feat: message reactions + link/image previews

Reactions (full stack):
- Wire: MsgReaction peer message (reaction_mid, reaction_emoji)
- Store: reactions table (mid, emoji, from_peer), SaveReaction, ReactionsForRoom
- Daemon: CmdSendReaction IPC command; EvtReaction IPC event; stored reactions
  replayed to newly-connected IPC clients alongside history
- Web UI: reactions state (mid → emoji → [fromId]); hover a message to reveal
  a + button; click opens a 6-emoji picker (👍❤️😂😮😢🙏); reaction chips
  appear below the message with count and tooltip; own reactions highlighted

Link/image previews:
- URLs in message text rendered as clickable <a> links
- Image URLs (.jpg/.jpeg/.png/.gif/.webp/blob:/data:image) rendered as inline
  thumbnails (max 320×200px) below the link

Also scoped push notifications architecture in FUTURE.md.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

FUTURE.md

@@ -137,6 +137,19 @@ Web frontend (React, already built) + [Wails v2](https://wails.io) shell for nat
 | ✅ shipped | P2P message history gossip (EXT-007) — new peers receive recent history from first connected peer |
 | ✅ shipped | Date-aware timestamps in TUI and web UI |
 | ✅ shipped | Historical peer alias resolution in web UI |
+| 🔜 planned | Push notifications (PWA Web Push + service worker) |
+| 🔜 planned | Message reactions (emoji, full-stack gossip) |
+| 🔜 planned | Link rendering + image preview in messages |
+
+### Push Notifications (planned)
+The web UI is already a PWA (installable, has manifest). The missing half is a service worker + Web Push subscription:
+
+1. **Service worker** — intercepts `push` events and shows OS notifications via `showNotification()`.
+2. **VAPID key pair** — generated once by the daemon (`-vapid-key` flag); the public key is served to the browser so it can subscribe.
+3. **Subscription persistence** — the browser's `PushSubscription` JSON is sent to the daemon over IPC (`register_push` command). The daemon stores it per-network-per-peer.
+4. **Daemon relay** — when a `message_received` event fires with no active IPC WebSocket connection, the daemon POSTs a Web Push notification to the stored subscription endpoint.
+
+This keeps the architecture clean: the daemon already runs in the background; it becomes the notification relay. No third-party push server is required for self-hosted setups (coturn already in use for TURN; a lightweight Web Push POST is similar).
 
 ---
 

internal/ipc/ipc.go

@@ -244,6 +244,34 @@ func handleClient(conn net.Conn, mgr *netmgr.Manager) {
 				})
 			}
 
+		case proto.CmdSendReaction:
+			n := mgr.Resolve(cmd.NetworkID)
+			if n == nil {
+				send(errMsg("send_reaction: not joined to any network"))
+				continue
+			}
+			if cmd.ReactionMID == "" || cmd.ReactionEmoji == "" {
+				send(errMsg("send_reaction: reaction_mid and reaction_emoji are required"))
+				continue
+			}
+			wire, err := json.Marshal(proto.PeerMessage{
+				Type:          proto.MsgReaction,
+				ReactionMID:   cmd.ReactionMID,
+				ReactionEmoji: cmd.ReactionEmoji,
+			})
+			if err != nil {
+				continue
+			}
+			n.Mesh.Broadcast(wire)
+			n.Mesh.SaveReaction(cmd.ReactionMID, cmd.ReactionEmoji, string(n.Identity.PeerID()))
+			n.Mesh.Emit(proto.IpcMessage{
+				Type:          proto.EvtReaction,
+				NetworkID:     n.ID,
+				PeerID:        ptr(n.Identity.PeerID()),
+				ReactionMID:   cmd.ReactionMID,
+				ReactionEmoji: cmd.ReactionEmoji,
+			})
+
 		case proto.CmdCreateRoom:
 			n := mgr.Resolve(cmd.NetworkID)
 			if n == nil {
@@ -505,6 +533,25 @@ func sendStoredHistory(mgr *netmgr.Manager, send func(proto.IpcMessage)) {
 			Room:      room,
 			Messages:  msgs,
 		})
+		// Send stored reactions for this room's messages.
+		rxns, err := n.Store.ReactionsForRoom(room)
+		if err != nil {
+			continue
+		}
+		for mid, byEmoji := range rxns {
+			for emoji, fromPeers := range byEmoji {
+				for _, fromPeer := range fromPeers {
+					pid := proto.PeerID(fromPeer)
+					send(proto.IpcMessage{
+						Type:          proto.EvtReaction,
+						NetworkID:     n.ID,
+						PeerID:        &pid,
+						ReactionMID:   mid,
+						ReactionEmoji: emoji,
+					})
+				}
+			}
+		}
 	}
 }
 

