diff --git a/services/commtest/tests/identity_device_list_tests.rs b/services/commtest/tests/identity_device_list_tests.rs
--- a/services/commtest/tests/identity_device_list_tests.rs
+++ b/services/commtest/tests/identity_device_list_tests.rs
@@ -1,3 +1,4 @@
+use std::collections::{HashMap, HashSet};
 use std::str::FromStr;
 
 use commtest::identity::device::{
@@ -7,7 +8,9 @@
 use commtest::service_addr;
 use grpc_clients::identity::authenticated::ChainedInterceptedAuthClient;
 use grpc_clients::identity::get_auth_client;
-use grpc_clients::identity::protos::auth::UpdateDeviceListRequest;
+use grpc_clients::identity::protos::auth::{
+  PeersDeviceListsRequest, UpdateDeviceListRequest,
+};
 use grpc_clients::identity::protos::authenticated::GetDeviceListRequest;
 use grpc_clients::identity::DeviceType;
 use serde::Deserialize;
@@ -223,6 +226,65 @@
   assert_eq!(device_lists_response, expected_device_list);
 }
 
+#[tokio::test]
+async fn test_device_list_multifetch() {
+  // Create viewer (user that only auths request)
+  let viewer = register_user_device(None, None).await;
+  let mut auth_client = get_auth_client(
+    &service_addr::IDENTITY_GRPC.to_string(),
+    viewer.user_id.clone(),
+    viewer.device_id,
+    viewer.access_token,
+    PLACEHOLDER_CODE_VERSION,
+    DEVICE_TYPE.to_string(),
+  )
+  .await
+  .expect("Couldn't connect to identity service");
+
+  // Register users and prepare expected device lists
+  let mut expected_device_lists = HashMap::new();
+  for _ in 0..5 {
+    let user = register_user_device(None, None).await;
+    expected_device_lists.insert(user.user_id, vec![user.device_id]);
+  }
+
+  // Fetch device lists from server
+  let user_ids: Vec<_> = expected_device_lists.keys().cloned().collect();
+  let request = PeersDeviceListsRequest { user_ids };
+  let response_device_lists = auth_client
+    .get_device_lists_for_users(request)
+    .await
+    .expect("GetDeviceListsForUser RPC failed")
+    .into_inner()
+    .users_device_lists;
+
+  // verify if response has the same user IDs as request
+  let expected_user_ids: HashSet<String> =
+    expected_device_lists.keys().cloned().collect();
+  let response_user_ids: HashSet<String> =
+    response_device_lists.keys().cloned().collect();
+  let difference: HashSet<_> = expected_user_ids
+    .symmetric_difference(&response_user_ids)
+    .collect();
+  assert!(difference.is_empty(), "User IDs differ: {:?}", difference);
+
+  // verify device list for each user
+  for (user_id, expected_devices) in expected_device_lists {
+    let response_payload = response_device_lists.get(&user_id).unwrap();
+
+    let returned_devices = SignedDeviceList::from_str(response_payload)
+      .expect("failed to deserialize signed device list")
+      .into_raw()
+      .devices;
+
+    assert_eq!(
+      returned_devices, expected_devices,
+      "Device list differs for user: {}, Expected {:?}, but got {:?}",
+      user_id, expected_devices, returned_devices
+    );
+  }
+}
+
 // See GetDeviceListResponse in identity_authenticated.proto
 // for details on the response format.
 #[derive(Deserialize)]
diff --git a/services/identity/src/grpc_services/authenticated.rs b/services/identity/src/grpc_services/authenticated.rs
--- a/services/identity/src/grpc_services/authenticated.rs
+++ b/services/identity/src/grpc_services/authenticated.rs
@@ -24,7 +24,10 @@
   UpdateUserPasswordStartRequest, UpdateUserPasswordStartResponse,
   UploadOneTimeKeysRequest,
 };
-use super::protos::auth::{UserIdentityRequest, UserIdentityResponse};
+use super::protos::auth::{
+  PeersDeviceListsRequest, PeersDeviceListsResponse, UserIdentityRequest,
+  UserIdentityResponse,
+};
 use super::protos::unauth::Empty;
 
