diff --git a/keyserver/src/fetchers/thread-permission-fetchers.js b/keyserver/src/fetchers/thread-permission-fetchers.js
index 71df9ba93..1d051f821 100644
--- a/keyserver/src/fetchers/thread-permission-fetchers.js
+++ b/keyserver/src/fetchers/thread-permission-fetchers.js
@@ -1,441 +1,457 @@
 // @flow
 
 import _keyBy from 'lodash/fp/keyBy.js';
 import _mapValues from 'lodash/fp/mapValues.js';
 
 import genesis from 'lib/facts/genesis.js';
 import {
   permissionLookup,
   makePermissionsBlob,
   getRoleForPermissions,
 } from 'lib/permissions/thread-permissions.js';
 import { relationshipBlockedInEitherDirection } from 'lib/shared/relationship-utils.js';
 import {
   permissionsDisabledByBlock,
   threadIsWithBlockedUserOnlyWithoutAdminRoleCheck,
   threadMembersWithoutAddedAdmin,
   roleIsAdminRole,
 } from 'lib/shared/thread-utils.js';
 import type {
   MemberInfoWithPermissions,
   RelativeMemberInfo,
   ThreadInfo,
 } from 'lib/types/minimally-encoded-thread-permissions-types.js';
 import { userRelationshipStatus } from 'lib/types/relationship-types.js';
 import type {
   ThreadPermission,
   ThreadPermissionsBlob,
   ThreadRolePermissionsBlob,
 } from 'lib/types/thread-permission-types.js';
 import type { ThreadType } from 'lib/types/thread-types-enum.js';
 import { values } from 'lib/utils/objects.js';
 
 import { fetchThreadInfos } from './thread-fetchers.js';
 import { fetchKnownUserInfos } from './user-fetchers.js';
 import { dbQuery, SQL } from '../database/database.js';
 import type { Viewer } from '../session/viewer.js';
 
 // Note that it's risky to verify permissions by inspecting the blob directly.
 // There are other factors that can override permissions in the permissions
 // blob, such as when one user blocks another. It's always better to go through
 // checkThreads and friends, or by looking at the ThreadInfo through
 // threadHasPermission.
 async function fetchThreadPermissionsBlob(
   viewer: Viewer,
   threadID: string,
 ): Promise<?ThreadPermissionsBlob> {
   const viewerID = viewer.id;
   const query = SQL`
     SELECT permissions
     FROM memberships
     WHERE thread = ${threadID} AND user = ${viewerID}
   `;
   const [result] = await dbQuery(query);
 
   if (result.length === 0) {
     return null;
   }
   const row = result[0];
   return JSON.parse(row.permissions);
 }
 
 function checkThreadPermission(
   viewer: Viewer,
   threadID: string,
   permission: ThreadPermission,
 ): Promise<boolean> {
   return checkThread(viewer, threadID, [{ check: 'permission', permission }]);
 }
 
 function viewerIsMember(viewer: Viewer, threadID: string): Promise<boolean> {
   return checkThread(viewer, threadID, [{ check: 'is_member' }]);
 }
 
+async function viewerHasPositiveRole(
+  viewer: Viewer,
+  threadID: string,
+): Promise<boolean> {
+  const query = SQL`
+    SELECT role
+    FROM memberships
+    WHERE thread = ${threadID} AND user = ${viewer.userID}
+  `;
+
+  const [queryResult] = await dbQuery(query);
+  const positiveRoles = queryResult.filter(row => Number(row.role) > 0);
+  return positiveRoles.length > 0;
+}
+
 type Check =
   | { +check: 'is_member' }
   | { +check: 'permission', +permission: ThreadPermission };
 
 function isThreadValid(
   permissions: ?ThreadPermissionsBlob,
   role: number,
   checks: $ReadOnlyArray<Check>,
 ): boolean {
   for (const check of checks) {
     if (check.check === 'is_member') {
       if (role <= 0) {
         return false;
       }
     } else if (check.check === 'permission') {
       if (!permissionLookup(permissions, check.permission)) {
         return false;
       }
     }
   }
   return true;
 }
 
 async function checkThreads(
   viewer: Viewer,
   threadIDs: $ReadOnlyArray<string>,
   checks: $ReadOnlyArray<Check>,
 ): Promise<Set<string>> {
   if (viewer.isScriptViewer) {
     // script viewers are all-powerful
     return new Set(threadIDs);
   }
 
   const threadRows = await getValidThreads(viewer, threadIDs, checks);
   return new Set(threadRows.map(row => row.threadID));
 }
 
 type PartialMembershipRow = {
   +threadID: string,
   +role: number,
   +permissions: ThreadPermissionsBlob,
 };
 async function getValidThreads(
   viewer: Viewer,
   threadIDs: $ReadOnlyArray<string>,
   checks: $ReadOnlyArray<Check>,
 ): Promise<PartialMembershipRow[]> {
   const query = SQL`
     SELECT thread AS threadID, permissions, role
     FROM memberships
     WHERE thread IN (${threadIDs}) AND user = ${viewer.userID}
   `;
 
   const permissionsToCheck = [];
   for (const check of checks) {
     if (check.check === 'permission') {
       permissionsToCheck.push(check.permission);
     }
   }
 
   const [[result], disabledThreadIDs] = await Promise.all([
     dbQuery(query),
     checkThreadsFrozen(viewer, permissionsToCheck, threadIDs),
   ]);
 
   return result
     .map(row => ({
       ...row,
       threadID: row.threadID.toString(),
       permissions: JSON.parse(row.permissions),
     }))
     .filter(
       row =>
         isThreadValid(row.permissions, row.role, checks) &&
         !disabledThreadIDs.has(row.threadID),
     );
 }
 
 async function checkThreadsFrozen(
   viewer: Viewer,
   permissionsToCheck: $ReadOnlyArray<ThreadPermission>,
   threadIDs: $ReadOnlyArray<string>,
 ): Promise<$ReadOnlySet<string>> {
   const threadIDsWithDisabledPermissions = new Set<string>();
 
   const permissionMightBeDisabled = permissionsToCheck.some(permission =>
     permissionsDisabledByBlock.has(permission),
   );
   if (!permissionMightBeDisabled) {
     return threadIDsWithDisabledPermissions;
   }
 
