components/sync/protocol/attachment.proto

// Copyright 2026 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// If you change or add any fields in this file, update proto_visitors.h and
// potentially proto_enum_conversions.{h, cc}.

syntax = "proto2";

option java_multiple_files = true;
option java_package = "org.chromium.components.sync.protocol";

option optimize_for = LITE_RUNTIME;

package sync_pb;

// An attachment represents a payload (usually large) that is associated with an
// entity but is not uploaded or downloaded within the Sync HTTP protocol, but
// an external side channel.
message Attachment {
  // Populated by the client only, when a commit is adding a new attachment to
  // an entity (either newly-created entity or a pre-existing one). Note that
  // each entity is associated to at most one attachment, so committing a new
  // blob ID overrides any previous one.
  optional string temporary_blob_id = 1;

  // Set to the timestamp the attachment was last updated.
  optional int64 modification_time_unix_epoch_millis = 2;
}