diff --git a/keyserver/src/fetchers/message-fetchers.js b/keyserver/src/fetchers/message-fetchers.js
index c3710d1df..5b7cb7efa 100644
--- a/keyserver/src/fetchers/message-fetchers.js
+++ b/keyserver/src/fetchers/message-fetchers.js
@@ -1,730 +1,732 @@
 // @flow
 
 import invariant from 'invariant';
 
 import {
   sortMessageInfoList,
   shimUnsupportedRawMessageInfos,
 } from 'lib/shared/message-utils.js';
 import { messageSpecs } from 'lib/shared/messages/message-specs.js';
-import { notifCollapseKeyForRawMessageInfo } from 'lib/shared/notif-utils.js';
+import { getNotifCollapseKey } from 'lib/shared/notif-utils.js';
 import { hasMinCodeVersion } from 'lib/shared/version-utils.js';
 import {
   type RawMessageInfo,
   type RawComposableMessageInfo,
   type RawRobotextMessageInfo,
   messageTypes,
   type MessageType,
   assertMessageType,
   type MessageSelectionCriteria,
   type MessageTruncationStatus,
   messageTruncationStatus,
   type FetchMessageInfosResult,
   defaultMaxMessageAge,
 } from 'lib/types/message-types.js';
 import { threadPermissions } from 'lib/types/thread-types.js';
 import { ServerError } from 'lib/utils/errors.js';
 
 import {
   constructMediaFromMediaMessageContentsAndUploadRows,
   mediaFromRow,
 } from './upload-fetchers.js';
 import {
   dbQuery,
   SQL,
   mergeOrConditions,
   mergeAndConditions,
 } from '../database/database.js';
 import type { SQLStatementType } from '../database/types.js';
 import type { PushInfo } from '../push/send.js';
 import type { Viewer } from '../session/viewer.js';
 import {
   creationString,
   localIDFromCreationString,
 } from '../utils/idempotent.js';
 
 export type CollapsableNotifInfo = {
   collapseKey: ?string,
   existingMessageInfos: RawMessageInfo[],
   newMessageInfos: RawMessageInfo[],
 };
 export type FetchCollapsableNotifsResult = {
   [userID: string]: CollapsableNotifInfo[],
 };
 
 const visibleExtractString = `$.${threadPermissions.VISIBLE}.value`;
 
 // This function doesn't filter RawMessageInfos based on what messageTypes the
 // client supports, since each user can have multiple clients. The caller must
 // handle this filtering.
 async function fetchCollapsableNotifs(
   pushInfo: PushInfo,
 ): Promise<FetchCollapsableNotifsResult> {
   // First, we need to fetch any notifications that should be collapsed
   const usersToCollapseKeysToInfo = {};
   const usersToCollapsableNotifInfo = {};
   for (const userID in pushInfo) {
     usersToCollapseKeysToInfo[userID] = {};
     usersToCollapsableNotifInfo[userID] = [];
-    for (const rawMessageInfo of pushInfo[userID].messageInfos) {
-      const collapseKey = notifCollapseKeyForRawMessageInfo(rawMessageInfo);
+    for (let i = 0; i < pushInfo[userID].messageInfos.length; i++) {
+      const rawMessageInfo = pushInfo[userID].messageInfos[i];
+      const messageData = pushInfo[userID].messageDatas[i];
+      const collapseKey = getNotifCollapseKey(rawMessageInfo, messageData);
       if (!collapseKey) {
         const collapsableNotifInfo = {
           collapseKey,
           existingMessageInfos: [],
           newMessageInfos: [rawMessageInfo],
         };
         usersToCollapsableNotifInfo[userID].push(collapsableNotifInfo);
         continue;
       }
       if (!usersToCollapseKeysToInfo[userID][collapseKey]) {
         usersToCollapseKeysToInfo[userID][collapseKey] = {
           collapseKey,
           existingMessageInfos: [],
           newMessageInfos: [],
         };
       }
       usersToCollapseKeysToInfo[userID][collapseKey].newMessageInfos.push(
         rawMessageInfo,
       );
     }
   }
 
   const sqlTuples = [];
   for (const userID in usersToCollapseKeysToInfo) {
     const collapseKeysToInfo = usersToCollapseKeysToInfo[userID];
     for (const collapseKey in collapseKeysToInfo) {
       sqlTuples.push(
         SQL`(n.user = ${userID} AND n.collapse_key = ${collapseKey})`,
       );
     }
   }
 
   if (sqlTuples.length === 0) {
     return usersToCollapsableNotifInfo;
   }
 
   const collapseQuery = SQL`
     SELECT m.id, m.thread AS threadID, m.content, m.time, m.type,
       m.user AS creatorID, m.target_message as targetMessageID,
       stm.permissions AS subthread_permissions, n.user,
       n.collapse_key, up.id AS uploadID, up.type AS uploadType,
       up.secret AS uploadSecret, up.extra AS uploadExtra
     FROM notifications n
     LEFT JOIN messages m ON m.id = n.message
     LEFT JOIN uploads up ON up.container = m.id
     LEFT JOIN memberships mm ON mm.thread = m.thread AND mm.user = n.user
     LEFT JOIN memberships stm
       ON m.type = ${messageTypes.CREATE_SUB_THREAD}
         AND stm.thread = m.content AND stm.user = n.user
     WHERE n.rescinded = 0 AND
       JSON_EXTRACT(mm.permissions, ${visibleExtractString}) IS TRUE AND
   `;
   collapseQuery.append(mergeOrConditions(sqlTuples));
   collapseQuery.append(SQL`ORDER BY m.time DESC, m.id DESC`);
   const [collapseResult] = await dbQuery(collapseQuery);
 
