diff --git a/keyserver/src/fetchers/thread-fetchers.js b/keyserver/src/fetchers/thread-fetchers.js
index 3bc013106..6988801f6 100644
--- a/keyserver/src/fetchers/thread-fetchers.js
+++ b/keyserver/src/fetchers/thread-fetchers.js
@@ -1,431 +1,442 @@
 // @flow
 
 import invariant from 'invariant';
 
 import { specialRoles } from 'lib/permissions/special-roles.js';
 import { getAllThreadPermissions } from 'lib/permissions/thread-permissions.js';
 import {
   rawThreadInfoFromServerThreadInfo,
   getContainingThreadID,
   getCommunity,
 } from 'lib/shared/thread-utils.js';
-import { hasMinCodeVersion } from 'lib/shared/version-utils.js';
+import {
+  hasMinCodeVersion,
+  FUTURE_CODE_VERSION,
+} from 'lib/shared/version-utils.js';
 import type { AvatarDBContent, ClientAvatar } from 'lib/types/avatar-types.js';
 import type { RawMessageInfo, MessageInfo } from 'lib/types/message-types.js';
 import type { RawThreadInfo } from 'lib/types/minimally-encoded-thread-permissions-types.js';
 import { threadTypes, type ThreadType } from 'lib/types/thread-types-enum.js';
 import {
   type ServerThreadInfo,
   type MixedRawThreadInfos,
   type LegacyRawThreadInfo,
   type ServerLegacyRoleInfo,
 } from 'lib/types/thread-types.js';
 import { ServerError } from 'lib/utils/errors.js';
 
 import { getUploadURL, makeUploadURI } from './upload-fetchers.js';
 import { dbQuery, SQL, mergeAndConditions } from '../database/database.js';
 import type { SQLStatementType } from '../database/types.js';
 import type { Viewer } from '../session/viewer.js';
 
 type FetchThreadInfosFilter = Partial<{
   +accessibleToUserID: string,
   +threadID: string,
   +threadIDs: $ReadOnlySet<string>,
   +parentThreadID: string,
   +sourceMessageID: string,
 }>;
 function constructWhereClause(
   filter: FetchThreadInfosFilter,
 ): SQLStatementType {
   const fromTable = filter.accessibleToUserID ? 'memberships' : 'threads';
 
   const conditions = [];
 
   if (filter.accessibleToUserID) {
     conditions.push(
       SQL`mm.user = ${filter.accessibleToUserID} AND mm.role > -1`,
     );
   }
 
   if (filter.threadID && fromTable === 'memberships') {
     conditions.push(SQL`mm.thread = ${filter.threadID}`);
   } else if (filter.threadID) {
     conditions.push(SQL`t.id = ${filter.threadID}`);
   }
 
   if (filter.threadIDs && fromTable === 'memberships') {
     conditions.push(SQL`mm.thread IN (${[...filter.threadIDs]})`);
   } else if (filter.threadIDs) {
     conditions.push(SQL`t.id IN (${[...filter.threadIDs]})`);
   }
 
   if (filter.parentThreadID) {
     conditions.push(SQL`t.parent_thread_id = ${filter.parentThreadID}`);
   }
 
   if (filter.sourceMessageID) {
     conditions.push(SQL`t.source_message = ${filter.sourceMessageID}`);
   }
 
   if (conditions.length === 0) {
     return SQL``;
   }
 
   const clause = mergeAndConditions(conditions);
   return SQL`WHERE `.append(clause);
 }
 
 type FetchServerThreadInfosResult = {
   +threadInfos: { +[id: string]: ServerThreadInfo },
 };
 
 async function fetchServerThreadInfos(
   filter?: FetchThreadInfosFilter,
 ): Promise<FetchServerThreadInfosResult> {
   if (filter?.threadIDs?.size === 0) {
     return { threadInfos: {} };
   }
 
   let primaryFetchClause;
   if (filter?.accessibleToUserID) {
     primaryFetchClause = SQL`
       FROM memberships mm
       LEFT JOIN threads t ON t.id = mm.thread
     `;
   } else {
     primaryFetchClause = SQL`
       FROM threads t
     `;
   }
 
   const whereClause = filter ? constructWhereClause(filter) : '';
 
   const rolesQuery = SQL`
     SELECT t.id, r.id AS role, r.name, r.permissions, r.special_role,
       r.special_role = ${specialRoles.DEFAULT_ROLE} AS is_default
   `
     .append(primaryFetchClause)
     .append(
       SQL`
       LEFT JOIN roles r ON r.thread = t.id
     `,
     )
     .append(whereClause);
 
   const threadsQuery = SQL`
     SELECT t.id, t.name, t.parent_thread_id, t.containing_thread_id,
       t.community, t.depth, t.color, t.description, t.type, t.creation_time,
       t.source_message, t.replies_count, t.avatar, t.pinned_count, m.user,
       m.role, m.permissions, m.subscription,
       m.last_read_message < m.last_message AS unread, m.sender,
       up.id AS upload_id, up.secret AS upload_secret, up.extra AS upload_extra
   `
     .append(primaryFetchClause)
     .append(
       SQL`
       LEFT JOIN memberships m ON m.thread = t.id AND m.role >= 0
       LEFT JOIN uploads up ON up.container = t.id
     `,
     )
     .append(whereClause)
     .append(SQL` ORDER BY m.user ASC`);
   const [[threadsResult], [rolesResult]] = await Promise.all([
     dbQuery(threadsQuery),
     dbQuery(rolesQuery),
   ]);
 
   const threadInfos = {};
   for (const threadsRow of threadsResult) {
     const threadID = threadsRow.id.toString();
     if (!threadInfos[threadID]) {
       threadInfos[threadID] = {
         id: threadID,
         type: threadsRow.type,
         name: threadsRow.name ? threadsRow.name : '',
         description: threadsRow.description ? threadsRow.description : '',
         color: threadsRow.color,
         creationTime: threadsRow.creation_time,
         parentThreadID: threadsRow.parent_thread_id
           ? threadsRow.parent_thread_id.toString()
           : null,
         containingThreadID: threadsRow.containing_thread_id
           ? threadsRow.containing_thread_id.toString()
           : null,
         depth: threadsRow.depth,
         community: threadsRow.community
           ? threadsRow.community.toString()
           : null,
         members: [],
         roles: {},
         repliesCount: threadsRow.replies_count,
         pinnedCount: threadsRow.pinned_count,
       };
       if (threadsRow.avatar) {
         const avatar: AvatarDBContent = JSON.parse(threadsRow.avatar);
         let clientAvatar: ?ClientAvatar;
         if (
           avatar &&
           avatar.type !== 'image' &&
           avatar.type !== 'encrypted_image'
         ) {
           clientAvatar = avatar;
         } else if (
           avatar &&
           (avatar.type === 'image' || avatar.type === 'encrypted_image') &&
           threadsRow.upload_id &&
           threadsRow.upload_secret
         ) {
           const uploadID = threadsRow.upload_id.toString();
           invariant(
             uploadID === avatar.uploadID,
             `uploadID of upload should match uploadID of image avatar`,
           );
           if (avatar.type === 'encrypted_image' && threadsRow.upload_extra) {
             const uploadExtra = JSON.parse(threadsRow.upload_extra);
             clientAvatar = {
               type: 'encrypted_image',
               blobURI: makeUploadURI(
                 uploadExtra.blobHash,
                 uploadID,
                 threadsRow.upload_secret,
               ),
               encryptionKey: uploadExtra.encryptionKey,
               thumbHash: uploadExtra.thumbHash,
             };
           } else {
             clientAvatar = {
               type: 'image',
               uri: getUploadURL(uploadID, threadsRow.upload_secret),
             };
           }
         }
 
         threadInfos[threadID] = {
           ...threadInfos[threadID],
           avatar: clientAvatar,
         };
       }
     }
     const sourceMessageID = threadsRow.source_message?.toString();
     if (sourceMessageID) {
       threadInfos[threadID].sourceMessageID = sourceMessageID;
     }
     if (threadsRow.user) {
       const userID = threadsRow.user.toString();
       const allPermissions = getAllThreadPermissions(
         JSON.parse(threadsRow.permissions),
         threadID,
       );
       threadInfos[threadID].members.push({
         id: userID,
         permissions: allPermissions,
         role: threadsRow.role ? threadsRow.role.toString() : null,
         subscription: JSON.parse(threadsRow.subscription),
         unread: threadsRow.role ? !!threadsRow.unread : null,
         isSender: !!threadsRow.sender,
       });
     }
   }
 
   for (const rolesRow of rolesResult) {
     const threadID = rolesRow.id.toString();
     if (!rolesRow.role) {
       continue;
     }
     const role = rolesRow.role.toString();
     if (!threadInfos[threadID].roles[role]) {
       const roleInfo: ServerLegacyRoleInfo = {
         id: role,
         name: rolesRow.name,
         permissions: JSON.parse(rolesRow.permissions),
         isDefault: Boolean(rolesRow.is_default),
         specialRole: rolesRow.special_role,
       };
       threadInfos[threadID].roles[role] = roleInfo;
     }
   }
 
   return { threadInfos };
 }
 
 export type FetchThreadInfosResult = {
   +threadInfos: MixedRawThreadInfos,
 };
 
 async function fetchThreadInfos(
   viewer: Viewer,
   inputFilter?: FetchThreadInfosFilter,
 ): Promise<FetchThreadInfosResult> {
   const filter = {
     accessibleToUserID: viewer.id,
     ...inputFilter,
   };
   const serverResult = await fetchServerThreadInfos(filter);
   return rawThreadInfosFromServerThreadInfos(viewer, serverResult);
 }
 
 function rawThreadInfosFromServerThreadInfos(
   viewer: Viewer,
   serverResult: FetchServerThreadInfosResult,
 ): FetchThreadInfosResult {
   const viewerID = viewer.id;
   const codeVersionBelow209 = !hasMinCodeVersion(viewer.platformDetails, {
     native: 209,
   });
   const codeVersionBelow213 = !hasMinCodeVersion(viewer.platformDetails, {
     native: 213,
   });
   const codeVersionBelow221 = !hasMinCodeVersion(viewer.platformDetails, {
     native: 221,
   });
   const codeVersionBelow283 = !hasMinCodeVersion(viewer.platformDetails, {
     native: 285,
   });
   const minimallyEncodedPermissionsSupported = hasMinCodeVersion(
     viewer.platformDetails,
     { native: 301, web: 56 },
   );
   const specialRoleFieldSupported = hasMinCodeVersion(viewer.platformDetails, {
     native: 336,
     web: 79,
   });
+  const addingUsersToCommunityRootSupported = !hasMinCodeVersion(
+    viewer.platformDetails,
+    {
+      native: FUTURE_CODE_VERSION,
+      web: FUTURE_CODE_VERSION,
+    },
+  );
 
   const threadInfos: {
     [string]: LegacyRawThreadInfo | RawThreadInfo,
   } = {};
   for (const threadID in serverResult.threadInfos) {
     const serverThreadInfo = serverResult.threadInfos[threadID];
     const threadInfo = rawThreadInfoFromServerThreadInfo(
       serverThreadInfo,
       viewerID,
       {
         filterThreadEditAvatarPermission: codeVersionBelow213,
         excludePinInfo: codeVersionBelow209,
         filterManageInviteLinksPermission: codeVersionBelow221,
         filterVoicedInAnnouncementChannelsPermission: codeVersionBelow283,
         minimallyEncodePermissions: minimallyEncodedPermissionsSupported,
         includeSpecialRoleFieldInRoles: specialRoleFieldSupported,
+        allowAddingUsersToCommunityRoot: addingUsersToCommunityRootSupported,
       },
     );
     if (threadInfo) {
       threadInfos[threadID] = threadInfo;
     }
   }
   return { threadInfos };
 }
 
 async function verifyThreadIDs(
   threadIDs: $ReadOnlyArray<string>,
 ): Promise<$ReadOnlyArray<string>> {
   if (threadIDs.length === 0) {
     return [];
   }
 
   const query = SQL`SELECT id FROM threads WHERE id IN (${threadIDs})`;
   const [result] = await dbQuery(query);
 
   const verified = [];
   for (const row of result) {
     verified.push(row.id.toString());
   }
   return verified;
 }
 
 async function verifyThreadID(threadID: string): Promise<boolean> {
   const result = await verifyThreadIDs([threadID]);
   return result.length !== 0;
 }
 
