diff --git a/keyserver/src/responders/website-responders.js b/keyserver/src/responders/website-responders.js
--- a/keyserver/src/responders/website-responders.js
+++ b/keyserver/src/responders/website-responders.js
@@ -28,7 +28,10 @@
 import { defaultWebEnabledApps } from 'lib/types/enabled-apps.js';
 import { entryStoreValidator } from 'lib/types/entry-types.js';
 import { defaultCalendarFilters } from 'lib/types/filter-types.js';
-import { keyserverStoreValidator } from 'lib/types/keyserver-types.js';
+import {
+  keyserverStoreValidator,
+  webKeyserverInfoValidator,
+} from 'lib/types/keyserver-types.js';
 import { inviteLinksStoreValidator } from 'lib/types/link-types.js';
 import {
   defaultNumberPerThread,
@@ -48,7 +51,13 @@
 import { promiseAll } from 'lib/utils/promises.js';
 import { defaultNotifPermissionAlertInfo } from 'lib/utils/push-alerts.js';
 import { infoFromURL } from 'lib/utils/url-utils.js';
-import { tBool, tNumber, tShape, tString } from 'lib/utils/validation-utils.js';
+import {
+  tBool,
+  tNumber,
+  tShape,
+  tString,
+  ashoatKeyserverID,
+} from 'lib/utils/validation-utils.js';
 import getTitle from 'web/title/getTitle.js';
 import { navInfoValidator } from 'web/types/nav-types.js';
 import { navInfoFromURL } from 'web/url-utils.js';
@@ -253,7 +262,7 @@
     'default lastCommunicatedPlatformDetails',
     _isEqual({}),
   ),
-  keyserverStore: keyserverStoreValidator,
+  keyserverStore: keyserverStoreValidator(webKeyserverInfoValidator),
 });
 
 async function websiteResponder(
@@ -498,6 +507,15 @@
     };
   })();
 
+  const keyserverStorePromise = (async () => {
+    const sessionID = await sessionIDPromise;
+    return {
+      keyserverInfos: {
+        [ashoatKeyserverID]: { cookie: undefined, sessionID },
+      },
+    };
+  })();
+
   const {
     jsURL,
     fontsURL,
@@ -600,7 +618,7 @@
     commServicesAccessToken: null,
     inviteLinksStore: inviteLinksStorePromise,
     lastCommunicatedPlatformDetails: {},
-    keyserverStore: { keyserverInfos: {} },
+    keyserverStore: keyserverStorePromise,
   });
   const validatedInitialReduxState = validateOutput(
     viewer.platformDetails,
diff --git a/lib/reducers/keyserver-reducer.js b/lib/reducers/keyserver-reducer.js
--- a/lib/reducers/keyserver-reducer.js
+++ b/lib/reducers/keyserver-reducer.js
@@ -7,9 +7,9 @@
 import { ashoatKeyserverID } from '../utils/validation-utils.js';
 
 export default function reduceKeyserverStore(
-  state: KeyserverStore,
+  state: KeyserverStore<*>,
   action: BaseAction,
-): KeyserverStore {
+): KeyserverStore<*> {
   // this action is only dispatched on native
   if (action.type === resetUserStateActionType) {
     const stateCookie = state.keyserverInfos[ashoatKeyserverID]?.cookie;
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
@@ -28,6 +28,7 @@
   registerActionTypes,
   logInActionTypes,
 } from '../actions/user-actions.js';
+import type { KeyserverInfo } from '../types/keyserver-types.js';
 import type { BaseNavInfo } from '../types/nav-types.js';
 import type { BaseAppState, BaseAction } from '../types/redux-types.js';
 import {
@@ -36,7 +37,11 @@
 } from '../types/socket-types.js';
 import type { StoreOperations } from '../types/store-ops-types.js';
 
-export default function baseReducer<N: BaseNavInfo, T: BaseAppState<N>>(
+export default function baseReducer<
+  N: BaseNavInfo,
+  K: KeyserverInfo,
+  T: BaseAppState<N, K>,
+>(
   state: T,
   action: BaseAction,
 ): { state: T, storeOperations: StoreOperations } {
diff --git a/lib/selectors/calendar-filter-selectors.js b/lib/selectors/calendar-filter-selectors.js
--- a/lib/selectors/calendar-filter-selectors.js
+++ b/lib/selectors/calendar-filter-selectors.js
@@ -27,9 +27,9 @@
 }
 
 const filteredThreadIDsSelector: (
-  state: BaseAppState<*>,
+  state: BaseAppState<*, *>,
 ) => ?$ReadOnlySet<string> = createSelector(
-  (state: BaseAppState<*>) => state.calendarFilters,
+  (state: BaseAppState<*, *>) => state.calendarFilters,
   filteredThreadIDs,
 );
 