   const rowsByUser = new Map();
   for (const row of collapseResult) {
     const user = row.user.toString();
     const currentRowsForUser = rowsByUser.get(user);
     if (currentRowsForUser) {
       currentRowsForUser.push(row);
     } else {
       rowsByUser.set(user, [row]);
     }
   }
 
   const derivedMessages = await fetchDerivedMessages(collapseResult);
   for (const userRows of rowsByUser.values()) {
     const messages = parseMessageSQLResult(userRows, derivedMessages);
     for (const message of messages) {
       const { rawMessageInfo, rows } = message;
       const [row] = rows;
       const info = usersToCollapseKeysToInfo[row.user][row.collapse_key];
       info.existingMessageInfos.push(rawMessageInfo);
     }
   }
 
   for (const userID in usersToCollapseKeysToInfo) {
     const collapseKeysToInfo = usersToCollapseKeysToInfo[userID];
     for (const collapseKey in collapseKeysToInfo) {
       const info = collapseKeysToInfo[collapseKey];
       usersToCollapsableNotifInfo[userID].push({
         collapseKey: info.collapseKey,
         existingMessageInfos: sortMessageInfoList(info.existingMessageInfos),
         newMessageInfos: sortMessageInfoList(info.newMessageInfos),
       });
     }
   }
 
   return usersToCollapsableNotifInfo;
 }
 
 type MessageSQLResult = $ReadOnlyArray<{
   rawMessageInfo: RawMessageInfo,
   rows: $ReadOnlyArray<Object>,
 }>;
 function parseMessageSQLResult(
   rows: $ReadOnlyArray<Object>,
   derivedMessages: $ReadOnlyMap<
     string,
     RawComposableMessageInfo | RawRobotextMessageInfo,
   >,
   viewer?: Viewer,
 ): MessageSQLResult {
   const rowsByID = new Map();
   for (const row of rows) {
     const id = row.id.toString();
     const currentRowsForID = rowsByID.get(id);
     if (currentRowsForID) {
       currentRowsForID.push(row);
     } else {
       rowsByID.set(id, [row]);
     }
   }
 
   const messages = [];
   for (const messageRows of rowsByID.values()) {
     const rawMessageInfo = rawMessageInfoFromRows(
       messageRows,
       viewer,
       derivedMessages,
     );
     if (rawMessageInfo) {
       messages.push({ rawMessageInfo, rows: messageRows });
     }
   }
 
   return messages;
 }
 
 function assertSingleRow(rows: $ReadOnlyArray<Object>): Object {
   if (rows.length === 0) {
     throw new Error('expected single row, but none present!');
   } else if (rows.length !== 1) {
     const messageIDs = rows.map(row => row.id.toString());
     console.warn(
       `expected single row, but there are multiple! ${messageIDs.join(', ')}`,
     );
   }
   return rows[0];
 }
 
 function mostRecentRowType(rows: $ReadOnlyArray<Object>): MessageType {
   if (rows.length === 0) {
     throw new Error('expected row, but none present!');
   }
   return assertMessageType(rows[0].type);
 }
 
 function rawMessageInfoFromRows(
   rawRows: $ReadOnlyArray<Object>,
   viewer?: Viewer,
   derivedMessages: $ReadOnlyMap<
     string,
     RawComposableMessageInfo | RawRobotextMessageInfo,
   >,
 ): ?RawMessageInfo {
   const rows = rawRows.map(row => ({
     ...row,
     subthread_permissions: JSON.parse(row.subthread_permissions),
   }));
 
   const type = mostRecentRowType(rows);
   const messageSpec = messageSpecs[type];
 
   if (type === messageTypes.IMAGES || type === messageTypes.MULTIMEDIA) {
     let media;
     if (type === messageTypes.MULTIMEDIA) {
       const mediaMessageContents = JSON.parse(rows[0].content);
       media = constructMediaFromMediaMessageContentsAndUploadRows(
         mediaMessageContents,
         rows,
       );
     } else {
       media = rows.filter(row => row.uploadID).map(mediaFromRow);
     }
     const [row] = rows;
     const localID = localIDFromCreationString(viewer, row.creation);
     invariant(
       messageSpec.rawMessageInfoFromServerDBRow,
       `multimedia message spec should have rawMessageInfoFromServerDBRow`,
     );
     return messageSpec.rawMessageInfoFromServerDBRow(row, {
       media,
       derivedMessages,
       localID,
     });
   }
 
   const row = assertSingleRow(rows);
   const localID = localIDFromCreationString(viewer, row.creation);
   invariant(
     messageSpec.rawMessageInfoFromServerDBRow,
     `message spec ${type} should have rawMessageInfoFromServerDBRow`,
   );
   return messageSpec.rawMessageInfoFromServerDBRow(row, {
     derivedMessages,
     localID,
   });
 }
 
 async function fetchMessageInfos(
   viewer: Viewer,
   criteria: MessageSelectionCriteria,
   numberPerThread: number,
 ): Promise<FetchMessageInfosResult> {
   const { sqlClause: selectionClause, timeFilterData } =
     parseMessageSelectionCriteria(viewer, criteria);
   const truncationStatuses = {};
 