 type ThreadAncestry = {
   +containingThreadID: ?string,
   +community: ?string,
   +depth: number,
 };
 async function determineThreadAncestry(
   parentThreadID: ?string,
   threadType: ThreadType,
 ): Promise<ThreadAncestry> {
   if (!parentThreadID) {
     return { containingThreadID: null, community: null, depth: 0 };
   }
   const parentThreadInfos = await fetchServerThreadInfos({
     threadID: parentThreadID,
   });
   const parentThreadInfo = parentThreadInfos.threadInfos[parentThreadID];
   if (!parentThreadInfo) {
     throw new ServerError('invalid_parameters');
   }
   const containingThreadID = getContainingThreadID(
     parentThreadInfo,
     threadType,
   );
   const community = getCommunity(parentThreadInfo);
   const depth = parentThreadInfo.depth + 1;
   return { containingThreadID, community, depth };
 }
 
 function personalThreadQuery(
   firstMemberID: string,
   secondMemberID: string,
 ): SQLStatementType {
   return SQL`
     SELECT t.id 
     FROM threads t
     INNER JOIN memberships m1 
       ON m1.thread = t.id AND m1.user = ${firstMemberID}
     INNER JOIN memberships m2
       ON m2.thread = t.id AND m2.user = ${secondMemberID}
     WHERE t.type = ${threadTypes.PERSONAL}
       AND m1.role > 0
       AND m2.role > 0
   `;
 }
 
 async function fetchPersonalThreadID(
   viewerID: string,
   otherMemberID: string,
 ): Promise<?string> {
   const query = personalThreadQuery(viewerID, otherMemberID);
   const [threads] = await dbQuery(query);
   return threads[0]?.id.toString();
 }
 
 async function serverThreadInfoFromMessageInfo(
   message: RawMessageInfo | MessageInfo,
 ): Promise<?ServerThreadInfo> {
   const threadID = message.threadID;
   const threads = await fetchServerThreadInfos({ threadID });
   return threads.threadInfos[threadID];
 }
 
 async function fetchContainedThreadIDs(
   parentThreadID: string,
 ): Promise<Array<string>> {
   const query = SQL`
     WITH RECURSIVE thread_tree AS (
       SELECT id, containing_thread_id
       FROM threads
       WHERE id = ${parentThreadID}
       UNION ALL
       SELECT t.id, t.containing_thread_id
       FROM threads t
       JOIN thread_tree tt ON t.containing_thread_id = tt.id
     )
     SELECT id FROM thread_tree
   `;
   const [result] = await dbQuery(query);
   return result.map(row => row.id.toString());
 }
 
 export {
   fetchServerThreadInfos,
   fetchThreadInfos,
   rawThreadInfosFromServerThreadInfos,
   verifyThreadIDs,
   verifyThreadID,
   determineThreadAncestry,
   personalThreadQuery,
   fetchPersonalThreadID,
   serverThreadInfoFromMessageInfo,
   fetchContainedThreadIDs,
 };
diff --git a/lib/permissions/thread-permissions.js b/lib/permissions/thread-permissions.js
index eac4a921c..62ac89824 100644
--- a/lib/permissions/thread-permissions.js
+++ b/lib/permissions/thread-permissions.js
@@ -1,505 +1,507 @@
 // @flow
 
 import invariant from 'invariant';
 
 import {
   parseThreadPermissionString,
   includeThreadPermissionForThreadType,
 } from './prefixes.js';
 import {
   configurableCommunityPermissions,
   threadPermissionFilterPrefixes,
   threadPermissionPropagationPrefixes,
   threadPermissions,
   userSurfacedPermissions,
 } from '../types/thread-permission-types.js';
 import type {
   ThreadPermission,
   ThreadPermissionInfo,
   ThreadPermissionsBlob,
   ThreadPermissionsInfo,
   ThreadRolePermissionsBlob,
   UserSurfacedPermission,
 } from '../types/thread-permission-types.js';
 import {
   type ThreadType,
   threadTypes,
   threadTypeIsAnnouncementThread,
 } from '../types/thread-types-enum.js';
 
 function permissionLookup(
   permissions: ?ThreadPermissionsBlob | ?ThreadPermissionsInfo,
   permission: ThreadPermission,
 ): boolean {
   return !!(
     permissions &&
     permissions[permission] &&
     permissions[permission].value &&
     permissions[threadPermissions.KNOW_OF] &&
     permissions[threadPermissions.KNOW_OF].value
   );
 }
 
 function getAllThreadPermissions(
   permissions: ?ThreadPermissionsBlob,
   threadID: string,
 ): ThreadPermissionsInfo {
   const result: { [permission: ThreadPermission]: ThreadPermissionInfo } = {};
   for (const permissionName in threadPermissions) {
     const permissionKey = threadPermissions[permissionName];
     const permission = permissionLookup(permissions, permissionKey);
     let entry: ThreadPermissionInfo = { value: false, source: null };
     if (permission) {
       const blobEntry = permissions ? permissions[permissionKey] : null;
       if (blobEntry) {
         invariant(
           blobEntry.value,
           'permissionLookup returned true but blob had false permission!',
         );
         entry = { value: true, source: blobEntry.source };
       } else {
         entry = { value: true, source: threadID };
       }
     }
     result[permissionKey] = entry;
   }
   return result;
 }
 
 // - rolePermissions can be null if role <= 0, ie. not a member
 // - permissionsFromParent can be null if there are no permissions from the
 //   parent
 // - return can be null if no permissions exist
 function makePermissionsBlob(
   rolePermissions: ?ThreadRolePermissionsBlob,
   permissionsFromParent: ?ThreadPermissionsBlob,
   threadID: string,
   threadType: ThreadType,
 ): ?ThreadPermissionsBlob {
   let permissions: { [permission: string]: ThreadPermissionInfo } = {};
 
   if (permissionsFromParent) {
     for (const permissionKey in permissionsFromParent) {
       const permissionValue = permissionsFromParent[permissionKey];
       const parsed = parseThreadPermissionString(permissionKey);
       if (!includeThreadPermissionForThreadType(parsed, threadType)) {
         continue;
       }
       if (parsed.propagationPrefix) {
         permissions[permissionKey] = permissionValue;
       } else {
         permissions[parsed.permission] = permissionValue;
       }
     }
   }
 
   const combinedPermissions: {
     [permission: string]: ThreadPermissionInfo,
   } = { ...permissions };
   if (rolePermissions) {
     for (const permissionKey in rolePermissions) {
       const permissionValue = rolePermissions[permissionKey];
       const currentValue = combinedPermissions[permissionKey];
       if (permissionValue) {
         combinedPermissions[permissionKey] = {
           value: true,
           source: threadID,
         };
       } else if (!currentValue || !currentValue.value) {
         combinedPermissions[permissionKey] = {
           value: false,
           source: null,
         };
       }
     }
   }
   if (permissionLookup(combinedPermissions, threadPermissions.KNOW_OF)) {
     permissions = combinedPermissions;
   }
 
   const threadIsAnnouncementThread = threadTypeIsAnnouncementThread(threadType);
   const hasVoicedInAnnouncementChannelsPermission = permissionLookup(
     (permissions: ThreadPermissionsBlob),
     threadPermissions.VOICED_IN_ANNOUNCEMENT_CHANNELS,
   );
   const isMember = !!rolePermissions;
 
   if (
     threadIsAnnouncementThread &&
     hasVoicedInAnnouncementChannelsPermission &&
     isMember
   ) {
     permissions[threadPermissions.VOICED] = {
       value: true,
       source: threadID,
     };
   }
 
   if (Object.keys(permissions).length === 0) {
     return null;
   }
 
   return permissions;
 }
 
 function makePermissionsForChildrenBlob(
   permissions: ?ThreadPermissionsBlob,
 ): ?ThreadPermissionsBlob {
   if (!permissions) {
     return null;
   }
   const permissionsForChildren: { [permission: string]: ThreadPermissionInfo } =
     {};
   for (const permissionKey in permissions) {
     const permissionValue = permissions[permissionKey];
     const parsed = parseThreadPermissionString(permissionKey);
     if (!parsed.propagationPrefix) {
       continue;
     }
     if (
       parsed.propagationPrefix ===
       threadPermissionPropagationPrefixes.DESCENDANT
     ) {
       permissionsForChildren[permissionKey] = permissionValue;
     }
     const permissionWithFilterPrefix = parsed.filterPrefix
       ? `${parsed.filterPrefix}${parsed.permission}`
       : parsed.permission;
     permissionsForChildren[permissionWithFilterPrefix] = permissionValue;
   }
   if (Object.keys(permissionsForChildren).length === 0) {
     return null;
   }
   return permissionsForChildren;
 }
 
 function getRoleForPermissions(
   inputRole: string,
   permissions: ?ThreadPermissionsBlob,
 ): string {
   if (!permissionLookup(permissions, threadPermissions.KNOW_OF)) {
     return '-1';
   } else if (Number(inputRole) <= 0) {
     return '0';
   } else {
     return inputRole;
   }
 }
 
 function getThreadPermissionBlobFromUserSurfacedPermissions(
   communityUserSurfacedPermissions: $ReadOnlyArray<UserSurfacedPermission>,
   threadType: ThreadType,
 ): ThreadRolePermissionsBlob {
   const mappedUserSurfacedPermissions = communityUserSurfacedPermissions
     .map(permission => [...configurableCommunityPermissions[permission]])
     .flat();
 
   const userSurfacedPermissionsObj = Object.fromEntries(
     mappedUserSurfacedPermissions.map(p => [p, true]),
   );
 
   const universalCommunityPermissions =
     getUniversalCommunityRootPermissionsBlob(threadType);
 
   return {
     ...universalCommunityPermissions,
     ...userSurfacedPermissionsObj,
   };
 }
 
 export type RolePermissionBlobs = {
   +Members: ThreadRolePermissionsBlob,
   +Admins?: ThreadRolePermissionsBlob,
 };
 
 const { CHILD, DESCENDANT } = threadPermissionPropagationPrefixes;
 const { OPEN, TOP_LEVEL, OPEN_TOP_LEVEL } = threadPermissionFilterPrefixes;
 const OPEN_CHILD = CHILD + OPEN;
 const OPEN_DESCENDANT = DESCENDANT + OPEN;
 const TOP_LEVEL_DESCENDANT = DESCENDANT + TOP_LEVEL;
 const OPEN_TOP_LEVEL_DESCENDANT = DESCENDANT + OPEN_TOP_LEVEL;
 
 const baseMemberUserSurfacedPermissions = [
   userSurfacedPermissions.REACT_TO_MESSAGES,
   userSurfacedPermissions.EDIT_MESSAGES,
   userSurfacedPermissions.ADD_MEMBERS,
 ];
 const baseVoicedUserSurfacedPermissions = [
   userSurfacedPermissions.EDIT_CALENDAR,
   userSurfacedPermissions.CREATE_AND_EDIT_CHANNELS,
 ];
 
 function getRolePermissionBlobsForCommunityRoot(
   threadType: ThreadType,
 ): RolePermissionBlobs {
   let memberUserSurfacedPermissions;
   if (threadType === threadTypes.GENESIS) {
     memberUserSurfacedPermissions = [];
   } else if (threadType === threadTypes.COMMUNITY_ANNOUNCEMENT_ROOT) {
     memberUserSurfacedPermissions = baseMemberUserSurfacedPermissions;
   } else {
     memberUserSurfacedPermissions = [
       ...baseMemberUserSurfacedPermissions,
       ...baseVoicedUserSurfacedPermissions,
     ];
   }
 
   const memberPermissions = getThreadPermissionBlobFromUserSurfacedPermissions(
     memberUserSurfacedPermissions,
     threadType,
   );
 
   const descendantKnowOf = DESCENDANT + threadPermissions.KNOW_OF;
   const descendantVisible = DESCENDANT + threadPermissions.VISIBLE;
   const topLevelDescendantJoinThread =
     TOP_LEVEL_DESCENDANT + threadPermissions.JOIN_THREAD;
   const childJoinThread = CHILD + threadPermissions.JOIN_THREAD;
   const descendantVoiced = DESCENDANT + threadPermissions.VOICED;
   const descendantEditEntries = DESCENDANT + threadPermissions.EDIT_ENTRIES;
   const descendantEditThreadName =
     DESCENDANT + threadPermissions.EDIT_THREAD_NAME;
   const descendantEditThreadColor =
     DESCENDANT + threadPermissions.EDIT_THREAD_COLOR;
   const descendantEditThreadDescription =
     DESCENDANT + threadPermissions.EDIT_THREAD_DESCRIPTION;
   const descendantEditThreadAvatar =
     DESCENDANT + threadPermissions.EDIT_THREAD_AVATAR;
   const topLevelDescendantCreateSubchannels =
     TOP_LEVEL_DESCENDANT + threadPermissions.CREATE_SUBCHANNELS;
   const topLevelDescendantCreateSidebars =
     TOP_LEVEL_DESCENDANT + threadPermissions.CREATE_SIDEBARS;
   const descendantAddMembers = DESCENDANT + threadPermissions.ADD_MEMBERS;
   const descendantDeleteThread = DESCENDANT + threadPermissions.DELETE_THREAD;
   const descendantEditPermissions =
     DESCENDANT + threadPermissions.EDIT_PERMISSIONS;
   const descendantRemoveMembers = DESCENDANT + threadPermissions.REMOVE_MEMBERS;
   const descendantChangeRole = DESCENDANT + threadPermissions.CHANGE_ROLE;
   const descendantManagePins = DESCENDANT + threadPermissions.MANAGE_PINS;
   const topLevelDescendantVoicedInAnnouncementChannels =
     TOP_LEVEL_DESCENDANT + threadPermissions.VOICED_IN_ANNOUNCEMENT_CHANNELS;
 