internal/mesh/mesh.go

@@ -146,6 +146,17 @@ func (m *Mesh) AddPeer(conn *PeerConn) {
 	})
 }
 
+// SaveReaction persists a reaction if a store is configured.
+// Duplicate (mid, emoji, fromPeer) triples are silently dropped.
+func (m *Mesh) SaveReaction(mid, emoji, fromPeer string) {
+	if m.Store == nil {
+		return
+	}
+	if err := m.Store.SaveReaction(mid, emoji, fromPeer); err != nil {
+		log.Printf("mesh: store reaction %s/%s: %v", mid, emoji, err)
+	}
+}
+
 // SaveMessage persists a chat message if a store is configured.
 // Duplicate mids are silently dropped.
 func (m *Mesh) SaveMessage(msg *proto.ChatMessage) {

internal/mesh/peer.go

@@ -307,6 +307,18 @@ func dispatchPeerMessage(msg proto.PeerMessage, from proto.PeerID, m *Mesh) {
 	case proto.MsgHistoryChunk:
 		go m.HandleHistoryChunk(msg.Room, msg.History)
 
+	case proto.MsgReaction:
+		if msg.ReactionMID == "" || msg.ReactionEmoji == "" {
+			return
+		}
+		m.SaveReaction(msg.ReactionMID, msg.ReactionEmoji, string(from))
+		m.emit(proto.IpcMessage{
+			Type:          proto.EvtReaction,
+			PeerID:        peerIDPtr(from),
+			ReactionMID:   msg.ReactionMID,
+			ReactionEmoji: msg.ReactionEmoji,
+		})
+
 	case proto.MsgPing:
 		log.Printf("mesh: ping from %s", from.Short())
 	case proto.MsgPong:

internal/proto/proto.go

@@ -51,6 +51,7 @@ const (
 	MsgPong            MsgType = "pong"
 	MsgHistoryRequest  MsgType = "history_request"
 	MsgHistoryChunk    MsgType = "history_chunk"
+	MsgReaction        MsgType = "reaction"
 )
 
 // PmMessage is a private message sent directly over a single peer link (§8 "pm").
@@ -97,6 +98,10 @@ type PeerMessage struct {
 	// history_chunk fields
 	History     []HistoryEntry `json:"history,omitempty"`
 	HistoryDone bool           `json:"history_done,omitempty"`
+
+	// reaction fields
+	ReactionMID   string `json:"reaction_mid,omitempty"`
+	ReactionEmoji string `json:"reaction_emoji,omitempty"`
 }
 
 // ResumableFile describes a partially-downloaded file found on daemon startup.
@@ -280,6 +285,7 @@ const (
 	CmdListShares     IpcMsgType = "list_shares"       // returns shares_list event
 	CmdCreateRoom       IpcMsgType = "create_room"        // field: room (name)
 	CmdSetDownloadDir   IpcMsgType = "set_download_dir"   // set per-network download directory at runtime; fields: network_id, path
+	CmdSendReaction     IpcMsgType = "send_reaction"      // fields: network_id, reaction_mid, reaction_emoji
 
 	// Events (daemon → UI)
 	EvtMessageReceived  IpcMsgType = "message_received"
@@ -302,6 +308,7 @@ const (
 	EvtRoomCreated      IpcMsgType = "room_created"    // field: room (name)
 	EvtHistoryLoaded      IpcMsgType = "history_loaded"       // fields: room, messages
 	EvtResumableTransfers IpcMsgType = "resumable_transfers"  // field: resumable_files
+	EvtReaction           IpcMsgType = "reaction"             // fields: reaction_mid, reaction_emoji, peer_id
 )
 
