diff --git a/lib/shared/dm-ops/add-viewer-to-thread-members-spec.js b/lib/shared/dm-ops/add-viewer-to-thread-members-spec.js
index ca992caa4..251ba1591 100644
--- a/lib/shared/dm-ops/add-viewer-to-thread-members-spec.js
+++ b/lib/shared/dm-ops/add-viewer-to-thread-members-spec.js
@@ -1,144 +1,144 @@
 // @flow
 
 import uuid from 'uuid';
 
 import { createThickRawThreadInfo } from './create-thread-spec.js';
 import type {
   DMOperationSpec,
   ProcessDMOperationUtilities,
 } from './dm-op-spec.js';
 import type { DMAddViewerToThreadMembersOperation } from '../../types/dm-ops.js';
 import { messageTypes } from '../../types/message-types-enum.js';
 import { messageTruncationStatus } from '../../types/message-types.js';
 import type { AddMembersMessageData } from '../../types/messages/add-members.js';
 import { joinThreadSubscription } from '../../types/subscription-types.js';
 import { updateTypes } from '../../types/update-types-enum.js';
 import { rawMessageInfoFromMessageData } from '../message-utils.js';
 import { userIsMember } from '../thread-utils.js';
 
 function createAddViewerToThreadMembersMessageDataFromDMOp(
   dmOperation: DMAddViewerToThreadMembersOperation,
 ): AddMembersMessageData {
   const { editorID, time, addedUserIDs, existingThreadDetails } = dmOperation;
   return {
     type: messageTypes.ADD_MEMBERS,
     threadID: existingThreadDetails.threadID,
     creatorID: editorID,
     time,
     addedUserIDs: [...addedUserIDs],
   };
 }
 
 const addViewerToThreadMembersSpec: DMOperationSpec<DMAddViewerToThreadMembersOperation> =
   Object.freeze({
     notificationsCreationData: async (
       dmOperation: DMAddViewerToThreadMembersOperation,
     ) => {
       const messageData =
         createAddViewerToThreadMembersMessageDataFromDMOp(dmOperation);
       return { messageDatas: [messageData] };
     },
     processDMOperation: async (
       dmOperation: DMAddViewerToThreadMembersOperation,
       viewerID: string,
       utilities: ProcessDMOperationUtilities,
     ) => {
       const { time, messageID, addedUserIDs, existingThreadDetails } =
         dmOperation;
       const messageData =
         createAddViewerToThreadMembersMessageDataFromDMOp(dmOperation);
 
-      const rawMessageInfos = [
-        rawMessageInfoFromMessageData(messageData, messageID),
-      ];
+      const rawMessageInfos = messageID
+        ? [rawMessageInfoFromMessageData(messageData, messageID)]
+        : [];
 
       const threadID = existingThreadDetails.threadID;
       const currentThreadInfo = utilities.threadInfos[threadID];
       if (currentThreadInfo && !currentThreadInfo.thick) {
         return {
           rawMessageInfos: [],
           updateInfos: [],
         };
       }
 
       const memberTimestamps = {
         ...currentThreadInfo?.timestamps?.members,
       };
       const newMembers = [];
       for (const userID of addedUserIDs) {
         if (!memberTimestamps[userID]) {
           memberTimestamps[userID] = {
             isMember: time,
             subscription: existingThreadDetails.creationTime,
           };
         }
 
         if (memberTimestamps[userID].isMember > time) {
           continue;
         }
 
         memberTimestamps[userID] = {
           ...memberTimestamps[userID],
           isMember: time,
         };
 
         if (!userIsMember(currentThreadInfo, userID)) {
           newMembers.push(userID);
         }
       }
 
       const resultThreadInfo = createThickRawThreadInfo(
         {
           ...existingThreadDetails,
           allMemberIDsWithSubscriptions: [
             ...existingThreadDetails.allMemberIDsWithSubscriptions,
             ...newMembers.map(id => ({
               id,
               subscription: joinThreadSubscription,
             })),
           ],
           timestamps: {
             ...existingThreadDetails.timestamps,
             members: {
               ...existingThreadDetails.timestamps.members,
               ...memberTimestamps,
             },
           },
         },
         viewerID,
       );
       const updateInfos = [
         {
           type: updateTypes.JOIN_THREAD,
           id: uuid.v4(),
           time,
           threadInfo: resultThreadInfo,
           rawMessageInfos,
           truncationStatus: messageTruncationStatus.EXHAUSTIVE,
           rawEntryInfos: [],
         },
       ];
       return { rawMessageInfos, updateInfos };
     },
     canBeProcessed(
       dmOperation: DMAddViewerToThreadMembersOperation,
       viewerID: string,
     ) {
       if (dmOperation.addedUserIDs.includes(viewerID)) {
         return { isProcessingPossible: true };
       }
       console.log('Invalid DM operation', dmOperation);
       return {
         isProcessingPossible: false,
         reason: {
           type: 'invalid',
         },
       };
     },
     supportsAutoRetry: true,
   });
 
