diff --git a/lib/shared/reaction-utils.js b/lib/shared/reaction-utils.js
--- a/lib/shared/reaction-utils.js
+++ b/lib/shared/reaction-utils.js
@@ -10,18 +10,20 @@
 import { useThreadHasPermission } from './thread-utils.js';
 import { threadSpecs } from './threads/thread-specs.js';
 import { stringForUserExplicit } from './user-utils.js';
+import { useGetLatestMessageEdit } from '../hooks/latest-message-edit.js';
 import { useSendReactionMessage } from '../hooks/message-hooks.js';
 import { useResolvableNames } from '../hooks/names-cache.js';
 import type { ReactionInfo } from '../selectors/chat-selectors.js';
 import type {
   ComposableMessageInfo,
+  MessageInfo,
   RobotextMessageInfo,
 } from '../types/message-types.js';
 import { isComposableMessageType } from '../types/message-types.js';
 import type { ThreadInfo } from '../types/minimally-encoded-thread-permissions-types.js';
 import { threadPermissions } from '../types/thread-permission-types.js';
 import { useDispatchActionPromise } from '../utils/redux-promise-utils.js';
-import { useSelector } from '../utils/redux-utils.js';
+import { useDispatch, useSelector } from '../utils/redux-utils.js';
 
 function useViewerAlreadySelectedMessageReactions(
   reactions: ReactionInfo,
@@ -116,7 +118,7 @@
 }
 
 function useSendReactionBase(
-  messageID: ?string,
+  messageInfo: ?MessageInfo,
   threadInfo: ThreadInfo,
   reactions: ReactionInfo,
   showErrorAlert: () => mixed,
@@ -129,10 +131,12 @@
   const dispatchActionPromise = useDispatchActionPromise();
   const processAndSendDMOperation = useProcessAndSendDMOperation();
   const farcasterSendReaction = useSendFarcasterReaction();
+  const dispatch = useDispatch();
+  const fetchMessage = useGetLatestMessageEdit();
 
   return React.useCallback(
     reaction => {
-      if (!messageID) {
+      if (!messageInfo) {
         return;
       }
 
@@ -145,7 +149,7 @@
 
       void threadSpecs[threadInfo.type].protocol().sendReaction(
         {
-          messageID,
+          messageInfo,
           threadInfo,
           reaction,
           action,
@@ -157,19 +161,23 @@
           keyserverSendReaction: callSendReactionMessage,
           dispatchActionPromise,
           farcasterSendReaction,
+          dispatch,
+          fetchMessage,
         },
       );
     },
     [
-      messageID,
-      viewerID,
-      reactions,
-      threadInfo,
-      showErrorAlert,
-      processAndSendDMOperation,
       callSendReactionMessage,
+      dispatch,
       dispatchActionPromise,
       farcasterSendReaction,
+      fetchMessage,
+      messageInfo,
+      processAndSendDMOperation,
+      reactions,
+      showErrorAlert,
+      threadInfo,
+      viewerID,
     ],
   );
 }
diff --git a/lib/shared/threads/protocols/dm-thread-protocol.js b/lib/shared/threads/protocols/dm-thread-protocol.js
--- a/lib/shared/threads/protocols/dm-thread-protocol.js
+++ b/lib/shared/threads/protocols/dm-thread-protocol.js
@@ -519,8 +519,12 @@
       input: ProtocolSendReactionInput,
       utils: SendReactionUtils,
     ) => {
-      const { threadInfo, viewerID, messageID, reaction, action } = input;
+      const { threadInfo, viewerID, messageInfo, reaction, action } = input;
       const threadID = threadInfo.id;
+      const messageID = messageInfo.id;
+      if (!messageID) {
+        return;
+      }
 