   const [{ threadInfos }, userInfos] = await Promise.all([
     fetchThreadInfos(viewer, { threadIDs: new Set(threadIDs) }),
     fetchKnownUserInfos(viewer),
   ]);
 
   const communityThreadIDs = new Set<string>();
   for (const threadInfo of values(threadInfos)) {
     const communityRootThreadID = threadInfo.community;
     if (!communityRootThreadID) {
       continue;
     }
     communityThreadIDs.add(communityRootThreadID);
   }
 
   const { threadInfos: communityThreadInfos } = await fetchThreadInfos(viewer, {
     threadIDs: communityThreadIDs,
   });
 
   const combinedThreadInfos = {
     ...threadInfos,
     ...communityThreadInfos,
   };
 
   const communityRootMembersToRole = _mapValues((threadInfo: ThreadInfo) => {
     const keyedMembers = _keyBy('id')(threadInfo.members);
     const keyedMembersToRole = _mapValues(
       (member: MemberInfoWithPermissions | RelativeMemberInfo) => {
         return member.role ? threadInfo.roles[member.role] : null;
       },
     )(keyedMembers);
     return keyedMembersToRole;
   })(combinedThreadInfos);
 
   for (const threadID in threadInfos) {
     const threadInfo = threadInfos[threadID];
 
     if (
       threadInfo.community &&
       !(threadInfo.community in communityRootMembersToRole)
     ) {
       threadIDsWithDisabledPermissions.add(threadID);
       continue;
     }
 
     // We fall back to threadID because the only case where threadInfo.community
     // is not set is for a community root, in which case the thread's community
     // root is the thread itself.
     const communityMembersToRole =
       communityRootMembersToRole[threadInfo.community ?? threadID];
 
     const memberHasAdminRole = threadMembersWithoutAddedAdmin(threadInfo).some(
       m => roleIsAdminRole(communityMembersToRole?.[m.id]),
     );
 
     if (memberHasAdminRole) {
       continue;
     }
 
     const blockedThread = threadIsWithBlockedUserOnlyWithoutAdminRoleCheck(
       threadInfo,
       viewer.id,
       userInfos,
       false,
     );
 
     if (blockedThread) {
       threadIDsWithDisabledPermissions.add(threadID);
     }
   }
 
   return threadIDsWithDisabledPermissions;
 }
 
 async function checkIfThreadIsBlocked(
   viewer: Viewer,
   threadID: string,
   permission: ThreadPermission,
 ): Promise<boolean> {
   const disabledThreadIDs = await checkThreadsFrozen(
     viewer,
     [permission],
     [threadID],
   );
 
   return disabledThreadIDs.has(threadID);
 }
 
 async function checkThread(
   viewer: Viewer,
   threadID: string,
   checks: $ReadOnlyArray<Check>,
 ): Promise<boolean> {
   const validThreads = await checkThreads(viewer, [threadID], checks);
   return validThreads.has(threadID);
 }
 
 // We pass this into getRoleForPermissions in order to check if a hypothetical
 // permissions blob would block membership by returning a non-positive result.
 // It doesn't matter what value we pass in, as long as it's positive.
 const arbitraryPositiveRole = '1';
 
 type ContainingStatus = 'member' | 'non-member' | 'no-containing-thread';
 
 type CandidateMembers = {
   +[key: string]: ?$ReadOnlyArray<string>,
 };
 type ValidateCandidateMembersParams = {
   +threadType: ThreadType,
   +parentThreadID: ?string,
   +containingThreadID: ?string,
   +defaultRolePermissions: ThreadRolePermissionsBlob,
   +communityID: ?string,
 };
 type ValidateCandidateMembersOptions = { +requireRelationship?: boolean };
 async function validateCandidateMembers(
   viewer: Viewer,
   candidates: CandidateMembers,
   params: ValidateCandidateMembersParams,
   options?: ValidateCandidateMembersOptions,
 ): Promise<CandidateMembers> {
   const requireRelationship = options?.requireRelationship ?? true;
 
   const allCandidatesSet = new Set<string>();
   for (const key in candidates) {
     const candidateGroup = candidates[key];
     if (!candidateGroup) {
       continue;
     }
     for (const candidate of candidateGroup) {
       allCandidatesSet.add(candidate);
     }
   }
   const allCandidates = [...allCandidatesSet];
 
   const fetchMembersPromise = fetchKnownUserInfos(viewer, allCandidates);
 
   const parentPermissionsPromise = (async () => {
     const parentPermissions = {};
     if (!params.parentThreadID || allCandidates.length === 0) {
       return parentPermissions;
     }
     const parentPermissionsQuery = SQL`
       SELECT user, permissions
       FROM memberships
       WHERE thread = ${params.parentThreadID} AND user IN (${allCandidates})
     `;
     const [result] = await dbQuery(parentPermissionsQuery);
     for (const row of result) {
       parentPermissions[row.user.toString()] = JSON.parse(row.permissions);
     }
     return parentPermissions;
   })();
 
   const memberOfContainingThreadPromise: Promise<
     Map<string, ContainingStatus>,
   > = (async () => {
     const results = new Map<string, ContainingStatus>();
     if (allCandidates.length === 0) {
       return results;
     }
     if (!params.containingThreadID) {
       for (const userID of allCandidates) {
         results.set(userID, 'no-containing-thread');
       }
       return results;
     }
     for (const userID of allCandidates) {
       results.set(userID, 'non-member');
     }
     const memberOfContainingThreadQuery = SQL`
       SELECT user, role AS containing_role
       FROM memberships
       WHERE thread = ${params.containingThreadID} AND user IN (${allCandidates})
     `;
     const [result] = await dbQuery(memberOfContainingThreadQuery);
     for (const row of result) {
       results.set(
         row.user.toString(),
         row.containing_role > 0 ? 'member' : 'non-member',
       );
     }
     return results;
   })();
 
   const [fetchedMembers, parentPermissions, memberOfContainingThread] =
     await Promise.all([
       fetchMembersPromise,
       parentPermissionsPromise,
       memberOfContainingThreadPromise,
     ]);
 