@@ -53,9 +53,9 @@
 }
 
 const nonThreadCalendarFiltersSelector: (
-  state: BaseAppState<*>,
+  state: BaseAppState<*, *>,
 ) => $ReadOnlyArray<CalendarFilter> = createSelector(
-  (state: BaseAppState<*>) => state.calendarFilters,
+  (state: BaseAppState<*, *>) => state.calendarFilters,
   nonThreadCalendarFilters,
 );
 
@@ -66,9 +66,9 @@
 }
 
 const nonExcludeDeletedCalendarFiltersSelector: (
-  state: BaseAppState<*>,
+  state: BaseAppState<*, *>,
 ) => $ReadOnlyArray<CalendarFilter> = createSelector(
-  (state: BaseAppState<*>) => state.calendarFilters,
+  (state: BaseAppState<*, *>) => state.calendarFilters,
   nonExcludeDeletedCalendarFilters,
 );
 
@@ -84,9 +84,9 @@
   return false;
 }
 
-const includeDeletedSelector: (state: BaseAppState<*>) => boolean =
+const includeDeletedSelector: (state: BaseAppState<*, *>) => boolean =
   createSelector(
-    (state: BaseAppState<*>) => state.calendarFilters,
+    (state: BaseAppState<*, *>) => state.calendarFilters,
     (calendarFilters: $ReadOnlyArray<CalendarFilter>) =>
       !filterExists(calendarFilters, calendarThreadFilterTypes.NOT_DELETED),
   );
diff --git a/lib/selectors/chat-selectors.js b/lib/selectors/chat-selectors.js
--- a/lib/selectors/chat-selectors.js
+++ b/lib/selectors/chat-selectors.js
@@ -76,12 +76,13 @@
   +pendingPersonalThreadUserInfo?: UserInfo,
 };
 
-const messageInfoSelector: (state: BaseAppState<*>) => {
+const messageInfoSelector: (state: BaseAppState<*, *>) => {
   +[id: string]: ?MessageInfo,
 } = createObjectSelector(
-  (state: BaseAppState<*>) => state.messageStore.messages,
-  (state: BaseAppState<*>) => state.currentUserInfo && state.currentUserInfo.id,
-  (state: BaseAppState<*>) => state.userStore.userInfos,
+  (state: BaseAppState<*, *>) => state.messageStore.messages,
+  (state: BaseAppState<*, *>) =>
+    state.currentUserInfo && state.currentUserInfo.id,
+  (state: BaseAppState<*, *>) => state.userStore.userInfos,
   threadInfoSelector,
   createMessageInfo,
 );
@@ -201,26 +202,27 @@
   };
 }
 
-const chatListData: (state: BaseAppState<*>) => $ReadOnlyArray<ChatThreadItem> =
-  createSelector(
-    threadInfoSelector,
-    (state: BaseAppState<*>) => state.messageStore,
-    messageInfoSelector,
-    sidebarInfoSelector,
-    (
-      threadInfos: { +[id: string]: ThreadInfo },
-      messageStore: MessageStore,
-      messageInfos: { +[id: string]: ?MessageInfo },
-      sidebarInfos: { +[id: string]: $ReadOnlyArray<SidebarInfo> },
-    ): $ReadOnlyArray<ChatThreadItem> =>
-      getChatThreadItems(
-        threadInfos,
-        messageStore,
-        messageInfos,
-        sidebarInfos,
-        threadIsTopLevel,
-      ),
-  );
+const chatListData: (
+  state: BaseAppState<*, *>,
+) => $ReadOnlyArray<ChatThreadItem> = createSelector(
+  threadInfoSelector,
+  (state: BaseAppState<*, *>) => state.messageStore,
+  messageInfoSelector,
+  sidebarInfoSelector,
+  (
+    threadInfos: { +[id: string]: ThreadInfo },
+    messageStore: MessageStore,
+    messageInfos: { +[id: string]: ?MessageInfo },
+    sidebarInfos: { +[id: string]: $ReadOnlyArray<SidebarInfo> },
+  ): $ReadOnlyArray<ChatThreadItem> =>
+    getChatThreadItems(
+      threadInfos,
+      messageStore,
+      messageInfos,
+      sidebarInfos,
+      threadIsTopLevel,
+    ),
+);
 
 function useFlattenedChatListData(): $ReadOnlyArray<ChatThreadItem> {
   return useFilteredChatListData(threadInChatList);
@@ -565,11 +567,11 @@
   additionalMessages: $ReadOnlyArray<MessageInfo>,
 ) =>
   createSelector(
-    (state: BaseAppState<*>) => state.messageStore,
+    (state: BaseAppState<*, *>) => state.messageStore,
     messageInfoSelector,
     threadInfoSelector,
     threadInfoFromSourceMessageIDSelector,
-    (state: BaseAppState<*>) =>
+    (state: BaseAppState<*, *>) =>
       state.currentUserInfo && state.currentUserInfo.id,
     (
       messageStore: MessageStore,
@@ -596,7 +598,7 @@
 const messageListData: (
   threadID: ?string,
   additionalMessages: $ReadOnlyArray<MessageInfo>,
-) => (state: BaseAppState<*>) => MessageListData =
+) => (state: BaseAppState<*, *>) => MessageListData =
   memoize2(baseMessageListData);
 
