        false
+      );
+    });
+
+    test('hasOwnersSubmitRequirement - should be `false` when change has different submit requirements', () => {
+      const differentSubmitRequirementAndRecord = {
+        submit_requirements: [
+          {
+            submittability_expression_result: {
+              expression: 'has:other_predicated',
+            },
+          },
+        ],
+      } as unknown as ChangeInfo;
+      assert.equal(
+        hasOwnersSubmitRequirement(differentSubmitRequirementAndRecord),
+        false
+      );
+    });
+
+    test('hasOwnersSubmitRequirement - should be `true` when change has owners submit requirement', () => {
+      const ownersSubmitRequirement = {
+        submit_requirements: [
+          {
+            submittability_expression_result: {
+              expression: 'has:approval_owners',
+            },
+          },
+        ],
+      } as unknown as ChangeInfo;
+      assert.equal(hasOwnersSubmitRequirement(ownersSubmitRequirement), true);
+    });
+
+    test('hasOwnersSubmitRequirement - should be `true` when change has owners submit rule', () => {
+      const ownersSubmitRule = {
+        submit_requirements: [
+          {
+            submittability_expression_result: {
+              expression:
+                'label:Code-Review from owners\u003downers~OwnersSubmitRequirement',
+            },
+          },
+        ],
+      } as unknown as ChangeInfo;
+      assert.equal(hasOwnersSubmitRequirement(ownersSubmitRule), true);
+    });
+  });
+});
+
+function account(id: number): AccountInfo {
+  return {
+    _account_id: id,
+  } as unknown as AccountInfo;
+}
+
+function flush() {
+  return new Promise((resolve, _reject) => {
+    setTimeout(resolve, 0);
+  });
+}

diff --git a/owners/web/plugin.ts b/owners/web/plugin.ts
new file mode 100644
index 0000000..596c8ab
--- /dev/null
+++ b/owners/web/plugin.ts

@@ -0,0 +1,66 @@
+/**
+ * @license
+ * Copyright (C) 2024 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.
+ */
+import '@gerritcodereview/typescript-api/gerrit';
+import {
+  FILES_OWNERS_COLUMN_CONTENT,
+  FILES_OWNERS_COLUMN_HEADER,
+  FilesColumnContent,
+  FilesColumnHeader,
+} from './gr-files';
+import {
+  OWNED_FILES_TAB_CONTENT,
+  OWNED_FILES_TAB_HEADER,
+  OwnedFilesTabContent,
+  OwnedFilesTabHeader,
+} from './gr-owned-files';
+
+window.Gerrit.install(plugin => {
+  const restApi = plugin.restApi();
+
+  plugin
+    .registerDynamicCustomComponent(
+      'change-view-file-list-header-prepend',
+      FILES_OWNERS_COLUMN_HEADER
+    )
+    .onAttached(view => {
+      (view as unknown as FilesColumnHeader).restApi = restApi;
+    });
+  plugin
+    .registerDynamicCustomComponent(
+      'change-view-file-list-content-prepend',
+      FILES_OWNERS_COLUMN_CONTENT
+    )
+    .onAttached(view => {
+      (view as unknown as FilesColumnContent).restApi = restApi;
+    });
+  plugin
+    .registerDynamicCustomComponent(
+      'change-view-tab-header',
+      OWNED_FILES_TAB_HEADER
+    )
+    .onAttached(view => {
+      (view as unknown as OwnedFilesTabHeader).restApi = restApi;
+    });
+  plugin
+    .registerDynamicCustomComponent(
+      'change-view-tab-content',
+      OWNED_FILES_TAB_CONTENT
+    )
+    .onAttached(view => {
+      (view as unknown as OwnedFilesTabContent).restApi = restApi;
+    });
+});

diff --git a/owners/web/test-utils.ts b/owners/web/test-utils.ts
new file mode 100644
index 0000000..8f0c8a6
--- /dev/null
+++ b/owners/web/test-utils.ts

@@ -0,0 +1,21 @@
+/**
+ * @license
+ * Copyright (C) 2024 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.
+ */
+
+export function getRandom<T>(...values: T[]): T {
+  const idx = Math.floor(Math.random() * values.length);
+  return values[idx];
+}

diff --git a/owners/web/tsconfig.json b/owners/web/tsconfig.json
new file mode 100644
index 0000000..0a15ca9
--- /dev/null
+++ b/owners/web/tsconfig.json