 #[derive(derive_more::Constructor)]
@@ -364,18 +367,62 @@
 
     let stringified_updates = device_list_updates
       .iter()
-      .map(serde_json::to_string)
-      .collect::<Result<Vec<_>, _>>()
-      .map_err(|err| {
-        error!("Failed to serialize device list updates: {}", err);
-        tonic::Status::failed_precondition("unexpected error")
-      })?;
+      .map(SignedDeviceList::as_json_string)
+      .collect::<Result<Vec<_>, _>>()?;
 
     Ok(Response::new(GetDeviceListResponse {
       device_list_updates: stringified_updates,
     }))
   }
 
+  async fn get_device_lists_for_users(
+    &self,
+    request: tonic::Request<PeersDeviceListsRequest>,
+  ) -> Result<tonic::Response<PeersDeviceListsResponse>, tonic::Status> {
+    let PeersDeviceListsRequest { user_ids } = request.into_inner();
+
+    // do all fetches concurrently
+    let mut fetch_tasks = tokio::task::JoinSet::new();
+    let mut device_lists = HashMap::with_capacity(user_ids.len());
+    for user_id in user_ids {
+      let db_client = self.db_client.clone();
+      fetch_tasks.spawn(async move {
+        let result = db_client.get_current_device_list(&user_id).await;
+        (user_id, result)
+      });
+    }
+
+    while let Some(task_result) = fetch_tasks.join_next().await {
+      match task_result {
+        Ok((user_id, Ok(Some(device_list_row)))) => {
+          let raw_list = RawDeviceList::from(device_list_row);
+          let signed_list = SignedDeviceList::try_from_raw(raw_list)?;
+          let serialized_list = signed_list.as_json_string()?;
+          device_lists.insert(user_id, serialized_list);
+        }
+        Ok((user_id, Ok(None))) => {
+          warn!(user_id, "User has no device list, skipping!");
+        }
+        Ok((user_id, Err(err))) => {
+          error!(user_id, "Failed fetching device list: {err}");
+          // abort fetching other users
+          fetch_tasks.abort_all();
+          return Err(handle_db_error(err));
+        }
+        Err(join_error) => {
+          error!("Failed to join device list task: {join_error}");
+          fetch_tasks.abort_all();
+          return Err(Status::aborted("unexpected error"));
+        }
+      }
+    }
+
+    let response = PeersDeviceListsResponse {
+      users_device_lists: device_lists,
+    };
+    Ok(Response::new(response))
+  }
+
   async fn update_device_list(
     &self,
     request: tonic::Request<UpdateDeviceListRequest>,
@@ -513,6 +560,14 @@
         tonic::Status::invalid_argument("invalid device list payload")
       })
   }
+
+  /// Serializes the signed device list to a JSON string
+  fn as_json_string(&self) -> Result<String, tonic::Status> {
+    serde_json::to_string(self).map_err(|err| {
+      error!("Failed to serialize device list updates: {}", err);
+      tonic::Status::failed_precondition("unexpected error")
+    })
+  }
 }
 
 impl TryFrom<UpdateDeviceListRequest> for SignedDeviceList {
diff --git a/shared/protos/identity_auth.proto b/shared/protos/identity_auth.proto
--- a/shared/protos/identity_auth.proto
+++ b/shared/protos/identity_auth.proto
@@ -58,6 +58,9 @@
   // Returns device list history
   rpc GetDeviceListForUser(GetDeviceListRequest) returns
     (GetDeviceListResponse) {}
+  // Returns current device list for a set of users
+  rpc GetDeviceListsForUsers (PeersDeviceListsRequest) returns
+    (PeersDeviceListsResponse) {}
 
   rpc UpdateDeviceList(UpdateDeviceListRequest) returns
     (identity.unauth.Empty) {}
@@ -198,6 +201,19 @@
   repeated string device_list_updates = 1;
 }
 
+// GetDeviceListsForUsers
+
+message PeersDeviceListsRequest {
+  repeated string user_ids = 1;
+}
+
+message PeersDeviceListsResponse {
+  // keys are user_id
+  // values are JSON-stringified device list payloads
+  // (see GetDeviceListResponse message for payload structure)
+  map<string, string> users_device_lists = 1;
+}
+
 // UpdateDeviceListForUser
 
 message UpdateDeviceListRequest {
diff --git a/web/protobufs/identity-auth-client.cjs b/web/protobufs/identity-auth-client.cjs
--- a/web/protobufs/identity-auth-client.cjs
+++ b/web/protobufs/identity-auth-client.cjs
@@ -688,6 +688,67 @@
 };
 