   const baseAdminPermissions = {
     [threadPermissions.KNOW_OF]: true,
     [threadPermissions.VISIBLE]: true,
     [threadPermissions.VOICED]: true,
     [threadPermissions.REACT_TO_MESSAGE]: true,
     [threadPermissions.EDIT_MESSAGE]: true,
     [threadPermissions.EDIT_ENTRIES]: true,
     [threadPermissions.EDIT_THREAD_NAME]: true,
     [threadPermissions.EDIT_THREAD_COLOR]: true,
     [threadPermissions.EDIT_THREAD_DESCRIPTION]: true,
     [threadPermissions.EDIT_THREAD_AVATAR]: true,
     [threadPermissions.CREATE_SUBCHANNELS]: true,
     [threadPermissions.CREATE_SIDEBARS]: true,
-    [threadPermissions.ADD_MEMBERS]: true,
     [threadPermissions.DELETE_THREAD]: true,
     [threadPermissions.REMOVE_MEMBERS]: true,
     [threadPermissions.CHANGE_ROLE]: true,
     [threadPermissions.MANAGE_PINS]: true,
     [threadPermissions.MANAGE_INVITE_LINKS]: true,
     [threadPermissions.VOICED_IN_ANNOUNCEMENT_CHANNELS]: true,
     [descendantKnowOf]: true,
     [descendantVisible]: true,
     [topLevelDescendantJoinThread]: true,
     [childJoinThread]: true,
     [descendantVoiced]: true,
     [descendantEditEntries]: true,
     [descendantEditThreadName]: true,
     [descendantEditThreadColor]: true,
     [descendantEditThreadDescription]: true,
     [descendantEditThreadAvatar]: true,
     [topLevelDescendantCreateSubchannels]: true,
     [topLevelDescendantCreateSidebars]: true,
     [descendantAddMembers]: true,
     [descendantDeleteThread]: true,
     [descendantEditPermissions]: true,
     [descendantRemoveMembers]: true,
     [descendantChangeRole]: true,
     [descendantManagePins]: true,
     [topLevelDescendantVoicedInAnnouncementChannels]: true,
   };
 
   let adminPermissions;
   if (threadType === threadTypes.GENESIS) {
-    adminPermissions = baseAdminPermissions;
+    adminPermissions = {
+      ...baseAdminPermissions,
+      [threadPermissions.ADD_MEMBERS]: true,
+    };
   } else {
     adminPermissions = {
       ...baseAdminPermissions,
       [threadPermissions.LEAVE_THREAD]: true,
     };
   }
 
   return {
     Members: memberPermissions,
     Admins: adminPermissions,
   };
 }
 
 const nonCommunityVoicedPermissions = {
   [threadPermissions.VOICED]: true,
   [threadPermissions.EDIT_ENTRIES]: true,
   [threadPermissions.EDIT_THREAD_NAME]: true,
   [threadPermissions.EDIT_THREAD_COLOR]: true,
   [threadPermissions.EDIT_THREAD_DESCRIPTION]: true,
   [threadPermissions.EDIT_THREAD_AVATAR]: true,
   [threadPermissions.CREATE_SUBCHANNELS]: true,
   [threadPermissions.ADD_MEMBERS]: true,
 };
 
 function getRolePermissionBlobs(threadType: ThreadType): RolePermissionBlobs {
   if (threadType === threadTypes.SIDEBAR) {
     const memberPermissions = {
       [threadPermissions.VOICED]: true,
       [threadPermissions.REACT_TO_MESSAGE]: true,
       [threadPermissions.EDIT_MESSAGE]: true,
       [threadPermissions.EDIT_THREAD_NAME]: true,
       [threadPermissions.EDIT_THREAD_COLOR]: true,
       [threadPermissions.EDIT_THREAD_DESCRIPTION]: true,
       [threadPermissions.EDIT_THREAD_AVATAR]: true,
       [threadPermissions.ADD_MEMBERS]: true,
       [threadPermissions.EDIT_PERMISSIONS]: true,
       [threadPermissions.REMOVE_MEMBERS]: true,
       [threadPermissions.LEAVE_THREAD]: true,
     };
     return {
       Members: memberPermissions,
     };
   }
 
   const openDescendantKnowOf = OPEN_DESCENDANT + threadPermissions.KNOW_OF;
   const openDescendantVisible = OPEN_DESCENDANT + threadPermissions.VISIBLE;
   const openChildJoinThread = OPEN_CHILD + threadPermissions.JOIN_THREAD;
 
   if (threadType === threadTypes.PRIVATE) {
     const memberPermissions = {
       [threadPermissions.KNOW_OF]: true,
       [threadPermissions.VISIBLE]: true,
       [threadPermissions.VOICED]: true,
       [threadPermissions.REACT_TO_MESSAGE]: true,
       [threadPermissions.EDIT_MESSAGE]: true,
       [threadPermissions.EDIT_THREAD_COLOR]: true,
       [threadPermissions.EDIT_THREAD_DESCRIPTION]: true,
       [threadPermissions.CREATE_SIDEBARS]: true,
       [threadPermissions.EDIT_ENTRIES]: true,
       [openDescendantKnowOf]: true,
       [openDescendantVisible]: true,
       [openChildJoinThread]: true,
     };
     return {
       Members: memberPermissions,
     };
   }
 
   if (threadType === threadTypes.PERSONAL) {
     return {
       Members: {
         [threadPermissions.KNOW_OF]: true,
         [threadPermissions.VISIBLE]: true,
         [threadPermissions.VOICED]: true,
         [threadPermissions.REACT_TO_MESSAGE]: true,
         [threadPermissions.EDIT_MESSAGE]: true,
         [threadPermissions.EDIT_ENTRIES]: true,
         [threadPermissions.EDIT_THREAD_NAME]: true,
         [threadPermissions.EDIT_THREAD_COLOR]: true,
         [threadPermissions.EDIT_THREAD_DESCRIPTION]: true,
         [threadPermissions.CREATE_SIDEBARS]: true,
         [openDescendantKnowOf]: true,
         [openDescendantVisible]: true,
         [openChildJoinThread]: true,
       },
     };
   }
 
   const openTopLevelDescendantJoinThread =
     OPEN_TOP_LEVEL_DESCENDANT + threadPermissions.JOIN_THREAD;
 
   const subthreadBasePermissions = {
     [threadPermissions.KNOW_OF]: true,
     [threadPermissions.VISIBLE]: true,
     [threadPermissions.REACT_TO_MESSAGE]: true,
     [threadPermissions.EDIT_MESSAGE]: true,
     [threadPermissions.CREATE_SIDEBARS]: true,
     [threadPermissions.LEAVE_THREAD]: true,
     [openDescendantKnowOf]: true,
     [openDescendantVisible]: true,
     [openTopLevelDescendantJoinThread]: true,
     [openChildJoinThread]: true,
   };
 
   if (
     threadType === threadTypes.COMMUNITY_OPEN_SUBTHREAD ||
     threadType === threadTypes.COMMUNITY_SECRET_SUBTHREAD
   ) {
     const memberPermissions = {
       [threadPermissions.REMOVE_MEMBERS]: true,
       [threadPermissions.EDIT_PERMISSIONS]: true,
       ...subthreadBasePermissions,
       ...nonCommunityVoicedPermissions,
     };
     return {
       Members: memberPermissions,
     };
   }
 
   if (
     threadType === threadTypes.COMMUNITY_OPEN_ANNOUNCEMENT_SUBTHREAD ||
     threadType === threadTypes.COMMUNITY_SECRET_ANNOUNCEMENT_SUBTHREAD
   ) {
     return {
       Members: subthreadBasePermissions,
     };
   }
 
   return getRolePermissionBlobsForCommunityRoot(threadType);
 }
 
 // ESLint doesn't recognize that invariant always throws
 // eslint-disable-next-line consistent-return
 function getUniversalCommunityRootPermissionsBlob(
   threadType: ThreadType,
 ): ThreadRolePermissionsBlob {
   const openDescendantKnowOf = OPEN_DESCENDANT + threadPermissions.KNOW_OF;
   const openDescendantVisible = OPEN_DESCENDANT + threadPermissions.VISIBLE;
   const openChildJoinThread = OPEN_CHILD + threadPermissions.JOIN_THREAD;
   const openTopLevelDescendantJoinThread =
     OPEN_TOP_LEVEL_DESCENDANT + threadPermissions.JOIN_THREAD;
 
   const genesisUniversalCommunityPermissions = {
     [threadPermissions.KNOW_OF]: true,
     [threadPermissions.VISIBLE]: true,
     [openDescendantKnowOf]: true,
     [openDescendantVisible]: true,
     [openTopLevelDescendantJoinThread]: true,
   };
 
   const baseUniversalCommunityPermissions = {
     ...genesisUniversalCommunityPermissions,
     [threadPermissions.CREATE_SIDEBARS]: true,
     [threadPermissions.LEAVE_THREAD]: true,
     [openChildJoinThread]: true,
   };
 
   if (threadType === threadTypes.GENESIS) {
     return genesisUniversalCommunityPermissions;
   } else if (threadType === threadTypes.COMMUNITY_ANNOUNCEMENT_ROOT) {
     return baseUniversalCommunityPermissions;
   } else if (threadType === threadTypes.COMMUNITY_ROOT) {
     return {
       ...baseUniversalCommunityPermissions,
       [threadPermissions.VOICED]: true,
     };
   }
 
   invariant(false, 'invalid threadType parameter');
 }
 
 export {
   permissionLookup,
   getAllThreadPermissions,
   makePermissionsBlob,
   makePermissionsForChildrenBlob,
   getRoleForPermissions,
   getThreadPermissionBlobFromUserSurfacedPermissions,
   getRolePermissionBlobs,
   getUniversalCommunityRootPermissionsBlob,
 };
diff --git a/lib/shared/thread-utils.js b/lib/shared/thread-utils.js
index e02f69933..4c00680f8 100644
--- a/lib/shared/thread-utils.js
+++ b/lib/shared/thread-utils.js
@@ -1,1703 +1,1723 @@
 // @flow
 
 import invariant from 'invariant';
 import _find from 'lodash/fp/find.js';
 import _keyBy from 'lodash/fp/keyBy.js';
 import _mapValues from 'lodash/fp/mapValues.js';
 import _omit from 'lodash/fp/omit.js';
 import _omitBy from 'lodash/fp/omitBy.js';
 import * as React from 'react';
 
 import { getUserAvatarForThread } from './avatar-utils.js';
 import { generatePendingThreadColor } from './color-utils.js';
 import { extractUserMentionsFromText } from './mention-utils.js';
 import { relationshipBlockedInEitherDirection } from './relationship-utils.js';
 import ashoat from '../facts/ashoat.js';
 import genesis from '../facts/genesis.js';
 import { useLoggedInUserInfo } from '../hooks/account-hooks.js';
 import { extractKeyserverIDFromID } from '../keyserver-conn/keyserver-call-utils.js';
 import {
   hasPermission,
   permissionsToBitmaskHex,
   threadPermissionsFromBitmaskHex,
 } from '../permissions/minimally-encoded-thread-permissions.js';
 import { specialRoles } from '../permissions/special-roles.js';
 import type { SpecialRole } from '../permissions/special-roles.js';
 import {
   permissionLookup,
   getAllThreadPermissions,
   makePermissionsBlob,
 } from '../permissions/thread-permissions.js';
 import type { ChatThreadItem } from '../selectors/chat-selectors.js';
 import {
   threadInfoSelector,
   pendingToRealizedThreadIDsSelector,
   threadInfosSelectorForThreadType,
   onScreenThreadInfos,
 } from '../selectors/thread-selectors.js';
 import {
   getRelativeMemberInfos,
   usersWithPersonalThreadSelector,
 } from '../selectors/user-selectors.js';
 import type {
   RelativeMemberInfo,
   RawThreadInfo,
   MemberInfo,
   ThreadCurrentUserInfo,
   RoleInfo,
   ThreadInfo,
 } from '../types/minimally-encoded-thread-permissions-types.js';
 import {
   decodeMinimallyEncodedRoleInfo,
   minimallyEncodeMemberInfo,
   minimallyEncodeRawThreadInfo,
   minimallyEncodeRoleInfo,
   minimallyEncodeThreadCurrentUserInfo,
 } from '../types/minimally-encoded-thread-permissions-types.js';
 import { userRelationshipStatus } from '../types/relationship-types.js';
 import {
   threadPermissionPropagationPrefixes,
   threadPermissions,
   configurableCommunityPermissions,
   type ThreadPermission,
   type ThreadPermissionsInfo,
   type ThreadRolePermissionsBlob,
   type UserSurfacedPermission,
   threadPermissionFilterPrefixes,
   threadPermissionsDisabledByBlock,
   type ThreadPermissionNotAffectedByBlock,
 } from '../types/thread-permission-types.js';
 import {
   type ThreadType,
   threadTypes,
   threadTypeIsCommunityRoot,
   assertThreadType,
 } from '../types/thread-types-enum.js';
 import type {
   LegacyRawThreadInfo,
   ClientLegacyRoleInfo,
   ServerThreadInfo,
   ServerMemberInfo,
   UserProfileThreadInfo,
   MixedRawThreadInfos,
   LegacyMemberInfo,
 } from '../types/thread-types.js';
 import { updateTypes } from '../types/update-types-enum.js';
 import { type ClientUpdateInfo } from '../types/update-types.js';
 import type {
   GlobalAccountUserInfo,
   UserInfos,
   AccountUserInfo,
   LoggedInUserInfo,
   UserInfo,
 } from '../types/user-types.js';
 import {
   ET,
   type ThreadEntity,
   type UserEntity,
 } from '../utils/entity-text.js';
 import { entries, values } from '../utils/objects.js';
 import { useSelector } from '../utils/redux-utils.js';
 import { firstLine } from '../utils/string-utils.js';
 import { pendingThreadIDRegex } from '../utils/validation-utils.js';
 
