diff --git a/lib/shared/thread-utils.js b/lib/shared/thread-utils.js
index daecead11..01810d568 100644
--- a/lib/shared/thread-utils.js
+++ b/lib/shared/thread-utils.js
@@ -1,1460 +1,1465 @@
 // @flow
 
 import invariant from 'invariant';
 import _find from 'lodash/fp/find';
 import * as React from 'react';
 import stringHash from 'string-hash';
 import tinycolor from 'tinycolor2';
 
 import {
   fetchMostRecentMessagesActionTypes,
   fetchMostRecentMessages,
 } from '../actions/message-actions';
 import {
   changeThreadMemberRolesActionTypes,
   newThreadActionTypes,
   removeUsersFromThreadActionTypes,
 } from '../actions/thread-actions';
 import { searchUsers as searchUserCall } from '../actions/user-actions';
 import ashoat from '../facts/ashoat';
 import genesis from '../facts/genesis';
 import {
   permissionLookup,
   getAllThreadPermissions,
   makePermissionsBlob,
 } from '../permissions/thread-permissions';
 import type {
   ChatThreadItem,
   ChatMessageInfoItem,
 } from '../selectors/chat-selectors';
 import { threadSearchIndex as threadSearchIndexSelector } from '../selectors/nav-selectors';
 import {
   threadInfoSelector,
   locallyUniqueToRealizedThreadIDsSelector,
 } from '../selectors/thread-selectors';
 import {
   getRelativeMemberInfos,
   usersWithPersonalThreadSelector,
 } from '../selectors/user-selectors';
 import type { CalendarQuery } from '../types/entry-types';
 import type {
   RobotextMessageInfo,
   ComposableMessageInfo,
 } from '../types/message-types';
 import { userRelationshipStatus } from '../types/relationship-types';
 import {
   type RawThreadInfo,
   type ThreadInfo,
   type ThreadPermission,
   type MemberInfo,
   type ServerThreadInfo,
   type RelativeMemberInfo,
   type ThreadCurrentUserInfo,
   type RoleInfo,
   type ServerMemberInfo,
   type ThreadPermissionsInfo,
   type ThreadType,
   type ClientNewThreadRequest,
   type NewThreadResult,
   type ChangeThreadSettingsPayload,
   threadTypes,
   threadPermissions,
   threadTypeIsCommunityRoot,
   assertThreadType,
 } from '../types/thread-types';
 import { type ClientUpdateInfo, updateTypes } from '../types/update-types';
 import type {
   GlobalAccountUserInfo,
   UserInfos,
   UserInfo,
   AccountUserInfo,
 } from '../types/user-types';
 import { useDispatchActionPromise, useServerCall } from '../utils/action-utils';
 import type { DispatchActionPromise } from '../utils/action-utils';
 import { values } from '../utils/objects';
 import { useSelector } from '../utils/redux-utils';
 import { firstLine } from '../utils/string-utils';
 import { pluralize, trimText } from '../utils/text-utils';
 import { type ParserRules } from './markdown';
 import { getMessageTitle } from './message-utils';
 import { relationshipBlockedInEitherDirection } from './relationship-utils';
 import threadWatcher from './thread-watcher';
 
 function colorIsDark(color: string): boolean {
   return tinycolor(`#${color}`).isDark();
 }
 
 const selectedThreadColorsObj = Object.freeze({
   a: '4b87aa',
   b: '5c9f5f',
   c: 'b8753d',
   d: 'aa4b4b',
   e: '6d49ab',
   f: 'c85000',
   g: '008f83',
   h: '648caa',
   i: '57697f',
   j: '575757',
 });
 
 const selectedThreadColors: $ReadOnlyArray<string> = values(
   selectedThreadColorsObj,
 );
 export type SelectedThreadColors = $Values<typeof selectedThreadColorsObj>;
 
 function generateRandomColor(): string {
   return selectedThreadColors[
     Math.floor(Math.random() * selectedThreadColors.length)
   ];
 }
 
 function generatePendingThreadColor(userIDs: $ReadOnlyArray<string>): string {
   const ids = [...userIDs].sort().join('#');
   const colorIdx = stringHash(ids) % selectedThreadColors.length;
   return selectedThreadColors[colorIdx];
 }
 
 function threadHasPermission(
   threadInfo: ?(ThreadInfo | RawThreadInfo),
   permission: ThreadPermission,
 ): boolean {
   if (!threadInfo) {
     return false;
   }
   invariant(
     !permissionsDisabledByBlock.has(permission) || threadInfo?.uiName,
     `${permission} can be disabled by a block, but threadHasPermission can't ` +
       'check for a block on RawThreadInfo. Please pass in ThreadInfo instead!',
   );
   if (!threadInfo.currentUser.permissions[permission]) {
     return false;
   }
   return threadInfo.currentUser.permissions[permission].value;
 }
 
 function viewerIsMember(threadInfo: ?(ThreadInfo | RawThreadInfo)): boolean {
   return !!(
     threadInfo &&
     threadInfo.currentUser.role !== null &&
     threadInfo.currentUser.role !== undefined
   );
 }
 
 function threadIsInHome(threadInfo: ?(ThreadInfo | RawThreadInfo)): boolean {
   return !!(threadInfo && threadInfo.currentUser.subscription.home);
 }
 
 // Can have messages
 function threadInChatList(threadInfo: ?(ThreadInfo | RawThreadInfo)): boolean {
   return (
     viewerIsMember(threadInfo) &&
     threadHasPermission(threadInfo, threadPermissions.VISIBLE)
   );
 }
 
 function threadIsTopLevel(threadInfo: ?(ThreadInfo | RawThreadInfo)): boolean {
   return threadInChatList(threadInfo) && threadIsChannel(threadInfo);
 }
 
 function threadIsChannel(threadInfo: ?(ThreadInfo | RawThreadInfo)): boolean {
   return !!(threadInfo && threadInfo.type !== threadTypes.SIDEBAR);
 }
 
+function threadIsSidebar(threadInfo: ?(ThreadInfo | RawThreadInfo)): boolean {
+  return threadInfo?.type === threadTypes.SIDEBAR;
+}
+
 function threadInBackgroundChatList(
   threadInfo: ?(ThreadInfo | RawThreadInfo),
 ): boolean {
   return threadInChatList(threadInfo) && !threadIsInHome(threadInfo);
 }
 
 function threadInHomeChatList(
   threadInfo: ?(ThreadInfo | RawThreadInfo),
 ): boolean {
   return threadInChatList(threadInfo) && threadIsInHome(threadInfo);
 }
 
