diff --git a/keyserver/src/creators/account-creator.js b/keyserver/src/creators/account-creator.js
--- a/keyserver/src/creators/account-creator.js
+++ b/keyserver/src/creators/account-creator.js
@@ -184,8 +184,10 @@
 
   return {
     id,
+    isNewAccount: true,
     rawMessageInfos,
     currentUserInfo,
+    serverTime: Date.now(),
     cookieChange: {
       threadInfos: threadsResult.threadInfos,
       userInfos: values(userInfos),
diff --git a/lib/actions/user-actions.js b/lib/actions/user-actions.js
--- a/lib/actions/user-actions.js
+++ b/lib/actions/user-actions.js
@@ -85,11 +85,42 @@
     registerCallServerEndpointOptions,
   );
   return {
+    isNewAccount: response.isNewAccount,
     currentUserInfo: response.currentUserInfo,
     rawMessageInfos: response.rawMessageInfos,
     threadInfos: response.cookieChange.threadInfos,
     userInfos: response.cookieChange.userInfos,
     calendarQuery: registerInfo.calendarQuery,
+    updatesCurrentAsOf: response.serverTime,
+  };
+};
+
+const siweActionTypes = Object.freeze({
+  started: 'SIWE_STARTED',
+  success: 'SIWE_SUCCESS',
+  failed: 'SIWE_FAILED',
+});
+const siwe = (
+  callServerEndpoint: CallServerEndpoint,
+): ((siweInfo: SIWEServerCall) => Promise<SIWEResult>) => async siweInfo => {
+  const watchedIDs = threadWatcher.getWatchedIDs();
+  const response = await callServerEndpoint(
+    'siwe',
+    {
+      ...siweInfo,
+      watchedIDs,
+      platformDetails: getConfig().platformDetails,
+    },
+    registerCallServerEndpointOptions,
+  );
+  return {
+    isNewAccount: response.isNewAccount,
+    currentUserInfo: response.currentUserInfo,
+    rawMessageInfos: response.rawMessageInfos,
+    threadInfos: response.cookieChange.threadInfos,
+    userInfos: response.cookieChange.userInfos,
+    calendarQuery: siweInfo.calendarQuery,
+    updatesCurrentAsOf: response.serverTime,
   };
 };
 
@@ -163,9 +194,9 @@
     threadInfos: response.cookieChange.threadInfos,
     currentUserInfo: response.currentUserInfo,
     calendarResult: {
-      calendarQuery: logInInfo.calendarQuery,
       rawEntryInfos: response.rawEntryInfos,
     },
+    calendarQuery: logInInfo.calendarQuery,
     messagesResult: {
       messageInfos: response.rawMessageInfos,
       truncationStatus: response.truncationStatuses,
diff --git a/lib/reducers/calendar-filters-reducer.js b/lib/reducers/calendar-filters-reducer.js
--- a/lib/reducers/calendar-filters-reducer.js
+++ b/lib/reducers/calendar-filters-reducer.js
@@ -9,8 +9,6 @@
 import {
   logOutActionTypes,
   deleteAccountActionTypes,
-  logInActionTypes,
-  registerActionTypes,
 } from '../actions/user-actions';
 import {
   filteredThreadIDs,
@@ -37,7 +35,10 @@
   type ClientUpdateInfo,
   processUpdatesActionType,
 } from '../types/update-types';
-import { setNewSessionActionType } from '../utils/action-utils';
+import {
+  setNewSessionActionType,
+  isSuccessfulAuthType,
+} from '../utils/action-utils';
 