 function threadHasPermission(
   threadInfo: ?(ThreadInfo | LegacyRawThreadInfo | RawThreadInfo),
   permission: ThreadPermissionNotAffectedByBlock,
 ): 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.minimallyEncoded) {
     return hasPermission(threadInfo.currentUser.permissions, permission);
   }
   return permissionLookup(threadInfo.currentUser.permissions, permission);
 }
 
 type CommunityRootMembersToRoleType = {
   +[threadID: ?string]: {
     +[memberID: string]: ?RoleInfo,
   },
 };
 function useCommunityRootMembersToRole(
   threadInfos: $ReadOnlyArray<RawThreadInfo | ThreadInfo>,
 ): CommunityRootMembersToRoleType {
   const communityRootMembersToRole = React.useMemo(() => {
     const communityThreadInfos = threadInfos.filter(threadInfo =>
       threadTypeIsCommunityRoot(threadInfo.type),
     );
     const communityRoots = _keyBy('id')(communityThreadInfos);
 
     return _mapValues((threadInfo: ThreadInfo) => {
       const keyedMembers = _keyBy('id')(threadInfo.members);
       const keyedMembersToRole = _mapValues(
         (member: MemberInfo | RelativeMemberInfo) => {
           return member.role ? threadInfo.roles[member.role] : null;
         },
       )(keyedMembers);
       return keyedMembersToRole;
     })(communityRoots);
   }, [threadInfos]);
 
   return communityRootMembersToRole;
 }
 
 function useThreadsWithPermission(
   threadInfos: $ReadOnlyArray<ThreadInfo>,
   permission: ThreadPermission,
 ): $ReadOnlyArray<ThreadInfo> {
   const loggedInUserInfo = useLoggedInUserInfo();
   const userInfos = useSelector(state => state.userStore.userInfos);
   const allThreadInfos = useSelector(state => state.threadStore.threadInfos);
   const allThreadInfosArray = React.useMemo(
     () => values(allThreadInfos),
     [allThreadInfos],
   );
 
   const communityRootMembersToRole =
     useCommunityRootMembersToRole(allThreadInfosArray);
 
   return React.useMemo(() => {
     return threadInfos.filter((threadInfo: ThreadInfo) => {
       const membersToRole = communityRootMembersToRole[threadInfo.id];
       const memberHasAdminRole = threadMembersWithoutAddedAdmin(
         threadInfo,
       ).some(member => roleIsAdminRole(membersToRole?.[member.id]));
 
       if (memberHasAdminRole || !loggedInUserInfo) {
         return hasPermission(threadInfo.currentUser.permissions, permission);
       }
 
       const threadFrozen = innerThreadFrozenDueToBlock(
         threadInfo,
         loggedInUserInfo.id,
         userInfos,
         true,
       );
 
       const permissions = threadFrozen
         ? filterOutDisabledPermissions(threadInfo.currentUser.permissions)
         : threadInfo.currentUser.permissions;
 
       return hasPermission(permissions, permission);
     });
   }, [
     threadInfos,
     communityRootMembersToRole,
     loggedInUserInfo,
     userInfos,
     permission,
   ]);
 }
 
 function useThreadHasPermission(
   threadInfo: ?ThreadInfo,
   permission: ThreadPermission,
 ): boolean {
   const threads = useThreadsWithPermission(
     threadInfo ? [threadInfo] : [],
     permission,
   );
   return threads.length === 1;
 }
 
 function viewerIsMember(
   threadInfo: ?(ThreadInfo | LegacyRawThreadInfo | RawThreadInfo),
 ): boolean {
   return !!(
     threadInfo &&
     threadInfo.currentUser.role !== null &&
     threadInfo.currentUser.role !== undefined
   );
 }
 
 function threadIsInHome(threadInfo: ?(RawThreadInfo | ThreadInfo)): boolean {
   return !!(threadInfo && threadInfo.currentUser.subscription.home);
 }
 
 // Can have messages
 function threadInChatList(
   threadInfo: ?(LegacyRawThreadInfo | RawThreadInfo | ThreadInfo),
 ): boolean {
   return (
     viewerIsMember(threadInfo) &&
     threadHasPermission(threadInfo, threadPermissions.VISIBLE)
   );
 }
 
 function useIsThreadInChatList(threadInfo: ?ThreadInfo): boolean {
   const threadIsVisible = useThreadHasPermission(
     threadInfo,
     threadPermissions.VISIBLE,
   );
   return viewerIsMember(threadInfo) && threadIsVisible;
 }
 
 function useThreadsInChatList(
   threadInfos: $ReadOnlyArray<ThreadInfo>,
 ): $ReadOnlyArray<ThreadInfo> {
   const visibleThreads = useThreadsWithPermission(
     threadInfos,
     threadPermissions.VISIBLE,
   );
   return React.useMemo(
     () => visibleThreads.filter(viewerIsMember),
     [visibleThreads],
   );
 }
 
 function threadIsTopLevel(threadInfo: ?(RawThreadInfo | ThreadInfo)): boolean {
   return threadInChatList(threadInfo) && threadIsChannel(threadInfo);
 }
 
 function threadIsChannel(threadInfo: ?(RawThreadInfo | ThreadInfo)): boolean {
   return !!(threadInfo && threadInfo.type !== threadTypes.SIDEBAR);
 }
 
 function threadIsSidebar(threadInfo: ?(RawThreadInfo | ThreadInfo)): boolean {
   return threadInfo?.type === threadTypes.SIDEBAR;
 }
 
 function threadInBackgroundChatList(
   threadInfo: ?(RawThreadInfo | ThreadInfo),
 ): boolean {
   return threadInChatList(threadInfo) && !threadIsInHome(threadInfo);
 }
 
 function threadInHomeChatList(
   threadInfo: ?(RawThreadInfo | ThreadInfo),
 ): boolean {
   return threadInChatList(threadInfo) && threadIsInHome(threadInfo);
 }
 
 // Can have Calendar entries,
 // does appear as a top-level entity in the thread list
 function threadInFilterList(
   threadInfo: ?(LegacyRawThreadInfo | RawThreadInfo | ThreadInfo),
 ): boolean {
   return (
     threadInChatList(threadInfo) &&
     !!threadInfo &&
     threadInfo.type !== threadTypes.SIDEBAR
   );
 }
 
 function userIsMember(
   threadInfo: ?(RawThreadInfo | ThreadInfo),
   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 threadOtherMembers<
   T: LegacyMemberInfo | MemberInfo | RelativeMemberInfo,
 >(memberInfos: $ReadOnlyArray<T>, viewerID: ?string): $ReadOnlyArray<T> {
   return memberInfos.filter(
     memberInfo => memberInfo.role && memberInfo.id !== viewerID,
   );
 }
 
 function threadMembersWithoutAddedAdmin<
   T: LegacyRawThreadInfo | RawThreadInfo | ThreadInfo,
 >(threadInfo: T): $PropertyType<T, 'members'> {
   if (threadInfo.community !== genesis().id) {
     return threadInfo.members;
   }
   const adminID = extractKeyserverIDFromID(threadInfo.id);
 
   return threadInfo.members.filter(
     member => member.id !== adminID || member.role,
   );
 }
 
 function threadIsGroupChat(threadInfo: ThreadInfo): boolean {
   return threadInfo.members.length > 2;
 }
 
 function threadOrParentThreadIsGroupChat(
   threadInfo: LegacyRawThreadInfo | RawThreadInfo | ThreadInfo,
 ) {
   return threadMembersWithoutAddedAdmin(threadInfo).length > 2;
 }
 
 function threadIsPending(threadID: ?string): boolean {
   return !!threadID?.startsWith('pending');
 }
 
 function threadIsPendingSidebar(threadID: ?string): boolean {
   return !!threadID?.startsWith('pending/sidebar/');
 }
 
 function getSingleOtherUser(
   threadInfo: LegacyRawThreadInfo | RawThreadInfo | ThreadInfo,
   viewerID: ?string,
 ): ?string {
   if (!viewerID) {
     return undefined;
   }
   const otherMembers = threadOtherMembers(threadInfo.members, viewerID);
   if (otherMembers.length !== 1) {
     return undefined;
   }
   return otherMembers[0].id;
 }
 
 function getPendingThreadID(
   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}`;
 }
 
 type PendingThreadIDContents = {
   +threadType: ThreadType,
   +memberIDs: $ReadOnlyArray<string>,
   +sourceMessageID: ?string,
 };
 
 function parsePendingThreadID(
   pendingThreadID: string,
 ): ?PendingThreadIDContents {
   const pendingRegex = new RegExp(`^${pendingThreadIDRegex}$`);
   const pendingThreadIDMatches = pendingRegex.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 UserIDAndUsername = {
   +id: string,
   +username: string,
   ...
 };
 type CreatePendingThreadArgs = {
   +viewerID: string,
   +threadType: ThreadType,
   +members: $ReadOnlyArray<UserIDAndUsername>,
   +parentThreadInfo?: ?ThreadInfo,
   +threadColor?: ?string,
   +name?: ?string,
   +sourceMessageID?: string,
 };
 
 function createPendingThread({
   viewerID,
   threadType,
   members,
   parentThreadInfo,
   threadColor,
   name,
   sourceMessageID,
 }: CreatePendingThreadArgs): ThreadInfo {
   const now = Date.now();
   if (!members.some(member => member.id === viewerID)) {
     throw new Error(
       'createPendingThread should be called with the viewer as a member',
     );
   }
 
   const memberIDs = members.map(member => member.id);
   const threadID = getPendingThreadID(threadType, memberIDs, sourceMessageID);
 
   const permissions: ThreadRolePermissionsBlob = {
     [threadPermissions.KNOW_OF]: true,
     [threadPermissions.VISIBLE]: true,
     [threadPermissions.VOICED]: true,
   };
 
   const membershipPermissions = getAllThreadPermissions(
     makePermissionsBlob(permissions, null, threadID, threadType),
     threadID,
   );
   const role: RoleInfo = {
     ...minimallyEncodeRoleInfo({
       id: `${threadID}/role`,
       name: 'Members',
       permissions,
       isDefault: true,
     }),
     specialRole: specialRoles.DEFAULT_ROLE,
   };
 
   const rawThreadInfo: RawThreadInfo = {
     minimallyEncoded: true,
     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: members.map(member =>
       minimallyEncodeMemberInfo({
         id: member.id,
         role: role.id,
         permissions: membershipPermissions,
         isSender: false,
       }),
     ),
     roles: {
       [role.id]: role,
     },
     currentUser: minimallyEncodeThreadCurrentUserInfo({
       role: role.id,
       permissions: membershipPermissions,
       subscription: {
         pushNotifs: false,
         home: false,
       },
       unread: false,
     }),
     repliesCount: 0,
     sourceMessageID,
     pinnedCount: 0,
   };
 
   const userInfos: { [string]: UserInfo } = {};
   for (const member of members) {
     const { id, username } = member;
     userInfos[id] = { id, username };
   }
 
   return threadInfoFromRawThreadInfo(rawThreadInfo, viewerID, userInfos);
 }
 
 type PendingPersonalThread = {
   +threadInfo: ThreadInfo,
   +pendingPersonalThreadUserInfo: UserInfo,
 };
 
 function createPendingPersonalThread(
   loggedInUserInfo: LoggedInUserInfo,
   userID: string,
   username: string,
 ): PendingPersonalThread {
   const pendingPersonalThreadUserInfo = {
     id: userID,
     username: username,
   };
 
   const threadInfo = createPendingThread({
     viewerID: loggedInUserInfo.id,
     threadType: threadTypes.PERSONAL,
     members: [loggedInUserInfo, pendingPersonalThreadUserInfo],
   });
 
   return { threadInfo, pendingPersonalThreadUserInfo };
 }
 
 function createPendingThreadItem(
   loggedInUserInfo: LoggedInUserInfo,
   user: UserIDAndUsername,
 ): ChatThreadItem {
   const { threadInfo, pendingPersonalThreadUserInfo } =
     createPendingPersonalThread(loggedInUserInfo, user.id, user.username);
 
   return {
     type: 'chatThreadItem',
     threadInfo,
     mostRecentMessageInfo: null,
     mostRecentNonLocalMessage: null,
     lastUpdatedTime: threadInfo.creationTime,
     lastUpdatedTimeIncludingSidebars: threadInfo.creationTime,
     sidebars: [],
     pendingPersonalThreadUserInfo,
   };
 }
 