 // Can have Calendar entries,
 // does appear as a top-level entity in the thread list
 function threadInFilterList(
   threadInfo: ?(ThreadInfo | RawThreadInfo),
 ): boolean {
   return (
     threadInChatList(threadInfo) &&
     !!threadInfo &&
     threadInfo.type !== threadTypes.SIDEBAR
   );
 }
 
 function userIsMember(
   threadInfo: ?(ThreadInfo | RawThreadInfo),
   userID: string,
 ): boolean {
   if (!threadInfo) {
     return false;
   }
   if (threadInfo.id === genesis.id) {
     return true;
   }
   return threadInfo.members.some(member => member.id === userID && member.role);
 }
 
 function threadActualMembers(
   memberInfos: $ReadOnlyArray<MemberInfo | RelativeMemberInfo>,
 ): $ReadOnlyArray<string> {
   return memberInfos
     .filter(memberInfo => memberInfo.role)
     .map(memberInfo => memberInfo.id);
 }
 
 function threadIsGroupChat(threadInfo: ThreadInfo | RawThreadInfo): boolean {
   return (
     threadInfo.members.filter(member => {
       if (
         member.id === ashoat.id &&
         !member.role &&
         threadInfo.community === genesis.id
       ) {
         return false;
       }
       return member.role || member.permissions[threadPermissions.VOICED]?.value;
     }).length > 2
   );
 }
 
 function threadOrParentThreadIsGroupChat(
   threadInfo: RawThreadInfo | ThreadInfo,
 ) {
   return threadInfo.members.length > 2;
 }
 
 function threadIsPending(threadID: ?string): boolean {
   return !!threadID?.startsWith('pending');
 }
 
 function getThreadOtherUsers(
   threadInfo: ThreadInfo | RawThreadInfo,
   viewerID: ?string,
 ): string[] {
   const otherUserIDs = [];
   for (const member of threadInfo.members) {
     if (!member.role || member.id === viewerID) {
       continue;
     }
     otherUserIDs.push(member.id);
   }
   return otherUserIDs;
 }
 
 function getSingleOtherUser(
   threadInfo: ThreadInfo | RawThreadInfo,
   viewerID: ?string,
 ): ?string {
   if (!viewerID) {
     return undefined;
   }
   const otherMemberIDs = getThreadOtherUsers(threadInfo, viewerID);
   if (otherMemberIDs.length !== 1) {
     return undefined;
   }
   return otherMemberIDs[0];
 }
 
 function getLocallyUniqueThreadID(
   threadType: ThreadType,
   memberIDs: $ReadOnlyArray<string>,
   sourceMessageID: ?string,
 ): string {
   const pendingThreadKey = sourceMessageID
     ? `sidebar/${sourceMessageID}`
     : [...memberIDs].sort().join('+');
   const pendingThreadTypeString = sourceMessageID ? '' : `type${threadType}/`;
   return `pending/${pendingThreadTypeString}${pendingThreadKey}`;
 }
 
 const locallyUniqueThreadIDRegex =
   'pending/(type[0-9]+/[0-9]+(\\+[0-9]+)*|sidebar/[0-9]+)';
 
 type LocallyUniqueThreadIDContents = {
   +threadType: ThreadType,
   +memberIDs: $ReadOnlyArray<string>,
   +sourceMessageID: ?string,
 };
 
 function parseLocallyUniqueThreadID(
   pendingThreadID: string,
 ): ?LocallyUniqueThreadIDContents {
   const locallyUniqueRegex = new RegExp(`^${locallyUniqueThreadIDRegex}$`);
   const pendingThreadIDMatches = locallyUniqueRegex.exec(pendingThreadID);
   if (!pendingThreadIDMatches) {
     return null;
   }
   const [threadTypeString, threadKey] = pendingThreadIDMatches[1].split('/');
   const threadType =
     threadTypeString === 'sidebar'
       ? threadTypes.SIDEBAR
       : assertThreadType(Number(threadTypeString.replace('type', '')));
   const memberIDs = threadTypeString === 'sidebar' ? [] : threadKey.split('+');
   const sourceMessageID = threadTypeString === 'sidebar' ? threadKey : null;
   return {
     threadType,
     memberIDs,
     sourceMessageID,
   };
 }
 
 type CreatePendingThreadArgs = {
   +viewerID: string,
   +threadType: ThreadType,
   +members?: $ReadOnlyArray<GlobalAccountUserInfo | UserInfo>,
   +parentThreadInfo?: ?ThreadInfo,
   +threadColor?: ?string,
   +name?: ?string,
   +sourceMessageID?: string,
 };
 
 function createPendingThread({
   viewerID,
   threadType,
   members,
   parentThreadInfo,
   threadColor,
   name,
   sourceMessageID,
 }: CreatePendingThreadArgs): ThreadInfo {
   const now = Date.now();
   const nonViewerMembers = members
     ? members.filter(member => member.id !== viewerID)
     : [];
   const nonViewerMemberIDs = nonViewerMembers.map(member => member.id);
   const memberIDs = [...nonViewerMemberIDs, viewerID];
   const threadID = getLocallyUniqueThreadID(
     threadType,
     memberIDs,
     sourceMessageID,
   );
 
   const permissions = {
     [threadPermissions.KNOW_OF]: true,
     [threadPermissions.VISIBLE]: true,
     [threadPermissions.VOICED]: true,
   };
 
   const membershipPermissions = getAllThreadPermissions(
     makePermissionsBlob(permissions, null, threadID, threadType),
     threadID,
   );
   const role = {
     id: `${threadID}/role`,
     name: 'Members',
     permissions,
     isDefault: true,
   };
 
   const rawThreadInfo = {
     id: threadID,
     type: threadType,
     name: name ?? null,
     description: null,
     color: threadColor ?? generatePendingThreadColor(memberIDs),
     creationTime: now,
     parentThreadID: parentThreadInfo?.id ?? null,
     containingThreadID: getContainingThreadID(parentThreadInfo, threadType),
     community: getCommunity(parentThreadInfo),
     members: [
       {
         id: viewerID,
         role: role.id,
         permissions: membershipPermissions,
         isSender: false,
       },
       ...nonViewerMembers.map(member => ({
         id: member.id,
         role: role.id,
         permissions: membershipPermissions,
         isSender: false,
       })),
     ],
     roles: {
       [role.id]: role,
     },
     currentUser: {
       role: role.id,
       permissions: membershipPermissions,
       subscription: {
         pushNotifs: false,
         home: false,
       },
       unread: false,
     },
     repliesCount: 0,
     sourceMessageID,
   };
 
   const userInfos = {};
   nonViewerMembers.forEach(member => (userInfos[member.id] = member));
 
