diff --git a/lib/components/chat-mention-context.react.js b/lib/components/chat-mention-context.react.js
new file mode 100644
--- /dev/null
+++ b/lib/components/chat-mention-context.react.js
@@ -0,0 +1,111 @@
+// @flow
+
+import invariant from 'invariant';
+import * as React from 'react';
+
+import genesis from '../facts/genesis.js';
+import SentencePrefixSearchIndex from '../shared/sentence-prefix-search-index.js';
+import {
+  useChatMentionCandidatesObjAndUtils,
+  useChatMentionSearchIndex,
+} from '../shared/thread-utils.js';
+import type {
+  ChatMentionCandidates,
+  ChatMentionCandidatesObj,
+  ThreadInfo,
+} from '../types/thread-types.js';
+
+type Props = {
+  +children: React.Node,
+};
+type ChatMentionContextType = {
+  +getChatMentionSearchIndex: (
+    threadInfo: ThreadInfo,
+  ) => SentencePrefixSearchIndex,
+  communityThreadIDForGenesisThreads: { +[id: string]: string },
+  chatMentionCandidatesObj: ChatMentionCandidatesObj,
+};
+
+const emptySearchIndex = new SentencePrefixSearchIndex();
+const ChatMentionContext: React.Context<?ChatMentionContextType> =
+  React.createContext<?ChatMentionContextType>({
+    getChatMentionSearchIndex: () => emptySearchIndex,
+    communityThreadIDForGenesisThreads: {},
+    chatMentionCandidatesObj: {},
+  });
+
+function ChatMentionProvider(props: Props): React.Node {
+  const { children } = props;
+
+  const { communityThreadIDForGenesisThreads, chatMentionCandidatesObj } =
+    useChatMentionCandidatesObjAndUtils();
+  const searchIndices = useChatMentionSearchIndex(chatMentionCandidatesObj);
+
+  const getChatMentionSearchIndex = React.useCallback(
+    (threadInfo: ThreadInfo) => {
+      if (threadInfo.community === genesis.id) {
+        return searchIndices[communityThreadIDForGenesisThreads[threadInfo.id]];
+      }
+      return searchIndices[threadInfo.community ?? threadInfo.id];
+    },
+    [communityThreadIDForGenesisThreads, searchIndices],
+  );
+
+  const value = React.useMemo(
+    () => ({
+      getChatMentionSearchIndex,
+      communityThreadIDForGenesisThreads,
+      chatMentionCandidatesObj,
+    }),
+    [
+      getChatMentionSearchIndex,
+      communityThreadIDForGenesisThreads,
+      chatMentionCandidatesObj,
+    ],
+  );
+
+  return (
+    <ChatMentionContext.Provider value={value}>
+      {children}
+    </ChatMentionContext.Provider>
+  );
+}
+
+function useChatMentionContext(): ChatMentionContextType {
+  const context = React.useContext(ChatMentionContext);
+  invariant(context, 'ChatMentionContext not found');
+
+  return context;
+}
+
+function useThreadChatMentionCandidates(
+  threadInfo: ThreadInfo,
+): ChatMentionCandidates {
+  const { communityThreadIDForGenesisThreads, chatMentionCandidatesObj } =
+    useChatMentionContext();
+  return React.useMemo(() => {
+    let communityID,
+      result = {};
+    if (threadInfo.community === genesis.id) {
+      communityID = communityThreadIDForGenesisThreads[threadInfo.id];
+    } else {
+      communityID = threadInfo.community ?? threadInfo.id;
+    }
+    if (chatMentionCandidatesObj[communityID]) {
+      result = { ...chatMentionCandidatesObj[communityID] };
+    }
+    delete result[threadInfo.id];
+    return result;
+  }, [
+    chatMentionCandidatesObj,
+    communityThreadIDForGenesisThreads,
+    threadInfo.community,
+    threadInfo.id,
+  ]);
+}
+
+export {
+  ChatMentionProvider,
+  useChatMentionContext,
+  useThreadChatMentionCandidates,
+};
diff --git a/lib/shared/thread-utils.js b/lib/shared/thread-utils.js
--- a/lib/shared/thread-utils.js
+++ b/lib/shared/thread-utils.js
@@ -1763,37 +1763,6 @@
   };
 }
 