   const viewerID = viewer.id;
   const query = SQL`
     WITH thread_window AS (
       SELECT m.id, m.thread AS threadID, m.user AS creatorID,
         m.target_message as targetMessageID, m.content, m.time, m.type,
         m.creation, stm.permissions AS subthread_permissions,
         ROW_NUMBER() OVER (
           PARTITION BY threadID ORDER BY m.time DESC, m.id DESC
         ) n
       FROM messages m
       LEFT JOIN memberships mm
         ON mm.thread = m.thread AND mm.user = ${viewerID}
       LEFT JOIN memberships stm ON m.type = ${messageTypes.CREATE_SUB_THREAD}
         AND stm.thread = m.content AND stm.user = ${viewerID}
       WHERE JSON_EXTRACT(mm.permissions, ${visibleExtractString}) IS TRUE AND
   `;
   query.append(selectionClause);
   query.append(SQL`
     )
     SELECT tw.*,
       up.id AS uploadID, up.type AS uploadType, up.secret AS uploadSecret,
       up.extra AS uploadExtra
     FROM thread_window tw
     LEFT JOIN uploads up ON up.container = tw.id
     WHERE tw.n <= ${numberPerThread}
     ORDER BY tw.threadID, tw.time DESC, tw.id DESC
   `);
 
   const [result] = await dbQuery(query);
   const derivedMessages = await fetchDerivedMessages(result, viewer);
   const messages = await parseMessageSQLResult(result, derivedMessages, viewer);
 
   const rawMessageInfos = [];
   const threadToMessageCount = new Map();
   for (const message of messages) {
     const { rawMessageInfo } = message;
     rawMessageInfos.push(rawMessageInfo);
     const { threadID } = rawMessageInfo;
     const currentCountValue = threadToMessageCount.get(threadID);
     const currentCount = currentCountValue ? currentCountValue : 0;
     threadToMessageCount.set(threadID, currentCount + 1);
   }
 
   for (const [threadID, messageCount] of threadToMessageCount) {
     // If we matched the exact amount we limited to, we're probably truncating
     // our result set. By setting TRUNCATED here, we tell the client that the
     // result set might not be continguous with what's already in their
     // MessageStore. More details about TRUNCATED can be found in
     // lib/types/message-types.js
     if (messageCount >= numberPerThread) {
       // We won't set TRUNCATED if a cursor was specified for a given thread,
       // since then the result is guaranteed to be contiguous with what the
       // client has
       if (criteria.threadCursors && criteria.threadCursors[threadID]) {
         truncationStatuses[threadID] = messageTruncationStatus.UNCHANGED;
       } else {
         truncationStatuses[threadID] = messageTruncationStatus.TRUNCATED;
       }
       continue;
     }
     const hasTimeFilter = hasTimeFilterForThread(timeFilterData, threadID);
     if (!hasTimeFilter) {
       // If there is no time filter for a given thread, and there are fewer
       // messages returned than the max we queried for a given thread, we can
       // conclude that our result set includes all messages for that thread
       truncationStatuses[threadID] = messageTruncationStatus.EXHAUSTIVE;
     }
   }
 
   for (const rawMessageInfo of rawMessageInfos) {
     if (messageSpecs[rawMessageInfo.type].startsThread) {
       truncationStatuses[rawMessageInfo.threadID] =
         messageTruncationStatus.EXHAUSTIVE;
     }
   }
 
   for (const threadID in criteria.threadCursors) {
     const truncationStatus = truncationStatuses[threadID];
     if (truncationStatus !== null && truncationStatus !== undefined) {
       continue;
     }
     const hasTimeFilter = hasTimeFilterForThread(timeFilterData, threadID);
     if (!hasTimeFilter) {
       // If there is no time filter for a given thread, and zero messages were
       // returned, we can conclude that this thread has zero messages. This is
       // a case of database corruption that should not be possible, but likely
       // we have some threads like this on prod (either due to some transient
       // issues or due to old buggy code)
       truncationStatuses[threadID] = messageTruncationStatus.EXHAUSTIVE;
     } else {
       // If this thread was explicitly queried for, and we got no results, but
       // we can't conclude that it's EXHAUSTIVE, then we'll set to UNCHANGED.
       truncationStatuses[threadID] = messageTruncationStatus.UNCHANGED;
     }
   }
 
   const shimmedRawMessageInfos = shimUnsupportedRawMessageInfos(
     rawMessageInfos,
     viewer.platformDetails,
   );
 
   return {
     rawMessageInfos: shimmedRawMessageInfos,
     truncationStatuses,
   };
 }
 
 function hasTimeFilterForThread(
   timeFilterData: TimeFilterData,
   threadID: string,
 ) {
   if (timeFilterData.timeFilter === 'ALL') {
     return true;
   } else if (timeFilterData.timeFilter === 'NONE') {
     return false;
   } else if (timeFilterData.timeFilter === 'ALL_EXCEPT_EXCLUDED') {
     return !timeFilterData.excludedFromTimeFilter.has(threadID);
   } else {
     invariant(
       false,
       `unrecognized timeFilter type ${timeFilterData.timeFilter}`,
     );
   }
 }
 