   return threadInfoFromRawThreadInfo(rawThreadInfo, viewerID, userInfos);
 }
 
 function createPendingThreadItem(
   viewerID: string,
   user: GlobalAccountUserInfo,
 ): ChatThreadItem {
   const threadInfo = createPendingThread({
     viewerID,
     threadType: threadTypes.PERSONAL,
     members: [user],
   });
 
   return {
     type: 'chatThreadItem',
     threadInfo,
     mostRecentMessageInfo: null,
     mostRecentNonLocalMessage: null,
     lastUpdatedTime: threadInfo.creationTime,
     lastUpdatedTimeIncludingSidebars: threadInfo.creationTime,
     sidebars: [],
     pendingPersonalThreadUserInfo: {
       id: user.id,
       username: user.username,
     },
   };
 }
 
 function createPendingSidebar(
   sourceMessageInfo: ComposableMessageInfo | RobotextMessageInfo,
   parentThreadInfo: ThreadInfo,
   viewerID: string,
   markdownRules: ParserRules,
 ): ThreadInfo {
   const { color, type: parentThreadType } = parentThreadInfo;
 
   const messageTitle = getMessageTitle(
     sourceMessageInfo,
     parentThreadInfo,
     markdownRules,
     'global_viewer',
   );
   const threadName = trimText(messageTitle, 30);
 
   const initialMembers = new Map();
   if (userIsMember(parentThreadInfo, sourceMessageInfo.creator.id)) {
     const {
       id: sourceAuthorID,
       username: sourceAuthorUsername,
     } = sourceMessageInfo.creator;
     invariant(
       sourceAuthorUsername,
       'sourceAuthorUsername should be set in createPendingSidebar',
     );
     const initialMemberUserInfo: GlobalAccountUserInfo = {
       id: sourceAuthorID,
       username: sourceAuthorUsername,
     };
     initialMembers.set(sourceAuthorID, initialMemberUserInfo);
   }
   const singleOtherUser = getSingleOtherUser(parentThreadInfo, viewerID);
   if (parentThreadType === threadTypes.PERSONAL && singleOtherUser) {
     const singleOtherUsername = parentThreadInfo.members.find(
       member => member.id === singleOtherUser,
     )?.username;
     invariant(
       singleOtherUsername,
       'singleOtherUsername should be set in createPendingSidebar',
     );
     const singleOtherUserInfo: GlobalAccountUserInfo = {
       id: singleOtherUser,
       username: singleOtherUsername,
     };
     initialMembers.set(singleOtherUser, singleOtherUserInfo);
   }
 
   return createPendingThread({
     viewerID,
     threadType: threadTypes.SIDEBAR,
     members: [...initialMembers.values()],
     parentThreadInfo,
     threadColor: color,
     name: threadName,
     sourceMessageID: sourceMessageInfo.id,
   });
 }
 
 function pendingThreadType(numberOfOtherMembers: number): 4 | 6 | 7 {
   if (numberOfOtherMembers === 0) {
     return threadTypes.PRIVATE;
   } else if (numberOfOtherMembers === 1) {
     return threadTypes.PERSONAL;
   } else {
     return threadTypes.LOCAL;
   }
 }
 
 function threadTypeCanBePending(threadType: ThreadType): boolean {
   return (
     threadType === threadTypes.PERSONAL ||
     threadType === threadTypes.LOCAL ||
     threadType === threadTypes.SIDEBAR ||
     threadType === threadTypes.PRIVATE
   );
 }
 
 type CreateRealThreadParameters = {
   +threadInfo: ThreadInfo,
   +dispatchActionPromise: DispatchActionPromise,
   +createNewThread: ClientNewThreadRequest => Promise<NewThreadResult>,
   +sourceMessageID: ?string,
   +viewerID: ?string,
   +handleError?: () => mixed,
   +calendarQuery: CalendarQuery,
 };
 async function createRealThreadFromPendingThread({
   threadInfo,
   dispatchActionPromise,
   createNewThread,
   sourceMessageID,
   viewerID,
   calendarQuery,
 }: CreateRealThreadParameters): Promise<string> {
   if (!threadIsPending(threadInfo.id)) {
     return threadInfo.id;
   }
 
   const otherMemberIDs = getThreadOtherUsers(threadInfo, viewerID);
   let resultPromise;
   if (threadInfo.type !== threadTypes.SIDEBAR) {
     invariant(
       otherMemberIDs.length > 0,
       'otherMemberIDs should not be empty for threads',
     );
     resultPromise = createNewThread({
       type: pendingThreadType(otherMemberIDs.length),
       initialMemberIDs: otherMemberIDs,
       color: threadInfo.color,
       calendarQuery,
     });
   } else {
     invariant(
       sourceMessageID,
       'sourceMessageID should be set when creating a sidebar',
     );
     resultPromise = createNewThread({
       type: threadTypes.SIDEBAR,
       initialMemberIDs: otherMemberIDs,
       color: threadInfo.color,
       sourceMessageID,
       parentThreadID: threadInfo.parentThreadID,
       name: threadInfo.name,
       calendarQuery,
     });
   }
   dispatchActionPromise(newThreadActionTypes, resultPromise);
   const { newThreadID } = await resultPromise;
   return newThreadID;
 }
 
 type RawThreadInfoOptions = {
   +includeVisibilityRules?: ?boolean,
   +filterMemberList?: ?boolean,
   +hideThreadStructure?: ?boolean,
   +shimThreadTypes?: ?{
     +[inType: ThreadType]: ThreadType,
   },
   +filterDetailedThreadEditPermissions?: boolean,
 };
 function rawThreadInfoFromServerThreadInfo(
   serverThreadInfo: ServerThreadInfo,
   viewerID: string,
   options?: RawThreadInfoOptions,
 ): ?RawThreadInfo {
   const includeVisibilityRules = options?.includeVisibilityRules;
   const filterMemberList = options?.filterMemberList;
   const hideThreadStructure = options?.hideThreadStructure;
   const shimThreadTypes = options?.shimThreadTypes;
   const filterDetailedThreadEditPermissions =
     options?.filterDetailedThreadEditPermissions;
 
   const members = [];
   let currentUser;
   for (const serverMember of serverThreadInfo.members) {
     if (
       filterMemberList &&
       serverMember.id !== viewerID &&
       !serverMember.role &&
       !memberHasAdminPowers(serverMember)
     ) {
       continue;
     }
     if (
       serverThreadInfo.id === genesis.id &&
       serverMember.id !== viewerID &&
       serverMember.id !== ashoat.id
     ) {
       continue;
     }
     const memberPermissions = filterThreadEditDetailedPermissions(
       serverMember.permissions,
       filterDetailedThreadEditPermissions,
     );
     members.push({
       id: serverMember.id,
       role: serverMember.role,
       permissions: memberPermissions,
       isSender: serverMember.isSender,
     });
     if (serverMember.id === viewerID) {
       currentUser = {
         role: serverMember.role,
         permissions: memberPermissions,
         subscription: serverMember.subscription,
         unread: serverMember.unread,
       };
     }
   }
 