   const ignoreMembers = new Set<string>();
   for (const memberID of allCandidates) {
     const member = fetchedMembers[memberID];
     if (!member && requireRelationship) {
       ignoreMembers.add(memberID);
       continue;
     }
     const relationshipStatus = member?.relationshipStatus;
     const memberRelationshipHasBlock = !!(
       relationshipStatus &&
       relationshipBlockedInEitherDirection(relationshipStatus)
     );
     if (memberRelationshipHasBlock) {
       ignoreMembers.add(memberID);
       continue;
     }
     const permissionsFromParent = parentPermissions[memberID];
     if (
       memberOfContainingThread.get(memberID) === 'non-member' &&
       (params.communityID !== genesis().id ||
         (relationshipStatus !== userRelationshipStatus.FRIEND &&
           requireRelationship))
     ) {
       ignoreMembers.add(memberID);
       continue;
     }
     if (
       memberOfContainingThread.get(memberID) === 'no-containing-thread' &&
       relationshipStatus !== userRelationshipStatus.FRIEND &&
       requireRelationship
     ) {
       ignoreMembers.add(memberID);
       continue;
     }
     const permissions = makePermissionsBlob(
       params.defaultRolePermissions,
       permissionsFromParent,
       '-1',
       params.threadType,
     );
     if (!permissions) {
       ignoreMembers.add(memberID);
       continue;
     }
     const targetRole = getRoleForPermissions(
       arbitraryPositiveRole,
       permissions,
     );
     if (Number(targetRole) <= 0) {
       ignoreMembers.add(memberID);
       continue;
     }
   }
   if (ignoreMembers.size === 0) {
     return candidates;
   }
 
   const result: { [string]: ?$ReadOnlyArray<string> } = {};
   for (const key in candidates) {
     const candidateGroup = candidates[key];
     if (!candidateGroup) {
       result[key] = candidateGroup;
       continue;
     }
     const resultForKey = [];
     for (const candidate of candidateGroup) {
       if (!ignoreMembers.has(candidate)) {
         resultForKey.push(candidate);
       }
     }
     result[key] = resultForKey;
   }
   return result;
 }
 
 export {
   fetchThreadPermissionsBlob,
   checkThreadPermission,
   viewerIsMember,
   checkThreads,
   getValidThreads,
   checkThread,
   checkIfThreadIsBlocked,
   validateCandidateMembers,
+  viewerHasPositiveRole,
 };
diff --git a/keyserver/src/updaters/thread-updaters.js b/keyserver/src/updaters/thread-updaters.js
index 46ff33313..f5e87006d 100644
--- a/keyserver/src/updaters/thread-updaters.js
+++ b/keyserver/src/updaters/thread-updaters.js
@@ -1,1111 +1,1111 @@
 // @flow
 
 import { specialRoles } from 'lib/permissions/special-roles.js';
 import { getRolePermissionBlobs } from 'lib/permissions/thread-permissions.js';
 import { filteredThreadIDs } from 'lib/selectors/calendar-filter-selectors.js';
 import { getPinnedContentFromMessage } from 'lib/shared/message-utils.js';
 import {
   threadHasAdminRole,
   roleIsAdminRole,
   viewerIsMember,
   getThreadTypeParentRequirement,
 } from 'lib/shared/thread-utils.js';
 import { messageTypes } from 'lib/types/message-types-enum.js';
 import type { RawMessageInfo, MessageData } from 'lib/types/message-types.js';
 import { threadPermissions } from 'lib/types/thread-permission-types.js';
 import { threadTypes } from 'lib/types/thread-types-enum.js';
 import {
   type RoleChangeRequest,
   type ChangeThreadSettingsResult,
   type RemoveMembersRequest,
   type LeaveThreadRequest,
   type LeaveThreadResult,
   type UpdateThreadRequest,
   type ServerThreadJoinRequest,
   type ThreadJoinResult,
   type ToggleMessagePinRequest,
   type ToggleMessagePinResult,
 } from 'lib/types/thread-types.js';
 import { updateTypes } from 'lib/types/update-types-enum.js';
 import { ServerError } from 'lib/utils/errors.js';
 import { canToggleMessagePin } from 'lib/utils/message-pinning-utils.js';
 import { promiseAll, ignorePromiseRejections } from 'lib/utils/promises.js';
 import { firstLine } from 'lib/utils/string-utils.js';
 import { validChatNameRegex } from 'lib/utils/validation-utils.js';
 
 import { reportLinkUsage } from './link-updaters.js';
 import { updateRoles } from './role-updaters.js';
 import {
   changeRole,
   recalculateThreadPermissions,
   commitMembershipChangeset,
   type MembershipChangeset,
   type MembershipRow,
 } from './thread-permission-updaters.js';
 import createMessages from '../creators/message-creator.js';
 import { createUpdates } from '../creators/update-creator.js';
 import { dbQuery, SQL } from '../database/database.js';
 import { fetchCommunityFarcasterChannelTag } from '../fetchers/community-fetchers.js';
 import { checkIfInviteLinkIsValid } from '../fetchers/link-fetchers.js';
 import { fetchMessageInfoByID } from '../fetchers/message-fetchers.js';
 import { fetchRoles } from '../fetchers/role-fetchers.js';
 import {
   fetchThreadInfos,
   fetchServerThreadInfos,
   determineThreadAncestry,
   rawThreadInfosFromServerThreadInfos,
   determineThreadAncestryForPossibleMemberResolution,
 } from '../fetchers/thread-fetchers.js';
 import {
   checkThreadPermission,
-  viewerIsMember as fetchViewerIsMember,
+  viewerHasPositiveRole,
   checkThread,
   validateCandidateMembers,
 } from '../fetchers/thread-permission-fetchers.js';
 import {
   verifyUserIDs,
   verifyUserOrCookieIDs,
 } from '../fetchers/user-fetchers.js';
 import type { Viewer } from '../session/viewer.js';
 import { neynarClient } from '../utils/fc-cache.js';
 import { findUserIdentities } from '../utils/identity-utils.js';
 import { redisCache } from '../utils/redis-cache.js';
 import RelationshipChangeset from '../utils/relationship-changeset.js';
 
 type UpdateRoleOptions = {
   +silenceNewMessages?: boolean,
   +forcePermissionRecalculation?: boolean,
 };
 async function updateRole(
   viewer: Viewer,
   request: RoleChangeRequest,
   options?: UpdateRoleOptions,
 ): Promise<ChangeThreadSettingsResult> {
   const silenceNewMessages = options?.silenceNewMessages;
   const forcePermissionRecalculation = options?.forcePermissionRecalculation;
 