 
+/**
+ * @const
+ * @type {!grpc.web.MethodDescriptor<
+ *   !proto.identity.auth.PeersDeviceListsRequest,
+ *   !proto.identity.auth.PeersDeviceListsResponse>}
+ */
+const methodDescriptor_IdentityClientService_GetDeviceListsForUsers = new grpc.web.MethodDescriptor(
+  '/identity.auth.IdentityClientService/GetDeviceListsForUsers',
+  grpc.web.MethodType.UNARY,
+  proto.identity.auth.PeersDeviceListsRequest,
+  proto.identity.auth.PeersDeviceListsResponse,
+  /**
+   * @param {!proto.identity.auth.PeersDeviceListsRequest} request
+   * @return {!Uint8Array}
+   */
+  function(request) {
+    return request.serializeBinary();
+  },
+  proto.identity.auth.PeersDeviceListsResponse.deserializeBinary
+);
+
+
+/**
+ * @param {!proto.identity.auth.PeersDeviceListsRequest} request The
+ *     request proto
+ * @param {?Object<string, string>} metadata User defined
+ *     call metadata
+ * @param {function(?grpc.web.RpcError, ?proto.identity.auth.PeersDeviceListsResponse)}
+ *     callback The callback function(error, response)
+ * @return {!grpc.web.ClientReadableStream<!proto.identity.auth.PeersDeviceListsResponse>|undefined}
+ *     The XHR Node Readable Stream
+ */
+proto.identity.auth.IdentityClientServiceClient.prototype.getDeviceListsForUsers =
+    function(request, metadata, callback) {
+  return this.client_.rpcCall(this.hostname_ +
+      '/identity.auth.IdentityClientService/GetDeviceListsForUsers',
+      request,
+      metadata || {},
+      methodDescriptor_IdentityClientService_GetDeviceListsForUsers,
+      callback);
+};
+
+
+/**
+ * @param {!proto.identity.auth.PeersDeviceListsRequest} request The
+ *     request proto
+ * @param {?Object<string, string>=} metadata User defined
+ *     call metadata
+ * @return {!Promise<!proto.identity.auth.PeersDeviceListsResponse>}
+ *     Promise that resolves to the response
+ */
+proto.identity.auth.IdentityClientServicePromiseClient.prototype.getDeviceListsForUsers =
+    function(request, metadata) {
+  return this.client_.unaryCall(this.hostname_ +
+      '/identity.auth.IdentityClientService/GetDeviceListsForUsers',
+      request,
+      metadata || {},
+      methodDescriptor_IdentityClientService_GetDeviceListsForUsers);
+};
+
+
 /**
  * @const
  * @type {!grpc.web.MethodDescriptor<
diff --git a/web/protobufs/identity-auth-client.cjs.flow b/web/protobufs/identity-auth-client.cjs.flow
--- a/web/protobufs/identity-auth-client.cjs.flow
+++ b/web/protobufs/identity-auth-client.cjs.flow
@@ -81,6 +81,13 @@
                response: identityAuthStructs.GetDeviceListResponse) => void
   ): grpcWeb.ClientReadableStream<identityAuthStructs.GetDeviceListResponse>;
 
+  getDeviceListsForUsers(
+    request: identityAuthStructs.PeersDeviceListsRequest,
+    metadata: grpcWeb.Metadata | void,
+    callback: (err: grpcWeb.RpcError,
+               response: identityAuthStructs.PeersDeviceListsResponse) => void
+  ): grpcWeb.ClientReadableStream<identityAuthStructs.PeersDeviceListsResponse>;
+
   updateDeviceList(
     request: identityAuthStructs.UpdateDeviceListRequest,
     metadata: grpcWeb.Metadata | void,
@@ -165,6 +172,11 @@
     metadata?: grpcWeb.Metadata
   ): Promise<identityAuthStructs.GetDeviceListResponse>;
 