   let currentUserPermissions;
   if (currentUser) {
     currentUserPermissions = currentUser.permissions;
   } else {
     currentUserPermissions = filterThreadEditDetailedPermissions(
       getAllThreadPermissions(null, serverThreadInfo.id),
       filterDetailedThreadEditPermissions,
     );
     currentUser = {
       role: null,
       permissions: currentUserPermissions,
       subscription: {
         home: false,
         pushNotifs: false,
       },
       unread: null,
     };
   }
   if (!permissionLookup(currentUserPermissions, threadPermissions.KNOW_OF)) {
     return null;
   }
 
   let { type } = serverThreadInfo;
   if (
     shimThreadTypes &&
     shimThreadTypes[type] !== null &&
     shimThreadTypes[type] !== undefined
   ) {
     type = shimThreadTypes[type];
   }
 
   let rawThreadInfo: any = {
     id: serverThreadInfo.id,
     type,
     name: serverThreadInfo.name,
     description: serverThreadInfo.description,
     color: serverThreadInfo.color,
     creationTime: serverThreadInfo.creationTime,
     parentThreadID: serverThreadInfo.parentThreadID,
     members,
     roles: serverThreadInfo.roles,
     currentUser,
     repliesCount: serverThreadInfo.repliesCount,
   };
   if (!hideThreadStructure) {
     rawThreadInfo = {
       ...rawThreadInfo,
       containingThreadID: serverThreadInfo.containingThreadID,
       community: serverThreadInfo.community,
     };
   }
   const sourceMessageID = serverThreadInfo.sourceMessageID;
   if (sourceMessageID) {
     rawThreadInfo = { ...rawThreadInfo, sourceMessageID };
   }
   if (includeVisibilityRules) {
     return {
       ...rawThreadInfo,
       visibilityRules: rawThreadInfo.type,
     };
   }
   return rawThreadInfo;
 }
 
 function filterThreadEditDetailedPermissions(
   permissions: ThreadPermissionsInfo,
   shouldFilter: ?boolean,
 ): ThreadPermissionsInfo {
   if (!shouldFilter) {
     return permissions;
   }
   const {
     edit_thread_color,
     edit_thread_description,
     ...newPermissions
   } = permissions;
   return newPermissions;
 }
 
 function robotextName(
   threadInfo: RawThreadInfo | ThreadInfo,
   viewerID: ?string,
   userInfos: UserInfos,
 ): string {
   const threadUsernames = getThreadOtherUsers(threadInfo, viewerID)
     .map(memberID => userInfos[memberID] && userInfos[memberID].username)
     .filter(Boolean);
   if (threadUsernames.length === 0) {
     return 'just you';
   }
   return pluralize(threadUsernames);
 }
 
 function threadUIName(
   threadInfo: RawThreadInfo | ThreadInfo,
   viewerID: ?string,
   userInfos: UserInfos,
 ): string {
   return firstLine(
     threadInfo.name || robotextName(threadInfo, viewerID, userInfos),
   );
 }
 
 function threadInfoFromRawThreadInfo(
   rawThreadInfo: RawThreadInfo,
   viewerID: ?string,
   userInfos: UserInfos,
 ): ThreadInfo {
   let threadInfo: ThreadInfo = {
     id: rawThreadInfo.id,
     type: rawThreadInfo.type,
     name: rawThreadInfo.name,
     uiName: threadUIName(rawThreadInfo, viewerID, userInfos),
     description: rawThreadInfo.description,
     color: rawThreadInfo.color,
     creationTime: rawThreadInfo.creationTime,
     parentThreadID: rawThreadInfo.parentThreadID,
     containingThreadID: rawThreadInfo.containingThreadID,
     community: rawThreadInfo.community,
     members: getRelativeMemberInfos(rawThreadInfo, viewerID, userInfos),
     roles: rawThreadInfo.roles,
     currentUser: getCurrentUser(rawThreadInfo, viewerID, userInfos),
     repliesCount: rawThreadInfo.repliesCount,
   };
   const { sourceMessageID } = rawThreadInfo;
   if (sourceMessageID) {
     threadInfo = { ...threadInfo, sourceMessageID };
   }
   return threadInfo;
 }
 
 function getCurrentUser(
   threadInfo: RawThreadInfo | ThreadInfo,
   viewerID: ?string,
   userInfos: UserInfos,
 ): ThreadCurrentUserInfo {
   if (!threadFrozenDueToBlock(threadInfo, viewerID, userInfos)) {
     return threadInfo.currentUser;
   }
 
   return {
     ...threadInfo.currentUser,
     permissions: {
       ...threadInfo.currentUser.permissions,
       ...disabledPermissions,
     },
   };
 }
 
 function threadIsWithBlockedUserOnly(
   threadInfo: RawThreadInfo | ThreadInfo,
   viewerID: ?string,
   userInfos: UserInfos,
   checkOnlyViewerBlock?: boolean,
 ): boolean {
   if (
     threadInfo.type !== threadTypes.PERSONAL &&
     (threadOrParentThreadIsGroupChat(threadInfo) ||
       threadOrParentThreadHasAdminRole(threadInfo))
   ) {
     return false;
   }
 
   const otherUserID = getSingleOtherUser(threadInfo, viewerID);
   if (!otherUserID) {
     return false;
   }
   const otherUserRelationshipStatus =
     userInfos[otherUserID]?.relationshipStatus;
 
   if (checkOnlyViewerBlock) {
     return (
       otherUserRelationshipStatus === userRelationshipStatus.BLOCKED_BY_VIEWER
     );
   }
 
   return (
     !!otherUserRelationshipStatus &&
     relationshipBlockedInEitherDirection(otherUserRelationshipStatus)
   );
 }
 
 function threadFrozenDueToBlock(
   threadInfo: RawThreadInfo | ThreadInfo,
   viewerID: ?string,
   userInfos: UserInfos,
 ): boolean {
   return threadIsWithBlockedUserOnly(threadInfo, viewerID, userInfos);
 }
 
 function threadFrozenDueToViewerBlock(
   threadInfo: RawThreadInfo | ThreadInfo,
   viewerID: ?string,
   userInfos: UserInfos,
 ): boolean {
   return threadIsWithBlockedUserOnly(threadInfo, viewerID, userInfos, true);
 }
 