   if (!viewer.loggedIn) {
     throw new ServerError('not_logged_in');
   }
 
   const [memberIDs, hasPermission, fetchThreadResult] = await Promise.all([
     verifyUserIDs(request.memberIDs),
     checkThreadPermission(
       viewer,
       request.threadID,
       threadPermissions.CHANGE_ROLE,
     ),
     fetchServerThreadInfos({ threadID: request.threadID }),
   ]);
   if (memberIDs.length === 0) {
     throw new ServerError('invalid_parameters');
   }
   if (!hasPermission) {
     throw new ServerError('invalid_credentials');
   }
 
   const threadInfo = fetchThreadResult.threadInfos[request.threadID];
   if (!threadInfo) {
     throw new ServerError('invalid_parameters');
   }
 
   const adminRoleID = Object.keys(threadInfo.roles).find(
     roleID => threadInfo.roles[roleID].name === 'Admins',
   );
 
   // Ensure that there will always still be at least one admin in a community
   if (adminRoleID && adminRoleID !== request.role) {
     const memberRoles = memberIDs.map(
       memberID =>
         threadInfo.members.find(member => member.id === memberID)?.role,
     );
 
     const communityAdminsCount = threadInfo.members.filter(
       member => member.role === adminRoleID,
     ).length;
 
     const changedAdminsCount = memberRoles.filter(
       memberRole => memberRole === adminRoleID,
     ).length;
 
     if (changedAdminsCount >= communityAdminsCount) {
       throw new ServerError('invalid_parameters');
     }
   }
 
   const query = SQL`
     SELECT user, role
     FROM memberships
     WHERE user IN (${memberIDs})
       AND thread = ${request.threadID}
   `;
   const [result] = await dbQuery(query);
 
   let nonMemberUser = false;
   let numResults = 0;
   for (const row of result) {
     if (row.role <= 0) {
       nonMemberUser = true;
       break;
     }
     numResults++;
   }
   if (nonMemberUser || numResults < memberIDs.length) {
     throw new ServerError('invalid_parameters');
   }
 
   const changeset = await changeRole(
     request.threadID,
     memberIDs,
     request.role,
     {
       forcePermissionRecalculation: !!forcePermissionRecalculation,
     },
   );
 
   const { viewerUpdates } = await commitMembershipChangeset(
     viewer,
     changeset,
     forcePermissionRecalculation
       ? { changedThreadIDs: new Set([request.threadID]) }
       : undefined,
   );
 
   let newMessageInfos: Array<RawMessageInfo> = [];
   if (!silenceNewMessages) {
     const messageData = {
       type: messageTypes.CHANGE_ROLE,
       threadID: request.threadID,
       creatorID: viewer.userID,
       time: Date.now(),
       userIDs: memberIDs,
       newRole: request.role,
       roleName: threadInfo.roles[request.role].name,
     };
     newMessageInfos = await createMessages(viewer, [messageData]);
   }
 
   return { updatesResult: { newUpdates: viewerUpdates }, newMessageInfos };
 }
 
 async function removeMembers(
   viewer: Viewer,
   request: RemoveMembersRequest,
 ): Promise<ChangeThreadSettingsResult> {
   const viewerID = viewer.userID;
   if (request.memberIDs.includes(viewerID)) {
     throw new ServerError('invalid_parameters');
   }
 
   const [memberIDs, hasPermission] = await Promise.all([
     verifyUserOrCookieIDs(request.memberIDs),
     checkThreadPermission(
       viewer,
       request.threadID,
       threadPermissions.REMOVE_MEMBERS,
     ),
   ]);
   if (memberIDs.length === 0) {
     throw new ServerError('invalid_parameters');
   }
   if (!hasPermission) {
     throw new ServerError('invalid_credentials');
   }
 
   const query = SQL`
     SELECT m.user, m.role, r.id AS default_role
     FROM memberships m
     LEFT JOIN roles r ON r.special_role = ${specialRoles.DEFAULT_ROLE}
       AND r.thread = ${request.threadID}
     WHERE m.user IN (${memberIDs})
       AND m.thread = ${request.threadID}
   `;
   const [result] = await dbQuery(query);
 
   let nonDefaultRoleUser = false;
   const actualMemberIDs = [];
   for (const row of result) {
     if (row.role <= 0) {
       continue;
     }
     actualMemberIDs.push(row.user.toString());
     if (row.role !== row.default_role) {
       nonDefaultRoleUser = true;
     }
   }
 
   if (nonDefaultRoleUser) {
     const hasChangeRolePermission = await checkThreadPermission(
       viewer,
       request.threadID,
       threadPermissions.CHANGE_ROLE,
     );
     if (!hasChangeRolePermission) {
       throw new ServerError('invalid_credentials');
     }
   }
 
   const changeset = await changeRole(request.threadID, actualMemberIDs, 0);
   const { viewerUpdates } = await commitMembershipChangeset(viewer, changeset);
 
   const newMessageInfos = await (async () => {
     if (actualMemberIDs.length === 0) {
       return [];
     }
     const messageData = {
       type: messageTypes.REMOVE_MEMBERS,
       threadID: request.threadID,
       creatorID: viewerID,
       time: Date.now(),
       removedUserIDs: actualMemberIDs,
     };
     return await createMessages(viewer, [messageData]);
   })();
 
   return { updatesResult: { newUpdates: viewerUpdates }, newMessageInfos };
 }
 
 async function leaveThread(
   viewer: Viewer,
   request: LeaveThreadRequest,
 ): Promise<LeaveThreadResult> {
   if (!viewer.loggedIn) {
     throw new ServerError('not_logged_in');
   }
 
   const [fetchThreadResult, hasPermission] = await Promise.all([
     fetchThreadInfos(viewer, { threadID: request.threadID }),
     checkThreadPermission(
       viewer,
       request.threadID,
       threadPermissions.LEAVE_THREAD,
     ),
   ]);
 
   const threadInfo = fetchThreadResult.threadInfos[request.threadID];
 
   if (!viewerIsMember(threadInfo)) {
     return {
       updatesResult: { newUpdates: [] },
     };
   }
 