+  getDeviceListsForUsers(
+    request: identityAuthStructs.PeersDeviceListsRequest,
+    metadata?: grpcWeb.Metadata
+  ): Promise<identityAuthStructs.PeersDeviceListsResponse>;
+
   updateDeviceList(
     request: identityAuthStructs.UpdateDeviceListRequest,
     metadata?: grpcWeb.Metadata
diff --git a/web/protobufs/identity-auth-structs.cjs b/web/protobufs/identity-auth-structs.cjs
--- a/web/protobufs/identity-auth-structs.cjs
+++ b/web/protobufs/identity-auth-structs.cjs
@@ -36,6 +36,8 @@
 goog.exportSymbol('proto.identity.auth.OutboundKeyInfo', null, global);
 goog.exportSymbol('proto.identity.auth.OutboundKeysForUserRequest', null, global);
 goog.exportSymbol('proto.identity.auth.OutboundKeysForUserResponse', null, global);
+goog.exportSymbol('proto.identity.auth.PeersDeviceListsRequest', null, global);
+goog.exportSymbol('proto.identity.auth.PeersDeviceListsResponse', null, global);
 goog.exportSymbol('proto.identity.auth.RefreshUserPrekeysRequest', null, global);
 goog.exportSymbol('proto.identity.auth.UpdateDeviceListRequest', null, global);
 goog.exportSymbol('proto.identity.auth.UpdateUserPasswordFinishRequest', null, global);
@@ -380,6 +382,48 @@
    */
   proto.identity.auth.GetDeviceListResponse.displayName = 'proto.identity.auth.GetDeviceListResponse';
 }
+/**
+ * Generated by JsPbCodeGenerator.
+ * @param {Array=} opt_data Optional initial data array, typically from a
+ * server response, or constructed directly in Javascript. The array is used
+ * in place and becomes part of the constructed object. It is not cloned.
+ * If no data is provided, the constructed object will be empty, but still
+ * valid.
+ * @extends {jspb.Message}
+ * @constructor
+ */
+proto.identity.auth.PeersDeviceListsRequest = function(opt_data) {
+  jspb.Message.initialize(this, opt_data, 0, -1, proto.identity.auth.PeersDeviceListsRequest.repeatedFields_, null);
+};
+goog.inherits(proto.identity.auth.PeersDeviceListsRequest, jspb.Message);
+if (goog.DEBUG && !COMPILED) {
+  /**
+   * @public
+   * @override
+   */
+  proto.identity.auth.PeersDeviceListsRequest.displayName = 'proto.identity.auth.PeersDeviceListsRequest';
+}
+/**
+ * Generated by JsPbCodeGenerator.
+ * @param {Array=} opt_data Optional initial data array, typically from a
+ * server response, or constructed directly in Javascript. The array is used
+ * in place and becomes part of the constructed object. It is not cloned.
+ * If no data is provided, the constructed object will be empty, but still
+ * valid.
+ * @extends {jspb.Message}
+ * @constructor
+ */
+proto.identity.auth.PeersDeviceListsResponse = function(opt_data) {
+  jspb.Message.initialize(this, opt_data, 0, -1, null, null);
+};
+goog.inherits(proto.identity.auth.PeersDeviceListsResponse, jspb.Message);
+if (goog.DEBUG && !COMPILED) {
+  /**
+   * @public
+   * @override
+   */
+  proto.identity.auth.PeersDeviceListsResponse.displayName = 'proto.identity.auth.PeersDeviceListsResponse';
+}
 /**
  * Generated by JsPbCodeGenerator.
  * @param {Array=} opt_data Optional initial data array, typically from a
@@ -3533,6 +3577,296 @@
 
 
 