-function useChatMentionCandidatesObj(): ChatMentionCandidatesObj {
-  const { chatMentionCandidatesObj } = useChatMentionCandidatesObjAndUtils();
-  return chatMentionCandidatesObj;
-}
-
-function useThreadChatMentionCandidates(
-  threadInfo: ThreadInfo,
-): ChatMentionCandidates {
-  const { chatMentionCandidatesObj, communityThreadIDForGenesisThreads } =
-    useChatMentionCandidatesObjAndUtils();
-  return React.useMemo(() => {
-    let communityID,
-      result = {};
-    if (threadInfo.community === genesis.id) {
-      communityID = communityThreadIDForGenesisThreads[threadInfo.id];
-    } else {
-      communityID = threadInfo.community ?? threadInfo.id;
-    }
-    if (chatMentionCandidatesObj[communityID]) {
-      result = { ...chatMentionCandidatesObj[communityID] };
-    }
-    delete result[threadInfo.id];
-    return result;
-  }, [
-    chatMentionCandidatesObj,
-    communityThreadIDForGenesisThreads,
-    threadInfo.community,
-    threadInfo.id,
-  ]);
-}
-
 function useUserProfileThreadInfo(userInfo: ?UserInfo): ?UserProfileThreadInfo {
   const userID = userInfo?.id;
   const username = userInfo?.username;
@@ -1852,10 +1821,11 @@
   ]);
 }
 
-function useChatMentionSearchIndex(): {
+function useChatMentionSearchIndex(
+  chatMentionCandidatesObj: ChatMentionCandidatesObj,
+): {
   +[id: string]: SentencePrefixSearchIndex,
 } {
-  const { chatMentionCandidatesObj } = useChatMentionCandidatesObjAndUtils();
   return React.useMemo(() => {
     const result = {};
     for (const communityThreadID in chatMentionCandidatesObj) {
@@ -1880,22 +1850,6 @@
   }, [chatMentionCandidatesObj]);
 }
 
-function useThreadChatMentionSearchIndex(
-  threadInfo: ThreadInfo,
-): SentencePrefixSearchIndex {
-  const chatMentionCandidatesSearchIndex = useChatMentionSearchIndex();
-  const { communityThreadIDForGenesisThreads } =
-    useChatMentionCandidatesObjAndUtils();
-  if (threadInfo.community === genesis.id) {
-    return chatMentionCandidatesSearchIndex[
-      communityThreadIDForGenesisThreads[threadInfo.id]
-    ];
-  }
-  return chatMentionCandidatesSearchIndex[
-    threadInfo.community ?? threadInfo.id
-  ];
-}
-
 export {
   threadHasPermission,
   viewerIsMember,
@@ -1961,8 +1915,7 @@
   useRoleMemberCountsForCommunity,
   useRoleUserSurfacedPermissions,
   getThreadsToDeleteText,
-  useChatMentionCandidatesObj,
-  useThreadChatMentionCandidates,
   useUserProfileThreadInfo,
-  useThreadChatMentionSearchIndex,
+  useChatMentionCandidatesObjAndUtils,
+  useChatMentionSearchIndex,
 };
diff --git a/native/chat/chat-input-bar.react.js b/native/chat/chat-input-bar.react.js
--- a/native/chat/chat-input-bar.react.js
+++ b/native/chat/chat-input-bar.react.js
@@ -31,6 +31,10 @@
   joinThread,
   newThreadActionTypes,
 } from 'lib/actions/thread-actions.js';
+import {
+  useChatMentionContext,
+  useThreadChatMentionCandidates,
+} from 'lib/components/chat-mention-context.react.js';
 import { createLoadingStatusSelector } from 'lib/selectors/loading-selectors.js';
 import { threadInfoSelector } from 'lib/selectors/thread-selectors.js';
 import { userStoreMentionSearchIndex } from 'lib/selectors/user-selectors.js';
@@ -58,8 +62,6 @@
   threadActualMembers,
   checkIfDefaultMembersAreVoiced,
   draftKeyFromThreadID,
-  useThreadChatMentionCandidates,
-  useThreadChatMentionSearchIndex,
 } from 'lib/shared/thread-utils.js';
 import type { CalendarQuery } from 'lib/types/entry-types.js';
 import type { LoadingStatus } from 'lib/types/loading-types.js';
@@ -1266,9 +1268,8 @@
 
   const userSearchIndex = useSelector(userStoreMentionSearchIndex);
 