   if (!hasPermission) {
     throw new ServerError('invalid_parameters');
   }
 
   const viewerID = viewer.userID;
   if (threadHasAdminRole(threadInfo)) {
     let otherUsersExist = false;
     let otherAdminsExist = false;
     for (const member of threadInfo.members) {
       const role = member.role;
       if (!role || member.id === viewerID) {
         continue;
       }
       otherUsersExist = true;
       if (roleIsAdminRole(threadInfo.roles[role])) {
         otherAdminsExist = true;
         break;
       }
     }
     if (otherUsersExist && !otherAdminsExist) {
       throw new ServerError('invalid_parameters');
     }
   }
 
   const changeset = await changeRole(request.threadID, [viewerID], 0);
   const { viewerUpdates } = await commitMembershipChangeset(viewer, changeset);
 
   const messageData = {
     type: messageTypes.LEAVE_THREAD,
     threadID: request.threadID,
     creatorID: viewerID,
     time: Date.now(),
   };
   await createMessages(viewer, [messageData]);
 
   return { updatesResult: { newUpdates: viewerUpdates } };
 }
 
 type UpdateThreadOptions = Partial<{
   +forceAddMembers: boolean,
   +forceUpdateRoot: boolean,
   +silenceMessages: boolean,
   +ignorePermissions: boolean,
 }>;
 
 async function updateThread(
   viewer: Viewer,
   request: UpdateThreadRequest,
   options?: UpdateThreadOptions,
 ): Promise<ChangeThreadSettingsResult> {
   if (!viewer.loggedIn) {
     throw new ServerError('not_logged_in');
   }
   const forceAddMembers = options?.forceAddMembers ?? false;
   const forceUpdateRoot = options?.forceUpdateRoot ?? false;
   const silenceMessages = options?.silenceMessages ?? false;
   const ignorePermissions =
     (options?.ignorePermissions && viewer.isScriptViewer) ?? false;
 
   const changedFields: { [string]: string | number } = {};
   const sqlUpdate: { [string]: ?string | number } = {};
   const untrimmedName = request.changes.name;
   if (untrimmedName !== undefined && untrimmedName !== null) {
     const name = firstLine(untrimmedName);
     if (name.search(validChatNameRegex) === -1) {
       throw new ServerError('invalid_chat_name');
     }
     changedFields.name = name;
     sqlUpdate.name = name;
   }
   const { description } = request.changes;
   if (description !== undefined && description !== null) {
     changedFields.description = description;
     sqlUpdate.description = description;
   }
   if (request.changes.color) {
     const color = request.changes.color.toLowerCase();
     changedFields.color = color;
     sqlUpdate.color = color;
   }
   const { parentThreadID } = request.changes;
   if (parentThreadID !== undefined) {
     // TODO some sort of message when this changes
     sqlUpdate.parent_thread_id = parentThreadID;
   }
 
   const { avatar } = request.changes;
   if (avatar) {
     changedFields.avatar =
       avatar.type !== 'remove' ? JSON.stringify(avatar) : '';
     sqlUpdate.avatar = avatar.type !== 'remove' ? JSON.stringify(avatar) : null;
   }
 
   const threadType = request.changes.type;
   if (threadType !== null && threadType !== undefined) {
     changedFields.type = threadType;
     sqlUpdate.type = threadType;
   }
 
   if (
     !ignorePermissions &&
     threadType !== null &&
     threadType !== undefined &&
     threadType !== threadTypes.COMMUNITY_OPEN_SUBTHREAD &&
     threadType !== threadTypes.COMMUNITY_SECRET_SUBTHREAD
   ) {
     throw new ServerError('invalid_parameters');
   }
 
   const newMemberIDs =
     request.changes.newMemberIDs && request.changes.newMemberIDs.length > 0
       ? [...new Set(request.changes.newMemberIDs)]
       : null;
 
   if (
     Object.keys(sqlUpdate).length === 0 &&
     !newMemberIDs &&
     !forceUpdateRoot
   ) {
     throw new ServerError('invalid_parameters');
   }
 
   const serverThreadInfosPromise = fetchServerThreadInfos({
     threadID: request.threadID,
   });
 
   const hasNecessaryPermissionsPromise = (async () => {
     if (ignorePermissions) {
       return;
     }
     const checks = [];
     if (sqlUpdate.name !== undefined) {
       checks.push({
         check: 'permission',
         permission: threadPermissions.EDIT_THREAD_NAME,
       });
     }
     if (sqlUpdate.description !== undefined) {
       checks.push({
         check: 'permission',
         permission: threadPermissions.EDIT_THREAD_DESCRIPTION,
       });
     }
     if (sqlUpdate.color !== undefined) {
       checks.push({
         check: 'permission',
         permission: threadPermissions.EDIT_THREAD_COLOR,
       });
     }
     if (sqlUpdate.avatar !== undefined) {
       checks.push({
         check: 'permission',
         permission: threadPermissions.EDIT_THREAD_AVATAR,
       });
     }
     if (parentThreadID !== undefined || sqlUpdate.type !== undefined) {
       checks.push({
         check: 'permission',
         permission: threadPermissions.EDIT_PERMISSIONS,
       });
     }
     if (newMemberIDs) {
       checks.push({
         check: 'permission',
         permission: threadPermissions.ADD_MEMBERS,
       });
     }
     const hasNecessaryPermissions = await checkThread(
       viewer,
       request.threadID,
       checks,
     );
     if (!hasNecessaryPermissions) {
       throw new ServerError('invalid_credentials');
     }
   })();
 
   const [serverThreadInfos] = await Promise.all([
     serverThreadInfosPromise,
     hasNecessaryPermissionsPromise,
   ]);
 
   const serverThreadInfo = serverThreadInfos.threadInfos[request.threadID];
   if (!serverThreadInfo) {
     throw new ServerError('internal_error');
   }
 
   // Threads with source message should be visible to everyone, but we can't
   // guarantee it for COMMUNITY_SECRET_SUBTHREAD threads so we forbid it for
   // now. In the future, if we want to support this, we would need to unlink the
   // source message.
   if (
     threadType !== null &&
     threadType !== undefined &&
     threadType !== threadTypes.SIDEBAR &&
     threadType !== threadTypes.COMMUNITY_OPEN_SUBTHREAD &&
     serverThreadInfo.sourceMessageID
   ) {
     throw new ServerError('invalid_parameters');
   }
 