 export {
   addViewerToThreadMembersSpec,
   createAddViewerToThreadMembersMessageDataFromDMOp,
 };
diff --git a/lib/types/dm-ops.js b/lib/types/dm-ops.js
index 75672da06..8296fd758 100644
--- a/lib/types/dm-ops.js
+++ b/lib/types/dm-ops.js
@@ -1,436 +1,438 @@
 // @flow
 
 import t, { type TInterface, type TUnion } from 'tcomb';
 
 import { clientAvatarValidator, type ClientAvatar } from './avatar-types.js';
 import type { RawMessageInfo } from './message-types.js';
 import type { NotificationsCreationData } from './notif-types.js';
 import type { OutboundP2PMessage } from './sqlite-types.js';
 import {
   type ThreadSubscription,
   threadSubscriptionValidator,
 } from './subscription-types.js';
 import {
   type NonSidebarThickThreadType,
   nonSidebarThickThreadTypes,
   type ThickThreadType,
   thickThreadTypeValidator,
 } from './thread-types-enum.js';
 import {
   threadTimestampsValidator,
   type ThreadTimestamps,
 } from './thread-types.js';
 import type { ClientUpdateInfo } from './update-types.js';
 import { values } from '../utils/objects.js';
 import { tColor, tShape, tString, tUserID } from '../utils/validation-utils.js';
 
 export const dmOperationTypes = Object.freeze({
   CREATE_THREAD: 'create_thread',
   CREATE_SIDEBAR: 'create_sidebar',
   SEND_TEXT_MESSAGE: 'send_text_message',
   SEND_REACTION_MESSAGE: 'send_reaction_message',
   SEND_EDIT_MESSAGE: 'send_edit_message',
   ADD_MEMBERS: 'add_members',
   ADD_VIEWER_TO_THREAD_MEMBERS: 'add_viewer_to_thread_members',
   JOIN_THREAD: 'join_thread',
   LEAVE_THREAD: 'leave_thread',
   REMOVE_MEMBERS: 'remove_members',
   CHANGE_THREAD_SETTINGS: 'change_thread_settings',
   CHANGE_THREAD_SUBSCRIPTION: 'change_thread_subscription',
   CHANGE_THREAD_READ_STATUS: 'change_thread_read_status',
 });
 export type DMOperationType = $Values<typeof dmOperationTypes>;
 
 type MemberIDWithSubscription = {
   +id: string,
   +subscription: ThreadSubscription,
 };
 export const memberIDWithSubscriptionValidator: TInterface<MemberIDWithSubscription> =
   tShape<MemberIDWithSubscription>({
     id: tUserID,
     subscription: threadSubscriptionValidator,
   });
 
 export type CreateThickRawThreadInfoInput = {
   +threadID: string,
   +threadType: ThickThreadType,
   +creationTime: number,
   +parentThreadID?: ?string,
   +allMemberIDsWithSubscriptions: $ReadOnlyArray<MemberIDWithSubscription>,
   +roleID: string,
   +unread: boolean,
   +timestamps: ThreadTimestamps,
   +name?: ?string,
   +avatar?: ?ClientAvatar,
   +description?: ?string,
   +color?: ?string,
   +containingThreadID?: ?string,
   +sourceMessageID?: ?string,
   +repliesCount?: ?number,
   +pinnedCount?: ?number,
 };
 export const createThickRawThreadInfoInputValidator: TInterface<CreateThickRawThreadInfoInput> =
   tShape<CreateThickRawThreadInfoInput>({
     threadID: t.String,
     threadType: thickThreadTypeValidator,
     creationTime: t.Number,
     parentThreadID: t.maybe(t.String),
     allMemberIDsWithSubscriptions: t.list(memberIDWithSubscriptionValidator),
     roleID: t.String,
     unread: t.Boolean,
     timestamps: threadTimestampsValidator,
     name: t.maybe(t.String),
     avatar: t.maybe(clientAvatarValidator),
     description: t.maybe(t.String),
     color: t.maybe(t.String),
     containingThreadID: t.maybe(t.String),
     sourceMessageID: t.maybe(t.String),
     repliesCount: t.maybe(t.Number),
     pinnedCount: t.maybe(t.Number),
   });
 