-  const chatMentionSearchIndex = useThreadChatMentionSearchIndex(
-    props.threadInfo,
-  );
+  const { getChatMentionSearchIndex } = useChatMentionContext();
+  const chatMentionSearchIndex = getChatMentionSearchIndex(props.threadInfo);
 
   const { parentThreadID } = props.threadInfo;
   const parentThreadInfo = useSelector(state =>
diff --git a/native/chat/message-list-types.js b/native/chat/message-list-types.js
--- a/native/chat/message-list-types.js
+++ b/native/chat/message-list-types.js
@@ -4,7 +4,7 @@
 import invariant from 'invariant';
 import * as React from 'react';
 
-import { useThreadChatMentionCandidates } from 'lib/shared/thread-utils.js';
+import { useThreadChatMentionCandidates } from 'lib/components/chat-mention-context.react.js';
 import type { ThreadInfo } from 'lib/types/thread-types.js';
 import { type UserInfo } from 'lib/types/user-types.js';
 
diff --git a/native/chat/message-preview.react.js b/native/chat/message-preview.react.js
--- a/native/chat/message-preview.react.js
+++ b/native/chat/message-preview.react.js
@@ -4,8 +4,8 @@
 import * as React from 'react';
 import { Text } from 'react-native';
 
+import { useThreadChatMentionCandidates } from 'lib/components/chat-mention-context.react.js';
 import { useMessagePreview } from 'lib/shared/message-utils.js';
-import { useThreadChatMentionCandidates } from 'lib/shared/thread-utils.js';
 import { type MessageInfo } from 'lib/types/message-types.js';
 import { type ThreadInfo } from 'lib/types/thread-types.js';
 
diff --git a/native/chat/sidebar-input-bar-height-measurer.react.js b/native/chat/sidebar-input-bar-height-measurer.react.js
--- a/native/chat/sidebar-input-bar-height-measurer.react.js
+++ b/native/chat/sidebar-input-bar-height-measurer.react.js
@@ -3,8 +3,8 @@
 import * as React from 'react';
 import { View, StyleSheet } from 'react-native';
 
+import { useThreadChatMentionCandidates } from 'lib/components/chat-mention-context.react.js';
 import { useLoggedInUserInfo } from 'lib/hooks/account-hooks.js';
-import { useThreadChatMentionCandidates } from 'lib/shared/thread-utils.js';
 
 import { DummyChatInputBar } from './chat-input-bar.react.js';
 import { useMessageListScreenWidth } from './composed-message-width.js';
diff --git a/native/chat/sidebar-navigation.js b/native/chat/sidebar-navigation.js
--- a/native/chat/sidebar-navigation.js
+++ b/native/chat/sidebar-navigation.js
@@ -3,12 +3,12 @@
 import invariant from 'invariant';
 import * as React from 'react';
 
+import { useThreadChatMentionCandidates } from 'lib/components/chat-mention-context.react.js';
 import { ENSCacheContext } from 'lib/components/ens-cache-provider.react.js';
 import { useLoggedInUserInfo } from 'lib/hooks/account-hooks.js';
 import {
   createPendingSidebar,
   createUnresolvedPendingSidebar,
-  useThreadChatMentionCandidates,
 } from 'lib/shared/thread-utils.js';
 import type {
   ThreadInfo,
diff --git a/native/chat/utils.js b/native/chat/utils.js
--- a/native/chat/utils.js
+++ b/native/chat/utils.js
@@ -4,13 +4,11 @@
 import * as React from 'react';
 import Animated from 'react-native-reanimated';
 