   // You can't change the parent thread of a current or former SIDEBAR
   if (parentThreadID !== undefined && serverThreadInfo.sourceMessageID) {
     throw new ServerError('invalid_parameters');
   }
 
   const oldThreadType = serverThreadInfo.type;
   const oldParentThreadID = serverThreadInfo.parentThreadID;
   const oldContainingThreadID = serverThreadInfo.containingThreadID;
   const oldCommunity = serverThreadInfo.community;
   const oldDepth = serverThreadInfo.depth;
 
   const nextThreadType =
     threadType !== null && threadType !== undefined
       ? threadType
       : oldThreadType;
   let nextParentThreadID =
     parentThreadID !== undefined ? parentThreadID : oldParentThreadID;
 
   // Does the new thread type preclude a parent?
   if (
     threadType !== undefined &&
     threadType !== null &&
     getThreadTypeParentRequirement(threadType) === 'disabled' &&
     nextParentThreadID !== null
   ) {
     nextParentThreadID = null;
     sqlUpdate.parent_thread_id = null;
   }
 
   // Does the new thread type require a parent?
   if (
     threadType !== undefined &&
     threadType !== null &&
     getThreadTypeParentRequirement(threadType) === 'required' &&
     nextParentThreadID === null
   ) {
     throw new ServerError('no_parent_thread_specified');
   }
 
   const determineThreadAncestryPromise = determineThreadAncestry(
     nextParentThreadID,
     nextThreadType,
   );
 
   const confirmParentPermissionPromise = (async () => {
     if (ignorePermissions || !nextParentThreadID) {
       return;
     }
     if (
       nextParentThreadID === oldParentThreadID &&
       (nextThreadType === threadTypes.SIDEBAR) ===
         (oldThreadType === threadTypes.SIDEBAR)
     ) {
       return;
     }
     const hasParentPermission = await checkThreadPermission(
       viewer,
       nextParentThreadID,
       nextThreadType === threadTypes.SIDEBAR
         ? threadPermissions.CREATE_SIDEBARS
         : threadPermissions.CREATE_SUBCHANNELS,
     );
     if (!hasParentPermission) {
       throw new ServerError('invalid_parameters');
     }
   })();
 
   const rolesNeedUpdate = forceUpdateRoot || nextThreadType !== oldThreadType;
 
   const validateNewMembersPromise = (async () => {
     if (!newMemberIDs || ignorePermissions) {
       return;
     }
 
     const defaultRolePermissionsPromise = (async () => {
       let rolePermissions;
       if (!rolesNeedUpdate) {
         const rolePermissionsQuery = SQL`
           SELECT r.permissions
           FROM threads t
           LEFT JOIN roles r ON r.special_role = ${specialRoles.DEFAULT_ROLE} 
             AND r.thread = ${request.threadID}
           WHERE t.id = ${request.threadID}
         `;
         const [result] = await dbQuery(rolePermissionsQuery);
         if (result.length > 0) {
           rolePermissions = JSON.parse(result[0].permissions);
         }
       }
       if (!rolePermissions) {
         rolePermissions = getRolePermissionBlobs(nextThreadType).Members;
       }
       return rolePermissions;
     })();
 
     const [defaultRolePermissions, nextThreadAncestry] = await Promise.all([
       defaultRolePermissionsPromise,
       determineThreadAncestryPromise,
     ]);
 
     const containingThreadIDForPossibleMemberResolution =
       determineThreadAncestryForPossibleMemberResolution(
         nextParentThreadID,
         nextThreadAncestry.containingThreadID,
       );
 
     const { newMemberIDs: validatedIDs } = await validateCandidateMembers(
       viewer,
       { newMemberIDs },
       {
         threadType: nextThreadType,
         parentThreadID: nextParentThreadID,
         containingThreadID: containingThreadIDForPossibleMemberResolution,
         defaultRolePermissions,
         communityID: nextThreadAncestry.community,
       },
       { requireRelationship: !forceAddMembers },
     );
     if (
       validatedIDs &&
       Number(validatedIDs?.length) < Number(newMemberIDs?.length)
     ) {
       throw new ServerError('invalid_credentials');
     }
   })();
 
   const { nextThreadAncestry } = await promiseAll({
     nextThreadAncestry: determineThreadAncestryPromise,
     confirmParentPermissionPromise,
     validateNewMembersPromise,
   });
   if (nextThreadAncestry.containingThreadID !== oldContainingThreadID) {
     sqlUpdate.containing_thread_id = nextThreadAncestry.containingThreadID;
   }
   if (nextThreadAncestry.community !== oldCommunity) {
     if (!ignorePermissions) {
       throw new ServerError('invalid_parameters');
     }
     sqlUpdate.community = nextThreadAncestry.community;
   }
   if (nextThreadAncestry.depth !== oldDepth) {
     sqlUpdate.depth = nextThreadAncestry.depth;
   }
 
   const updateQueryPromise = (async () => {
     if (Object.keys(sqlUpdate).length === 0) {
       return;
     }
 
     const { avatar: avatarUpdate, ...nonAvatarUpdates } = sqlUpdate;
     const updatePromises = [];
 
     if (Object.keys(nonAvatarUpdates).length > 0) {
       const nonAvatarUpdateQuery = SQL`
         UPDATE threads
         SET ${nonAvatarUpdates}
         WHERE id = ${request.threadID}
       `;
       updatePromises.push(dbQuery(nonAvatarUpdateQuery));
     }
 
     if (avatarUpdate !== undefined) {
       const avatarUploadID =
         avatar && (avatar.type === 'image' || avatar.type === 'encrypted_image')
           ? avatar.uploadID
           : null;
 
       const avatarUpdateQuery = SQL`
         START TRANSACTION;
 
         UPDATE uploads
         SET container = NULL
         WHERE container = ${request.threadID}
           AND (
             ${avatarUploadID} IS NULL
             OR EXISTS (
               SELECT 1
               FROM uploads
               WHERE id = ${avatarUploadID}
                 AND ${avatarUploadID} IS NOT NULL
                 AND uploader = ${viewer.userID}
                 AND container IS NULL
                 AND user_container IS NULL
                 AND thread IS NULL
              )
           );
 