 export default function reduceCalendarFilters(
   state: $ReadOnlyArray<CalendarFilter>,
@@ -46,8 +47,7 @@
   if (
     action.type === logOutActionTypes.success ||
     action.type === deleteAccountActionTypes.success ||
-    action.type === logInActionTypes.success ||
-    action.type === registerActionTypes.success ||
+    isSuccessfulAuthType(action) ||
     (action.type === setNewSessionActionType &&
       action.payload.sessionChange.cookieInvalidated)
   ) {
diff --git a/lib/reducers/connection-reducer.js b/lib/reducers/connection-reducer.js
--- a/lib/reducers/connection-reducer.js
+++ b/lib/reducers/connection-reducer.js
@@ -1,5 +1,4 @@
 // @flow
-
 import { updateActivityActionTypes } from '../actions/activity-actions';
 import { updateCalendarQueryActionTypes } from '../actions/entry-actions';
 import {
@@ -7,6 +6,7 @@
   deleteAccountActionTypes,
   logInActionTypes,
   registerActionTypes,
+  siweActionTypes,
 } from '../actions/user-actions';
 import { queueActivityUpdatesActionType } from '../types/activity-types';
 import { defaultCalendarQuery } from '../types/entry-types';
@@ -76,8 +76,10 @@
   } else if (action.type === logInActionTypes.success) {
     return {
       ...state,
-      actualizedCalendarQuery: action.payload.calendarResult.calendarQuery,
+      actualizedCalendarQuery: action.payload.calendarQuery,
     };
+  } else if (action.type === siweActionTypes.success) {
+    return { ...state, actualizedCalendarQuery: action.payload.calendarQuery };
   } else if (
     action.type === registerActionTypes.success ||
     action.type === updateCalendarQueryActionTypes.success ||
diff --git a/lib/reducers/data-loaded-reducer.js b/lib/reducers/data-loaded-reducer.js
--- a/lib/reducers/data-loaded-reducer.js
+++ b/lib/reducers/data-loaded-reducer.js
@@ -1,24 +1,19 @@
 // @flow
-
 import {
   logOutActionTypes,
   deleteAccountActionTypes,
-  logInActionTypes,
-  registerActionTypes,
-  siweActionTypes,
 } from '../actions/user-actions';
 import type { BaseAction } from '../types/redux-types';
-import { setNewSessionActionType } from '../utils/action-utils';
+import {
+  setNewSessionActionType,
+  isSuccessfulAuthType,
+} from '../utils/action-utils';
 