 function rawThreadInfoFromThreadInfo(threadInfo: ThreadInfo): RawThreadInfo {
   let rawThreadInfo: RawThreadInfo = {
     id: threadInfo.id,
     type: threadInfo.type,
     name: threadInfo.name,
     description: threadInfo.description,
     color: threadInfo.color,
     creationTime: threadInfo.creationTime,
     parentThreadID: threadInfo.parentThreadID,
     containingThreadID: threadInfo.containingThreadID,
     community: threadInfo.community,
     members: threadInfo.members.map(relativeMemberInfo => ({
       id: relativeMemberInfo.id,
       role: relativeMemberInfo.role,
       permissions: relativeMemberInfo.permissions,
       isSender: relativeMemberInfo.isSender,
     })),
     roles: threadInfo.roles,
     currentUser: threadInfo.currentUser,
     repliesCount: threadInfo.repliesCount,
   };
   const { sourceMessageID } = threadInfo;
   if (sourceMessageID) {
     rawThreadInfo = { ...rawThreadInfo, sourceMessageID };
   }
   return rawThreadInfo;
 }
 
 const threadTypeDescriptions: { [ThreadType]: string } = {
   [threadTypes.COMMUNITY_OPEN_SUBTHREAD]:
     'Anybody in the parent channel can see an open subchannel.',
   [threadTypes.COMMUNITY_SECRET_SUBTHREAD]:
     'Only visible to its members and admins of ancestor channels.',
 };
 
 function usersInThreadInfo(threadInfo: RawThreadInfo | ThreadInfo): string[] {
   const userIDs = new Set();
   for (const member of threadInfo.members) {
     userIDs.add(member.id);
   }
   return [...userIDs];
 }
 
 function memberIsAdmin(
   memberInfo: RelativeMemberInfo | MemberInfo,
   threadInfo: ThreadInfo | RawThreadInfo,
 ): boolean {
   return !!(
     memberInfo.role && roleIsAdminRole(threadInfo.roles[memberInfo.role])
   );
 }
 
 // Since we don't have access to all of the ancestor ThreadInfos, we approximate
 // "parent admin" as anybody with CHANGE_ROLE permissions.
 function memberHasAdminPowers(
   memberInfo: RelativeMemberInfo | MemberInfo | ServerMemberInfo,
 ): boolean {
   return !!memberInfo.permissions[threadPermissions.CHANGE_ROLE]?.value;
 }
 
 function roleIsAdminRole(roleInfo: ?RoleInfo): boolean {
   return !!(roleInfo && !roleInfo.isDefault && roleInfo.name === 'Admins');
 }
 
 function threadHasAdminRole(
   threadInfo: ?(RawThreadInfo | ThreadInfo | ServerThreadInfo),
 ): boolean {
   if (!threadInfo) {
     return false;
   }
   return !!_find({ name: 'Admins' })(threadInfo.roles);
 }
 
 function threadOrParentThreadHasAdminRole(
   threadInfo: RawThreadInfo | ThreadInfo,
 ) {
   return (
     threadInfo.members.filter(member => memberHasAdminPowers(member)).length > 0
   );
 }
 
 function identifyInvalidatedThreads(
   updateInfos: $ReadOnlyArray<ClientUpdateInfo>,
 ): Set<string> {
   const invalidated = new Set();
   for (const updateInfo of updateInfos) {
     if (updateInfo.type === updateTypes.DELETE_THREAD) {
       invalidated.add(updateInfo.threadID);
     }
   }
   return invalidated;
 }
 
 const permissionsDisabledByBlockArray = [
   threadPermissions.VOICED,
   threadPermissions.EDIT_ENTRIES,
   threadPermissions.EDIT_THREAD_NAME,
   threadPermissions.EDIT_THREAD_COLOR,
   threadPermissions.EDIT_THREAD_DESCRIPTION,
   threadPermissions.CREATE_SUBCHANNELS,
   threadPermissions.CREATE_SIDEBARS,
   threadPermissions.JOIN_THREAD,
   threadPermissions.EDIT_PERMISSIONS,
   threadPermissions.ADD_MEMBERS,
   threadPermissions.REMOVE_MEMBERS,
 ];
 
 const permissionsDisabledByBlock: Set<ThreadPermission> = new Set(
   permissionsDisabledByBlockArray,
 );
 
 const disabledPermissions: ThreadPermissionsInfo = permissionsDisabledByBlockArray.reduce(
   (permissions: ThreadPermissionsInfo, permission: string) => ({
     ...permissions,
     [permission]: { value: false, source: null },
   }),
   {},
 );
 
 // Consider updating itemHeight in native/chat/chat-thread-list.react.js
 // if you change this
 const emptyItemText: string =
   `Background chats are just like normal chats, except they don't ` +
   `contribute to your unread count.\n\n` +
   `To move a chat over here, switch the “Background” option in its settings.`;
 
 const threadSearchText = (
   threadInfo: RawThreadInfo | ThreadInfo,
   userInfos: UserInfos,
   viewerID: ?string,
 ): string => {
   const searchTextArray = [];
   if (threadInfo.name) {
     searchTextArray.push(threadInfo.name);
   }
   if (threadInfo.description) {
     searchTextArray.push(threadInfo.description);
   }
   for (const member of threadInfo.members) {
     const isParentAdmin = memberHasAdminPowers(member);
     if (!member.role && !isParentAdmin) {
       continue;
     }
     if (member.id === viewerID) {
       continue;
     }
     const userInfo = userInfos[member.id];
     if (userInfo && userInfo.username) {
       searchTextArray.push(userInfo.username);
     }
   }
   return searchTextArray.join(' ');
 };
 
 function threadNoun(threadType: ThreadType): string {
   return threadType === threadTypes.SIDEBAR ? 'thread' : 'chat';
 }
 
 function threadLabel(threadType: ThreadType): string {
   if (
     threadType === threadTypes.COMMUNITY_OPEN_SUBTHREAD ||
     threadType === threadTypes.COMMUNITY_OPEN_ANNOUNCEMENT_SUBTHREAD
   ) {
     return 'Open';
   } else if (threadType === threadTypes.PERSONAL) {
     return 'Personal';
   } else if (threadType === threadTypes.SIDEBAR) {
     return 'Thread';
   } else if (threadType === threadTypes.PRIVATE) {
     return 'Private';
   } else if (
     threadType === threadTypes.COMMUNITY_ROOT ||
     threadType === threadTypes.COMMUNITY_ANNOUNCEMENT_ROOT ||
     threadType === threadTypes.GENESIS
   ) {
     return 'Community';
   } else {
     return 'Secret';
   }
 }
 
 function useWatchThread(threadInfo: ?ThreadInfo) {
   const dispatchActionPromise = useDispatchActionPromise();
   const callFetchMostRecentMessages = useServerCall(fetchMostRecentMessages);
 