 // Returns map from lowercase username to AccountUserInfo
 function memberLowercaseUsernameMap(
   members: $ReadOnlyArray<RelativeMemberInfo>,
 ): Map<string, AccountUserInfo> {
   const memberMap = new Map<string, AccountUserInfo>();
   for (const member of members) {
     const { id, role, username } = member;
     if (!role || !username) {
       continue;
     }
     memberMap.set(username.toLowerCase(), { id, username });
   }
   return memberMap;
 }
 
 // Returns map from user ID to AccountUserInfo
 function extractMentionedMembers(
   text: string,
   threadInfo: ThreadInfo,
 ): Map<string, AccountUserInfo> {
   const memberMap = memberLowercaseUsernameMap(threadInfo.members);
   const mentions = extractUserMentionsFromText(text);
 
   const mentionedMembers = new Map<string, AccountUserInfo>();
   for (const mention of mentions) {
     const userInfo = memberMap.get(mention.toLowerCase());
     if (userInfo) {
       mentionedMembers.set(userInfo.id, userInfo);
     }
   }
   return mentionedMembers;
 }
 
 // When a member of the parent is mentioned in a sidebar,
 // they will be automatically added to that sidebar
 function extractNewMentionedParentMembers(
   messageText: string,
   threadInfo: ThreadInfo,
   parentThreadInfo: ThreadInfo,
 ): AccountUserInfo[] {
   const mentionedMembersOfParent = extractMentionedMembers(
     messageText,
     parentThreadInfo,
   );
   for (const member of threadInfo.members) {
     if (member.role) {
       mentionedMembersOfParent.delete(member.id);
     }
   }
   return [...mentionedMembersOfParent.values()];
 }
 
 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 RawThreadInfoOptions = {
   +filterThreadEditAvatarPermission?: boolean,
   +excludePinInfo?: boolean,
   +filterManageInviteLinksPermission?: boolean,
   +filterVoicedInAnnouncementChannelsPermission?: boolean,
   +minimallyEncodePermissions?: boolean,
   +includeSpecialRoleFieldInRoles?: boolean,
+  +allowAddingUsersToCommunityRoot?: boolean,
 };
 
 function rawThreadInfoFromServerThreadInfo(
   serverThreadInfo: ServerThreadInfo,
   viewerID: string,
   options?: RawThreadInfoOptions,
 ): ?LegacyRawThreadInfo | ?RawThreadInfo {
   const filterThreadEditAvatarPermission =
     options?.filterThreadEditAvatarPermission;
   const excludePinInfo = options?.excludePinInfo;
   const filterManageInviteLinksPermission =
     options?.filterManageInviteLinksPermission;
   const filterVoicedInAnnouncementChannelsPermission =
     options?.filterVoicedInAnnouncementChannelsPermission;
   const shouldMinimallyEncodePermissions = options?.minimallyEncodePermissions;
   const shouldIncludeSpecialRoleFieldInRoles =
     options?.includeSpecialRoleFieldInRoles;
+  const allowAddingUsersToCommunityRoot =
+    options?.allowAddingUsersToCommunityRoot;
 
-  const filterThreadPermissions = _omitBy(
-    (v, k) =>
-      (filterThreadEditAvatarPermission &&
-        [
-          threadPermissions.EDIT_THREAD_AVATAR,
-          threadPermissionPropagationPrefixes.DESCENDANT +
+  const filterThreadPermissions = (
+    innerThreadPermissions: ThreadPermissionsInfo,
+  ) => {
+    if (
+      allowAddingUsersToCommunityRoot &&
+      (serverThreadInfo.type === threadTypes.COMMUNITY_ANNOUNCEMENT_ROOT ||
+        serverThreadInfo.type === threadTypes.COMMUNITY_ROOT)
+    ) {
+      innerThreadPermissions = {
+        ...innerThreadPermissions,
+        [threadPermissions.ADD_MEMBERS]: {
+          value: true,
+          source: serverThreadInfo.id,
+        },
+      };
+    }
+    return _omitBy(
+      (v, k) =>
+        (filterThreadEditAvatarPermission &&
+          [
             threadPermissions.EDIT_THREAD_AVATAR,
-        ].includes(k)) ||
-      (excludePinInfo &&
-        [
-          threadPermissions.MANAGE_PINS,
-          threadPermissionPropagationPrefixes.DESCENDANT +
+            threadPermissionPropagationPrefixes.DESCENDANT +
+              threadPermissions.EDIT_THREAD_AVATAR,
+          ].includes(k)) ||
+        (excludePinInfo &&
+          [
             threadPermissions.MANAGE_PINS,
-        ].includes(k)) ||
-      (filterManageInviteLinksPermission &&
-        [threadPermissions.MANAGE_INVITE_LINKS].includes(k)) ||
-      (filterVoicedInAnnouncementChannelsPermission &&
-        [
-          threadPermissions.VOICED_IN_ANNOUNCEMENT_CHANNELS,
-          threadPermissionPropagationPrefixes.DESCENDANT +
-            threadPermissionFilterPrefixes.TOP_LEVEL +
+            threadPermissionPropagationPrefixes.DESCENDANT +
+              threadPermissions.MANAGE_PINS,
+          ].includes(k)) ||
+        (filterManageInviteLinksPermission &&
+          [threadPermissions.MANAGE_INVITE_LINKS].includes(k)) ||
+        (filterVoicedInAnnouncementChannelsPermission &&
+          [
             threadPermissions.VOICED_IN_ANNOUNCEMENT_CHANNELS,
-        ].includes(k)),
-  );
+            threadPermissionPropagationPrefixes.DESCENDANT +
+              threadPermissionFilterPrefixes.TOP_LEVEL +
+              threadPermissions.VOICED_IN_ANNOUNCEMENT_CHANNELS,
+          ].includes(k)),
+    )(innerThreadPermissions);
+  };
 
   const members = [];
   let currentUser;
   for (const serverMember of serverThreadInfo.members) {
     if (
       serverThreadInfo.id === genesis().id &&
       serverMember.id !== viewerID &&
       serverMember.id !== ashoat.id
     ) {
       continue;
     }
 
     const memberPermissions = filterThreadPermissions(serverMember.permissions);
 
     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 = filterThreadPermissions(
       getAllThreadPermissions(null, serverThreadInfo.id),
     );
     currentUser = {
       role: null,
       permissions: currentUserPermissions,
       subscription: {
         home: false,
         pushNotifs: false,
       },
       unread: null,
     };
   }
   if (!permissionLookup(currentUserPermissions, threadPermissions.KNOW_OF)) {
     return null;
   }
 
   const rolesWithFilteredThreadPermissions = _mapValues(role => ({
     ...role,
     permissions: filterThreadPermissions(role.permissions),
   }))(serverThreadInfo.roles);
 
   const rolesWithoutSpecialRoleField = _mapValues(role => {
     const { specialRole, ...roleSansSpecialRole } = role;
     return roleSansSpecialRole;
   })(rolesWithFilteredThreadPermissions);
 
   let rawThreadInfo: any = {
     id: serverThreadInfo.id,
     type: serverThreadInfo.type,
     name: serverThreadInfo.name,
     description: serverThreadInfo.description,
     color: serverThreadInfo.color,
     creationTime: serverThreadInfo.creationTime,
     parentThreadID: serverThreadInfo.parentThreadID,
     members,
     roles: rolesWithoutSpecialRoleField,
     currentUser,
     repliesCount: serverThreadInfo.repliesCount,
     containingThreadID: serverThreadInfo.containingThreadID,
     community: serverThreadInfo.community,
   };
   const sourceMessageID = serverThreadInfo.sourceMessageID;
   if (sourceMessageID) {
     rawThreadInfo = { ...rawThreadInfo, sourceMessageID };
   }
   if (serverThreadInfo.avatar) {
     rawThreadInfo = { ...rawThreadInfo, avatar: serverThreadInfo.avatar };
   }
   if (!excludePinInfo) {
     rawThreadInfo = {
       ...rawThreadInfo,
       pinnedCount: serverThreadInfo.pinnedCount,
     };
   }
 
   if (!shouldMinimallyEncodePermissions) {
     return rawThreadInfo;
   }
 
   const minimallyEncoded = minimallyEncodeRawThreadInfo(rawThreadInfo);
   if (shouldIncludeSpecialRoleFieldInRoles) {
     return minimallyEncoded;
   }
 
   const minimallyEncodedRolesWithoutSpecialRoleField = Object.fromEntries(
     entries(minimallyEncoded.roles).map(([key, role]) => [
       key,
       {
         ..._omit('specialRole')(role),
         isDefault: roleIsDefaultRole(role),
       },
     ]),
   );
 
   return {
     ...minimallyEncoded,
     roles: minimallyEncodedRolesWithoutSpecialRoleField,
   };
 }
 
 function threadUIName(threadInfo: ThreadInfo): string | ThreadEntity {
   if (threadInfo.name) {
     return firstLine(threadInfo.name);
   }
 
   const threadMembers: $ReadOnlyArray<RelativeMemberInfo> =
     threadInfo.members.filter(memberInfo => memberInfo.role);
   const memberEntities: $ReadOnlyArray<UserEntity> = threadMembers.map(member =>
     ET.user({ userInfo: member }),
   );
 
   return {
     type: 'thread',
     id: threadInfo.id,
     name: threadInfo.name,
     display: 'uiName',
     uiName: memberEntities,
     ifJustViewer:
       threadInfo.type === threadTypes.PRIVATE
         ? 'viewer_username'
         : 'just_you_string',
   };
 }
 
 function threadInfoFromRawThreadInfo(
   rawThreadInfo: RawThreadInfo,
   viewerID: ?string,
   userInfos: UserInfos,
 ): ThreadInfo {
   let threadInfo: ThreadInfo = {
     minimallyEncoded: true,
     id: rawThreadInfo.id,
     type: rawThreadInfo.type,
     name: rawThreadInfo.name,
     uiName: '',
     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,
   };
 
   threadInfo = {
     ...threadInfo,
     uiName: threadUIName(threadInfo),
   };
   const { sourceMessageID, avatar, pinnedCount } = rawThreadInfo;
   if (sourceMessageID) {
     threadInfo = { ...threadInfo, sourceMessageID };
   }
 
   if (avatar) {
     threadInfo = { ...threadInfo, avatar };
   } else if (
     rawThreadInfo.type === threadTypes.PERSONAL ||
     rawThreadInfo.type === threadTypes.PRIVATE
   ) {
     threadInfo = {
       ...threadInfo,
       avatar: getUserAvatarForThread(rawThreadInfo, viewerID, userInfos),
     };
   }
 
   if (pinnedCount) {
     threadInfo = { ...threadInfo, pinnedCount };
   }
   return threadInfo;
 }
 
 function filterOutDisabledPermissions(permissionsBitmask: string): string {
   const decodedPermissions: ThreadPermissionsInfo =
     threadPermissionsFromBitmaskHex(permissionsBitmask);
   const updatedPermissions = { ...decodedPermissions, ...disabledPermissions };
   const encodedUpdatedPermissions: string =
     permissionsToBitmaskHex(updatedPermissions);
   return encodedUpdatedPermissions;
 }
 
 function getCurrentUser(
   threadInfo: RawThreadInfo | ThreadInfo,
   viewerID: ?string,
   userInfos: UserInfos,
 ): ThreadCurrentUserInfo {
   if (!threadFrozenDueToBlock(threadInfo, viewerID, userInfos)) {
     return threadInfo.currentUser;
   }
   return {
     ...threadInfo.currentUser,
     permissions: filterOutDisabledPermissions(
       threadInfo.currentUser.permissions,
     ),
   };
 }
 