         UPDATE uploads
         SET container = ${request.threadID}
         WHERE id = ${avatarUploadID}
           AND ${avatarUploadID} IS NOT NULL
           AND uploader = ${viewer.userID}
           AND container IS NULL
           AND user_container IS NULL
           AND thread IS NULL;
 
         UPDATE threads
         SET avatar = ${avatarUpdate}
         WHERE id = ${request.threadID}
           AND (
             ${avatarUploadID} IS NULL
             OR EXISTS (
               SELECT 1
               FROM uploads
               WHERE id = ${avatarUploadID}
                 AND ${avatarUploadID} IS NOT NULL
                 AND uploader = ${viewer.userID}
                 AND container = ${request.threadID}
                 AND thread IS NULL
             )
           );
 
         COMMIT;
       `;
 
       updatePromises.push(
         dbQuery(avatarUpdateQuery, { multipleStatements: true }),
       );
     }
 
     await Promise.all(updatePromises);
   })();
 
   const updateRolesPromise = (async () => {
     if (rolesNeedUpdate) {
       await updateRoles(viewer, request.threadID, nextThreadType);
     }
   })();
 
   const addMembersChangesetPromise: Promise<?MembershipChangeset> =
     (async () => {
       if (!newMemberIDs) {
         return undefined;
       }
       await Promise.all([updateQueryPromise, updateRolesPromise]);
       return await changeRole(request.threadID, newMemberIDs, null, {
         setNewMembersToUnread: true,
       });
     })();
 
   const recalculatePermissionsChangesetPromise: Promise<?MembershipChangeset> =
     (async () => {
       const threadRootChanged =
         rolesNeedUpdate || nextParentThreadID !== oldParentThreadID;
       if (!threadRootChanged) {
         return undefined;
       }
       await Promise.all([updateQueryPromise, updateRolesPromise]);
       return await recalculateThreadPermissions(request.threadID);
     })();
 
   const [addMembersChangeset, recalculatePermissionsChangeset] =
     await Promise.all([
       addMembersChangesetPromise,
       recalculatePermissionsChangesetPromise,
       updateQueryPromise,
       updateRolesPromise,
     ]);
 
   const membershipRows: Array<MembershipRow> = [];
   const relationshipChangeset = new RelationshipChangeset();
   if (recalculatePermissionsChangeset) {
     const {
       membershipRows: recalculateMembershipRows,
       relationshipChangeset: recalculateRelationshipChangeset,
     } = recalculatePermissionsChangeset;
     membershipRows.push(...recalculateMembershipRows);
     relationshipChangeset.addAll(recalculateRelationshipChangeset);
   }
   let addedMemberIDs;
   if (addMembersChangeset) {
     const {
       membershipRows: addMembersMembershipRows,
       relationshipChangeset: addMembersRelationshipChangeset,
     } = addMembersChangeset;
     addedMemberIDs = addMembersMembershipRows
       .filter(
         row =>
           row.operation === 'save' &&
           row.threadID === request.threadID &&
           Number(row.role) > 0,
       )
       .map(row => row.userID);
     membershipRows.push(...addMembersMembershipRows);
     relationshipChangeset.addAll(addMembersRelationshipChangeset);
   }
 
   const changeset = { membershipRows, relationshipChangeset };
   const { viewerUpdates } = await commitMembershipChangeset(viewer, changeset, {
     // This forces an update for this thread,
     // regardless of whether any membership rows are changed
     changedThreadIDs:
       Object.keys(sqlUpdate).length > 0
         ? new Set([request.threadID])
         : new Set(),
     // last_message will be updated automatically if we send a message,
     // so we only need to handle it here when we silence new messages
     updateMembershipsLastMessage: silenceMessages,
   });
 
   let newMessageInfos: Array<RawMessageInfo> = [];
   if (!silenceMessages) {
     const time = Date.now();
     const messageDatas: Array<MessageData> = [];
     for (const fieldName in changedFields) {
       const newValue = changedFields[fieldName];
       messageDatas.push({
         type: messageTypes.CHANGE_SETTINGS,
         threadID: request.threadID,
         creatorID: viewer.userID,
         time,
         field: fieldName,
         value: newValue,
       });
     }
     if (addedMemberIDs && addedMemberIDs.length > 0) {
       messageDatas.push({
         type: messageTypes.ADD_MEMBERS,
         threadID: request.threadID,
         creatorID: viewer.userID,
         time,
         addedUserIDs: addedMemberIDs,
       });
     }
     newMessageInfos = await createMessages(viewer, messageDatas);
   }
 
   return { updatesResult: { newUpdates: viewerUpdates }, newMessageInfos };
 }
 
 async function joinThread(
   viewer: Viewer,
   request: ServerThreadJoinRequest,
 ): Promise<ThreadJoinResult> {
   if (!viewer.loggedIn) {
     throw new ServerError('not_logged_in');
   }
 
   const communityFarcasterChannelTagPromise = fetchCommunityFarcasterChannelTag(
     viewer,
     request.threadID,
   );
 
   const permissionPromise = (async () => {
     if (request.inviteLinkSecret) {
       return await checkIfInviteLinkIsValid(
         request.inviteLinkSecret,
         request.threadID,
       );
     }
 
     const threadPermissionPromise = checkThreadPermission(
       viewer,
       request.threadID,
       threadPermissions.JOIN_THREAD,
     );
 
     const [threadPermission, communityFarcasterChannelTag] = await Promise.all([
       threadPermissionPromise,
       communityFarcasterChannelTagPromise,
     ]);
 
     return threadPermission || !!communityFarcasterChannelTag;
   })();
 
   const [isMember, hasPermission, communityFarcasterChannelTag] =
     await Promise.all([
-      fetchViewerIsMember(viewer, request.threadID),
+      viewerHasPositiveRole(viewer, request.threadID),
       permissionPromise,
       communityFarcasterChannelTagPromise,
     ]);
 
   if (!hasPermission) {
     throw new ServerError('invalid_parameters');
   }
 
   const { calendarQuery } = request;
   if (isMember) {
     const response: ThreadJoinResult = {
       rawMessageInfos: [],
       truncationStatuses: {},
       userInfos: {},
       updatesResult: {
         newUpdates: [],
       },
     };
     return response;
   }
 
   if (calendarQuery) {
     const threadFilterIDs = filteredThreadIDs(calendarQuery.filters);
     if (
       !threadFilterIDs ||
       threadFilterIDs.size !== 1 ||
       threadFilterIDs.values().next().value !== request.threadID
     ) {
       throw new ServerError('invalid_parameters');
     }
   }
 