 export type UseMessageListDataArgs = {
diff --git a/lib/selectors/loading-selectors.js b/lib/selectors/loading-selectors.js
--- a/lib/selectors/loading-selectors.js
+++ b/lib/selectors/loading-selectors.js
@@ -43,12 +43,12 @@
 const baseCreateLoadingStatusSelector = (
   actionTypes: ActionTypes<*, *, *>,
   overrideKey?: string,
-): ((state: BaseAppState<*>) => LoadingStatus) => {
+): ((state: BaseAppState<*, *>) => LoadingStatus) => {
   // This makes sure that reduceLoadingStatuses tracks this action
   registerFetchKey(actionTypes);
   const trackingKey = getTrackingKey(actionTypes, overrideKey);
   return createSelector(
-    (state: BaseAppState<*>) => state.loadingStatuses[trackingKey],
+    (state: BaseAppState<*, *>) => state.loadingStatuses[trackingKey],
     (loadingStatusInfo: { [idx: number]: LoadingStatus }) =>
       loadingStatusFromInfo(loadingStatusInfo),
   );
@@ -57,7 +57,7 @@
 const createLoadingStatusSelector: (
   actionTypes: ActionTypes<*, *, *>,
   overrideKey?: string,
-) => (state: BaseAppState<*>) => LoadingStatus = _memoize(
+) => (state: BaseAppState<*, *>) => LoadingStatus = _memoize(
   baseCreateLoadingStatusSelector,
   getTrackingKey,
 );
@@ -77,19 +77,18 @@
   return errorExists ? 'error' : 'inactive';
 }
 
-const globalLoadingStatusSelector: (state: BaseAppState<*>) => LoadingStatus =
-  createSelector(
-    (state: BaseAppState<*>) => state.loadingStatuses,
-    (loadingStatusInfos: {
-      [key: string]: { [idx: number]: LoadingStatus },
-    }): LoadingStatus => {
-      const loadingStatusInfoValues = values(loadingStatusInfos);
-      const loadingStatuses = loadingStatusInfoValues.map(
-        loadingStatusFromInfo,
-      );
-      return combineLoadingStatuses(...loadingStatuses);
-    },
-  );
+const globalLoadingStatusSelector: (
+  state: BaseAppState<*, *>,
+) => LoadingStatus = createSelector(
+  (state: BaseAppState<*, *>) => state.loadingStatuses,
+  (loadingStatusInfos: {
+    [key: string]: { [idx: number]: LoadingStatus },
+  }): LoadingStatus => {
+    const loadingStatusInfoValues = values(loadingStatusInfos);
+    const loadingStatuses = loadingStatusInfoValues.map(loadingStatusFromInfo);
+    return combineLoadingStatuses(...loadingStatuses);
+  },
+);
 
 export {
   createLoadingStatusSelector,
diff --git a/lib/selectors/local-id-selectors.js b/lib/selectors/local-id-selectors.js
--- a/lib/selectors/local-id-selectors.js
+++ b/lib/selectors/local-id-selectors.js
@@ -12,7 +12,7 @@
   return parseInt(matches[1], 10);
 }
 
-function highestLocalIDSelector(state: ?BaseAppState<*>): number {
+function highestLocalIDSelector(state: ?BaseAppState<*, *>): number {
   let highestLocalIDFound = -1;
 
   if (state && state.messageStore) {
diff --git a/lib/selectors/nav-selectors.js b/lib/selectors/nav-selectors.js
--- a/lib/selectors/nav-selectors.js
+++ b/lib/selectors/nav-selectors.js
@@ -41,11 +41,11 @@
 }
 
 const currentCalendarQuery: (
-  state: BaseAppState<*>,
+  state: BaseAppState<*, *>,
 ) => (calendarActive: boolean) => CalendarQuery = createSelector(
-  (state: BaseAppState<*>) => state.entryStore.lastUserInteractionCalendar,
-  (state: BaseAppState<*>) => state.navInfo,
-  (state: BaseAppState<*>) => state.calendarFilters,
+  (state: BaseAppState<*, *>) => state.entryStore.lastUserInteractionCalendar,
+  (state: BaseAppState<*, *>) => state.navInfo,
+  (state: BaseAppState<*, *>) => state.calendarFilters,
   (
     lastUserInteractionCalendar: number,
     navInfo: BaseNavInfo,
diff --git a/lib/selectors/relationship-selectors.js b/lib/selectors/relationship-selectors.js
--- a/lib/selectors/relationship-selectors.js
+++ b/lib/selectors/relationship-selectors.js
@@ -10,40 +10,41 @@
 } from '../types/relationship-types.js';
 import type { UserInfos } from '../types/user-types.js';
 