 type ThreadIsWithBlockedUserOnlyOptions = {
   +checkOnlyViewerBlock: boolean,
   +skipMemberAdminRoleCheck: boolean,
 };
 
 function threadIsWithBlockedUserOnly(
   threadInfo: LegacyRawThreadInfo | RawThreadInfo | ThreadInfo,
   viewerID: ?string,
   userInfos: UserInfos,
   options: ThreadIsWithBlockedUserOnlyOptions,
 ): boolean {
   const { checkOnlyViewerBlock, skipMemberAdminRoleCheck } = options;
   if (
     threadOrParentThreadIsGroupChat(threadInfo) ||
     (!skipMemberAdminRoleCheck && 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 innerThreadFrozenDueToBlock(
   threadInfo: LegacyRawThreadInfo | RawThreadInfo | ThreadInfo,
   viewerID: ?string,
   userInfos: UserInfos,
   skipMemberAdminRoleCheck: boolean,
 ): boolean {
   const options: ThreadIsWithBlockedUserOnlyOptions = {
     checkOnlyViewerBlock: false,
     skipMemberAdminRoleCheck,
   };
 
   return threadIsWithBlockedUserOnly(threadInfo, viewerID, userInfos, options);
 }
 
 function threadFrozenDueToBlock(
   threadInfo: LegacyRawThreadInfo | RawThreadInfo | ThreadInfo,
   viewerID: ?string,
   userInfos: UserInfos,
 ): boolean {
   return innerThreadFrozenDueToBlock(threadInfo, viewerID, userInfos, false);
 }
 
 function threadFrozenDueToViewerBlock(
   threadInfo: ThreadInfo,
   communityThreadInfo: ?ThreadInfo,
   viewerID: ?string,
   userInfos: UserInfos,
 ): boolean {
   const options: ThreadIsWithBlockedUserOnlyOptions = {
     checkOnlyViewerBlock: true,
     skipMemberAdminRoleCheck: false,
   };
 
   return threadIsWithBlockedUserOnly(threadInfo, viewerID, userInfos, options);
 }
 
 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.',
 };
 
 // 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
     | LegacyMemberInfo
     | MemberInfo
     | ServerMemberInfo,
 ): boolean {
   if (memberInfo.minimallyEncoded) {
     return hasPermission(memberInfo.permissions, threadPermissions.CHANGE_ROLE);
   }
   return !!memberInfo.permissions[threadPermissions.CHANGE_ROLE]?.value;
 }
 
 function roleIsDefaultRole(
   roleInfo: ?ClientLegacyRoleInfo | ?RoleInfo,
 ): boolean {
   if (roleInfo?.specialRole === specialRoles.DEFAULT_ROLE) {
     return true;
   }
   return !!(roleInfo && roleInfo.isDefault);
 }
 
 function roleIsAdminRole(roleInfo: ?ClientLegacyRoleInfo | ?RoleInfo): boolean {
   if (roleInfo?.specialRole === specialRoles.ADMIN_ROLE) {
     return true;
   }
   return !!(roleInfo && !roleInfo.isDefault && roleInfo.name === 'Admins');
 }
 
 function threadHasAdminRole(
   threadInfo: ?(
     | LegacyRawThreadInfo
     | RawThreadInfo
     | ThreadInfo
     | ServerThreadInfo
   ),
 ): boolean {
   if (!threadInfo) {
     return false;
   }
   let hasSpecialRoleFieldBeenEncountered = false;
   for (const role of Object.values(threadInfo.roles)) {
     if (role.specialRole === specialRoles.ADMIN_ROLE) {
       return true;
     }
     if (role.specialRole !== undefined) {
       hasSpecialRoleFieldBeenEncountered = true;
     }
   }
   if (hasSpecialRoleFieldBeenEncountered) {
     return false;
   }
   return !!_find({ name: 'Admins' })(threadInfo.roles);
 }
 
 function threadOrParentThreadHasAdminRole(
   threadInfo: LegacyRawThreadInfo | RawThreadInfo | ThreadInfo,
 ) {
   return (
     threadMembersWithoutAddedAdmin(threadInfo).filter(member =>
       memberHasAdminPowers(member),
     ).length > 0
   );
 }
 
 function identifyInvalidatedThreads(
   updateInfos: $ReadOnlyArray<ClientUpdateInfo>,
 ): Set<string> {
   const invalidated = new Set<string>();
   for (const updateInfo of updateInfos) {
     if (updateInfo.type === updateTypes.DELETE_THREAD) {
       invalidated.add(updateInfo.threadID);
     }
   }
   return invalidated;
 }
 
 const permissionsDisabledByBlockArray = values(
   threadPermissionsDisabledByBlock,
 );
 
 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.`;
 
 function threadNoun(threadType: ThreadType, parentThreadID: ?string): string {
   if (threadType === threadTypes.SIDEBAR) {
     return 'thread';
   } else if (
     threadType === threadTypes.COMMUNITY_SECRET_SUBTHREAD &&
     parentThreadID === genesis().id
   ) {
     return 'chat';
   } else if (
     threadType === threadTypes.COMMUNITY_ROOT ||
     threadType === threadTypes.COMMUNITY_ANNOUNCEMENT_ROOT ||
     threadType === threadTypes.COMMUNITY_OPEN_SUBTHREAD ||
     threadType === threadTypes.COMMUNITY_OPEN_ANNOUNCEMENT_SUBTHREAD ||
     threadType === threadTypes.COMMUNITY_SECRET_SUBTHREAD ||
     threadType === threadTypes.COMMUNITY_SECRET_ANNOUNCEMENT_SUBTHREAD ||
     threadType === threadTypes.GENESIS
   ) {
     return 'channel';
   } else {
     return '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';
   }
 }
 
 type ExistingThreadInfoFinderParams = {
   +searching: boolean,
   +userInfoInputArray: $ReadOnlyArray<AccountUserInfo>,
 };
 type ExistingThreadInfoFinder = (
   params: ExistingThreadInfoFinderParams,
 ) => ?ThreadInfo;
 
 function useExistingThreadInfoFinder(
   baseThreadInfo: ?ThreadInfo,
 ): ExistingThreadInfoFinder {
   const threadInfos = useSelector(threadInfoSelector);
   const loggedInUserInfo = useLoggedInUserInfo();
   const userInfos = useSelector(state => state.userStore.userInfos);
 
   const pendingToRealizedThreadIDs = useSelector(state =>
     pendingToRealizedThreadIDsSelector(state.threadStore.threadInfos),
   );
   return React.useCallback(
     (params: ExistingThreadInfoFinderParams): ?ThreadInfo => {
       if (!baseThreadInfo) {
         return null;
       }
 
       const realizedThreadInfo = threadInfos[baseThreadInfo.id];
       if (realizedThreadInfo) {
         return realizedThreadInfo;
       }
 
       if (!loggedInUserInfo || !threadIsPending(baseThreadInfo.id)) {
         return baseThreadInfo;
       }
       const viewerID = loggedInUserInfo?.id;
 
       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
         ? getPendingThreadID(
             pendingThreadType(userInfoInputArray.length),
             [...userInfoInputArray.map(user => user.id), viewerID],
             sourceMessageID,
           )
         : getPendingThreadID(
             baseThreadInfo.type,
             baseThreadInfo.members.map(member => member.id),
             sourceMessageID,
           );
 
       const realizedThreadID = pendingToRealizedThreadIDs.get(pendingThreadID);
       if (realizedThreadID && threadInfos[realizedThreadID]) {
         return threadInfos[realizedThreadID];
       }
 
       const updatedThread = searching
         ? createPendingThread({
             viewerID,
             threadType: pendingThreadType(userInfoInputArray.length),
             members: [loggedInUserInfo, ...userInfoInputArray],
           })
         : baseThreadInfo;
 
       return {
         ...updatedThread,
         currentUser: getCurrentUser(updatedThread, viewerID, userInfos),
       };
     },
     [
       baseThreadInfo,
       threadInfos,
       loggedInUserInfo,
       pendingToRealizedThreadIDs,
       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: ThreadInfo,
   memberID: string,
   permission: ThreadPermission,
 ): boolean {
   for (const member of threadInfo.members) {
     if (member.id !== memberID) {
       continue;
     }
     return hasPermission(member.permissions, permission);
   }
   return false;
 }
 
 function checkIfDefaultMembersAreVoiced(threadInfo: ThreadInfo): boolean {
   const defaultRoleID = Object.keys(threadInfo.roles).find(roleID =>
     roleIsDefaultRole(threadInfo.roles[roleID]),
   );
   invariant(
     defaultRoleID !== undefined,
     'all threads should have a default role',
   );
   const defaultRole = threadInfo.roles[defaultRoleID];
   const defaultRolePermissions =
     decodeMinimallyEncodedRoleInfo(defaultRole).permissions;
 
   return !!defaultRolePermissions[threadPermissions.VOICED];
 }
 
 const draftKeySuffix = '/message_composer';
 
 function draftKeyFromThreadID(threadID: string): string {
   return `${threadID}${draftKeySuffix}`;
 }
 
 function getContainingThreadID(
   parentThreadInfo:
     | ?ServerThreadInfo
     | LegacyRawThreadInfo
     | 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
     | LegacyRawThreadInfo
     | 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>,
   loggedInUserInfo: ?LoggedInUserInfo,
 ): $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: ChatThreadItem[] = [
     ...privateThreads,
     ...personalThreads,
     ...otherThreads,
   ];
   if (loggedInUserInfo) {
     chatItems.push(
       ...usersSearchResults.map(user =>
         createPendingThreadItem(loggedInUserInfo, user),
       ),
     );
   }
   return chatItems;
 }
 
 function reorderThreadSearchResults<T: RawThreadInfo | ThreadInfo>(
   threadInfos: $ReadOnlyArray<T>,
   threadSearchResults: $ReadOnlyArray<string>,
 ): T[] {
   const privateThreads = [];
   const personalThreads = [];
   const otherThreads = [];
   const threadSearchResultsSet = new Set(threadSearchResults);
   for (const threadInfo of threadInfos) {
     if (!threadSearchResultsSet.has(threadInfo.id)) {
       continue;
     }
     if (threadInfo.type === threadTypes.PRIVATE) {
       privateThreads.push(threadInfo);
     } else if (threadInfo.type === threadTypes.PERSONAL) {
       personalThreads.push(threadInfo);
     } else {
       otherThreads.push(threadInfo);
     }
   }
 
   return [...privateThreads, ...personalThreads, ...otherThreads];
 }
 
 function useAvailableThreadMemberActions(
   memberInfo: RelativeMemberInfo,
   threadInfo: ThreadInfo,
   canEdit: ?boolean = true,
 ): $ReadOnlyArray<'change_role' | 'remove_user'> {
   const canRemoveMembers = useThreadHasPermission(
     threadInfo,
     threadPermissions.REMOVE_MEMBERS,
   );
   const canChangeRoles = useThreadHasPermission(
     threadInfo,
     threadPermissions.CHANGE_ROLE,
   );
 
   return React.useMemo(() => {
     const { role } = memberInfo;
     if (!canEdit || !role) {
       return [];
     }
 
     const result = [];
 
     if (
       canChangeRoles &&
       memberInfo.username &&
       threadHasAdminRole(threadInfo)
     ) {
       result.push('change_role');
     }
 
     if (
       canRemoveMembers &&
       !memberInfo.isViewer &&
       (canChangeRoles || roleIsDefaultRole(threadInfo.roles[role]))
     ) {
       result.push('remove_user');
     }
 
     return result;
   }, [canChangeRoles, canEdit, canRemoveMembers, memberInfo, threadInfo]);
 }
 
 function patchThreadInfoToIncludeMentionedMembersOfParent(
   threadInfo: ThreadInfo,
   parentThreadInfo: ThreadInfo,
   messageText: string,
   viewerID: string,
 ): ThreadInfo {
   const members: UserIDAndUsername[] = threadInfo.members
     .map(({ id, username }) =>
       username ? ({ id, username }: UserIDAndUsername) : null,
     )
     .filter(Boolean);
   const mentionedNewMembers = extractNewMentionedParentMembers(
     messageText,
     threadInfo,
     parentThreadInfo,
   );
   if (mentionedNewMembers.length === 0) {
     return threadInfo;
   }
   members.push(...mentionedNewMembers);
   return createPendingThread({
     viewerID,
     threadType: threadTypes.SIDEBAR,
     members,
     parentThreadInfo,
     threadColor: threadInfo.color,
     name: threadInfo.name,
     sourceMessageID: threadInfo.sourceMessageID,
   });
 }
 
 function threadInfoInsideCommunity(
   threadInfo: RawThreadInfo | ThreadInfo,
   communityID: string,
 ): boolean {
   return threadInfo.community === communityID || threadInfo.id === communityID;
 }
 
 type RoleAndMemberCount = {
   [roleName: string]: number,
 };
 
 function useRoleMemberCountsForCommunity(
   threadInfo: ThreadInfo,
 ): RoleAndMemberCount {
   return React.useMemo(() => {
     const roleIDsToNames: { [string]: string } = {};
 