   let role = null;
   if (communityFarcasterChannelTag) {
     role = await fetchUserRoleForThread(
       viewer,
       request.threadID,
       communityFarcasterChannelTag,
     );
   }
 
   const changeset = await changeRole(request.threadID, [viewer.userID], role, {
     defaultSubscription: request.defaultSubscription,
   });
 
   const membershipResult = await commitMembershipChangeset(viewer, changeset, {
     calendarQuery,
   });
 
   if (request.inviteLinkSecret) {
     ignorePromiseRejections(reportLinkUsage(request.inviteLinkSecret));
   }
 
   const messageData = {
     type: messageTypes.JOIN_THREAD,
     threadID: request.threadID,
     creatorID: viewer.userID,
     time: Date.now(),
   };
   const newMessages = await createMessages(viewer, [messageData]);
 
   return {
     rawMessageInfos: newMessages,
     truncationStatuses: {},
     userInfos: membershipResult.userInfos,
     updatesResult: {
       newUpdates: membershipResult.viewerUpdates,
     },
   };
 }
 
 async function fetchUserRoleForThread(
   viewer: Viewer,
   threadID: string,
   communityFarcasterChannelTag: string,
 ): Promise<string | null> {
   const farcasterID = await getUserFarcasterID(viewer.userID);
 
   if (!farcasterID) {
     return null;
   }
 
   const leadsChannel = await userLeadsChannel(
     communityFarcasterChannelTag,
     farcasterID,
   );
   if (!leadsChannel) {
     return null;
   }
 
   const roleInfos = await fetchRoles(threadID);
   for (const roleInfo of roleInfos) {
     if (roleInfo.specialRole === specialRoles.ADMIN_ROLE) {
       return roleInfo.id;
     }
   }
 
   return null;
 }
 
 async function getUserFarcasterID(userID: string): Promise<?string> {
   const cachedUserIdentity = await redisCache.getUserIdentity(userID);
   if (cachedUserIdentity) {
     return cachedUserIdentity.farcasterID;
   }
 
   const response = await findUserIdentities([userID]);
   const userIdentity = response.identities[userID];
   if (!userIdentity) {
     return null;
   }
 
   ignorePromiseRejections(redisCache.setUserIdentity(userID, userIdentity));
   return userIdentity.farcasterID;
 }
 
 async function userLeadsChannel(
   communityFarcasterChannelTag: string,
   farcasterID: string,
 ) {
   const cachedChannelInfo = await redisCache.getChannelInfo(
     communityFarcasterChannelTag,
   );
   if (cachedChannelInfo) {
     return cachedChannelInfo.lead.fid === parseInt(farcasterID);
   }
 
   // In the background, we fetch and cache followed channels
   ignorePromiseRejections(
     (async () => {
       const followedChannels =
         await neynarClient?.fetchFollowedFarcasterChannels(farcasterID);
       if (followedChannels) {
         await Promise.allSettled(
           followedChannels.map(followedChannel =>
             redisCache.setChannelInfo(followedChannel.id, followedChannel),
           ),
         );
       }
     })(),
   );
 
   const channelInfo = await neynarClient?.fetchFarcasterChannelByID(
     communityFarcasterChannelTag,
   );
   if (channelInfo) {
     return channelInfo.lead.fid === parseInt(farcasterID);
   }
 
   return false;
 }
 
 async function toggleMessagePinForThread(
   viewer: Viewer,
   request: ToggleMessagePinRequest,
 ): Promise<ToggleMessagePinResult> {
   const { messageID, action } = request;
 
   const targetMessage = await fetchMessageInfoByID(viewer, messageID);
   if (!targetMessage) {
     throw new ServerError('invalid_parameters');
   }
 
   const { threadID } = targetMessage;
   const fetchServerThreadInfosResult = await fetchServerThreadInfos({
     threadID,
   });
   const { threadInfos: rawThreadInfos } = rawThreadInfosFromServerThreadInfos(
     viewer,
     fetchServerThreadInfosResult,
   );
   const rawThreadInfo = rawThreadInfos[threadID];
 
   const canTogglePin = canToggleMessagePin(targetMessage, rawThreadInfo);
   if (!canTogglePin) {
     throw new ServerError('invalid_parameters');
   }
 
   const pinnedValue = action === 'pin' ? 1 : 0;
   const pinTimeValue = action === 'pin' ? Date.now() : null;
   const pinnedCountValue = action === 'pin' ? 1 : -1;
 
   const query = SQL`
     UPDATE messages AS m, threads AS t
     SET m.pinned = ${pinnedValue},
       m.pin_time = ${pinTimeValue},
       t.pinned_count = t.pinned_count + ${pinnedCountValue}
     WHERE m.id = ${messageID}
       AND m.thread = ${threadID}
       AND t.id = ${threadID}
       AND m.pinned != ${pinnedValue}
   `;
 
   const [result] = await dbQuery(query);
 
   if (result.affectedRows === 0) {
     return {
       newMessageInfos: [],
       threadID,
     };
   }
 
   const createMessagesAsync = async () => {
     const messageData = {
       type: messageTypes.TOGGLE_PIN,
       threadID,
       targetMessageID: messageID,
       action,
       pinnedContent: getPinnedContentFromMessage(targetMessage),
       creatorID: viewer.userID,
       time: Date.now(),
     };
     const newMessageInfos = await createMessages(viewer, [messageData]);
     return newMessageInfos;
   };
 
   const createUpdatesAsync = async () => {
     const { threadInfos: serverThreadInfos } = fetchServerThreadInfosResult;
     const time = Date.now();
     const updates = [];
     for (const member of serverThreadInfos[threadID].members) {
       updates.push({
         userID: member.id,
         time,
         threadID,
         type: updateTypes.UPDATE_THREAD,
       });
     }
     await createUpdates(updates);
   };
 
   const [newMessageInfos] = await Promise.all([
     createMessagesAsync(),
     createUpdatesAsync(),
   ]);
 
   return {
     newMessageInfos,
     threadID,
   };
 }
 
 export {
   updateRole,
   removeMembers,
   leaveThread,
   updateThread,
   joinThread,
   toggleMessagePinForThread,
 };