+/**
+ * List of repeated fields within this message type.
+ * @private {!Array<number>}
+ * @const
+ */
+proto.identity.auth.PeersDeviceListsRequest.repeatedFields_ = [1];
+
+
+
+if (jspb.Message.GENERATE_TO_OBJECT) {
+/**
+ * Creates an object representation of this proto.
+ * Field names that are reserved in JavaScript and will be renamed to pb_name.
+ * Optional fields that are not set will be set to undefined.
+ * To access a reserved field use, foo.pb_<name>, eg, foo.pb_default.
+ * For the list of reserved names please see:
+ *     net/proto2/compiler/js/internal/generator.cc#kKeyword.
+ * @param {boolean=} opt_includeInstance Deprecated. whether to include the
+ *     JSPB instance for transitional soy proto support:
+ *     http://goto/soy-param-migration
+ * @return {!Object}
+ */
+proto.identity.auth.PeersDeviceListsRequest.prototype.toObject = function(opt_includeInstance) {
+  return proto.identity.auth.PeersDeviceListsRequest.toObject(opt_includeInstance, this);
+};
+
+
+/**
+ * Static version of the {@see toObject} method.
+ * @param {boolean|undefined} includeInstance Deprecated. Whether to include
+ *     the JSPB instance for transitional soy proto support:
+ *     http://goto/soy-param-migration
+ * @param {!proto.identity.auth.PeersDeviceListsRequest} msg The msg instance to transform.
+ * @return {!Object}
+ * @suppress {unusedLocalVariables} f is only used for nested messages
+ */
+proto.identity.auth.PeersDeviceListsRequest.toObject = function(includeInstance, msg) {
+  var f, obj = {
+    userIdsList: (f = jspb.Message.getRepeatedField(msg, 1)) == null ? undefined : f
+  };
+
+  if (includeInstance) {
+    obj.$jspbMessageInstance = msg;
+  }
+  return obj;
+};
+}
+
+
+/**
+ * Deserializes binary data (in protobuf wire format).
+ * @param {jspb.ByteSource} bytes The bytes to deserialize.
+ * @return {!proto.identity.auth.PeersDeviceListsRequest}
+ */
+proto.identity.auth.PeersDeviceListsRequest.deserializeBinary = function(bytes) {
+  var reader = new jspb.BinaryReader(bytes);
+  var msg = new proto.identity.auth.PeersDeviceListsRequest;
+  return proto.identity.auth.PeersDeviceListsRequest.deserializeBinaryFromReader(msg, reader);
+};
+
+
+/**
+ * Deserializes binary data (in protobuf wire format) from the
+ * given reader into the given message object.
+ * @param {!proto.identity.auth.PeersDeviceListsRequest} msg The message object to deserialize into.
+ * @param {!jspb.BinaryReader} reader The BinaryReader to use.
+ * @return {!proto.identity.auth.PeersDeviceListsRequest}
+ */
+proto.identity.auth.PeersDeviceListsRequest.deserializeBinaryFromReader = function(msg, reader) {
+  while (reader.nextField()) {
+    if (reader.isEndGroup()) {
+      break;
+    }
+    var field = reader.getFieldNumber();
+    switch (field) {
+    case 1:
+      var value = /** @type {string} */ (reader.readString());
+      msg.addUserIds(value);
+      break;
+    default:
+      reader.skipField();
+      break;
+    }
+  }
+  return msg;
+};
+
+
+/**
+ * Serializes the message to binary data (in protobuf wire format).
+ * @return {!Uint8Array}
+ */
+proto.identity.auth.PeersDeviceListsRequest.prototype.serializeBinary = function() {
+  var writer = new jspb.BinaryWriter();
+  proto.identity.auth.PeersDeviceListsRequest.serializeBinaryToWriter(this, writer);
+  return writer.getResultBuffer();
+};
+
+
+/**
+ * Serializes the given message to binary data (in protobuf wire
+ * format), writing to the given BinaryWriter.
+ * @param {!proto.identity.auth.PeersDeviceListsRequest} message
+ * @param {!jspb.BinaryWriter} writer
+ * @suppress {unusedLocalVariables} f is only used for nested messages
+ */
+proto.identity.auth.PeersDeviceListsRequest.serializeBinaryToWriter = function(message, writer) {
+  var f = undefined;
+  f = message.getUserIdsList();
+  if (f.length > 0) {
+    writer.writeRepeatedString(
+      1,
+      f
+    );
+  }
+};
+
+
+/**
+ * repeated string user_ids = 1;
+ * @return {!Array<string>}
+ */
+proto.identity.auth.PeersDeviceListsRequest.prototype.getUserIdsList = function() {
+  return /** @type {!Array<string>} */ (jspb.Message.getRepeatedField(this, 1));
+};
+
+
+/**
+ * @param {!Array<string>} value
+ * @return {!proto.identity.auth.PeersDeviceListsRequest} returns this
+ */
+proto.identity.auth.PeersDeviceListsRequest.prototype.setUserIdsList = function(value) {
+  return jspb.Message.setField(this, 1, value || []);
+};
+
+
+/**
+ * @param {string} value
+ * @param {number=} opt_index
+ * @return {!proto.identity.auth.PeersDeviceListsRequest} returns this
+ */
+proto.identity.auth.PeersDeviceListsRequest.prototype.addUserIds = function(value, opt_index) {
+  return jspb.Message.addToRepeatedField(this, 1, value, opt_index);
+};
+
+
+/**
+ * Clears the list making it empty but non-null.
+ * @return {!proto.identity.auth.PeersDeviceListsRequest} returns this
+ */