-const userRelationshipsSelector: (state: BaseAppState<*>) => UserRelationships =
-  createSelector(
-    (state: BaseAppState<*>) => state.userStore.userInfos,
-    (userInfos: UserInfos) => {
-      const unorderedFriendRequests = [];
-      const unorderedFriends = [];
-      const blocked = [];
-      for (const userID in userInfos) {
-        const userInfo = userInfos[userID];
-        const { id, username, relationshipStatus } = userInfo;
-        if (!username) {
-          continue;
-        }
-        if (
-          relationshipStatus === userRelationshipStatus.REQUEST_RECEIVED ||
-          relationshipStatus === userRelationshipStatus.REQUEST_SENT
-        ) {
-          unorderedFriendRequests.push({ id, username, relationshipStatus });
-        } else if (relationshipStatus === userRelationshipStatus.FRIEND) {
-          unorderedFriends.push({ id, username, relationshipStatus });
-        } else if (
-          relationshipStatus === userRelationshipStatus.BLOCKED_BY_VIEWER ||
-          relationshipStatus === userRelationshipStatus.BOTH_BLOCKED
-        ) {
-          blocked.push({ id, username, relationshipStatus });
-        }
+const userRelationshipsSelector: (
+  state: BaseAppState<*, *>,
+) => UserRelationships = createSelector(
+  (state: BaseAppState<*, *>) => state.userStore.userInfos,
+  (userInfos: UserInfos) => {
+    const unorderedFriendRequests = [];
+    const unorderedFriends = [];
+    const blocked = [];
+    for (const userID in userInfos) {
+      const userInfo = userInfos[userID];
+      const { id, username, relationshipStatus } = userInfo;
+      if (!username) {
+        continue;
       }
-      const friendRequests = _orderBy('relationshipStatus')('desc')(
-        unorderedFriendRequests,
-      );
-      const friends = friendRequests.concat(unorderedFriends);
+      if (
+        relationshipStatus === userRelationshipStatus.REQUEST_RECEIVED ||
+        relationshipStatus === userRelationshipStatus.REQUEST_SENT
+      ) {
+        unorderedFriendRequests.push({ id, username, relationshipStatus });
+      } else if (relationshipStatus === userRelationshipStatus.FRIEND) {
+        unorderedFriends.push({ id, username, relationshipStatus });
+      } else if (
+        relationshipStatus === userRelationshipStatus.BLOCKED_BY_VIEWER ||
+        relationshipStatus === userRelationshipStatus.BOTH_BLOCKED
+      ) {
+        blocked.push({ id, username, relationshipStatus });
+      }
+    }
+    const friendRequests = _orderBy('relationshipStatus')('desc')(
+      unorderedFriendRequests,
+    );
+    const friends = friendRequests.concat(unorderedFriends);
 
-      return { friends, blocked };
-    },
-  );
+    return { friends, blocked };
+  },
+);
 
 export { userRelationshipsSelector };
diff --git a/lib/selectors/thread-selectors.js b/lib/selectors/thread-selectors.js
--- a/lib/selectors/thread-selectors.js
+++ b/lib/selectors/thread-selectors.js
@@ -55,18 +55,19 @@
 
 const _mapValuesWithKeys = _mapValues.convert({ cap: false });
 
-type ThreadInfoSelectorType = (state: BaseAppState<*>) => {
+type ThreadInfoSelectorType = (state: BaseAppState<*, *>) => {
   +[id: string]: ThreadInfo,
 };
 const threadInfoSelector: ThreadInfoSelectorType = createObjectSelector(
-  (state: BaseAppState<*>) => state.threadStore.threadInfos,
-  (state: BaseAppState<*>) => state.currentUserInfo && state.currentUserInfo.id,
-  (state: BaseAppState<*>) => state.userStore.userInfos,
+  (state: BaseAppState<*, *>) => state.threadStore.threadInfos,
+  (state: BaseAppState<*, *>) =>
+    state.currentUserInfo && state.currentUserInfo.id,
+  (state: BaseAppState<*, *>) => state.userStore.userInfos,
   threadInfoFromRawThreadInfo,
 );
 
 const communityThreadSelector: (
-  state: BaseAppState<*>,
+  state: BaseAppState<*, *>,
 ) => $ReadOnlyArray<ThreadInfo> = createSelector(
   threadInfoSelector,
   (threadInfos: { +[id: string]: ThreadInfo }) => {
@@ -83,7 +84,7 @@
 );
 
 const canBeOnScreenThreadInfos: (
-  state: BaseAppState<*>,
+  state: BaseAppState<*, *>,
 ) => $ReadOnlyArray<ThreadInfo> = createSelector(
   threadInfoSelector,
   (threadInfos: { +[id: string]: ThreadInfo }) => {
@@ -100,7 +101,7 @@
 );
 
 const onScreenThreadInfos: (
-  state: BaseAppState<*>,
+  state: BaseAppState<*, *>,
 ) => $ReadOnlyArray<ThreadInfo> = createSelector(
   filteredThreadIDsSelector,
   canBeOnScreenThreadInfos,
@@ -117,7 +118,7 @@
 );
 
 const onScreenEntryEditableThreadInfos: (
-  state: BaseAppState<*>,
+  state: BaseAppState<*, *>,
 ) => $ReadOnlyArray<ThreadInfo> = createSelector(
   onScreenThreadInfos,
   (threadInfos: $ReadOnlyArray<ThreadInfo>) =>
@@ -126,24 +127,25 @@
     ),
 );
 