 export default function reduceDataLoaded(
   state: boolean,
   action: BaseAction,
 ): boolean {
-  if (
-    action.type === logInActionTypes.success ||
-    action.type === registerActionTypes.success ||
-    action.type === siweActionTypes.success
-  ) {
+  if (isSuccessfulAuthType(action)) {
     return true;
   } else if (
     action.type === setNewSessionActionType &&
diff --git a/lib/reducers/entry-reducer.js b/lib/reducers/entry-reducer.js
--- a/lib/reducers/entry-reducer.js
+++ b/lib/reducers/entry-reducer.js
@@ -1,5 +1,4 @@
 // @flow
-
 import invariant from 'invariant';
 import _filter from 'lodash/fp/filter';
 import _flow from 'lodash/fp/flow';
@@ -37,6 +36,7 @@
   logOutActionTypes,
   deleteAccountActionTypes,
   logInActionTypes,
+  siweActionTypes,
 } from '../actions/user-actions';
 import {
   entryID,
@@ -487,7 +487,10 @@
       },
       [],
     ];
-  } else if (action.type === logInActionTypes.success) {
+  } else if (
+    action.type === logInActionTypes.success ||
+    (action.type === siweActionTypes.success && !action.payload.isNewAccount)
+  ) {
     const { calendarResult } = action.payload;
     if (calendarResult) {
       const [updatedEntryInfos, updatedDaysToEntries] = mergeNewEntryInfos(
diff --git a/lib/reducers/master-reducer.js b/lib/reducers/master-reducer.js
--- a/lib/reducers/master-reducer.js
+++ b/lib/reducers/master-reducer.js
@@ -1,6 +1,4 @@
 // @flow
-
-import { registerActionTypes, logInActionTypes } from '../actions/user-actions';
 import type { BaseNavInfo } from '../types/nav-types';
 import type { BaseAppState, BaseAction } from '../types/redux-types';
 import {
@@ -8,6 +6,7 @@
   incrementalStateSyncActionType,
 } from '../types/socket-types';
 import type { StoreOperations } from '../types/store-ops-types';
+import { isSuccessfulAuthType } from '../utils/action-utils';
 import reduceCalendarFilters from './calendar-filters-reducer';
 import reduceConnectionInfo from './connection-reducer';
 import reduceDataLoaded from './data-loaded-reducer';
@@ -62,8 +61,7 @@
     connection.status !== 'connected' &&
     action.type !== incrementalStateSyncActionType &&
     action.type !== fullStateSyncActionType &&
-    action.type !== registerActionTypes.success &&
-    action.type !== logInActionTypes.success
+    !isSuccessfulAuthType(action)
   ) {
     if (messageStore.currentAsOf !== state.messageStore.currentAsOf) {
       messageStore = {
diff --git a/lib/reducers/message-reducer.js b/lib/reducers/message-reducer.js
--- a/lib/reducers/message-reducer.js
+++ b/lib/reducers/message-reducer.js
@@ -1,5 +1,4 @@
 // @flow
-
 import invariant from 'invariant';
 import _difference from 'lodash/fp/difference';
 import _flow from 'lodash/fp/flow';
@@ -48,6 +47,7 @@
   deleteAccountActionTypes,
   logInActionTypes,
   registerActionTypes,
+  siweActionTypes,
 } from '../actions/user-actions';
 import { pendingToRealizedThreadIDsSelector } from '../selectors/thread-selectors';
 import {
@@ -688,7 +688,11 @@
   action: BaseAction,
   newThreadInfos: { +[id: string]: RawThreadInfo },
 ): ReduceMessageStoreResult {
-  if (action.type === logInActionTypes.success) {
+  if (
+    action.type === logInActionTypes.success ||
+    (action.type === siweActionTypes.success && !action.payload.isNewAccount)
+  ) {
+    // $FlowFixMe
     const messagesResult = action.payload.messagesResult;
     const {
       messageStoreOperations,
@@ -844,6 +848,23 @@
       truncationStatuses,
       newThreadInfos,
     );
+  } else if (
+    action.type === siweActionTypes.success &&
+    action.payload.isNewAccount
+  ) {
+    const truncationStatuses = {};
+    // $FlowFixMe
+    for (const messageInfo of action.payload.rawMessageInfos) {
+      truncationStatuses[messageInfo.threadID] =
+        messageTruncationStatus.EXHAUSTIVE;
+    }
+    return mergeNewMessages(
+      messageStore,
+      // $FlowFixMe
+      action.payload.rawMessageInfos,
+      truncationStatuses,
+      newThreadInfos,
+    );
   } else if (
     action.type === changeThreadSettingsActionTypes.success ||
     action.type === removeUsersFromThreadActionTypes.success ||
diff --git a/lib/reducers/thread-reducer.js b/lib/reducers/thread-reducer.js
--- a/lib/reducers/thread-reducer.js
+++ b/lib/reducers/thread-reducer.js
@@ -20,8 +20,6 @@
 import {
   logOutActionTypes,
   deleteAccountActionTypes,
-  logInActionTypes,
-  registerActionTypes,
   updateSubscriptionActionTypes,
 } from '../actions/user-actions';
 import type { BaseAction } from '../types/redux-types';
@@ -48,7 +46,10 @@
   processUpdatesActionType,
 } from '../types/update-types';
 import { actionLogger } from '../utils/action-logger';
-import { setNewSessionActionType } from '../utils/action-utils';
+import {
+  setNewSessionActionType,
+  isSuccessfulAuthType,
+} from '../utils/action-utils';
 import { getConfig } from '../utils/config';
 import { sanitizeActionSecrets } from '../utils/sanitization';
 
@@ -156,11 +157,8 @@
   newThreadInconsistencies: $ReadOnlyArray<ClientThreadInconsistencyReportCreationRequest>,
   threadStoreOperations: $ReadOnlyArray<ThreadStoreOperation>,
 } {
-  if (
-    action.type === logInActionTypes.success ||
-    action.type === registerActionTypes.success ||
-    action.type === fullStateSyncActionType
-  ) {
+  if (isSuccessfulAuthType(action) || action.type === fullStateSyncActionType) {
+    // $FlowFixMe
     const newThreadInfos = action.payload.threadInfos;
     const threadStoreOperations = [
       {
diff --git a/lib/reducers/updates-reducer.js b/lib/reducers/updates-reducer.js
--- a/lib/reducers/updates-reducer.js
+++ b/lib/reducers/updates-reducer.js
@@ -1,6 +1,5 @@
 // @flow
-
-import { logInActionTypes } from '../actions/user-actions';
+import { logInActionTypes, siweActionTypes } from '../actions/user-actions';
 import type { BaseAction } from '../types/redux-types';
 import {
   fullStateSyncActionType,
@@ -12,7 +11,10 @@
   currentAsOf: number,
   action: BaseAction,
 ): number {
-  if (action.type === logInActionTypes.success) {
+  if (
+    action.type === logInActionTypes.success ||
+    action.type === siweActionTypes.success
+  ) {
     return action.payload.updatesCurrentAsOf;
   } else if (action.type === fullStateSyncActionType) {
     return action.payload.updatesCurrentAsOf;
diff --git a/lib/types/account-types.js b/lib/types/account-types.js
--- a/lib/types/account-types.js
+++ b/lib/types/account-types.js
@@ -55,12 +55,14 @@
 