 export type DMCreateThreadOperation = {
   +type: 'create_thread',
   +threadID: string,
   +creatorID: string,
   +time: number,
   +threadType: NonSidebarThickThreadType,
   +memberIDs: $ReadOnlyArray<string>,
   +roleID: string,
   +newMessageID: string,
 };
 export const dmCreateThreadOperationValidator: TInterface<DMCreateThreadOperation> =
   tShape<DMCreateThreadOperation>({
     type: tString(dmOperationTypes.CREATE_THREAD),
     threadID: t.String,
     creatorID: tUserID,
     time: t.Number,
     threadType: t.enums.of(values(nonSidebarThickThreadTypes)),
     memberIDs: t.list(tUserID),
     roleID: t.String,
     newMessageID: t.String,
   });
 
 export type DMCreateSidebarOperation = {
   +type: 'create_sidebar',
   +threadID: string,
   +creatorID: string,
   +time: number,
   +parentThreadID: string,
   +memberIDs: $ReadOnlyArray<string>,
   +sourceMessageID: string,
   +roleID: string,
   +newSidebarSourceMessageID: string,
   +newCreateSidebarMessageID: string,
 };
 export const dmCreateSidebarOperationValidator: TInterface<DMCreateSidebarOperation> =
   tShape<DMCreateSidebarOperation>({
     type: tString(dmOperationTypes.CREATE_SIDEBAR),
     threadID: t.String,
     creatorID: tUserID,
     time: t.Number,
     parentThreadID: t.String,
     memberIDs: t.list(tUserID),
     sourceMessageID: t.String,
     roleID: t.String,
     newSidebarSourceMessageID: t.String,
     newCreateSidebarMessageID: t.String,
   });
 
 export type DMSendTextMessageOperation = {
   +type: 'send_text_message',
   +threadID: string,
   +creatorID: string,
   +time: number,
   +messageID: string,
   +text: string,
 };
 export const dmSendTextMessageOperationValidator: TInterface<DMSendTextMessageOperation> =
   tShape<DMSendTextMessageOperation>({
     type: tString(dmOperationTypes.SEND_TEXT_MESSAGE),
     threadID: t.String,
     creatorID: tUserID,
     time: t.Number,
     messageID: t.String,
     text: t.String,
   });
 
 export type DMSendReactionMessageOperation = {
   +type: 'send_reaction_message',
   +threadID: string,
   +creatorID: string,
   +time: number,
   +messageID: string,
   +targetMessageID: string,
   +reaction: string,
   +action: 'add_reaction' | 'remove_reaction',
 };
 export const dmSendReactionMessageOperationValidator: TInterface<DMSendReactionMessageOperation> =
   tShape<DMSendReactionMessageOperation>({
     type: tString(dmOperationTypes.SEND_REACTION_MESSAGE),
     threadID: t.String,
     creatorID: tUserID,
     time: t.Number,
     messageID: t.String,
     targetMessageID: t.String,
     reaction: t.String,
     action: t.enums.of(['add_reaction', 'remove_reaction']),
   });
 
 export type DMSendEditMessageOperation = {
   +type: 'send_edit_message',
   +threadID: string,
   +creatorID: string,
   +time: number,
   +messageID: string,
   +targetMessageID: string,
   +text: string,
 };
 export const dmSendEditMessageOperationValidator: TInterface<DMSendEditMessageOperation> =
   tShape<DMSendEditMessageOperation>({
     type: tString(dmOperationTypes.SEND_EDIT_MESSAGE),
     threadID: t.String,
     creatorID: tUserID,
     time: t.Number,
     messageID: t.String,
     targetMessageID: t.String,
     text: t.String,
   });
 
 type DMAddMembersBase = {
   +editorID: string,
   +time: number,
-  +messageID: string,
   +addedUserIDs: $ReadOnlyArray<string>,
 };
 const dmAddMembersBaseValidatorShape = {
   editorID: tUserID,
   time: t.Number,
-  messageID: t.String,
   addedUserIDs: t.list(tUserID),
 };
 