-const entryInfoSelector: (state: BaseAppState<*>) => {
+const entryInfoSelector: (state: BaseAppState<*, *>) => {
   +[id: string]: EntryInfo,
 } = createObjectSelector(
-  (state: BaseAppState<*>) => state.entryStore.entryInfos,
-  (state: BaseAppState<*>) => state.currentUserInfo && state.currentUserInfo.id,
-  (state: BaseAppState<*>) => state.userStore.userInfos,
+  (state: BaseAppState<*, *>) => state.entryStore.entryInfos,
+  (state: BaseAppState<*, *>) =>
+    state.currentUserInfo && state.currentUserInfo.id,
+  (state: BaseAppState<*, *>) => state.userStore.userInfos,
   createEntryInfo,
 );
 
 // "current" means within startDate/endDate range, not deleted, and in
 // onScreenThreadInfos
-const currentDaysToEntries: (state: BaseAppState<*>) => {
+const currentDaysToEntries: (state: BaseAppState<*, *>) => {
   +[dayString: string]: EntryInfo[],
 } = createSelector(
   entryInfoSelector,
-  (state: BaseAppState<*>) => state.entryStore.daysToEntries,
-  (state: BaseAppState<*>) => state.navInfo.startDate,
-  (state: BaseAppState<*>) => state.navInfo.endDate,
+  (state: BaseAppState<*, *>) => state.entryStore.daysToEntries,
+  (state: BaseAppState<*, *>) => state.navInfo.startDate,
+  (state: BaseAppState<*, *>) => state.navInfo.endDate,
   onScreenThreadInfos,
   includeDeletedSelector,
   (
@@ -179,7 +181,7 @@
   },
 );
 
-const childThreadInfos: (state: BaseAppState<*>) => {
+const childThreadInfos: (state: BaseAppState<*, *>) => {
   +[id: string]: $ReadOnlyArray<ThreadInfo>,
 } = createSelector(
   threadInfoSelector,
@@ -214,11 +216,11 @@
   return null;
 }
 
-const sidebarInfoSelector: (state: BaseAppState<*>) => {
+const sidebarInfoSelector: (state: BaseAppState<*, *>) => {
   +[id: string]: $ReadOnlyArray<SidebarInfo>,
 } = createObjectSelector(
   childThreadInfos,
-  (state: BaseAppState<*>) => state.messageStore,
+  (state: BaseAppState<*, *>) => state.messageStore,
   (childThreads: $ReadOnlyArray<ThreadInfo>, messageStore: MessageStore) => {
     const sidebarInfos = [];
     for (const childThreadInfo of childThreads) {
@@ -248,8 +250,8 @@
   },
 );
 
-const unreadCount: (state: BaseAppState<*>) => number = createSelector(
-  (state: BaseAppState<*>) => state.threadStore.threadInfos,
+const unreadCount: (state: BaseAppState<*, *>) => number = createSelector(
+  (state: BaseAppState<*, *>) => state.threadStore.threadInfos,
   (threadInfos: { +[id: string]: RawThreadInfo }): number =>
     values(threadInfos).filter(
       threadInfo =>
@@ -257,9 +259,9 @@
     ).length,
 );
 
-const unreadBackgroundCount: (state: BaseAppState<*>) => number =
+const unreadBackgroundCount: (state: BaseAppState<*, *>) => number =
   createSelector(
-    (state: BaseAppState<*>) => state.threadStore.threadInfos,
+    (state: BaseAppState<*, *>) => state.threadStore.threadInfos,
     (threadInfos: { +[id: string]: RawThreadInfo }): number =>
       values(threadInfos).filter(
         threadInfo =>
@@ -270,7 +272,7 @@
 
 const baseAncestorThreadInfos = (threadID: string) =>
   createSelector(
-    (state: BaseAppState<*>) => threadInfoSelector(state),
+    (state: BaseAppState<*, *>) => threadInfoSelector(state),
     (threadInfos: {
       +[id: string]: ThreadInfo,
     }): $ReadOnlyArray<ThreadInfo> => {
@@ -287,13 +289,13 @@
 
 const ancestorThreadInfos: (
   threadID: string,
-) => (state: BaseAppState<*>) => $ReadOnlyArray<ThreadInfo> = _memoize(
+) => (state: BaseAppState<*, *>) => $ReadOnlyArray<ThreadInfo> = _memoize(
   baseAncestorThreadInfos,
 );
 