@@ -0,0 +1,15 @@
+{
+  "extends": "../../tsconfig-plugins-base.json",
+  "compilerOptions": {
+    "outDir": "../../../.ts-out/plugins/owners", /* overridden by bazel */
+    "lib": [
+      "dom",
+      "dom.iterable",
+      "es2021",
+      "webworker"
+    ],
+  },
+  "include": [
+    "**/*.ts"
+  ],
+}

diff --git a/owners/web/utils.ts b/owners/web/utils.ts
new file mode 100644
index 0000000..81e0adb
--- /dev/null
+++ b/owners/web/utils.ts

@@ -0,0 +1,222 @@
+/**
+ * @license
+ * Copyright (C) 2024 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.
+ */
+
+import {SpecialFilePath} from './gerrit-model';
+
+export function deepEqual<T>(a: T, b: T): boolean {
+  if (a === b) return true;
+  if (a === undefined || b === undefined) return false;
+  if (a === null || b === null) return false;
+  if (a instanceof Date || b instanceof Date) {
+    if (!(a instanceof Date && b instanceof Date)) return false;
+    return a.getTime() === b.getTime();
+  }
+
+  if (a instanceof Set || b instanceof Set) {
+    if (!(a instanceof Set && b instanceof Set)) return false;
+    if (a.size !== b.size) return false;
+    for (const ai of a) if (!b.has(ai)) return false;
+    return true;
+  }
+  if (a instanceof Map || b instanceof Map) {
+    if (!(a instanceof Map && b instanceof Map)) return false;
+    if (a.size !== b.size) return false;
+    for (const [aKey, aValue] of a.entries()) {
+      if (!b.has(aKey) || !deepEqual(aValue, b.get(aKey))) return false;
+    }
+    return true;
+  }
+
+  if (typeof a === 'object') {
+    if (typeof b !== 'object') return false;
+    const aObj = a as Record<string, unknown>;
+    const bObj = b as Record<string, unknown>;
+    const aKeys = Object.keys(aObj);
+    const bKeys = Object.keys(bObj);
+    if (aKeys.length !== bKeys.length) return false;
+    for (const key of aKeys) {
+      if (!deepEqual(aObj[key], bObj[key])) return false;
+    }
+    return true;
+  }
+
+  return false;
+}
+
+/**
+ * Queries for child element specified with a selector. Copied from Gerrit's common-util.ts.
+ */
+export function query<E extends Element = Element>(
+  el: Element | null | undefined,
+  selector: string
+): E | undefined {
+  if (!el) return undefined;
+  if (el.shadowRoot) {
+    const r = el.shadowRoot.querySelector<E>(selector);
+    if (r) return r;
+  }
+  return el.querySelector<E>(selector) ?? undefined;
+}
+
+/**
+ * Copied from Gerrit's path-list-util.ts.
+ */
+export function computeDisplayPath(path?: string) {
+  if (path === SpecialFilePath.COMMIT_MESSAGE) {
+    return 'Commit message';
+  } else if (path === SpecialFilePath.MERGE_LIST) {
+    return 'Merge list';
+  }
+  return path ?? '';
+}
+
+/**
+ *  Separates a path into:
+ *  - The part that matches another path,
+ *  - The part that does not match the other path,
+ *  - The file name
+ *
+ *  For example:
+ *    diffFilePaths('same/part/new/part/foo.js', 'same/part/different/foo.js');
+ *  yields: {
+ *      matchingFolders: 'same/part/',
+ *      newFolders: 'new/part/',
+ *      fileName: 'foo.js',
+ *    }
+ *
+ *  Copied from Gerrit's string-util.ts.
+ */
+export function diffFilePaths(filePath: string, otherFilePath?: string) {
+  // Separate each string into an array of folder names + file name.
+  const displayPath = computeDisplayPath(filePath);
+  const previousFileDisplayPath = computeDisplayPath(otherFilePath);
+  const displayPathParts = displayPath.split('/');
+  const previousFileDisplayPathParts = previousFileDisplayPath.split('/');
+
+  // Construct separate strings for matching folders, new folders, and file
+  // name.
+  const firstDifferencePartIndex = displayPathParts.findIndex(
+    (part, index) => previousFileDisplayPathParts[index] !== part
+  );
+  const matchingSection = displayPathParts
+    .slice(0, firstDifferencePartIndex)
+    .join('/');
+  const newFolderSection = displayPathParts