 export type DMAddMembersOperation = $ReadOnly<{
   +type: 'add_members',
   +threadID: string,
+  +messageID: string,
   ...DMAddMembersBase,
 }>;
 export const dmAddMembersOperationValidator: TInterface<DMAddMembersOperation> =
   tShape<DMAddMembersOperation>({
     type: tString(dmOperationTypes.ADD_MEMBERS),
     threadID: t.String,
+    messageID: t.String,
     ...dmAddMembersBaseValidatorShape,
   });
 
 export type DMAddViewerToThreadMembersOperation = $ReadOnly<{
   +type: 'add_viewer_to_thread_members',
+  +messageID: ?string,
   +existingThreadDetails: CreateThickRawThreadInfoInput,
   ...DMAddMembersBase,
 }>;
 export const dmAddViewerToThreadMembersValidator: TInterface<DMAddViewerToThreadMembersOperation> =
   tShape<DMAddViewerToThreadMembersOperation>({
     type: tString(dmOperationTypes.ADD_VIEWER_TO_THREAD_MEMBERS),
+    messageID: t.maybe(t.String),
     existingThreadDetails: createThickRawThreadInfoInputValidator,
     ...dmAddMembersBaseValidatorShape,
   });
 
 export type DMJoinThreadOperation = {
   +type: 'join_thread',
   +joinerID: string,
   +time: number,
   +messageID: string,
   +existingThreadDetails: CreateThickRawThreadInfoInput,
 };
 export const dmJoinThreadOperationValidator: TInterface<DMJoinThreadOperation> =
   tShape<DMJoinThreadOperation>({
     type: tString(dmOperationTypes.JOIN_THREAD),
     joinerID: tUserID,
     time: t.Number,
     messageID: t.String,
     existingThreadDetails: createThickRawThreadInfoInputValidator,
   });
 
 export type DMLeaveThreadOperation = {
   +type: 'leave_thread',
   +editorID: string,
   +time: number,
   +messageID: string,
   +threadID: string,
 };
 export const dmLeaveThreadOperationValidator: TInterface<DMLeaveThreadOperation> =
   tShape<DMLeaveThreadOperation>({
     type: tString(dmOperationTypes.LEAVE_THREAD),
     editorID: tUserID,
     time: t.Number,
     messageID: t.String,
     threadID: t.String,
   });
 
 export type DMRemoveMembersOperation = {
   +type: 'remove_members',
   +editorID: string,
   +time: number,
   +messageID: string,
   +threadID: string,
   +removedUserIDs: $ReadOnlyArray<string>,
 };
 export const dmRemoveMembersOperationValidator: TInterface<DMRemoveMembersOperation> =
   tShape<DMRemoveMembersOperation>({
     type: tString(dmOperationTypes.REMOVE_MEMBERS),
     editorID: tUserID,
     time: t.Number,
     messageID: t.String,
     threadID: t.String,
     removedUserIDs: t.list(tUserID),
   });
 
 export type DMThreadSettingsChanges = {
   +name?: string,
   +description?: string,
   +color?: string,
   +avatar?: ClientAvatar,
 };
 
 export type DMChangeThreadSettingsOperation = $ReadOnly<{
   +type: 'change_thread_settings',
   +threadID: string,
   +editorID: string,
   +time: number,
   +changes: DMThreadSettingsChanges,
   +messageIDsPrefix: string,
 }>;
 export const dmChangeThreadSettingsOperationValidator: TInterface<DMChangeThreadSettingsOperation> =
   tShape<DMChangeThreadSettingsOperation>({
     type: tString(dmOperationTypes.CHANGE_THREAD_SETTINGS),
     threadID: t.String,
     editorID: tUserID,
     time: t.Number,
     changes: tShape({
       name: t.maybe(t.String),
       description: t.maybe(t.String),
       color: t.maybe(tColor),
       avatar: t.maybe(clientAvatarValidator),
     }),
     messageIDsPrefix: t.String,
   });
 