 const baseOtherUsersButNoOtherAdmins = (threadID: string) =>
   createSelector(
-    (state: BaseAppState<*>) => state.threadStore.threadInfos[threadID],
+    (state: BaseAppState<*, *>) => state.threadStore.threadInfos[threadID],
     relativeMemberInfoSelectorForMembersOfThread(threadID),
     (
       threadInfo: ?RawThreadInfo,
@@ -324,7 +326,7 @@
 
 const otherUsersButNoOtherAdmins: (
   threadID: string,
-) => (state: BaseAppState<*>) => boolean = _memoize(
+) => (state: BaseAppState<*, *>) => boolean = _memoize(
   baseOtherUsersButNoOtherAdmins,
 );
 
@@ -359,17 +361,17 @@
   return mostRecent ? mostRecent.threadID : null;
 }
 
-const mostRecentlyReadThreadSelector: (state: BaseAppState<*>) => ?string =
+const mostRecentlyReadThreadSelector: (state: BaseAppState<*, *>) => ?string =
   createSelector(
-    (state: BaseAppState<*>) => state.messageStore,
-    (state: BaseAppState<*>) => state.threadStore.threadInfos,
+    (state: BaseAppState<*, *>) => state.messageStore,
+    (state: BaseAppState<*, *>) => state.threadStore.threadInfos,
     mostRecentlyReadThread,
   );
 
-const threadInfoFromSourceMessageIDSelector: (state: BaseAppState<*>) => {
+const threadInfoFromSourceMessageIDSelector: (state: BaseAppState<*, *>) => {
   +[id: string]: ThreadInfo,
 } = createSelector(
-  (state: BaseAppState<*>) => state.threadStore.threadInfos,
+  (state: BaseAppState<*, *>) => state.threadStore.threadInfos,
   threadInfoSelector,
   (
     rawThreadInfos: { +[id: string]: RawThreadInfo },
@@ -423,8 +425,8 @@
   containingThreadID: ?string,
 ) =>
   createSelector(
-    (state: BaseAppState<*>) => threadInfoSelector(state)[threadID],
-    (state: BaseAppState<*>) =>
+    (state: BaseAppState<*, *>) => threadInfoSelector(state)[threadID],
+    (state: BaseAppState<*, *>) =>
       containingThreadID ? threadInfoSelector(state)[containingThreadID] : null,
     (threadInfo: ThreadInfo, containingThreadInfo: ?ThreadInfo) => {
       return () => {
@@ -440,7 +442,7 @@
 const savedEmojiAvatarSelectorForThread: (
   threadID: string,
   containingThreadID: ?string,
-) => (state: BaseAppState<*>) => () => ClientEmojiAvatar = _memoize(
+) => (state: BaseAppState<*, *>) => () => ClientEmojiAvatar = _memoize(
   baseSavedEmojiAvatarSelectorForThread,
 );
 
diff --git a/lib/selectors/user-selectors.js b/lib/selectors/user-selectors.js
--- a/lib/selectors/user-selectors.js
+++ b/lib/selectors/user-selectors.js
@@ -101,25 +101,25 @@
     return () => emptyArray;
   }
   return createSelector(
-    (state: BaseAppState<*>) => state.threadStore.threadInfos[threadID],
-    (state: BaseAppState<*>) =>
+    (state: BaseAppState<*, *>) => state.threadStore.threadInfos[threadID],
+    (state: BaseAppState<*, *>) =>
       state.currentUserInfo && state.currentUserInfo.id,
-    (state: BaseAppState<*>) => state.userStore.userInfos,
+    (state: BaseAppState<*, *>) => state.userStore.userInfos,
     getRelativeMemberInfos,
   );
 };
 
 const relativeMemberInfoSelectorForMembersOfThread: (
   threadID: ?string,
-) => (state: BaseAppState<*>) => $ReadOnlyArray<RelativeMemberInfo> = _memoize(
-  baseRelativeMemberInfoSelectorForMembersOfThread,
-);
+) => (state: BaseAppState<*, *>) => $ReadOnlyArray<RelativeMemberInfo> =
+  _memoize(baseRelativeMemberInfoSelectorForMembersOfThread);
 
-const userInfoSelectorForPotentialMembers: (state: BaseAppState<*>) => {
+const userInfoSelectorForPotentialMembers: (state: BaseAppState<*, *>) => {
   [id: string]: AccountUserInfo,
 } = createSelector(
-  (state: BaseAppState<*>) => state.userStore.userInfos,
-  (state: BaseAppState<*>) => state.currentUserInfo && state.currentUserInfo.id,
+  (state: BaseAppState<*, *>) => state.userStore.userInfos,
+  (state: BaseAppState<*, *>) =>
+    state.currentUserInfo && state.currentUserInfo.id,
   (
     userInfos: UserInfos,
     currentUserID: ?string,
@@ -153,22 +153,22 @@
 }
 
 const userSearchIndexForPotentialMembers: (
-  state: BaseAppState<*>,
+  state: BaseAppState<*, *>,
 ) => SearchIndex = createSelector(
   userInfoSelectorForPotentialMembers,
   searchIndexFromUserInfos,
 );
 