       const op: DMSendReactionMessageOperation = {
         type: 'send_reaction_message',
diff --git a/lib/shared/threads/protocols/farcaster-thread-protocol.js b/lib/shared/threads/protocols/farcaster-thread-protocol.js
--- a/lib/shared/threads/protocols/farcaster-thread-protocol.js
+++ b/lib/shared/threads/protocols/farcaster-thread-protocol.js
@@ -18,11 +18,13 @@
   DeleteEntryResult,
   SaveEntryResult,
 } from '../../../types/entry-types.js';
+import { messageTypes } from '../../../types/message-types-enum.js';
 import {
   defaultNumberPerThread,
   type SendMessagePayload,
   type SendMultimediaMessagePayload,
 } from '../../../types/message-types.js';
+import type { CompoundReactionInfo } from '../../../types/messages/compound-reaction.js';
 import type {
   FarcasterRawThreadInfo,
   MemberInfoSansPermissions,
@@ -46,8 +48,10 @@
   ThreadJoinPayload,
 } from '../../../types/thread-types.js';
 import { updateTypes } from '../../../types/update-types-enum.js';
+import { messageIDToCompoundReactionID } from '../../../utils/convert-farcaster-message-to-comm-messages.js';
 import { farcasterThreadIDRegExp } from '../../../utils/validation-utils.js';
 import { generatePendingThreadColor } from '../../color-utils.js';
+import { processFarcasterOpsActionType } from '../../farcaster/farcaster-actions.js';
 import {
   type ModifyFarcasterMembershipInput,
   type SendReactionInput,
@@ -270,8 +274,56 @@
     input: ProtocolSendReactionInput,
     utils: SendReactionUtils,
   ) => {
-    const { threadInfo, reaction, action, messageID } = input;
+    const { threadInfo, reaction, action, messageInfo } = input;
     const conversationId = conversationIDFromFarcasterThreadID(threadInfo.id);
+    const messageID = messageInfo.id;
+    if (!messageID) {
+      return;
+    }
+
+    const reactionsMessageID = messageIDToCompoundReactionID(messageID);
+    const currentReactionsMessage =
+      await utils.fetchMessage(reactionsMessageID);
+    const reactionCountChange = action === 'add_reaction' ? 1 : -1;
+    let currentCount = 0;
+    if (
+      currentReactionsMessage &&
+      currentReactionsMessage.type === messageTypes.COMPOUND_REACTION
+    ) {
+      currentCount = currentReactionsMessage.reactions[reaction]?.count ?? 0;
+    }
+
+    const newCount = currentCount + reactionCountChange;
+    const updatedReaction = {
+      count: currentCount + reactionCountChange,
+      viewerReacted: action === 'add_reaction',
+    };
+    const { [reaction]: oldReaction, ...rest } =
+      (currentReactionsMessage?.reactions ?? {}: {
+        +[reaction: string]: CompoundReactionInfo,
+      });
+    let updatedReactions = rest;
+    if (newCount > 0) {
+      updatedReactions = {
+        ...currentReactionsMessage?.reactions,
+        [reaction]: updatedReaction,
+      };
+    }
+
+    const updatedMessage = {
+      id: reactionsMessageID,
+      type: messageTypes.COMPOUND_REACTION,
+      threadID: threadInfo.id,
+      creatorID: messageInfo.creator.id,
+      time: messageInfo.time,
+      targetMessageID: messageID,
+      reactions: updatedReactions,
+    };
+    utils.dispatch({
+      type: processFarcasterOpsActionType,
+      payload: { rawMessageInfos: [updatedMessage], updateInfos: [] },
+    });
+
     const payload: SendReactionInput = {
       conversationId,
       messageId: messageID,
diff --git a/lib/shared/threads/protocols/keyserver-thread-protocol.js b/lib/shared/threads/protocols/keyserver-thread-protocol.js
--- a/lib/shared/threads/protocols/keyserver-thread-protocol.js
+++ b/lib/shared/threads/protocols/keyserver-thread-protocol.js
@@ -301,13 +301,17 @@
       const {
         threadInfo,
         viewerID,
-        messageID,
+        messageInfo,
         reaction,
         action,
         showErrorAlert,
       } = input;
       const threadID = threadInfo.id;
       const localID = getNextLocalID();
+      const messageID = messageInfo.id;
+      if (!messageID) {
+        return;
+      }
 
       const reactionMessagePromise = (async () => {
         try {
diff --git a/lib/shared/threads/thread-spec.js b/lib/shared/threads/thread-spec.js
--- a/lib/shared/threads/thread-spec.js
+++ b/lib/shared/threads/thread-spec.js
@@ -53,6 +53,8 @@
   FetchMessageInfosPayload,
   DeleteMessageRequest,
   DeleteMessageResponse,
+  RawMessageInfo,
+  MessageInfo,
 } from '../../types/message-types.js';
 import type { RawTextMessageInfo } from '../../types/messages/text.js';
 import type {
@@ -211,7 +213,7 @@
 };
 
 export type ProtocolSendReactionInput = {
-  +messageID: string,
+  +messageInfo: MessageInfo,
   +threadInfo: ThreadInfo,
   +reaction: string,
   +action: 'remove_reaction' | 'add_reaction',
@@ -223,6 +225,8 @@
   +keyserverSendReaction: SendReactionMessageRequest => Promise<SendMessageResult>,
   +farcasterSendReaction: SendReactionInput => Promise<void>,
   +dispatchActionPromise: DispatchActionPromise,
+  +dispatch: Dispatch,
+  +fetchMessage: (messageID: string) => Promise<?RawMessageInfo>,
 };
 