 export type RegisterResponse = {
   id: string,
+  isNewAccount: boolean,
   rawMessageInfos: $ReadOnlyArray<RawMessageInfo>,
   currentUserInfo: OldLoggedInUserInfo | LoggedInUserInfo,
   cookieChange: {
     threadInfos: { +[id: string]: RawThreadInfo },
     userInfos: $ReadOnlyArray<UserInfo>,
   },
+  serverTime: number,
 };
 
 export type RegisterResult = {
@@ -69,6 +71,9 @@
   +threadInfos: { +[id: string]: RawThreadInfo },
   +userInfos: $ReadOnlyArray<UserInfo>,
   +calendarQuery: CalendarQuery,
+  +isNewAccount: boolean,
+  +calendarResult?: ?CalendarResult,
+  +updatesCurrentAsOf: number,
 };
 
 export type DeleteAccountRequest = {
@@ -137,8 +142,10 @@
   +messagesResult: GenericMessagesResult,
   +userInfos: $ReadOnlyArray<UserInfo>,
   +calendarResult: CalendarResult,
+  +calendarQuery: CalendarQuery,
   +updatesCurrentAsOf: number,
   +logInActionSource: LogInActionSource,
+  +isNewAccount?: boolean,
 };
 
 export type SIWERequest = {
diff --git a/lib/types/entry-types.js b/lib/types/entry-types.js
--- a/lib/types/entry-types.js
+++ b/lib/types/entry-types.js
@@ -196,7 +196,6 @@
 
 export type CalendarResult = {
   +rawEntryInfos: $ReadOnlyArray<RawEntryInfo>,
-  +calendarQuery: CalendarQuery,
 };
 
 export type CalendarQueryUpdateStartingPayload = {
diff --git a/lib/utils/action-utils.js b/lib/utils/action-utils.js
--- a/lib/utils/action-utils.js
+++ b/lib/utils/action-utils.js
@@ -5,6 +5,11 @@
 import { useSelector, useDispatch } from 'react-redux';
 import { createSelector } from 'reselect';
 
+import {
+  logInActionTypes,
+  registerActionTypes,
+  siweActionTypes,
+} from '../actions/user-actions';
 import { serverCallStateSelector } from '../selectors/server-calls';
 import {
   logInActionSources,
@@ -366,6 +371,29 @@
   connectionStatus: ConnectionStatus,
 };
 
+function isSuccessfulAuthType(action: BaseAction): boolean {
+  const isAuthType: boolean =
+    action.type === logInActionTypes.success ||
+    action.type === registerActionTypes.success ||
+    action.type === siweActionTypes.success;
+  return isAuthType;
+}
+
+function isSuccessfulLogin(action: BaseAction): boolean {
+  if (
+    action.type !== logInActionTypes.success ||
+    action.type !== siweActionTypes.success
+  ) {
+    return false;
+  }
+  let isNewAccount = false;
+  if (action.type === siweActionTypes.success) {
+    isNewAccount = action.payload.isNewAccount;
+  }
+  const isLogin: boolean = action.type === logInActionTypes.success;
+  return isLogin || !isNewAccount;
+}
+
 // All server calls needs to include some information from the Redux state
 // (namely, the cookie). This information is used deep in the server call,
 // at the point where callServerEndpoint is called. We don't want to bother
@@ -437,4 +465,6 @@
   createBoundServerCallsSelector,
   registerActiveSocket,
   useServerCall,
+  isSuccessfulAuthType,
+  isSuccessfulLogin,
 };