 type TimeFilterData =
   | { +timeFilter: 'ALL' | 'NONE' }
   | {
       +timeFilter: 'ALL_EXCEPT_EXCLUDED',
       +excludedFromTimeFilter: $ReadOnlySet<string>,
     };
 type ParsedMessageSelectionCriteria = {
   +sqlClause: SQLStatementType,
   +timeFilterData: TimeFilterData,
 };
 function parseMessageSelectionCriteria(
   viewer: Viewer,
   criteria: MessageSelectionCriteria,
 ): ParsedMessageSelectionCriteria {
   const minMessageTime = Date.now() - defaultMaxMessageAge;
   const shouldApplyTimeFilter = hasMinCodeVersion(viewer.platformDetails, 130);
 
   let globalTimeFilter;
   if (criteria.newerThan) {
     globalTimeFilter = SQL`m.time > ${criteria.newerThan}`;
   } else if (!criteria.threadCursors && shouldApplyTimeFilter) {
     globalTimeFilter = SQL`m.time > ${minMessageTime}`;
   }
 
   const threadConditions = [];
   if (
     criteria.joinedThreads === true &&
     shouldApplyTimeFilter &&
     !globalTimeFilter
   ) {
     threadConditions.push(SQL`(mm.role > 0 AND m.time > ${minMessageTime})`);
   } else if (criteria.joinedThreads === true) {
     threadConditions.push(SQL`mm.role > 0`);
   }
   if (criteria.threadCursors) {
     for (const threadID in criteria.threadCursors) {
       const cursor = criteria.threadCursors[threadID];
       if (cursor) {
         threadConditions.push(
           SQL`(m.thread = ${threadID} AND m.id < ${cursor})`,
         );
       } else {
         threadConditions.push(SQL`m.thread = ${threadID}`);
       }
     }
   }
   if (threadConditions.length === 0) {
     throw new ServerError('internal_error');
   }
   const threadClause = mergeOrConditions(threadConditions);
 
   let timeFilterData;
   if (globalTimeFilter) {
     timeFilterData = { timeFilter: 'ALL' };
   } else if (!shouldApplyTimeFilter) {
     timeFilterData = { timeFilter: 'NONE' };
   } else {
     invariant(
       criteria.threadCursors,
       'ALL_EXCEPT_EXCLUDED should correspond to threadCursors being set',
     );
     const excludedFromTimeFilter = new Set(Object.keys(criteria.threadCursors));
     timeFilterData = {
       timeFilter: 'ALL_EXCEPT_EXCLUDED',
       excludedFromTimeFilter,
     };
   }
 
   const conditions = [globalTimeFilter, threadClause].filter(Boolean);
   const sqlClause = mergeAndConditions(conditions);
 
   return { sqlClause, timeFilterData };
 }
 
 function messageSelectionCriteriaToInitialTruncationStatuses(
   criteria: MessageSelectionCriteria,
   defaultTruncationStatus: MessageTruncationStatus,
 ) {
   const truncationStatuses = {};
   if (criteria.threadCursors) {
     for (const threadID in criteria.threadCursors) {
       truncationStatuses[threadID] = defaultTruncationStatus;
     }
   }
   return truncationStatuses;
 }
 
 async function fetchMessageInfosSince(
   viewer: Viewer,
   criteria: MessageSelectionCriteria,
   maxNumberPerThread: number,
 ): Promise<FetchMessageInfosResult> {
   const { sqlClause: selectionClause } = parseMessageSelectionCriteria(
     viewer,
     criteria,
   );
   const truncationStatuses =
     messageSelectionCriteriaToInitialTruncationStatuses(
       criteria,
       messageTruncationStatus.UNCHANGED,
     );
 
   const viewerID = viewer.id;
   const query = SQL`
     SELECT m.id, m.thread AS threadID, m.content, m.time, m.type,
       m.creation, m.user AS creatorID, m.target_message as targetMessageID,
       stm.permissions AS subthread_permissions, up.id AS uploadID,
       up.type AS uploadType, up.secret AS uploadSecret, up.extra AS uploadExtra
     FROM messages m
     LEFT JOIN uploads up ON up.container = m.id
     LEFT JOIN memberships mm ON mm.thread = m.thread AND mm.user = ${viewerID}
     LEFT JOIN memberships stm ON m.type = ${messageTypes.CREATE_SUB_THREAD}
       AND stm.thread = m.content AND stm.user = ${viewerID}
     WHERE JSON_EXTRACT(mm.permissions, ${visibleExtractString}) IS TRUE AND
   `;
   query.append(selectionClause);
   query.append(SQL`
     ORDER BY m.thread, m.time DESC, m.id DESC
   `);
   const [result] = await dbQuery(query);
   const derivedMessages = await fetchDerivedMessages(result, viewer);
   const messages = await parseMessageSQLResult(result, derivedMessages, viewer);
 
   const rawMessageInfos = [];
   let currentThreadID = null;
   let numMessagesForCurrentThreadID = 0;
   for (const message of messages) {
     const { rawMessageInfo } = message;
     const { threadID } = rawMessageInfo;
     if (threadID !== currentThreadID) {
       currentThreadID = threadID;
       numMessagesForCurrentThreadID = 1;
       truncationStatuses[threadID] = messageTruncationStatus.UNCHANGED;
     } else {
       numMessagesForCurrentThreadID++;
     }
     if (numMessagesForCurrentThreadID <= maxNumberPerThread) {
       if (messageSpecs[rawMessageInfo.type].startsThread) {
         truncationStatuses[threadID] = messageTruncationStatus.EXHAUSTIVE;
       }
       rawMessageInfos.push(rawMessageInfo);
     } else if (numMessagesForCurrentThreadID === maxNumberPerThread + 1) {
       truncationStatuses[threadID] = messageTruncationStatus.TRUNCATED;
     }
   }
 