   const threadID = threadInfo?.id;
   const threadNotInChatList = !threadInChatList(threadInfo);
   React.useEffect(() => {
     if (threadID && threadNotInChatList) {
       threadWatcher.watchID(threadID);
       dispatchActionPromise(
         fetchMostRecentMessagesActionTypes,
         callFetchMostRecentMessages(threadID),
       );
     }
     return () => {
       if (threadID && threadNotInChatList) {
         threadWatcher.removeID(threadID);
       }
     };
   }, [
     callFetchMostRecentMessages,
     dispatchActionPromise,
     threadNotInChatList,
     threadID,
   ]);
 }
 
 type ExistingThreadInfoFinderParams = {
   +searching: boolean,
   +userInfoInputArray: $ReadOnlyArray<AccountUserInfo>,
 };
 type ExistingThreadInfoFinder = (
   params: ExistingThreadInfoFinderParams,
 ) => ?ThreadInfo;
 function useExistingThreadInfoFinder(
   baseThreadInfo: ?ThreadInfo,
 ): ExistingThreadInfoFinder {
   const threadInfos = useSelector(threadInfoSelector);
   const viewerID = useSelector(
     state => state.currentUserInfo && state.currentUserInfo.id,
   );
   const userInfos = useSelector(state => state.userStore.userInfos);
 
   const locallyUniqueToRealizedThreadIDs = useSelector(state =>
     locallyUniqueToRealizedThreadIDsSelector(state.threadStore.threadInfos),
   );
   return React.useCallback(
     (params: ExistingThreadInfoFinderParams): ?ThreadInfo => {
       if (!baseThreadInfo) {
         return null;
       }
 
       const realizedThreadInfo = threadInfos[baseThreadInfo.id];
       if (realizedThreadInfo) {
         return realizedThreadInfo;
       }
 
       if (!viewerID || !threadIsPending(baseThreadInfo.id)) {
         return baseThreadInfo;
       }
 
       invariant(
         threadTypeCanBePending(baseThreadInfo.type),
         `ThreadInfo has pending ID ${baseThreadInfo.id}, but type that ` +
           `should not be pending ${baseThreadInfo.type}`,
       );
 
       const { searching, userInfoInputArray } = params;
 
       const { sourceMessageID } = baseThreadInfo;
       const pendingThreadID = searching
         ? getLocallyUniqueThreadID(
             pendingThreadType(userInfoInputArray.length),
             [...userInfoInputArray.map(user => user.id), viewerID],
             sourceMessageID,
           )
         : getLocallyUniqueThreadID(
             baseThreadInfo.type,
             baseThreadInfo.members.map(member => member.id),
             sourceMessageID,
           );
 
       const realizedThreadID = locallyUniqueToRealizedThreadIDs.get(
         pendingThreadID,
       );
       if (realizedThreadID && threadInfos[realizedThreadID]) {
         return threadInfos[realizedThreadID];
       }
 
       const updatedThread = searching
         ? createPendingThread({
             viewerID,
             threadType: pendingThreadType(userInfoInputArray.length),
             members: userInfoInputArray,
           })
         : baseThreadInfo;
       return {
         ...updatedThread,
         currentUser: getCurrentUser(updatedThread, viewerID, userInfos),
       };
     },
     [
       baseThreadInfo,
       threadInfos,
       viewerID,
       locallyUniqueToRealizedThreadIDs,
       userInfos,
     ],
   );
 }
 
 type ThreadTypeParentRequirement = 'optional' | 'required' | 'disabled';
 function getThreadTypeParentRequirement(
   threadType: ThreadType,
 ): ThreadTypeParentRequirement {
   if (
     threadType === threadTypes.COMMUNITY_OPEN_SUBTHREAD ||
     threadType === threadTypes.COMMUNITY_OPEN_ANNOUNCEMENT_SUBTHREAD ||
     //threadType === threadTypes.COMMUNITY_SECRET_SUBTHREAD ||
     threadType === threadTypes.COMMUNITY_SECRET_ANNOUNCEMENT_SUBTHREAD ||
     threadType === threadTypes.SIDEBAR
   ) {
     return 'required';
   } else if (
     threadType === threadTypes.COMMUNITY_ROOT ||
     threadType === threadTypes.COMMUNITY_ANNOUNCEMENT_ROOT ||
     threadType === threadTypes.GENESIS ||
     threadType === threadTypes.PERSONAL ||
     threadType === threadTypes.PRIVATE
   ) {
     return 'disabled';
   } else {
     return 'optional';
   }
 }
 
 function threadMemberHasPermission(
   threadInfo: ServerThreadInfo | RawThreadInfo | ThreadInfo,
   memberID: string,
   permission: ThreadPermission,
 ): boolean {
   for (const member of threadInfo.members) {
     if (member.id !== memberID) {
       continue;
     }
     return permissionLookup(member.permissions, permission);
   }
   return false;
 }
 
 function useCanCreateSidebarFromMessage(
   threadInfo: ThreadInfo,
   messageInfo: ComposableMessageInfo | RobotextMessageInfo,
 ): boolean {
   const messageCreatorUserInfo = useSelector(
     state => state.userStore.userInfos[messageInfo.creator.id],
   );
 
   if (!messageInfo.id || threadInfo.sourceMessageID === messageInfo.id) {
     return false;
   }
 
   const messageCreatorRelationship = messageCreatorUserInfo?.relationshipStatus;
   const creatorRelationshipHasBlock =
     messageCreatorRelationship &&
     relationshipBlockedInEitherDirection(messageCreatorRelationship);
 
   const hasPermission = threadHasPermission(
     threadInfo,
     threadPermissions.CREATE_SIDEBARS,
   );
 
   return hasPermission && !creatorRelationshipHasBlock;
 }
 
 function useSidebarExistsOrCanBeCreated(
   threadInfo: ThreadInfo,
   messageItem: ChatMessageInfoItem,
 ): boolean {
   const canCreateSidebarFromMessage = useCanCreateSidebarFromMessage(
     threadInfo,
     messageItem.messageInfo,
   );
   return !!messageItem.threadCreatedFromMessage || canCreateSidebarFromMessage;
 }
 
 function checkIfDefaultMembersAreVoiced(threadInfo: ThreadInfo): boolean {
   const defaultRoleID = Object.keys(threadInfo.roles).find(
     roleID => threadInfo.roles[roleID].isDefault,
   );
   invariant(
     defaultRoleID !== undefined,
     'all threads should have a default role',
   );
   const defaultRole = threadInfo.roles[defaultRoleID];
   return !!defaultRole.permissions[threadPermissions.VOICED];
 }
 
 function draftKeyFromThreadID(threadID: string): string {
   return `${threadID}/message_composer`;
 }
 