 export type ProtocolAddThreadMembersInput = {
diff --git a/lib/types/message-types.js b/lib/types/message-types.js
--- a/lib/types/message-types.js
+++ b/lib/types/message-types.js
@@ -28,6 +28,12 @@
   type RawChangeSettingsMessageInfo,
   rawChangeSettingsMessageInfoValidator,
 } from './messages/change-settings.js';
+import {
+  type RawCompoundReactionMessageInfo,
+  rawCompoundReactionMessageInfoValidator,
+  type CompoundReactionMessageData,
+  type CompoundReactionMessageInfo,
+} from './messages/compound-reaction.js';
 import {
   type CreateEntryMessageData,
   type CreateEntryMessageInfo,
@@ -113,12 +119,6 @@
   type ReactionMessageData,
   type ReactionMessageInfo,
 } from './messages/reaction.js';
-import {
-  type RawCompoundReactionMessageInfo,
-  rawCompoundReactionMessageInfoValidator,
-  type CompoundReactionMessageData,
-  type CompoundReactionMessageInfo,
-} from './messages/compound-reaction.js';
 import {
   type RawRemoveMembersMessageInfo,
   rawRemoveMembersMessageInfoValidator,
diff --git a/lib/utils/convert-farcaster-message-to-comm-messages.js b/lib/utils/convert-farcaster-message-to-comm-messages.js
--- a/lib/utils/convert-farcaster-message-to-comm-messages.js
+++ b/lib/utils/convert-farcaster-message-to-comm-messages.js
@@ -12,6 +12,10 @@
 import type { RawMessageInfo } from '../types/message-types.js';
 import type { CompoundReactionInfo } from '../types/messages/compound-reaction.js';
 
+function messageIDToCompoundReactionID(messageID: string): string {
+  return `${messageID}/reactions`;
+}
+
 function convertFarcasterMessageToCommMessages(
   farcasterMessage: FarcasterMessage,
   fcUserInfos: FCUserInfos,
@@ -37,7 +41,7 @@
       };
     }
     result.push({
-      id: `${farcasterMessage.messageId}/reactions`,
+      id: messageIDToCompoundReactionID(farcasterMessage.messageId),
       type: messageTypes.COMPOUND_REACTION,
       threadID,
       creatorID, // Doesn't matter - we don't use it
@@ -134,4 +138,4 @@
   return result;
 }
 
-export { convertFarcasterMessageToCommMessages };
+export { convertFarcasterMessageToCommMessages, messageIDToCompoundReactionID };
diff --git a/native/chat/inline-engagement.react.js b/native/chat/inline-engagement.react.js
--- a/native/chat/inline-engagement.react.js
+++ b/native/chat/inline-engagement.react.js
@@ -251,7 +251,7 @@
     repliesText,
   ]);
 
-  const sendReaction = useSendReaction(messageInfo.id, threadInfo, reactions);
+  const sendReaction = useSendReaction(messageInfo, threadInfo, reactions);
 
   const onPressReaction = React.useCallback(
     (reaction: string) => sendReaction(reaction),
diff --git a/native/chat/multimedia-message-tooltip-button.react.js b/native/chat/multimedia-message-tooltip-button.react.js
--- a/native/chat/multimedia-message-tooltip-button.react.js
+++ b/native/chat/multimedia-message-tooltip-button.react.js
@@ -112,7 +112,7 @@
     messageInfo,
   );
 
-  const sendReaction = useSendReaction(messageInfo.id, threadInfo, reactions);
+  const sendReaction = useSendReaction(messageInfo, threadInfo, reactions);
 
   const [emojiPickerOpen, setEmojiPickerOpen] = React.useState<boolean>(false);
   const openEmojiPicker = React.useCallback(() => {
diff --git a/native/chat/reaction-message-utils.js b/native/chat/reaction-message-utils.js
--- a/native/chat/reaction-message-utils.js
+++ b/native/chat/reaction-message-utils.js
@@ -4,6 +4,7 @@
 
 import type { ReactionInfo } from 'lib/selectors/chat-selectors.js';
 import { useSendReactionBase } from 'lib/shared/reaction-utils.js';
+import type { MessageInfo } from 'lib/types/message-types.js';
 import type { ThreadInfo } from 'lib/types/minimally-encoded-thread-permissions-types';
 
 import { useSelector } from '../redux/redux-utils.js';
@@ -25,12 +26,12 @@
 }
 
 function useSendReaction(
-  messageID: ?string,
+  messageInfo: ?MessageInfo,
   threadInfo: ThreadInfo,
   reactions: ReactionInfo,
 ): (reaction: string) => mixed {
   return useSendReactionBase(
-    messageID,
+    messageInfo,
     threadInfo,
     reactions,
     showReactionErrorAlert,
diff --git a/native/chat/robotext-message-tooltip-button.react.js b/native/chat/robotext-message-tooltip-button.react.js
--- a/native/chat/robotext-message-tooltip-button.react.js
+++ b/native/chat/robotext-message-tooltip-button.react.js
@@ -81,7 +81,7 @@
   );
 
   const sendReaction = useSendReaction(
-    engagementTargetMessageInfo?.id,
+    engagementTargetMessageInfo,
     threadInfo,
     reactions,
   );
diff --git a/native/chat/text-message-tooltip-button.react.js b/native/chat/text-message-tooltip-button.react.js
--- a/native/chat/text-message-tooltip-button.react.js
+++ b/native/chat/text-message-tooltip-button.react.js
@@ -109,7 +109,7 @@
     messageInfo,
   );
 