+proto.identity.auth.PeersDeviceListsRequest.prototype.clearUserIdsList = function() {
+  return this.setUserIdsList([]);
+};
+
+
+
+
+
+if (jspb.Message.GENERATE_TO_OBJECT) {
+/**
+ * Creates an object representation of this proto.
+ * Field names that are reserved in JavaScript and will be renamed to pb_name.
+ * Optional fields that are not set will be set to undefined.
+ * To access a reserved field use, foo.pb_<name>, eg, foo.pb_default.
+ * For the list of reserved names please see:
+ *     net/proto2/compiler/js/internal/generator.cc#kKeyword.
+ * @param {boolean=} opt_includeInstance Deprecated. whether to include the
+ *     JSPB instance for transitional soy proto support:
+ *     http://goto/soy-param-migration
+ * @return {!Object}
+ */
+proto.identity.auth.PeersDeviceListsResponse.prototype.toObject = function(opt_includeInstance) {
+  return proto.identity.auth.PeersDeviceListsResponse.toObject(opt_includeInstance, this);
+};
+
+
+/**
+ * Static version of the {@see toObject} method.
+ * @param {boolean|undefined} includeInstance Deprecated. Whether to include
+ *     the JSPB instance for transitional soy proto support:
+ *     http://goto/soy-param-migration
+ * @param {!proto.identity.auth.PeersDeviceListsResponse} msg The msg instance to transform.
+ * @return {!Object}
+ * @suppress {unusedLocalVariables} f is only used for nested messages
+ */
+proto.identity.auth.PeersDeviceListsResponse.toObject = function(includeInstance, msg) {
+  var f, obj = {
+    usersDeviceListsMap: (f = msg.getUsersDeviceListsMap()) ? f.toObject(includeInstance, undefined) : []
+  };
+
+  if (includeInstance) {
+    obj.$jspbMessageInstance = msg;
+  }
+  return obj;
+};
+}
+
+
+/**
+ * Deserializes binary data (in protobuf wire format).
+ * @param {jspb.ByteSource} bytes The bytes to deserialize.
+ * @return {!proto.identity.auth.PeersDeviceListsResponse}
+ */
+proto.identity.auth.PeersDeviceListsResponse.deserializeBinary = function(bytes) {
+  var reader = new jspb.BinaryReader(bytes);
+  var msg = new proto.identity.auth.PeersDeviceListsResponse;
+  return proto.identity.auth.PeersDeviceListsResponse.deserializeBinaryFromReader(msg, reader);
+};
+
+
+/**
+ * Deserializes binary data (in protobuf wire format) from the
+ * given reader into the given message object.
+ * @param {!proto.identity.auth.PeersDeviceListsResponse} msg The message object to deserialize into.
+ * @param {!jspb.BinaryReader} reader The BinaryReader to use.
+ * @return {!proto.identity.auth.PeersDeviceListsResponse}
+ */
+proto.identity.auth.PeersDeviceListsResponse.deserializeBinaryFromReader = function(msg, reader) {
+  while (reader.nextField()) {
+    if (reader.isEndGroup()) {
+      break;
+    }
+    var field = reader.getFieldNumber();
+    switch (field) {
+    case 1:
+      var value = msg.getUsersDeviceListsMap();
+      reader.readMessage(value, function(message, reader) {
+        jspb.Map.deserializeBinary(message, reader, jspb.BinaryReader.prototype.readString, jspb.BinaryReader.prototype.readString, null, "", "");
+         });
+      break;
+    default:
+      reader.skipField();
+      break;
+    }
+  }
+  return msg;
+};
+
+
+/**
+ * Serializes the message to binary data (in protobuf wire format).
+ * @return {!Uint8Array}
+ */
+proto.identity.auth.PeersDeviceListsResponse.prototype.serializeBinary = function() {
+  var writer = new jspb.BinaryWriter();
+  proto.identity.auth.PeersDeviceListsResponse.serializeBinaryToWriter(this, writer);
+  return writer.getResultBuffer();
+};
+
+
+/**
+ * Serializes the given message to binary data (in protobuf wire
+ * format), writing to the given BinaryWriter.
+ * @param {!proto.identity.auth.PeersDeviceListsResponse} message
+ * @param {!jspb.BinaryWriter} writer
+ * @suppress {unusedLocalVariables} f is only used for nested messages
+ */
+proto.identity.auth.PeersDeviceListsResponse.serializeBinaryToWriter = function(message, writer) {
+  var f = undefined;
+  f = message.getUsersDeviceListsMap(true);
+  if (f && f.getLength() > 0) {
+    f.serializeBinary(1, writer, jspb.BinaryWriter.prototype.writeString, jspb.BinaryWriter.prototype.writeString);
+  }
+};
+
+
+/**
+ * map<string, string> users_device_lists = 1;
+ * @param {boolean=} opt_noLazyCreate Do not create the map if
+ * empty, instead returning `undefined`
+ * @return {!jspb.Map<string,string>}
+ */
+proto.identity.auth.PeersDeviceListsResponse.prototype.getUsersDeviceListsMap = function(opt_noLazyCreate) {
+  return /** @type {!jspb.Map<string,string>} */ (
+      jspb.Message.getMapField(this, 1, opt_noLazyCreate,
+      null));
+};
+
+
+/**
+ * Clears values from the map. The map will be non-null.
+ * @return {!proto.identity.auth.PeersDeviceListsResponse} returns this
+ */
+proto.identity.auth.PeersDeviceListsResponse.prototype.clearUsersDeviceListsMap = function() {
+  this.getUsersDeviceListsMap().clear();
+  return this;
+};
+
+
+
 