   const shimmedRawMessageInfos = shimUnsupportedRawMessageInfos(
     rawMessageInfos,
     viewer.platformDetails,
   );
 
   return {
     rawMessageInfos: shimmedRawMessageInfos,
     truncationStatuses,
   };
 }
 
 function getMessageFetchResultFromRedisMessages(
   viewer: Viewer,
   rawMessageInfos: $ReadOnlyArray<RawMessageInfo>,
 ): FetchMessageInfosResult {
   const truncationStatuses = {};
   for (const rawMessageInfo of rawMessageInfos) {
     truncationStatuses[rawMessageInfo.threadID] =
       messageTruncationStatus.UNCHANGED;
   }
   const shimmedRawMessageInfos = shimUnsupportedRawMessageInfos(
     rawMessageInfos,
     viewer.platformDetails,
   );
   return {
     rawMessageInfos: shimmedRawMessageInfos,
     truncationStatuses,
   };
 }
 
 async function fetchMessageInfoForLocalID(
   viewer: Viewer,
   localID: ?string,
 ): Promise<?RawMessageInfo> {
   if (!localID || !viewer.hasSessionInfo) {
     return null;
   }
   const creation = creationString(viewer, localID);
   const viewerID = viewer.id;
   const query = SQL`
     SELECT m.id, m.thread AS threadID, m.content, m.time, m.type, m.creation,
       m.user AS creatorID, m.target_message as targetMessageID,
       stm.permissions AS subthread_permissions, up.id AS uploadID,
       up.type AS uploadType, up.secret AS uploadSecret, up.extra AS uploadExtra
     FROM messages m
     LEFT JOIN uploads up ON up.container = m.id
     LEFT JOIN memberships mm ON mm.thread = m.thread AND mm.user = ${viewerID}
     LEFT JOIN memberships stm ON m.type = ${messageTypes.CREATE_SUB_THREAD}
       AND stm.thread = m.content AND stm.user = ${viewerID}
     WHERE m.user = ${viewerID} AND m.creation = ${creation} AND
       JSON_EXTRACT(mm.permissions, ${visibleExtractString}) IS TRUE
   `;
 
   const [result] = await dbQuery(query);
   if (result.length === 0) {
     return null;
   }
   const derivedMessages = await fetchDerivedMessages(result, viewer);
   return rawMessageInfoFromRows(result, viewer, derivedMessages);
 }
 
 const entryIDExtractString = '$.entryID';
 async function fetchMessageInfoForEntryAction(
   viewer: Viewer,
   messageType: MessageType,
   entryID: string,
   threadID: string,
 ): Promise<?RawMessageInfo> {
   const viewerID = viewer.id;
   const query = SQL`
     SELECT m.id, m.thread AS threadID, m.content, m.time, m.type, m.creation,
       m.user AS creatorID, m.target_message as targetMessageID,
       up.id AS uploadID, up.type AS uploadType, up.secret AS uploadSecret,
       up.extra AS uploadExtra
     FROM messages m
     LEFT JOIN uploads up ON up.container = m.id
     LEFT JOIN memberships mm ON mm.thread = m.thread AND mm.user = ${viewerID}
     WHERE m.user = ${viewerID} AND m.thread = ${threadID} AND
       m.type = ${messageType} AND
       JSON_EXTRACT(m.content, ${entryIDExtractString}) = ${entryID} AND
       JSON_EXTRACT(mm.permissions, ${visibleExtractString}) IS TRUE
   `;
 
   const [result] = await dbQuery(query);
   if (result.length === 0) {
     return null;
   }
   const derivedMessages = await fetchDerivedMessages(result, viewer);
   return rawMessageInfoFromRows(result, viewer, derivedMessages);
 }
 
 async function fetchMessageRowsByIDs(messageIDs: $ReadOnlyArray<string>) {
   const query = SQL`
     SELECT m.id, m.thread AS threadID, m.content, m.time, m.type, m.creation, 
       m.user AS creatorID, m.target_message as targetMessageID,
       stm.permissions AS subthread_permissions, up.id AS uploadID,
       up.type AS uploadType, up.secret AS uploadSecret, up.extra AS uploadExtra
     FROM messages m
     LEFT JOIN uploads up ON up.container = m.id
     LEFT JOIN memberships stm ON m.type = ${messageTypes.CREATE_SUB_THREAD}
       AND stm.thread = m.content AND stm.user = m.user
     WHERE m.id IN (${messageIDs})
   `;
   const [result] = await dbQuery(query);
   return result;
 }
 
 async function fetchDerivedMessages(
   rows: $ReadOnlyArray<Object>,
   viewer?: Viewer,
 ): Promise<
   $ReadOnlyMap<string, RawComposableMessageInfo | RawRobotextMessageInfo>,
 > {
   const requiredIDs = new Set<string>();
   for (const row of rows) {
     if (row.type === messageTypes.SIDEBAR_SOURCE) {
       const content = JSON.parse(row.content);
       requiredIDs.add(content.sourceMessageID);
     }
   }
 