 function getContainingThreadID(
   parentThreadInfo: ?ServerThreadInfo | RawThreadInfo | ThreadInfo,
   threadType: ThreadType,
 ): ?string {
   if (!parentThreadInfo) {
     return null;
   }
   if (threadType === threadTypes.SIDEBAR) {
     return parentThreadInfo.id;
   }
   if (!parentThreadInfo.containingThreadID) {
     return parentThreadInfo.id;
   }
   return parentThreadInfo.containingThreadID;
 }
 
 function getCommunity(
   parentThreadInfo: ?ServerThreadInfo | RawThreadInfo | ThreadInfo,
 ): ?string {
   if (!parentThreadInfo) {
     return null;
   }
   const { id, community, type } = parentThreadInfo;
   if (community !== null && community !== undefined) {
     return community;
   }
   if (threadTypeIsCommunityRoot(type)) {
     return id;
   }
   return null;
 }
 
 function getThreadListSearchResults(
   chatListData: $ReadOnlyArray<ChatThreadItem>,
   searchText: string,
   threadFilter: ThreadInfo => boolean,
   threadSearchResults: $ReadOnlySet<string>,
   usersSearchResults: $ReadOnlyArray<GlobalAccountUserInfo>,
   viewerID: ?string,
 ): $ReadOnlyArray<ChatThreadItem> {
   if (!searchText) {
     return chatListData.filter(
       item =>
         threadIsTopLevel(item.threadInfo) && threadFilter(item.threadInfo),
     );
   }
 
   const privateThreads = [];
   const personalThreads = [];
   const otherThreads = [];
   for (const item of chatListData) {
     if (!threadSearchResults.has(item.threadInfo.id)) {
       continue;
     }
     if (item.threadInfo.type === threadTypes.PRIVATE) {
       privateThreads.push({ ...item, sidebars: [] });
     } else if (item.threadInfo.type === threadTypes.PERSONAL) {
       personalThreads.push({ ...item, sidebars: [] });
     } else {
       otherThreads.push({ ...item, sidebars: [] });
     }
   }
 
   const chatItems = [...privateThreads, ...personalThreads, ...otherThreads];
   if (viewerID) {
     chatItems.push(
       ...usersSearchResults.map(user =>
         createPendingThreadItem(viewerID, user),
       ),
     );
   }
   return chatItems;
 }
 
 type ThreadListSearchResult = {
   +threadSearchResults: $ReadOnlySet<string>,
   +usersSearchResults: $ReadOnlyArray<GlobalAccountUserInfo>,
 };
 function useThreadListSearch(
   chatListData: $ReadOnlyArray<ChatThreadItem>,
   searchText: string,
   viewerID: ?string,
 ): ThreadListSearchResult {
   const callSearchUsers = useServerCall(searchUserCall);
   const usersWithPersonalThread = useSelector(usersWithPersonalThreadSelector);
   const searchUsers = React.useCallback(
     async (usernamePrefix: string) => {
       if (usernamePrefix.length === 0) {
         return [];
       }
 
       const { userInfos } = await callSearchUsers(usernamePrefix);
       return userInfos.filter(
         info => !usersWithPersonalThread.has(info.id) && info.id !== viewerID,
       );
     },
     [callSearchUsers, usersWithPersonalThread, viewerID],
   );
 
   const [threadSearchResults, setThreadSearchResults] = React.useState(
     new Set(),
   );
   const [usersSearchResults, setUsersSearchResults] = React.useState([]);
   const threadSearchIndex = useSelector(threadSearchIndexSelector);
   React.useEffect(() => {
     (async () => {
       const results = threadSearchIndex.getSearchResults(searchText);
       setThreadSearchResults(new Set(results));
       const usersResults = await searchUsers(searchText);
       setUsersSearchResults(usersResults);
     })();
   }, [searchText, chatListData, threadSearchIndex, searchUsers]);
 
   return { threadSearchResults, usersSearchResults };
 }
 
 function removeMemberFromThread(
   threadInfo: ThreadInfo,
   memberInfo: RelativeMemberInfo,
   dispatchActionPromise: DispatchActionPromise,
   removeUserFromThreadServerCall: (
     threadID: string,
     memberIDs: $ReadOnlyArray<string>,
   ) => Promise<ChangeThreadSettingsPayload>,
 ) {
   const customKeyName = `${removeUsersFromThreadActionTypes.started}:${memberInfo.id}`;
   dispatchActionPromise(
     removeUsersFromThreadActionTypes,
     removeUserFromThreadServerCall(threadInfo.id, [memberInfo.id]),
     { customKeyName },
   );
 }
 
 function switchMemberAdminRoleInThread(
   threadInfo: ThreadInfo,
   memberInfo: RelativeMemberInfo,
   isCurrentlyAdmin: boolean,
   dispatchActionPromise: DispatchActionPromise,
   changeUserRoleServerCall: (
     threadID: string,
     memberIDs: $ReadOnlyArray<string>,
     newRole: string,
   ) => Promise<ChangeThreadSettingsPayload>,
 ) {
   let newRole = null;
   for (const roleID in threadInfo.roles) {
     const role = threadInfo.roles[roleID];
     if (isCurrentlyAdmin && role.isDefault) {
       newRole = role.id;
       break;
     } else if (!isCurrentlyAdmin && roleIsAdminRole(role)) {
       newRole = role.id;
       break;
     }
   }
   invariant(newRole !== null, 'Could not find new role');
 
   const customKeyName = `${changeThreadMemberRolesActionTypes.started}:${memberInfo.id}`;
   dispatchActionPromise(
     changeThreadMemberRolesActionTypes,
     changeUserRoleServerCall(threadInfo.id, [memberInfo.id], newRole),
     { customKeyName },
   );
 }
 
 function getAvailableThreadMemberActions(
   memberInfo: RelativeMemberInfo,
   threadInfo: ThreadInfo,
   canEdit: ?boolean = true,
 ): $ReadOnlyArray<'remove_user' | 'remove_admin' | 'make_admin'> {
   const role = memberInfo.role;
   if (!canEdit || !role) {
     return [];
   }
 
   const canRemoveMembers = threadHasPermission(
     threadInfo,
     threadPermissions.REMOVE_MEMBERS,
   );
   const canChangeRoles = threadHasPermission(
     threadInfo,
     threadPermissions.CHANGE_ROLE,
   );
 
   const result = [];
   if (
     canRemoveMembers &&
     !memberInfo.isViewer &&
     (canChangeRoles || threadInfo.roles[role]?.isDefault)
   ) {
     result.push('remove_user');
   }
 
   if (canChangeRoles && memberInfo.username && threadHasAdminRole(threadInfo)) {
     result.push(
       memberIsAdmin(memberInfo, threadInfo) ? 'remove_admin' : 'make_admin',
     );
   }
 