-const isLoggedIn = (state: BaseAppState<*>): boolean =>
+const isLoggedIn = (state: BaseAppState<*, *>): boolean =>
   !!(
     state.currentUserInfo &&
     !state.currentUserInfo.anonymous &&
     state.dataLoaded
   );
 
-const userStoreSearchIndex: (state: BaseAppState<*>) => SearchIndex =
+const userStoreSearchIndex: (state: BaseAppState<*, *>) => SearchIndex =
   createSelector(
-    (state: BaseAppState<*>) => state.userStore.userInfos,
+    (state: BaseAppState<*, *>) => state.userStore.userInfos,
     (userInfos: UserInfos) => {
       const searchIndex = new SearchIndex();
       for (const id in userInfos) {
@@ -183,7 +183,7 @@
   );
 
 const usersWithPersonalThreadSelector: (
-  state: BaseAppState<*>,
+  state: BaseAppState<*, *>,
 ) => $ReadOnlySet<string> = createSelector(
   state => state.currentUserInfo && state.currentUserInfo.id,
   state => state.threadStore.threadInfos,
@@ -208,9 +208,9 @@
 );
 
 const savedEmojiAvatarSelectorForCurrentUser: (
-  state: BaseAppState<*>,
+  state: BaseAppState<*, *>,
 ) => () => ClientEmojiAvatar = createSelector(
-  (state: BaseAppState<*>) => state.currentUserInfo && state.currentUserInfo,
+  (state: BaseAppState<*, *>) => state.currentUserInfo && state.currentUserInfo,
   (currentUser: ?CurrentUserInfo) => {
     return () => {
       let userAvatar = getAvatarForUser(currentUser);
diff --git a/lib/types/keyserver-types.js b/lib/types/keyserver-types.js
--- a/lib/types/keyserver-types.js
+++ b/lib/types/keyserver-types.js
@@ -1,26 +1,42 @@
 // @flow
 
-import t, { type TInterface } from 'tcomb';
+import t, { type TInterface, type TType } from 'tcomb';
 
 import { tShape } from '../utils/validation-utils.js';
 
 // Once we start using the cookie field on web,
 // the cookie field type should be changed to string | null.
 // See https://linear.app/comm/issue/ENG-4347/stop-using-browser-cookies
-export type KeyserverInfo = {
+export type BaseKeyserverInfo = {
   +cookie?: ?string,
+  ...
 };
 
-export type KeyserverStore = {
-  +keyserverInfos: { +[key: string]: KeyserverInfo },
+export type WebKeyserverInfo = {
+  ...$Exact<BaseKeyserverInfo>,
+  +sessionID: ?string,
 };
 
-export const keyserverInfoValidator: TInterface<KeyserverInfo> =
-  tShape<KeyserverInfo>({
+export type NativeKeyserverInfo = {
+  ...$Exact<BaseKeyserverInfo>,
+  +sessionID?: void,
+};
+
+export type KeyserverInfo = NativeKeyserverInfo | WebKeyserverInfo;
+
+export type KeyserverStore<KeyserverInfoType: KeyserverInfo> = {
+  +keyserverInfos: { +[key: string]: KeyserverInfoType },
+};
+
+export const webKeyserverInfoValidator: TInterface<WebKeyserverInfo> =
+  tShape<WebKeyserverInfo>({
     cookie: t.maybe(t.String),
+    sessionID: t.maybe(t.String),
   });
 
-export const keyserverStoreValidator: TInterface<KeyserverStore> =
-  tShape<KeyserverStore>({
-    keyserverInfos: t.dict(t.String, keyserverInfoValidator),
+export const keyserverStoreValidator = <T: KeyserverInfo>(
+  typ: TType<T>,
+): TInterface<KeyserverStore<T>> =>
+  tShape<KeyserverStore<T>>({
+    keyserverInfos: t.dict(t.String, typ),
   });
diff --git a/lib/types/redux-types.js b/lib/types/redux-types.js
--- a/lib/types/redux-types.js
+++ b/lib/types/redux-types.js
@@ -39,7 +39,12 @@
   CalendarThreadFilter,
   SetCalendarDeletedFilterPayload,
 } from './filter-types.js';
-import type { KeyserverStore } from './keyserver-types.js';
+import type {
+  KeyserverStore,
+  NativeKeyserverInfo,
+  WebKeyserverInfo,
+  KeyserverInfo,
+} from './keyserver-types.js';
 import type { LifecycleState } from './lifecycle-state-types.js';
 import type {
   FetchInviteLinksResponse,
@@ -114,7 +119,10 @@
 import type { Shape } from '../types/core.js';
 import type { NotifPermissionAlertInfo } from '../utils/push-alerts.js';
 