     Object.keys(threadInfo.roles).forEach(roleID => {
       roleIDsToNames[roleID] = threadInfo.roles[roleID].name;
     });
 
     const roleNamesToMemberCount: RoleAndMemberCount = {};
 
     threadInfo.members.forEach(({ role: roleID }) => {
       invariant(roleID, 'Community member should have a role');
       const roleName = roleIDsToNames[roleID];
 
       roleNamesToMemberCount[roleName] =
         (roleNamesToMemberCount[roleName] ?? 0) + 1;
     });
 
     // For all community roles with no members, add them to the list with 0
     Object.keys(roleIDsToNames).forEach(roleName => {
       if (roleNamesToMemberCount[roleIDsToNames[roleName]] === undefined) {
         roleNamesToMemberCount[roleIDsToNames[roleName]] = 0;
       }
     });
 
     return roleNamesToMemberCount;
   }, [threadInfo.members, threadInfo.roles]);
 }
 
 function useRoleNamesToSpecialRole(threadInfo: ThreadInfo): {
   +[roleName: string]: ?SpecialRole,
 } {
   return React.useMemo(() => {
     const roleNamesToSpecialRole: { [roleName: string]: ?SpecialRole } = {};
     values(threadInfo.roles).forEach(role => {
       if (roleNamesToSpecialRole[role.name] !== undefined) {
         return;
       }
       if (roleIsDefaultRole(role)) {
         roleNamesToSpecialRole[role.name] = specialRoles.DEFAULT_ROLE;
       } else if (roleIsAdminRole(role)) {
         roleNamesToSpecialRole[role.name] = specialRoles.ADMIN_ROLE;
       } else {
         roleNamesToSpecialRole[role.name] = null;
       }
     });
     return roleNamesToSpecialRole;
   }, [threadInfo.roles]);
 }
 
 type RoleUserSurfacedPermissions = {
   +[roleName: string]: $ReadOnlySet<UserSurfacedPermission>,
 };
 // Iterates through the existing roles in the community and 'reverse maps'
 // the set of permission literals for each role to user-facing permission enums
 // to help pre-populate the permission checkboxes when editing roles.
 function useRoleUserSurfacedPermissions(
   threadInfo: ThreadInfo,
 ): RoleUserSurfacedPermissions {
   return React.useMemo(() => {
     const roleNamesToPermissions: { [string]: Set<UserSurfacedPermission> } =
       {};
 
     Object.keys(threadInfo.roles).forEach(roleID => {
       const roleName = threadInfo.roles[roleID].name;
       const rolePermissions = Object.keys(
         decodeMinimallyEncodedRoleInfo(threadInfo.roles[roleID]).permissions,
       );
 
       const setOfUserSurfacedPermissions = new Set<UserSurfacedPermission>();
 
       rolePermissions.forEach(rolePermission => {
         const userSurfacedPermission = Object.keys(
           configurableCommunityPermissions,
         ).find(key =>
           configurableCommunityPermissions[key].has(rolePermission),
         );
 
         if (userSurfacedPermission) {
           setOfUserSurfacedPermissions.add(userSurfacedPermission);
         }
       });
       roleNamesToPermissions[roleName] = setOfUserSurfacedPermissions;
     });
 
     return roleNamesToPermissions;
   }, [threadInfo.roles]);
 }
 
 function communityOrThreadNoun(threadInfo: RawThreadInfo | ThreadInfo): string {
   return threadTypeIsCommunityRoot(threadInfo.type)
     ? 'community'
     : threadNoun(threadInfo.type, threadInfo.parentThreadID);
 }
 
 function getThreadsToDeleteText(
   threadInfo: RawThreadInfo | ThreadInfo,
 ): string {
   return `${
     threadTypeIsCommunityRoot(threadInfo.type)
       ? 'Subchannels and threads'
       : 'Threads'
   } within this ${communityOrThreadNoun(threadInfo)}`;
 }
 
 function useUserProfileThreadInfo(userInfo: ?UserInfo): ?UserProfileThreadInfo {
   const userID = userInfo?.id;
   const username = userInfo?.username;
 
   const loggedInUserInfo = useLoggedInUserInfo();
   const isViewerProfile = loggedInUserInfo?.id === userID;
 
   const privateThreadInfosSelector = threadInfosSelectorForThreadType(
     threadTypes.PRIVATE,
   );
   const privateThreadInfos = useSelector(privateThreadInfosSelector);
 
   const personalThreadInfosSelector = threadInfosSelectorForThreadType(
     threadTypes.PERSONAL,
   );
 
   const personalThreadInfos = useSelector(personalThreadInfosSelector);
 
   const usersWithPersonalThread = useSelector(usersWithPersonalThreadSelector);
 
   return React.useMemo(() => {
     if (!loggedInUserInfo || !userID || !username) {
       return null;
     }
 
     if (isViewerProfile) {
       const privateThreadInfo: ?ThreadInfo = privateThreadInfos[0];
 
       return privateThreadInfo ? { threadInfo: privateThreadInfo } : null;
     }
 
     if (usersWithPersonalThread.has(userID)) {
       const personalThreadInfo: ?ThreadInfo = personalThreadInfos.find(
         threadInfo =>
           userID === getSingleOtherUser(threadInfo, loggedInUserInfo.id),
       );
 
       return personalThreadInfo ? { threadInfo: personalThreadInfo } : null;
     }
 
     const pendingPersonalThreadInfo = createPendingPersonalThread(
       loggedInUserInfo,
       userID,
       username,
     );
 
     return pendingPersonalThreadInfo;
   }, [
     isViewerProfile,
     loggedInUserInfo,
     personalThreadInfos,
     privateThreadInfos,
     userID,
     username,
     usersWithPersonalThread,
   ]);
 }
 
 function assertAllThreadInfosAreLegacy(rawThreadInfos: MixedRawThreadInfos): {
   [id: string]: LegacyRawThreadInfo,
 } {
   return Object.fromEntries(
     Object.entries(rawThreadInfos).map(([id, rawThreadInfo]) => {
       invariant(
         !rawThreadInfo.minimallyEncoded,
         `rawThreadInfos shouldn't be minimallyEncoded`,
       );
       return [id, rawThreadInfo];
     }),
   );
 }
 
 function useOnScreenEntryEditableThreadInfos(): $ReadOnlyArray<ThreadInfo> {
   const visibleThreadInfos = useSelector(onScreenThreadInfos);
   const editableVisibleThreadInfos = useThreadsWithPermission(
     visibleThreadInfos,
     threadPermissions.EDIT_ENTRIES,
   );
   return editableVisibleThreadInfos;
 }
 
 export {
   threadHasPermission,
   useCommunityRootMembersToRole,
   useThreadHasPermission,
   viewerIsMember,
   threadInChatList,
   useIsThreadInChatList,
   useThreadsInChatList,
   threadIsTopLevel,
   threadIsChannel,
   threadIsSidebar,
   threadInBackgroundChatList,
   threadInHomeChatList,
   threadIsInHome,
   threadInFilterList,
   userIsMember,
   threadActualMembers,
   threadOtherMembers,
   threadIsGroupChat,
   threadIsPending,
   threadIsPendingSidebar,
   getSingleOtherUser,
   getPendingThreadID,
   parsePendingThreadID,
   createPendingThread,
   extractNewMentionedParentMembers,
   pendingThreadType,
   filterOutDisabledPermissions,
   getCurrentUser,
   threadFrozenDueToBlock,
   threadFrozenDueToViewerBlock,
   rawThreadInfoFromServerThreadInfo,
   threadUIName,
   threadInfoFromRawThreadInfo,
   threadTypeDescriptions,
   memberHasAdminPowers,
   roleIsDefaultRole,
   roleIsAdminRole,
   threadHasAdminRole,
   identifyInvalidatedThreads,
   permissionsDisabledByBlock,
   emptyItemText,
   threadNoun,
   threadLabel,
   useExistingThreadInfoFinder,
   getThreadTypeParentRequirement,
   threadMemberHasPermission,
   checkIfDefaultMembersAreVoiced,
   draftKeySuffix,
   draftKeyFromThreadID,
   threadTypeCanBePending,
   getContainingThreadID,
   getCommunity,
   getThreadListSearchResults,
   reorderThreadSearchResults,
   useAvailableThreadMemberActions,
   threadMembersWithoutAddedAdmin,
   patchThreadInfoToIncludeMentionedMembersOfParent,
   threadInfoInsideCommunity,
   useRoleMemberCountsForCommunity,
   useRoleNamesToSpecialRole,
   useRoleUserSurfacedPermissions,
   getThreadsToDeleteText,
   useUserProfileThreadInfo,
   assertAllThreadInfosAreLegacy,
   useOnScreenEntryEditableThreadInfos,
   extractMentionedMembers,
 };
diff --git a/lib/types/thread-permission-types.js b/lib/types/thread-permission-types.js
index 05b702d92..563c21894 100644
--- a/lib/types/thread-permission-types.js
+++ b/lib/types/thread-permission-types.js
@@ -1,343 +1,342 @@
 // @flow
 
 import invariant from 'invariant';
 import t, { type TDict, type TUnion, type TEnums } from 'tcomb';
 
 import { values } from '../utils/objects.js';
 import { tBool, tShape, tID } from '../utils/validation-utils.js';
 
 export const threadPermissionsDisabledByBlock = Object.freeze({
   VOICED: 'voiced',
   EDIT_ENTRIES: 'edit_entries',
   EDIT_THREAD_NAME: 'edit_thread',
   EDIT_THREAD_DESCRIPTION: 'edit_thread_description',
   EDIT_THREAD_COLOR: 'edit_thread_color',
   CREATE_SUBCHANNELS: 'create_subthreads',
   CREATE_SIDEBARS: 'create_sidebars',
   JOIN_THREAD: 'join_thread',
   EDIT_PERMISSIONS: 'edit_permissions',
   ADD_MEMBERS: 'add_members',
   REMOVE_MEMBERS: 'remove_members',
 });
 
 export const threadPermissionsNotAffectedByBlock = Object.freeze({
   KNOW_OF: 'know_of',
   VISIBLE: 'visible',
   DELETE_THREAD: 'delete_thread',
   CHANGE_ROLE: 'change_role',
   LEAVE_THREAD: 'leave_thread',
   REACT_TO_MESSAGE: 'react_to_message',
   EDIT_MESSAGE: 'edit_message',
   EDIT_THREAD_AVATAR: 'edit_thread_avatar',
   MANAGE_PINS: 'manage_pins',
   MANAGE_INVITE_LINKS: 'manage_invite_links',
   VOICED_IN_ANNOUNCEMENT_CHANNELS: 'voiced_in_announcement_channels',
 });
 
 export type ThreadPermissionNotAffectedByBlock = $Values<
   typeof threadPermissionsNotAffectedByBlock,
 >;
 
 // When a new permission is added, if it should be configurable for a role, it
 // should be either added to an existing set or a new set alongside a
 // new user-facing permission. If it is a permission that should be ensured
 // across all roles, it should be added to `universalCommunityPermissions`.
 export const threadPermissions = Object.freeze({
   ...threadPermissionsDisabledByBlock,
   ...threadPermissionsNotAffectedByBlock,
 });
 export type ThreadPermission = $Values<typeof threadPermissions>;
 
 export function assertThreadPermissions(
   ourThreadPermissions: string,
 ): ThreadPermission {
   invariant(
     ourThreadPermissions === 'know_of' ||
       ourThreadPermissions === 'visible' ||
       ourThreadPermissions === 'voiced' ||
       ourThreadPermissions === 'edit_entries' ||
       ourThreadPermissions === 'edit_thread' ||
       ourThreadPermissions === 'edit_thread_description' ||
       ourThreadPermissions === 'edit_thread_color' ||
       ourThreadPermissions === 'delete_thread' ||
       ourThreadPermissions === 'create_subthreads' ||
       ourThreadPermissions === 'create_sidebars' ||
       ourThreadPermissions === 'join_thread' ||
       ourThreadPermissions === 'edit_permissions' ||
       ourThreadPermissions === 'add_members' ||
       ourThreadPermissions === 'remove_members' ||
       ourThreadPermissions === 'change_role' ||
       ourThreadPermissions === 'leave_thread' ||
       ourThreadPermissions === 'react_to_message' ||
       ourThreadPermissions === 'edit_message' ||
       ourThreadPermissions === 'edit_thread_avatar' ||
       ourThreadPermissions === 'manage_pins' ||
       ourThreadPermissions === 'manage_invite_links' ||
       ourThreadPermissions === 'voiced_in_announcement_channels',
     'string is not threadPermissions enum',
   );
   return ourThreadPermissions;
 }
 
 const threadPermissionValidator = t.enums.of(values(threadPermissions));
 export const threadPermissionPropagationPrefixes = Object.freeze({
   DESCENDANT: 'descendant_',
   CHILD: 'child_',
 });
 export type ThreadPermissionPropagationPrefix = $Values<
   typeof threadPermissionPropagationPrefixes,
 >;
 export const threadPermissionFilterPrefixes = Object.freeze({
   // includes only SIDEBAR, COMMUNITY_OPEN_SUBTHREAD,
   // COMMUNITY_OPEN_ANNOUNCEMENT_SUBTHREAD
   OPEN: 'open_',
   // excludes only SIDEBAR
   TOP_LEVEL: 'toplevel_',
   // includes only COMMUNITY_OPEN_SUBTHREAD,
   // COMMUNITY_OPEN_ANNOUNCEMENT_SUBTHREAD
   OPEN_TOP_LEVEL: 'opentoplevel_',
 });
 export type ThreadPermissionFilterPrefix = $Values<
   typeof threadPermissionFilterPrefixes,
 >;
 