   return result;
 }
 
 export {
   colorIsDark,
   generateRandomColor,
   generatePendingThreadColor,
   threadHasPermission,
   viewerIsMember,
   threadInChatList,
   threadIsTopLevel,
   threadIsChannel,
+  threadIsSidebar,
   threadInBackgroundChatList,
   threadInHomeChatList,
   threadIsInHome,
   threadInFilterList,
   userIsMember,
   threadActualMembers,
   threadIsGroupChat,
   threadIsPending,
   getSingleOtherUser,
   getLocallyUniqueThreadID,
   locallyUniqueThreadIDRegex,
   parseLocallyUniqueThreadID,
   createPendingThread,
   createPendingThreadItem,
   createPendingSidebar,
   pendingThreadType,
   createRealThreadFromPendingThread,
   getCurrentUser,
   threadFrozenDueToBlock,
   threadFrozenDueToViewerBlock,
   rawThreadInfoFromServerThreadInfo,
   filterThreadEditDetailedPermissions,
   robotextName,
   threadInfoFromRawThreadInfo,
   rawThreadInfoFromThreadInfo,
   threadTypeDescriptions,
   usersInThreadInfo,
   memberIsAdmin,
   memberHasAdminPowers,
   roleIsAdminRole,
   threadHasAdminRole,
   identifyInvalidatedThreads,
   permissionsDisabledByBlock,
   emptyItemText,
   threadSearchText,
   threadNoun,
   threadLabel,
   useWatchThread,
   useExistingThreadInfoFinder,
   getThreadTypeParentRequirement,
   threadMemberHasPermission,
   useCanCreateSidebarFromMessage,
   useSidebarExistsOrCanBeCreated,
   checkIfDefaultMembersAreVoiced,
   draftKeyFromThreadID,
   threadTypeCanBePending,
   getContainingThreadID,
   getCommunity,
   getThreadListSearchResults,
   useThreadListSearch,
   removeMemberFromThread,
   switchMemberAdminRoleInThread,
   getAvailableThreadMemberActions,
   selectedThreadColors,
 };
diff --git a/web/modals/threads/sidebars/sidebars-modal.css b/web/modals/threads/sidebars/sidebars-modal.css
index 64a776d86..faa7e4555 100644
--- a/web/modals/threads/sidebars/sidebars-modal.css
+++ b/web/modals/threads/sidebars/sidebars-modal.css
@@ -1,63 +1,71 @@
+div.sidebarListContainer {
+  display: flex;
+  flex-direction: column;
+  line-height: var(--line-height-text);
+  width: 383px;
+  height: 458px;
+}
+
 div.sidebarList {
   overflow: auto;
   color: var(--sidebars-modal-color);
 }
 
 div.noSidebars {
   padding: 16px;
   text-align: center;
   color: var(--sidebars-modal-color);
 }
 
 button.sidebarContainer {
   cursor: pointer;
   display: flex;
   padding: 0 16px;
   column-gap: 8px;
   align-items: flex-start;
   width: 100%;
   border: none;
   font-size: inherit;
   text-align: inherit;
   line-height: inherit;
   color: inherit;
   background: inherit;
 }
 
 button.sidebarContainer:hover {
   color: var(--sidebars-modal-color-hover);
 }
 
 div.sidebarInfo {
   flex: 1;
   display: flex;
   flex-direction: column;
   overflow: hidden;
   padding: 8px 0;
 }
 
 div.longTextEllipsis {
   text-overflow: ellipsis;
   overflow: hidden;
   white-space: nowrap;
 }
 
 div.lastMessage {
   display: flex;
   justify-content: space-between;
   column-gap: 14px;
 }
 
 div.noMessage {
   text-align: center;
   font-style: italic;
 }
 
 div.lastActivity {
   white-space: nowrap;
 }
 
 img.sidebarArrow {
   position: relative;
   top: -12px;
 }
diff --git a/web/modals/threads/sidebars/sidebars-modal.react.js b/web/modals/threads/sidebars/sidebars-modal.react.js
new file mode 100644
index 000000000..c9bf37b5d
--- /dev/null
+++ b/web/modals/threads/sidebars/sidebars-modal.react.js
@@ -0,0 +1,80 @@
+// @flow
+
+import * as React from 'react';
+
+import { useFilteredChildThreads } from 'lib/hooks/child-threads';
+import { threadInChatList, threadIsSidebar } from 'lib/shared/thread-utils';
+
+import Tabs from '../../../components/tabs.react';
+import SearchModal from '../../search-modal.react';
+import SidebarList from './sidebar-list.react';
+import css from './sidebars-modal.css';
+
+type SidebarTab = 'All Threads' | 'My Threads';
+
+type ContentProps = {
+  +searchText: string,
+  +threadID: string,
+  +defaultTab: SidebarTab,
+};
+
+function SidebarsModalContent(props: ContentProps): React.Node {
+  const { searchText, threadID, defaultTab } = props;
+  const [tab, setTab] = React.useState<SidebarTab>(defaultTab);
+
+  const sidebarList = useFilteredChildThreads(threadID, {
+    predicate: threadIsSidebar,
+    searchText,
+  });
+
+  const sidebarsChatListVisibleInChat = sidebarList.filter(chatItem =>
+    threadInChatList(chatItem.threadInfo),
+  );
+
+  return (
+    <div className={css.sidebarListContainer}>
+      <Tabs.Container activeTab={tab} setTab={setTab}>
+        <Tabs.Item id="All Threads" header="All Threads">
+          <SidebarList sidebars={sidebarList} />
+        </Tabs.Item>
+        <Tabs.Item id="My Threads" header="My Threads">
+          <SidebarList sidebars={sidebarsChatListVisibleInChat} />
+        </Tabs.Item>
+      </Tabs.Container>
+    </div>
+  );
+}
+
+type Props = {
+  +threadID: string,
+  +onClose: () => void,
+  +defaultTab?: SidebarTab,
+};
+
+function SidebarsModal(props: Props): React.Node {
+  const { threadID, onClose, defaultTab = 'All Threads' } = props;
+
+  const sidebarsContent = React.useCallback(
+    (searchText: string) => (
+      <SidebarsModalContent
+        searchText={searchText}
+        defaultTab={defaultTab}
+        threadID={threadID}
+      />
+    ),
+    [defaultTab, threadID],
+  );
+
+  return (
+    <SearchModal
+      name="Threads"
+      searchPlaceholder="Search"
+      onClose={onClose}
+      size="fit-content"
+    >
+      {sidebarsContent}
+    </SearchModal>
+  );
+}
+
+export default SidebarsModal;