+import { useThreadChatMentionCandidates } from 'lib/components/chat-mention-context.react.js';
 import { useLoggedInUserInfo } from 'lib/hooks/account-hooks.js';
 import { colorIsDark } from 'lib/shared/color-utils.js';
 import { messageKey } from 'lib/shared/message-utils.js';
-import {
-  viewerIsMember,
-  useThreadChatMentionCandidates,
-} from 'lib/shared/thread-utils.js';
+import { viewerIsMember } from 'lib/shared/thread-utils.js';
 import type { ThreadInfo } from 'lib/types/thread-types.js';
 
 import { clusterEndHeight } from './chat-constants.js';
diff --git a/native/root.react.js b/native/root.react.js
--- a/native/root.react.js
+++ b/native/root.react.js
@@ -19,6 +19,7 @@
 import { Provider } from 'react-redux';
 import { PersistGate as ReduxPersistGate } from 'redux-persist/es/integration/react.js';
 
+import { ChatMentionProvider } from 'lib/components/chat-mention-context.react.js';
 import { EditUserAvatarProvider } from 'lib/components/edit-user-avatar-provider.react.js';
 import { ENSCacheProvider } from 'lib/components/ens-cache-provider.react.js';
 import IntegrityHandler from 'lib/components/integrity-handler.react.js';
@@ -259,7 +260,9 @@
         <BottomSheetModalProvider>
           <ChatContextProvider>
             <DeepLinksContextProvider>
-              <RootNavigator />
+              <ChatMentionProvider>
+                <RootNavigator />
+              </ChatMentionProvider>
             </DeepLinksContextProvider>
           </ChatContextProvider>
           <NavigationHandler />
diff --git a/web/chat/chat-input-bar.react.js b/web/chat/chat-input-bar.react.js
--- a/web/chat/chat-input-bar.react.js
+++ b/web/chat/chat-input-bar.react.js
@@ -9,6 +9,10 @@
   joinThread,
   newThreadActionTypes,
 } from 'lib/actions/thread-actions.js';
+import {
+  useChatMentionContext,
+  useThreadChatMentionCandidates,
+} from 'lib/components/chat-mention-context.react.js';
 import SWMansionIcon from 'lib/components/SWMansionIcon.react.js';
 import { createLoadingStatusSelector } from 'lib/selectors/loading-selectors.js';
 import { threadInfoSelector } from 'lib/selectors/thread-selectors.js';
@@ -28,8 +32,6 @@
   threadFrozenDueToViewerBlock,
   threadActualMembers,
   checkIfDefaultMembersAreVoiced,
-  useThreadChatMentionCandidates,
-  useThreadChatMentionSearchIndex,
 } from 'lib/shared/thread-utils.js';
 import type { CalendarQuery } from 'lib/types/entry-types.js';
 import type { LoadingStatus } from 'lib/types/loading-types.js';
@@ -581,9 +583,8 @@
     const dispatchActionPromise = useDispatchActionPromise();
     const callJoinThread = useServerCall(joinThread);
     const userSearchIndex = useSelector(userStoreMentionSearchIndex);
-    const chatMentionSearchIndex = useThreadChatMentionSearchIndex(
-      props.threadInfo,
-    );
+    const { getChatMentionSearchIndex } = useChatMentionContext();
+    const chatMentionSearchIndex = getChatMentionSearchIndex(props.threadInfo);
 
     const { parentThreadID } = props.threadInfo;
     const parentThreadInfo = useSelector(state =>
diff --git a/web/chat/chat-message-list.react.js b/web/chat/chat-message-list.react.js
--- a/web/chat/chat-message-list.react.js
+++ b/web/chat/chat-message-list.react.js
@@ -12,6 +12,7 @@
   fetchMostRecentMessagesActionTypes,
   fetchMostRecentMessages,
 } from 'lib/actions/message-actions.js';
+import { useThreadChatMentionCandidates } from 'lib/components/chat-mention-context.react.js';
 import { useOldestMessageServerID } from 'lib/hooks/message-hooks.js';
 import { registerFetchKey } from 'lib/reducers/loading-reducer.js';
 import {
@@ -19,10 +20,7 @@
   useMessageListData,
 } from 'lib/selectors/chat-selectors.js';
 import { messageKey } from 'lib/shared/message-utils.js';
-import {
-  threadIsPending,
-  useThreadChatMentionCandidates,
-} from 'lib/shared/thread-utils.js';
+import { threadIsPending } from 'lib/shared/thread-utils.js';
 import type { FetchMessageInfosPayload } from 'lib/types/message-types.js';
 import { threadTypes } from 'lib/types/thread-types-enum.js';
 import { type ThreadInfo } from 'lib/types/thread-types.js';
diff --git a/web/chat/message-preview.react.js b/web/chat/message-preview.react.js
--- a/web/chat/message-preview.react.js
+++ b/web/chat/message-preview.react.js
@@ -4,8 +4,8 @@
 import invariant from 'invariant';
 import * as React from 'react';
 
