diff --git a/api/v3/api_proto/feature_objects.proto b/api/v3/api_proto/feature_objects.proto
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+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file or at
+// https://developers.google.com/open-source/licenses/bsd
+
+// This file defines protobufs for features and related business
+// objects, e.g., hotlists.
+
+syntax = "proto3";
+
+package monorail.v3;
+
+option go_package = "api/v3/api_proto";
+
+import "google/api/field_behavior.proto";
+import "google/api/resource.proto";
+import "google/protobuf/timestamp.proto";
+import "api/v3/api_proto/issue_objects.proto";
+
+// A user-owned list of Issues.
+// Next available tag: 9
+message Hotlist {
+  option (google.api.resource) = {
+    type: "api.crbug.com/Hotlist"
+    pattern: "hotlists/{hotlist_id}"
+  };
+
+  // Resource name of the hotlist.
+  string name = 1;
+  // `display_name` must follow pattern found at `framework_bizobj.RE_HOTLIST_NAME_PATTERN`.
+  string display_name = 2 [ (google.api.field_behavior) = REQUIRED ];
+  // Resource name of the hotlist owner.
+  // Owners can update hotlist settings, editors, owner, and HotlistItems.
+  // TODO(monorail:7023): field_behavior may be changed in the future.
+  string owner = 3 [
+      (google.api.resource_reference) = {type: "api.crbug.com/User"},
+      (google.api.field_behavior) = REQUIRED ];
+  // Resource names of the hotlist editors.
+  // Editors can update hotlist HotlistItems.
+  repeated string editors = 4 [ (google.api.resource_reference) = {type: "api.crbug.com/User"} ];
+  // Summary of the hotlist.
+  string summary = 5 [ (google.api.field_behavior) = REQUIRED ];
+  // More detailed description of the purpose of the hotlist.
+  string description = 6 [ (google.api.field_behavior) = REQUIRED ];
+  // Ordered list of default columns shown on hotlist's issues list view.
+  repeated IssuesListColumn default_columns = 7;
+
+  // Privacy level of a Hotlist.
+  // Next available tag: 2
+  enum HotlistPrivacy {
+    // This value is unused.
+    HOTLIST_PRIVACY_UNSPECIFIED = 0;
+    // Only the owner and editors of the hotlist can view the hotlist.
+    PRIVATE = 1;
+    // Anyone on the web can view the hotlist.
+    PUBLIC = 2;
+  }
+  HotlistPrivacy hotlist_privacy = 8;
+}
+
+
+// Represents the the position of an Issue in a Hotlist.
+// Next available tag: 7
+message HotlistItem {
+  option (google.api.resource) = {
+    type: "api.crbug.com/HotlistItem"
+    pattern: "hotlists/{hotlist_id}/items/{item_id}"
+  };
+
+  // Resource name of the HotlistItem.
+  string name = 1;
+  // The Issue associated with this item.
+  string issue = 2 [
+      (google.api.resource_reference) = {type: "api.crbug.com/Issue"},
+      (google.api.field_behavior) = IMMUTABLE ];
+  // Represents the item's position in the Hotlist in decreasing priority order.
+  // Values will be from 1 to N (the size of the hotlist), each item having a unique rank.
+  // Changes to rank must be made in `RerankHotlistItems`.
+  uint32 rank = 3 [(google.api.field_behavior) = OUTPUT_ONLY];
+  // Resource name of the adder of HotlistItem.
+  string adder = 4 [
+      (google.api.resource_reference) = {type: "api.crbug.com/User"},
+      (google.api.field_behavior) = OUTPUT_ONLY ];
+  // The time this HotlistItem was added to the hotlist.
+  google.protobuf.Timestamp create_time = 5  [ (google.api.field_behavior) = OUTPUT_ONLY ];
+  // User-provided additional details about this item.
+  string note = 6;
+}
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