-export type BaseAppState<NavInfo: BaseNavInfo> = {
+export type BaseAppState<
+  NavInfo: BaseNavInfo,
+  KeyserverInfoType: KeyserverInfo,
+> = {
   navInfo: NavInfo,
   currentUserInfo: ?CurrentUserInfo,
   draftStore: DraftStore,
@@ -139,17 +147,17 @@
   +commServicesAccessToken: ?string,
   +inviteLinksStore: InviteLinksStore,
   +lastCommunicatedPlatformDetails: LastCommunicatedPlatformDetails,
-  +keyserverStore: KeyserverStore,
+  +keyserverStore: KeyserverStore<KeyserverInfoType>,
   ...
 };
 
 // Web JS runtime doesn't have access to the cookie for security reasons.
 // Native JS doesn't have a sessionID because the cookieID is used instead.
-export type NativeAppState = BaseAppState<*> & {
+export type NativeAppState = BaseAppState<*, NativeKeyserverInfo> & {
   sessionID?: void,
   ...
 };
-export type WebAppState = BaseAppState<*> & {
+export type WebAppState = BaseAppState<*, WebKeyserverInfo> & {
   sessionID: ?string,
   cryptoStore: CryptoStore,
   pushApiPublicKey: ?string,
@@ -474,7 +482,7 @@
     }
   | {
       +type: 'persist/REHYDRATE',
-      +payload: ?BaseAppState<*>,
+      +payload: ?BaseAppState<*, *>,
     }
   | {
       +type: 'FETCH_MESSAGES_BEFORE_CURSOR_STARTED',
diff --git a/lib/utils/sanitization.js b/lib/utils/sanitization.js
--- a/lib/utils/sanitization.js
+++ b/lib/utils/sanitization.js
@@ -295,6 +295,7 @@
   state: AppState,
   redactionHelpers: RedactionHelpers,
 ): AppState {
+  // $FlowIssue[incompatible-type]
   const keyserverInfos = { ...state.keyserverStore.keyserverInfos };
   for (const key in keyserverInfos) {
     if (keyserverInfos[key].cookie === undefined) {
@@ -303,6 +304,7 @@
     keyserverInfos[key] = { ...keyserverInfos[key], cookie: null };
   }
   const keyserverStore = { ...state.keyserverStore, keyserverInfos };
+  // $FlowIssue[incompatible-type]
   state = { ...state, keyserverStore };
 
   if (state.deviceToken !== undefined && state.deviceToken !== null) {
diff --git a/native/redux/state-types.js b/native/redux/state-types.js
--- a/native/redux/state-types.js
+++ b/native/redux/state-types.js
@@ -8,7 +8,10 @@
 import type { EnabledApps } from 'lib/types/enabled-apps.js';
 import type { EntryStore } from 'lib/types/entry-types.js';
 import type { CalendarFilter } from 'lib/types/filter-types.js';
-import type { KeyserverStore } from 'lib/types/keyserver-types.js';
+import type {
+  KeyserverStore,
+  NativeKeyserverInfo,
+} from 'lib/types/keyserver-types.js';
 import type { LifecycleState } from 'lib/types/lifecycle-state-types.js';
 import type { InviteLinksStore } from 'lib/types/link-types.js';
 import type { LoadingStatus } from 'lib/types/loading-types.js';
@@ -61,5 +64,5 @@
   +commServicesAccessToken: ?string,
   +inviteLinksStore: InviteLinksStore,
   +lastCommunicatedPlatformDetails: LastCommunicatedPlatformDetails,
-  +keyserverStore: KeyserverStore,
+  +keyserverStore: KeyserverStore<NativeKeyserverInfo>,
 };
diff --git a/web/redux/redux-setup.js b/web/redux/redux-setup.js
--- a/web/redux/redux-setup.js
+++ b/web/redux/redux-setup.js
@@ -23,7 +23,10 @@
 import type { EnabledApps } from 'lib/types/enabled-apps.js';
 import type { EntryStore } from 'lib/types/entry-types.js';
 import { type CalendarFilter } from 'lib/types/filter-types.js';
-import type { KeyserverStore } from 'lib/types/keyserver-types.js';
+import type {
+  KeyserverStore,
+  WebKeyserverInfo,
+} from 'lib/types/keyserver-types.js';
 import type { LifecycleState } from 'lib/types/lifecycle-state-types.js';
 import type { InviteLinksStore } from 'lib/types/link-types.js';
 import type { LoadingStatus } from 'lib/types/loading-types.js';
@@ -100,7 +103,7 @@
   +commServicesAccessToken: ?string,
   +inviteLinksStore: InviteLinksStore,
   +lastCommunicatedPlatformDetails: LastCommunicatedPlatformDetails,
-  +keyserverStore: KeyserverStore,
+  +keyserverStore: KeyserverStore<WebKeyserverInfo>,
 };
 
 export type Action =