 // These are the set of user-facing permissions that we display as configurable
 // to the user when they are creating a custom role for their given community.
 // They are per-community rather than per-thread, so when configured they are
 // to be expected to be propagated across the community. Also notably,
 // `threadPermissions` is used on the keyserver for permission checks to
 // validate actions, but these `userSurfacedPermissions` are only used
 // on the client for the UI and propagated to the server. The
 // `configurableCommunityPermissions` mapping below is the association between
 // each userSurfacedPermission and a set of threadPermissions.
 export const userSurfacedPermissions = Object.freeze({
   EDIT_CALENDAR: 'edit_calendar',
   KNOW_OF_SECRET_CHANNELS: 'know_of_secret_channels',
   VOICED_IN_ANNOUNCEMENT_CHANNELS: 'voiced_in_announcement_channels',
   CREATE_AND_EDIT_CHANNELS: 'create_and_edit_channels',
   DELETE_CHANNELS: 'delete_channels',
   ADD_MEMBERS: 'add_members',
   REMOVE_MEMBERS: 'remove_members',
   CHANGE_ROLES: 'change_roles',
   EDIT_VISIBILITY: 'edit_visibility',
   MANAGE_PINS: 'manage_pins',
   REACT_TO_MESSAGES: 'react_to_messages',
   EDIT_MESSAGES: 'edit_messages',
   MANAGE_INVITE_LINKS: 'manage_invite_links',
 });
 export type UserSurfacedPermission = $Values<typeof userSurfacedPermissions>;
 export const userSurfacedPermissionsSet: $ReadOnlySet<UserSurfacedPermission> =
   new Set(values(userSurfacedPermissions));
 export const userSurfacedPermissionValidator: TEnums = t.enums.of(
   values(userSurfacedPermissions),
 );
 
 const editCalendarPermission = {
   title: 'Edit calendar',
   description: 'Allows members to edit the community calendar',
   userSurfacedPermission: userSurfacedPermissions.EDIT_CALENDAR,
 };
 const editEntries = threadPermissions.EDIT_ENTRIES;
 const editCalendarPermissions = new Set([editEntries]);
 
 const knowOfSecretChannelsPermission = {
   title: 'Know of secret channels',
   description: 'Allows members to know of all secret channels',
   userSurfacedPermission: userSurfacedPermissions.KNOW_OF_SECRET_CHANNELS,
 };
 const descendantKnowOf =
   threadPermissionPropagationPrefixes.DESCENDANT + threadPermissions.KNOW_OF;
 const descendantVisible =
   threadPermissionPropagationPrefixes.DESCENDANT + threadPermissions.VISIBLE;
 const descendantTopLevelJoinThread =
   threadPermissionPropagationPrefixes.DESCENDANT +
   threadPermissionFilterPrefixes.TOP_LEVEL +
   threadPermissions.JOIN_THREAD;
 const descendantJoinThread =
   threadPermissionPropagationPrefixes.DESCENDANT +
   threadPermissions.JOIN_THREAD;
 const childJoinThread =
   threadPermissionPropagationPrefixes.CHILD + threadPermissions.JOIN_THREAD;
 const knowOfSecretChannelsPermissions = new Set([
   descendantKnowOf,
   descendantVisible,
   descendantTopLevelJoinThread,
   descendantJoinThread,
   childJoinThread,
 ]);
 
 const voicedPermission = {
   title: 'Voiced in announcement channels',
   description: 'Allows members to send messages in announcement channels',
   userSurfacedPermission:
     userSurfacedPermissions.VOICED_IN_ANNOUNCEMENT_CHANNELS,
 };
 const voicedInAnnouncementChannels =
   threadPermissions.VOICED_IN_ANNOUNCEMENT_CHANNELS;
 const descendantTopLevelVoicedInAnnouncementChannels =
   threadPermissionPropagationPrefixes.DESCENDANT +
   threadPermissionFilterPrefixes.TOP_LEVEL +
   threadPermissions.VOICED_IN_ANNOUNCEMENT_CHANNELS;
 const voicedPermissions = new Set([
   voicedInAnnouncementChannels,
   descendantTopLevelVoicedInAnnouncementChannels,
 ]);
 
 const createAndEditChannelsPermission = {
   title: 'Create and edit channels',
   description: 'Allows members to create new and edit existing channels',
   userSurfacedPermission: userSurfacedPermissions.CREATE_AND_EDIT_CHANNELS,
 };
 const editThreadName = threadPermissions.EDIT_THREAD_NAME;
 const editThreadDescription = threadPermissions.EDIT_THREAD_DESCRIPTION;
 const editThreadColor = threadPermissions.EDIT_THREAD_COLOR;
 const createSubchannels = threadPermissions.CREATE_SUBCHANNELS;
 const editThreadAvatar = threadPermissions.EDIT_THREAD_AVATAR;
 const createAndEditChannelsPermissions = new Set([
   editThreadName,
   editThreadDescription,
   editThreadColor,
   createSubchannels,
   editThreadAvatar,
 ]);
 
 const deleteChannelsPermission = {
   title: 'Delete channels',
   description: 'Allows members to delete channels',
   userSurfacedPermission: userSurfacedPermissions.DELETE_CHANNELS,
 };
 const deleteThread = threadPermissions.DELETE_THREAD;
 const deleteChannelsPermissions = new Set([deleteThread]);
 
 const addMembersPermission = {
   title: 'Add members',
   description: 'Allows members to add other members to channels',
   userSurfacedPermission: userSurfacedPermissions.ADD_MEMBERS,
 };
-const addMembers = threadPermissions.ADD_MEMBERS;
 const childOpenAddMembers =
   threadPermissionPropagationPrefixes.CHILD +
   threadPermissionFilterPrefixes.OPEN +
   threadPermissions.ADD_MEMBERS;
-const addMembersPermissions = new Set([addMembers, childOpenAddMembers]);
+const addMembersPermissions = new Set([childOpenAddMembers]);
 
 const removeMembersPermission = {
   title: 'Remove members',
   description: 'Allows members to remove anybody they can demote from channels',
   userSurfacedPermission: userSurfacedPermissions.REMOVE_MEMBERS,
 };
 const removeMembers = threadPermissions.REMOVE_MEMBERS;
 const removeMembersPermissions = new Set([removeMembers]);
 
 const changeRolePermission = {
   title: 'Change roles',
   description: 'Allows members to promote and demote other members',
   userSurfacedPermission: userSurfacedPermissions.CHANGE_ROLES,
 };
 const changeRole = threadPermissions.CHANGE_ROLE;
 const changeRolePermissions = new Set([changeRole]);
 
 const editVisibilityPermission = {
   title: 'Edit visibility',
   description: 'Allows members to edit visibility permissions of channels',
   userSurfacedPermission: userSurfacedPermissions.EDIT_VISIBILITY,
 };
 const editPermissions = threadPermissions.EDIT_PERMISSIONS;
 const editVisibilityPermissions = new Set([editPermissions]);
 
 const managePinsPermission = {
   title: 'Manage pins',
   description: 'Allows members to pin or unpin messages in channels',
   userSurfacedPermission: userSurfacedPermissions.MANAGE_PINS,
 };
 const managePins = threadPermissions.MANAGE_PINS;
 const managePinsPermissions = new Set([managePins]);
 
 const reactToMessagePermission = {
   title: 'React to messages',
   description: 'Allows members to add reactions to messages',
   userSurfacedPermission: userSurfacedPermissions.REACT_TO_MESSAGES,
 };
 const reactToMessage = threadPermissions.REACT_TO_MESSAGE;
 const reactToMessagePermissions = new Set([reactToMessage]);
 
 const editMessagePermission = {
   title: 'Edit messages',
   description: 'Allows members to edit their sent messages',
   userSurfacedPermission: userSurfacedPermissions.EDIT_MESSAGES,
 };
 const editMessage = threadPermissions.EDIT_MESSAGE;
 const editMessagePermissions = new Set([editMessage]);
 
 const manageInviteLinksPermission = {
   title: 'Manage invite links',
   description: 'Allows members to create and delete invite links',
   userSurfacedPermission: userSurfacedPermissions.MANAGE_INVITE_LINKS,
 };
 const manageInviteLinks = threadPermissions.MANAGE_INVITE_LINKS;
 const manageInviteLinksPermissions = new Set([manageInviteLinks]);
 
 export type UserSurfacedPermissionOption = {
   +title: string,
   +description: string,
   +userSurfacedPermission: UserSurfacedPermission,
 };
 export const userSurfacedPermissionOptions: $ReadOnlySet<UserSurfacedPermissionOption> =
   new Set([
     editCalendarPermission,
     knowOfSecretChannelsPermission,
     voicedPermission,
     createAndEditChannelsPermission,
     deleteChannelsPermission,
     addMembersPermission,
     removeMembersPermission,
     changeRolePermission,
     editVisibilityPermission,
     managePinsPermission,
     reactToMessagePermission,
     editMessagePermission,
     manageInviteLinksPermission,
   ]);
 
 type ConfigurableCommunityPermission = {
   +[permission: UserSurfacedPermission]: $ReadOnlySet<string>,
 };
 export const configurableCommunityPermissions: ConfigurableCommunityPermission =
   Object.freeze({
     [userSurfacedPermissions.EDIT_CALENDAR]: editCalendarPermissions,
     [userSurfacedPermissions.KNOW_OF_SECRET_CHANNELS]:
       knowOfSecretChannelsPermissions,
     [userSurfacedPermissions.VOICED_IN_ANNOUNCEMENT_CHANNELS]:
       voicedPermissions,
     [userSurfacedPermissions.CREATE_AND_EDIT_CHANNELS]:
       createAndEditChannelsPermissions,
     [userSurfacedPermissions.DELETE_CHANNELS]: deleteChannelsPermissions,
     [userSurfacedPermissions.ADD_MEMBERS]: addMembersPermissions,
     [userSurfacedPermissions.REMOVE_MEMBERS]: removeMembersPermissions,
     [userSurfacedPermissions.CHANGE_ROLES]: changeRolePermissions,
     [userSurfacedPermissions.EDIT_VISIBILITY]: editVisibilityPermissions,
     [userSurfacedPermissions.MANAGE_PINS]: managePinsPermissions,
     [userSurfacedPermissions.REACT_TO_MESSAGES]: reactToMessagePermissions,
     [userSurfacedPermissions.EDIT_MESSAGES]: editMessagePermissions,
     [userSurfacedPermissions.MANAGE_INVITE_LINKS]: manageInviteLinksPermissions,
   });
 
 export type ThreadPermissionInfo =
   | { +value: true, +source: string }
   | { +value: false, +source: null };
 export const threadPermissionInfoValidator: TUnion<ThreadPermissionInfo> =
   t.union([
     tShape({ value: tBool(true), source: tID }),
     tShape({ value: tBool(false), source: t.Nil }),
   ]);
 export type ThreadPermissionsBlob = {
   +[permission: string]: ThreadPermissionInfo,
 };
 export type ThreadRolePermissionsBlob = { +[permission: string]: boolean };
 export const threadRolePermissionsBlobValidator: TDict<ThreadRolePermissionsBlob> =
   t.dict(t.String, t.Boolean);
 export type ThreadPermissionsInfo = {
   +[permission: ThreadPermission]: ThreadPermissionInfo,
 };
 export const threadPermissionsInfoValidator: TDict<ThreadPermissionsInfo> =
   t.dict(threadPermissionValidator, threadPermissionInfoValidator);