-  const sendReaction = useSendReaction(messageInfo.id, threadInfo, reactions);
+  const sendReaction = useSendReaction(messageInfo, threadInfo, reactions);
 
   const [emojiPickerOpen, setEmojiPickerOpen] = React.useState<boolean>(false);
   const openEmojiPicker = React.useCallback(() => {
diff --git a/web/chat/inline-engagement.react.js b/web/chat/inline-engagement.react.js
--- a/web/chat/inline-engagement.react.js
+++ b/web/chat/inline-engagement.react.js
@@ -88,12 +88,12 @@
       <ReactionPill
         key={reaction}
         reaction={reaction}
-        messageID={messageInfo.id}
+        messageInfo={messageInfo}
         threadInfo={threadInfo}
         reactions={reactions}
       />
     ));
-  }, [reactions, deleted, messageInfo.id, threadInfo]);
+  }, [reactions, deleted, messageInfo, threadInfo]);
 
   const containerClasses = classNames([
     css.inlineEngagementContainer,
diff --git a/web/chat/reaction-message-utils.js b/web/chat/reaction-message-utils.js
--- a/web/chat/reaction-message-utils.js
+++ b/web/chat/reaction-message-utils.js
@@ -5,6 +5,7 @@
 import { useModalContext } from 'lib/components/modal-provider.react.js';
 import type { ReactionInfo } from 'lib/selectors/chat-selectors.js';
 import { useSendReactionBase } from 'lib/shared/reaction-utils.js';
+import type { MessageInfo } from 'lib/types/message-types.js';
 import type { ThreadInfo } from 'lib/types/minimally-encoded-thread-permissions-types.js';
 
 import Alert from '../modals/alert.react.js';
@@ -15,7 +16,7 @@
 import { getAppContainerPositionInfo } from '../utils/window-utils.js';
 
 function useSendReaction(
-  messageID: ?string,
+  messageInfo: ?MessageInfo,
   threadInfo: ThreadInfo,
   reactions: ReactionInfo,
 ): (reaction: string) => mixed {
@@ -30,7 +31,12 @@
       ),
     [pushModal],
   );
-  return useSendReactionBase(messageID, threadInfo, reactions, showErrorAlert);
+  return useSendReactionBase(
+    messageInfo,
+    threadInfo,
+    reactions,
+    showErrorAlert,
+  );
 }
 
 type EmojiKeyboardPosition = {
diff --git a/web/chat/reaction-pill.react.js b/web/chat/reaction-pill.react.js
--- a/web/chat/reaction-pill.react.js
+++ b/web/chat/reaction-pill.react.js
@@ -4,6 +4,7 @@
 import * as React from 'react';
 
 import type { ReactionInfo } from 'lib/selectors/chat-selectors.js';
+import type { MessageInfo } from 'lib/types/message-types.js';
 import type { ThreadInfo } from 'lib/types/minimally-encoded-thread-permissions-types.js';
 
 import { useSendReaction } from './reaction-message-utils.js';
@@ -18,15 +19,15 @@
 
 type Props = {
   +reaction: string,
-  +messageID: ?string,
+  +messageInfo: MessageInfo,
   +threadInfo: ThreadInfo,
   +reactions: ReactionInfo,
 };
 
 function ReactionPill(props: Props): React.Node {
-  const { reaction, messageID, threadInfo, reactions } = props;
+  const { reaction, messageInfo, threadInfo, reactions } = props;
 
-  const sendReaction = useSendReaction(messageID, threadInfo, reactions);
+  const sendReaction = useSendReaction(messageInfo, threadInfo, reactions);
 
   const onClickReaction = React.useCallback(
     (event: SyntheticEvent<HTMLElement>) => {
diff --git a/web/tooltips/message-tooltip.react.js b/web/tooltips/message-tooltip.react.js
--- a/web/tooltips/message-tooltip.react.js
+++ b/web/tooltips/message-tooltip.react.js
@@ -173,7 +173,7 @@
   const engagementTargetMessageInfo =
     chatMessageItemEngagementTargetMessageInfo(item);
   const sendReaction = useSendReaction(
-    engagementTargetMessageInfo?.id,
+    engagementTargetMessageInfo,
     threadInfo,
     reactions,
   );