   const messagesByID = new Map<
     string,
     RawComposableMessageInfo | RawRobotextMessageInfo,
   >();
   if (requiredIDs.size === 0) {
     return messagesByID;
   }
 
   const result = await fetchMessageRowsByIDs([...requiredIDs]);
   const messages = await parseMessageSQLResult(result, new Map(), viewer);
 
   for (const message of messages) {
     const { rawMessageInfo } = message;
     if (rawMessageInfo.id) {
       invariant(
         rawMessageInfo.type !== messageTypes.SIDEBAR_SOURCE &&
           rawMessageInfo.type !== messageTypes.REACTION,
         'SIDEBAR_SOURCE should not point to a SIDEBAR_SOURCE or REACTION',
       );
       messagesByID.set(rawMessageInfo.id, rawMessageInfo);
     }
   }
   return messagesByID;
 }
 
 async function fetchMessageInfoByID(
   viewer?: Viewer,
   messageID: string,
 ): Promise<?RawMessageInfo> {
   const result = await fetchMessageRowsByIDs([messageID]);
   if (result.length === 0) {
     return null;
   }
   const derivedMessages = await fetchDerivedMessages(result, viewer);
   return rawMessageInfoFromRows(result, viewer, derivedMessages);
 }
 
 async function fetchThreadMessagesCount(threadID: string): Promise<number> {
   const query = SQL`
     SELECT COUNT(*) AS count
     FROM messages
     WHERE thread = ${threadID}
   `;
   const [result] = await dbQuery(query);
   return result[0].count;
 }
 
 export {
   fetchCollapsableNotifs,
   fetchMessageInfos,
   fetchMessageInfosSince,
   getMessageFetchResultFromRedisMessages,
   fetchMessageInfoForLocalID,
   fetchMessageInfoForEntryAction,
   fetchMessageInfoByID,
   fetchThreadMessagesCount,
 };
diff --git a/lib/shared/messages/message-spec.js b/lib/shared/messages/message-spec.js
index 8cefbccce..50249e346 100644
--- a/lib/shared/messages/message-spec.js
+++ b/lib/shared/messages/message-spec.js
@@ -1,114 +1,117 @@
 // @flow
 
 import type { PlatformDetails } from '../../types/device-types.js';
 import type { Media } from '../../types/media-types.js';
 import type {
   MessageInfo,
   ClientDBMessageInfo,
   RawComposableMessageInfo,
   RawMessageInfo,
   RawRobotextMessageInfo,
 } from '../../types/message-types.js';
 import type { RawUnsupportedMessageInfo } from '../../types/messages/unsupported.js';
 import type { NotifTexts } from '../../types/notif-types.js';
 import type { ThreadInfo } from '../../types/thread-types.js';
 import type { RelativeUserInfo, UserInfo } from '../../types/user-types.js';
 import type { EntityText } from '../../utils/entity-text.js';
 import { type ParserRules } from '../markdown.js';
 
 export type MessageTitleParam<Info> = {
   +messageInfo: Info,
   +threadInfo: ThreadInfo,
   +markdownRules: ParserRules,
 };
 
 export type RawMessageInfoFromServerDBRowParams = {
   +localID: ?string,
   +media?: $ReadOnlyArray<Media>,
   +derivedMessages: $ReadOnlyMap<
     string,
     RawComposableMessageInfo | RawRobotextMessageInfo,
   >,
 };
 
 export type CreateMessageInfoParams = {
   +threadInfos: { +[id: string]: ThreadInfo },
   +createMessageInfoFromRaw: (rawInfo: RawMessageInfo) => ?MessageInfo,
   +createRelativeUserInfos: (
     userIDs: $ReadOnlyArray<string>,
   ) => RelativeUserInfo[],
 };
 
 export type RobotextParams = {
   +threadInfo: ?ThreadInfo,
 };
 
 export type NotificationTextsParams = {
   +notificationTexts: (
     messageInfos: $ReadOnlyArray<MessageInfo>,
     threadInfo: ThreadInfo,
   ) => Promise<NotifTexts>,
   +notifTargetUserInfo: UserInfo,
 };
 
 export type GeneratesNotifsParams = {
   +notifTargetUserID: string,
   +userNotMemberOfSubthreads: Set<string>,
   +fetchMessageInfoByID: (messageID: string) => Promise<?RawMessageInfo>,
 };
 
 export const pushTypes = Object.freeze({
   NOTIF: 'notif',
   RESCIND: 'rescind',
 });
 export type PushType = $Values<typeof pushTypes>;
 
 export type CreationSideEffectsFunc<RawInfo> = (
   messageInfo: RawInfo,
   threadInfo: ThreadInfo,
   parentThreadInfo: ?ThreadInfo,
 ) => Promise<mixed>;
 