+    .slice(firstDifferencePartIndex, -1)
+    .join('/');
+  const fileNameSection = displayPathParts[displayPathParts.length - 1];
+
+  // Note: folder sections need '/' appended back.
+  return {
+    matchingFolders: matchingSection.length > 0 ? `${matchingSection}/` : '',
+    newFolders: newFolderSection.length > 0 ? `${newFolderSection}/` : '',
+    fileName: fileNameSection,
+  };
+}
+
+/**
+ * Truncates URLs to display filename only
+ * Example
+ * // returns '.../text.html'
+ * util.truncatePath.('dir/text.html');
+ * Example
+ * // returns 'text.html'
+ * util.truncatePath.('text.html');
+ *
+ * Copied from Gerrit's path-list-util.ts.
+ */
+export function truncatePath(path: string, threshold = 1) {
+  const pathPieces = path.split('/');
+
+  if (pathPieces.length <= threshold) {
+    return path;
+  }
+
+  const index = pathPieces.length - threshold;
+  // Character is an ellipsis.
+  return `\u2026/${pathPieces.slice(index).join('/')}`;
+}
+
+/**
+ * Encodes *parts* of a URL. See inline comments below for the details.
+ * Note specifically that ? & = # are encoded. So this is very close to
+ * encodeURIComponent() with some tweaks.
+ *
+ * Copied from Gerrit's url-util.ts.
+ */
+export function encodeURL(url: string): string {
+  // gr-page decodes the entire URL, and then decodes once more the
+  // individual regex matching groups. It uses `decodeURIComponent()`, which
+  // will choke on singular `%` chars without two trailing digits. We prefer
+  // to not double encode *everything* (just for readaiblity and simplicity),
+  // but `%` *must* be double encoded.
+  let output = url.replaceAll('%', '%25'); // `replaceAll` function requires `es2021` hence the `lib` section was added to `tsconfig.json`
+  // `+` also requires double encoding, because `%2B` would be decoded to `+`
+  // and then replaced by ` `.
+  output = output.replaceAll('+', '%2B');
+
+  // This escapes ALL characters EXCEPT:
+  // A–Z a–z 0–9 - _ . ! ~ * ' ( )
+  // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/encodeURIComponent
+  output = encodeURIComponent(output);
+
+  // If we would use `encodeURI()` instead of `encodeURIComponent()`, then we
+  // would also NOT encode:
+  // ; / ? : @ & = + $ , #
+  //
+  // That would be more readable, but for example ? and & have special meaning
+  // in the URL, so they must be encoded. Let's discuss all these chars and
+  // decide whether we have to encode them or not.
+  //
+  // ? & = # have to be encoded. Otherwise we might mess up the URL.
+  //
+  // : @ do not have to be encoded, because we are only dealing with path,
+  // query and fragment of the URL, not with scheme, user, host, port.
+  // For search queries it is much nicer to not encode those chars, think of
+  // searching for `owner:spearce@spearce.org`.
+  //
+  // / does not have to be encoded, because we don't care about individual path
+  // components. File path and repo names are so much nicer to read without /
+  // being encoded!
+  //
+  // + must be encoded, because we want to use it instead of %20 for spaces, see
+  // below.
+  //
+  // ; $ , probably don't have to be encoded, but we don't bother about them
+  // much, so we don't reverse the encoding here, but we don't think it would
+  // cause any harm, if we did.
+  output = output.replace(/%3A/g, ':');
+  output = output.replace(/%40/g, '@');
+  output = output.replace(/%2F/g, '/');
+
+  // gr-page replaces `+` by ` ` in addition to calling `decodeURIComponent()`.
+  // So we can use `+` to increase readability.
+  output = output.replace(/%20/g, '+');
+
+  return output;
+}
+
+/**
+ * Function to obtain the base URL.
+ *
+ * Copied from Gerrit's url-util.ts.
+ */
+export function getBaseUrl(): string {
+  // window is not defined in service worker, therefore no CANONICAL_PATH
+  if (typeof window === 'undefined') return '';
+  return self.CANONICAL_PATH || '';
+}