 export type DMChangeThreadSubscriptionOperation = {
   +type: 'change_thread_subscription',
   +time: number,
   +threadID: string,
   +creatorID: string,
   +subscription: ThreadSubscription,
 };
 export const dmChangeThreadSubscriptionOperationValidator: TInterface<DMChangeThreadSubscriptionOperation> =
   tShape<DMChangeThreadSubscriptionOperation>({
     type: tString(dmOperationTypes.CHANGE_THREAD_SUBSCRIPTION),
     time: t.Number,
     threadID: t.String,
     creatorID: tUserID,
     subscription: threadSubscriptionValidator,
   });
 
 export type DMChangeThreadReadStatusOperation = {
   +type: 'change_thread_read_status',
   +time: number,
   +threadID: string,
   +creatorID: string,
   +unread: boolean,
 };
 export const dmChangeThreadReadStatusOperationValidator: TInterface<DMChangeThreadReadStatusOperation> =
   tShape<DMChangeThreadReadStatusOperation>({
     type: tString(dmOperationTypes.CHANGE_THREAD_READ_STATUS),
     time: t.Number,
     threadID: t.String,
     creatorID: tUserID,
     unread: t.Boolean,
   });
 
 export type DMOperation =
   | DMCreateThreadOperation
   | DMCreateSidebarOperation
   | DMSendTextMessageOperation
   | DMSendReactionMessageOperation
   | DMSendEditMessageOperation
   | DMAddMembersOperation
   | DMAddViewerToThreadMembersOperation
   | DMJoinThreadOperation
   | DMLeaveThreadOperation
   | DMRemoveMembersOperation
   | DMChangeThreadSettingsOperation
   | DMChangeThreadSubscriptionOperation
   | DMChangeThreadReadStatusOperation;
 export const dmOperationValidator: TUnion<DMOperation> = t.union([
   dmCreateThreadOperationValidator,
   dmCreateSidebarOperationValidator,
   dmSendTextMessageOperationValidator,
   dmSendReactionMessageOperationValidator,
   dmSendEditMessageOperationValidator,
   dmAddMembersOperationValidator,
   dmAddViewerToThreadMembersValidator,
   dmJoinThreadOperationValidator,
   dmLeaveThreadOperationValidator,
   dmRemoveMembersOperationValidator,
   dmChangeThreadSettingsOperationValidator,
   dmChangeThreadSubscriptionOperationValidator,
   dmChangeThreadReadStatusOperationValidator,
 ]);
 
 export type DMOperationResult = {
   rawMessageInfos: Array<RawMessageInfo>,
   updateInfos: Array<ClientUpdateInfo>,
 };
 
 export const processDMOpsActionType = 'PROCESS_DM_OPS';
 
 export type ProcessDMOpsPayload = {
   +rawMessageInfos: $ReadOnlyArray<RawMessageInfo>,
   +updateInfos: $ReadOnlyArray<ClientUpdateInfo>,
   +outboundP2PMessages: ?$ReadOnlyArray<OutboundP2PMessage>,
   // For messages that could be retried from UI, we need to bind DM `messageID`
   // with `outboundP2PMessages` to keep track of whether all P2P messages
   // were queued on Tunnelbroker.
   +messageIDWithoutAutoRetry: ?string,
   +notificationsCreationData: ?NotificationsCreationData,
 };
 
 export const queueDMOpsActionType = 'QUEUE_DM_OPS';
 export type QueueDMOpsPayload = {
   +operation: DMOperation,
   +threadID: string,
   +timestamp: number,
 };
 
 export const pruneDMOpsQueueActionType = 'PRUNE_DM_OPS_QUEUE';
 export type PruneDMOpsQueuePayload = {
   +pruneMaxTimestamp: number,
 };
 
 export const clearQueuedThreadDMOpsActionType = 'CLEAR_QUEUED_THREAD_DM_OPS';
 export type ClearQueuedThreadDMOpsPayload = {
   +threadID: string,
 };
 
 export type QueuedDMOperations = {
   +operations: {
     +[threadID: string]: $ReadOnlyArray<{
       +operation: DMOperation,
       +timestamp: number,
     }>,
   },
 };
 
 export type SendDMStartedPayload = {
   +messageID: string,
 };
 
 export type SendDMOpsSuccessPayload = {
   +messageID: string,
   +outboundP2PMessageIDs: $ReadOnlyArray<string>,
 };
 
 export const sendDMActionTypes = Object.freeze({
   started: 'SEND_DM_STARTED',
   success: 'SEND_DM_SUCCESS',
   failed: 'SEND_DM_FAILED',
 });