+import { useThreadChatMentionCandidates } from 'lib/components/chat-mention-context.react.js';
 import { useMessagePreview } from 'lib/shared/message-utils.js';
-import { useThreadChatMentionCandidates } from 'lib/shared/thread-utils.js';
 import { type MessageInfo } from 'lib/types/message-types.js';
 import { type ThreadInfo } from 'lib/types/thread-types.js';
 
diff --git a/web/components/message-result.react.js b/web/components/message-result.react.js
--- a/web/components/message-result.react.js
+++ b/web/components/message-result.react.js
@@ -3,9 +3,9 @@
 import classNames from 'classnames';
 import * as React from 'react';
 
+import { useThreadChatMentionCandidates } from 'lib/components/chat-mention-context.react.js';
 import { useStringForUser } from 'lib/hooks/ens-cache.js';
 import type { ChatMessageInfoItem } from 'lib/selectors/chat-selectors.js';
-import { useThreadChatMentionCandidates } from 'lib/shared/thread-utils.js';
 import type { ThreadInfo } from 'lib/types/thread-types.js';
 import { longAbsoluteDate } from 'lib/utils/date-utils.js';
 
diff --git a/web/modals/threads/sidebars/sidebar.react.js b/web/modals/threads/sidebars/sidebar.react.js
--- a/web/modals/threads/sidebars/sidebar.react.js
+++ b/web/modals/threads/sidebars/sidebar.react.js
@@ -3,10 +3,10 @@
 import classNames from 'classnames';
 import * as React from 'react';
 
+import { useThreadChatMentionCandidates } from 'lib/components/chat-mention-context.react.js';
 import { useModalContext } from 'lib/components/modal-provider.react.js';
 import type { ChatThreadItem } from 'lib/selectors/chat-selectors.js';
 import { useMessagePreview } from 'lib/shared/message-utils.js';
-import { useThreadChatMentionCandidates } from 'lib/shared/thread-utils.js';
 import { shortAbsoluteDate } from 'lib/utils/date-utils.js';
 import { useResolvedThreadInfo } from 'lib/utils/entity-helpers.js';
 
diff --git a/web/modals/threads/subchannels/subchannel.react.js b/web/modals/threads/subchannels/subchannel.react.js
--- a/web/modals/threads/subchannels/subchannel.react.js
+++ b/web/modals/threads/subchannels/subchannel.react.js
@@ -3,10 +3,10 @@
 import classNames from 'classnames';
 import * as React from 'react';
 
+import { useThreadChatMentionCandidates } from 'lib/components/chat-mention-context.react.js';
 import { useModalContext } from 'lib/components/modal-provider.react.js';
 import { type ChatThreadItem } from 'lib/selectors/chat-selectors.js';
 import { useMessagePreview } from 'lib/shared/message-utils.js';
-import { useThreadChatMentionCandidates } from 'lib/shared/thread-utils.js';
 import { shortAbsoluteDate } from 'lib/utils/date-utils.js';
 import { useResolvedThreadInfo } from 'lib/utils/entity-helpers.js';
 
diff --git a/web/selectors/thread-selectors.js b/web/selectors/thread-selectors.js
--- a/web/selectors/thread-selectors.js
+++ b/web/selectors/thread-selectors.js
@@ -5,12 +5,12 @@
 import { useDispatch } from 'react-redux';
 import { createSelector } from 'reselect';
 
+import { useThreadChatMentionCandidates } from 'lib/components/chat-mention-context.react.js';
 import { ENSCacheContext } from 'lib/components/ens-cache-provider.react.js';
 import { useLoggedInUserInfo } from 'lib/hooks/account-hooks.js';
 import {
   createPendingSidebar,
   threadInHomeChatList,
-  useThreadChatMentionCandidates,
 } from 'lib/shared/thread-utils.js';
 import type {
   ComposableMessageInfo,