 
 if (jspb.Message.GENERATE_TO_OBJECT) {
diff --git a/web/protobufs/identity-auth-structs.cjs.flow b/web/protobufs/identity-auth-structs.cjs.flow
--- a/web/protobufs/identity-auth-structs.cjs.flow
+++ b/web/protobufs/identity-auth-structs.cjs.flow
@@ -379,6 +379,40 @@
   deviceListUpdatesList: Array<string>,
 }
 
+declare export class PeersDeviceListsRequest extends Message {
+  getUserIdsList(): Array<string>;
+  setUserIdsList(value: Array<string>): PeersDeviceListsRequest;
+  clearUserIdsList(): PeersDeviceListsRequest;
+  addUserIds(value: string, index?: number): PeersDeviceListsRequest;
+
+  serializeBinary(): Uint8Array;
+  toObject(includeInstance?: boolean): PeersDeviceListsRequestObject;
+  static toObject(includeInstance: boolean, msg: PeersDeviceListsRequest): PeersDeviceListsRequestObject;
+  static serializeBinaryToWriter(message: PeersDeviceListsRequest, writer: BinaryWriter): void;
+  static deserializeBinary(bytes: Uint8Array): PeersDeviceListsRequest;
+  static deserializeBinaryFromReader(message: PeersDeviceListsRequest, reader: BinaryReader): PeersDeviceListsRequest;
+}
+
+export type PeersDeviceListsRequestObject = {
+  userIdsList: Array<string>,
+}
+
+declare export class PeersDeviceListsResponse extends Message {
+  getUsersDeviceListsMap(): ProtoMap<string, string>;
+  clearUsersDeviceListsMap(): PeersDeviceListsResponse;
+
+  serializeBinary(): Uint8Array;
+  toObject(includeInstance?: boolean): PeersDeviceListsResponseObject;
+  static toObject(includeInstance: boolean, msg: PeersDeviceListsResponse): PeersDeviceListsResponseObject;
+  static serializeBinaryToWriter(message: PeersDeviceListsResponse, writer: BinaryWriter): void;
+  static deserializeBinary(bytes: Uint8Array): PeersDeviceListsResponse;
+  static deserializeBinaryFromReader(message: PeersDeviceListsResponse, reader: BinaryReader): PeersDeviceListsResponse;
+}
+
+export type PeersDeviceListsResponseObject = {
+  usersDeviceListsMap: Array<[string, string]>,
+}
+
 declare export class UpdateDeviceListRequest extends Message {
   getNewDeviceList(): string;
   setNewDeviceList(value: string): UpdateDeviceListRequest;