 export type MessageSpec<Data, RawInfo, Info> = {
   +messageContentForServerDB?: (data: Data | RawInfo) => string,
   +messageContentForClientDB?: (data: RawInfo) => string,
   +messageTitle?: (param: MessageTitleParam<Info>) => EntityText,
   +rawMessageInfoFromServerDBRow?: (
     row: Object,
     params: RawMessageInfoFromServerDBRowParams,
   ) => ?RawInfo,
   +rawMessageInfoFromClientDB: (
     clientDBMessageInfo: ClientDBMessageInfo,
   ) => RawInfo,
   +createMessageInfo: (
     rawMessageInfo: RawInfo,
     creator: RelativeUserInfo,
     params: CreateMessageInfoParams,
   ) => ?Info,
   +rawMessageInfoFromMessageData?: (messageData: Data, id: ?string) => RawInfo,
   +robotext?: (messageInfo: Info, params: RobotextParams) => EntityText,
   +shimUnsupportedMessageInfo?: (
     rawMessageInfo: RawInfo,
     platformDetails: ?PlatformDetails,
   ) => RawInfo | RawUnsupportedMessageInfo,
   +unshimMessageInfo?: (
     unwrapped: RawInfo,
     messageInfo: RawMessageInfo,
   ) => ?RawMessageInfo,
   +notificationTexts?: (
     messageInfos: $ReadOnlyArray<MessageInfo>,
     threadInfo: ThreadInfo,
     params: NotificationTextsParams,
   ) => Promise<NotifTexts>,
-  +notificationCollapseKey?: (rawMessageInfo: RawInfo) => string,
+  +notificationCollapseKey?: (
+    rawMessageInfo: RawInfo,
+    messageData: Data,
+  ) => string,
   +generatesNotifs: (
     rawMessageInfo: RawInfo,
     messageData: Data,
     params: GeneratesNotifsParams,
   ) => Promise<?PushType>,
   +userIDs?: (rawMessageInfo: RawInfo) => $ReadOnlyArray<string>,
   +startsThread?: boolean,
   +threadIDs?: (rawMessageInfo: RawInfo) => $ReadOnlyArray<string>,
   +includedInRepliesCount?: boolean,
   +useCreationSideEffectsFunc?: () => CreationSideEffectsFunc<RawInfo>,
 };
diff --git a/lib/shared/notif-utils.js b/lib/shared/notif-utils.js
index 266de209e..01293d6bb 100644
--- a/lib/shared/notif-utils.js
+++ b/lib/shared/notif-utils.js
@@ -1,252 +1,256 @@
 // @flow
 
 import invariant from 'invariant';
 
 import { robotextForMessageInfo } from './message-utils.js';
 import { messageSpecs } from './messages/message-specs.js';
 import { threadNoun } from './thread-utils.js';
 import {
   type MessageInfo,
   type RawMessageInfo,
   type RobotextMessageInfo,
   type MessageType,
+  type MessageData,
   messageTypes,
 } from '../types/message-types.js';
 import type { NotifTexts, ResolvedNotifTexts } from '../types/notif-types.js';
 import type { ThreadInfo, ThreadType } from '../types/thread-types.js';
 import type { RelativeUserInfo, UserInfo } from '../types/user-types.js';
 import { prettyDate } from '../utils/date-utils.js';
 import type { GetENSNames } from '../utils/ens-helpers.js';
 import {
   ET,
   getEntityTextAsString,
   type EntityText,
   type ThreadEntity,
 } from '../utils/entity-text.js';
 import { promiseAll } from '../utils/promises.js';
 import { trimText } from '../utils/text-utils.js';
 
 async function notifTextsForMessageInfo(
   messageInfos: MessageInfo[],
   threadInfo: ThreadInfo,
   notifTargetUserInfo: UserInfo,
   getENSNames: ?GetENSNames,
 ): Promise<ResolvedNotifTexts> {
   const fullNotifTexts = await fullNotifTextsForMessageInfo(
     messageInfos,
     threadInfo,
     notifTargetUserInfo,
     getENSNames,
   );
   const merged = trimText(fullNotifTexts.merged, 300);
   const body = trimText(fullNotifTexts.body, 300);
   const title = trimText(fullNotifTexts.title, 100);
   if (!fullNotifTexts.prefix) {
     return { merged, body, title };
   }
   const prefix = trimText(fullNotifTexts.prefix, 50);
   return { merged, body, title, prefix };
 }
 
 function notifTextsForEntryCreationOrEdit(
   messageInfos: $ReadOnlyArray<MessageInfo>,
   threadInfo: ThreadInfo,
 ): NotifTexts {
   const hasCreateEntry = messageInfos.some(
     messageInfo => messageInfo.type === messageTypes.CREATE_ENTRY,
   );
   const messageInfo = messageInfos[0];
 
   const thread = ET.thread({ display: 'shortName', threadInfo });
   const creator = ET.user({ userInfo: messageInfo.creator });
   const prefix = ET`${creator}`;
 
   if (!hasCreateEntry) {
     invariant(
       messageInfo.type === messageTypes.EDIT_ENTRY,
       'messageInfo should be messageTypes.EDIT_ENTRY!',
     );
     const date = prettyDate(messageInfo.date);
     let body = ET`updated the text of an event in ${thread}`;
     body = ET`${body} scheduled for ${date}: "${messageInfo.text}"`;
     const merged = ET`${prefix} ${body}`;
     return {
       merged,
       title: threadInfo.uiName,
       body,
       prefix,
     };
   }
   invariant(
     messageInfo.type === messageTypes.CREATE_ENTRY ||
       messageInfo.type === messageTypes.EDIT_ENTRY,
     'messageInfo should be messageTypes.CREATE_ENTRY/EDIT_ENTRY!',
   );
   const date = prettyDate(messageInfo.date);
   let body = ET`created an event in ${thread}`;
   body = ET`${body} scheduled for ${date}: "${messageInfo.text}"`;
   const merged = ET`${prefix} ${body}`;
   return {
     merged,
     title: threadInfo.uiName,
     body,
     prefix,
   };
 }
 
 type NotifTextsForSubthreadCreationInput = {
   +creator: RelativeUserInfo,
   +threadType: ThreadType,
   +parentThreadInfo: ThreadInfo,
   +childThreadName: ?string,
   +childThreadUIName: string | ThreadEntity,
 };
 function notifTextsForSubthreadCreation(
   input: NotifTextsForSubthreadCreationInput,
 ): NotifTexts {
   const {
     creator,
     threadType,
     parentThreadInfo,
     childThreadName,
     childThreadUIName,
   } = input;
 
   const prefix = ET`${ET.user({ userInfo: creator })}`;
 
   let body = `created a new ${threadNoun(threadType)}`;
   if (parentThreadInfo.name) {
     body = ET`${body} in ${parentThreadInfo.name}`;
   }
 
   let merged = ET`${prefix} ${body}`;
   if (childThreadName) {
     merged = ET`${merged} called "${childThreadName}"`;
   }
 
   return {
     merged,
     body,
     title: childThreadUIName,
     prefix,
   };
 }
 
 function mostRecentMessageInfoType(
   messageInfos: $ReadOnlyArray<MessageInfo>,
 ): MessageType {
   if (messageInfos.length === 0) {
     throw new Error('expected MessageInfo, but none present!');
   }
   return messageInfos[0].type;
 }
 
 async function fullNotifTextsForMessageInfo(
   messageInfos: $ReadOnlyArray<MessageInfo>,
   threadInfo: ThreadInfo,
   notifTargetUserInfo: UserInfo,
   getENSNames: ?GetENSNames,
 ): Promise<ResolvedNotifTexts> {
   const mostRecentType = mostRecentMessageInfoType(messageInfos);
   const messageSpec = messageSpecs[mostRecentType];
   invariant(
     messageSpec.notificationTexts,
     `we're not aware of messageType ${mostRecentType}`,
   );
   const innerNotificationTexts = (
     innerMessageInfos: $ReadOnlyArray<MessageInfo>,
     innerThreadInfo: ThreadInfo,
   ) =>
     fullNotifTextsForMessageInfo(
       innerMessageInfos,
       innerThreadInfo,
       notifTargetUserInfo,
       getENSNames,
     );
   const unresolvedNotifTexts = await messageSpec.notificationTexts(
     messageInfos,
     threadInfo,
     { notifTargetUserInfo, notificationTexts: innerNotificationTexts },
   );
 
   const resolveToString = async (
     entityText: string | EntityText,
   ): Promise<string> => {
     if (typeof entityText === 'string') {
       return entityText;
     }
     const notifString = await getEntityTextAsString(entityText, getENSNames, {
       prefixThisThreadNounWith: 'your',
     });
     invariant(
       notifString !== null && notifString !== undefined,
       'getEntityTextAsString only returns falsey when passed falsey',
     );
     return notifString;
   };
   let promises = {
     merged: resolveToString(unresolvedNotifTexts.merged),
     body: resolveToString(unresolvedNotifTexts.body),
     title: resolveToString(ET`${unresolvedNotifTexts.title}`),
   };
   if (unresolvedNotifTexts.prefix) {
     promises = {
       ...promises,
       prefix: resolveToString(unresolvedNotifTexts.prefix),
     };
   }
   return await promiseAll(promises);
 }
 
 function notifRobotextForMessageInfo(
   messageInfo: RobotextMessageInfo,
   threadInfo: ThreadInfo,
 ): EntityText {
   const robotext = robotextForMessageInfo(messageInfo, threadInfo);
   return robotext.map(entity => {
     if (
       typeof entity !== 'string' &&
       entity.type === 'thread' &&
       entity.id === threadInfo.id
     ) {
       return ET.thread({
         display: 'shortName',
         threadInfo,
         possessive: entity.possessive,
       });
     }
     return entity;
   });
 }
 
-function notifCollapseKeyForRawMessageInfo(
+function getNotifCollapseKey(
   rawMessageInfo: RawMessageInfo,
+  messageData: MessageData,
 ): ?string {
   const messageSpec = messageSpecs[rawMessageInfo.type];
-  return messageSpec.notificationCollapseKey?.(rawMessageInfo) ?? null;
+  return (
+    messageSpec.notificationCollapseKey?.(rawMessageInfo, messageData) ?? null
+  );
 }
 
 type Unmerged = $ReadOnly<{
   body: string,
   title: string,
   prefix?: string,
   ...
 }>;
 type Merged = {
   body: string,
   title: string,
 };
 function mergePrefixIntoBody(unmerged: Unmerged): Merged {
   const { body, title, prefix } = unmerged;
   const merged = prefix ? `${prefix} ${body}` : body;
   return { body: merged, title };
 }
 
 export {
   notifRobotextForMessageInfo,
   notifTextsForMessageInfo,
   notifTextsForEntryCreationOrEdit,
   notifTextsForSubthreadCreation,
-  notifCollapseKeyForRawMessageInfo,
+  getNotifCollapseKey,
   mergePrefixIntoBody,
 };