 // NetworkInfo summarises one joined network for state_snapshot and network_joined events.
@@ -359,6 +366,8 @@ type IpcMessage struct {
 	Files          []FileEntry    `json:"files,omitempty"`
 	Messages        []ChatMessage   `json:"messages,omitempty"`          // history_loaded
 	ResumableFiles  []ResumableFile `json:"resumable_files,omitempty"`   // resumable_transfers
+	ReactionMID     string          `json:"reaction_mid,omitempty"`      // reaction
+	ReactionEmoji   string          `json:"reaction_emoji,omitempty"`    // reaction
 	Shares         []ShareEntry `json:"shares,omitempty"`
 	ShareNetworks  []string     `json:"network_ids,omitempty"` // for add_share command: scope to specific network IDs, or ["*"] for global
 	// export_identity / import_identity

internal/store/store.go

@@ -38,10 +38,19 @@ CREATE TABLE IF NOT EXISTS rooms (
 
 // migrations run after the base schema. ALTER TABLE ADD COLUMN fails with
 // "duplicate column name" on subsequent opens — we swallow that error.
+// CREATE TABLE IF NOT EXISTS and CREATE INDEX IF NOT EXISTS are idempotent.
 var migrations = []string{
 	// EXT-007: canonical message ID for history dedup (NULL for pre-feature messages).
 	`ALTER TABLE messages ADD COLUMN msg_id TEXT`,
 	`CREATE UNIQUE INDEX IF NOT EXISTS idx_messages_msg_id ON messages (msg_id) WHERE msg_id IS NOT NULL`,
+	// Reactions: (mid, emoji, from_peer) triple is the unique dedup key.
+	`CREATE TABLE IF NOT EXISTS reactions (
+		mid        TEXT NOT NULL,
+		emoji      TEXT NOT NULL,
+		from_peer  TEXT NOT NULL,
+		reacted_at DATETIME NOT NULL,
+		PRIMARY KEY (mid, emoji, from_peer)
+	)`,
 }
 
 // Store is a local SQLite-backed message and peer store.
@@ -208,6 +217,43 @@ func (s *Store) KnownPeers() (map[proto.PeerID]string, error) {
 	return out, rows.Err()
 }
 
+// SaveReaction persists a reaction. Duplicate (mid, emoji, from_peer) triples are silently ignored.
+func (s *Store) SaveReaction(mid, emoji, fromPeer string) error {
+	_, err := s.db.Exec(
+		`INSERT OR IGNORE INTO reactions (mid, emoji, from_peer, reacted_at) VALUES (?, ?, ?, ?)`,
+		mid, emoji, fromPeer, time.Now().UTC(),
+	)
+	return err
+}
+
+// ReactionsForRoom returns all reactions for messages in a given room.
+// Result: mid → emoji → []fromPeer (ordered by reaction time).
+func (s *Store) ReactionsForRoom(room string) (map[string]map[string][]string, error) {
+	rows, err := s.db.Query(`
+		SELECT r.mid, r.emoji, r.from_peer
+		FROM reactions r
+		JOIN messages m ON m.mid = r.mid
+		WHERE m.room = ?
+		ORDER BY r.reacted_at
+	`, room)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	out := make(map[string]map[string][]string)
+	for rows.Next() {
+		var mid, emoji, from string
+		if err := rows.Scan(&mid, &emoji, &from); err != nil {
+			return nil, err
+		}
+		if out[mid] == nil {
+			out[mid] = make(map[string][]string)
+		}
+		out[mid][emoji] = append(out[mid][emoji], from)
+	}
+	return out, rows.Err()
+}
+
 func nullableString(s string) any {
 	if s == "" {
 		return nil

web/src/App.css

@@ -165,6 +165,26 @@ details summary { color: var(--muted); font-size: 12px; cursor: pointer; }
 .history-divider { display: flex; align-items: center; gap: 8px; margin: 10px 0 6px; color: var(--muted); font-size: 11px; }
 .history-divider::before, .history-divider::after { content: ''; flex: 1; height: 1px; background: var(--border); }
 
+/* ── message links + image preview ── */
+.msg-link { color: var(--accent); text-decoration: underline; word-break: break-all; }
+.msg-link:hover { opacity: 0.8; }
+.message-text { display: flex; flex-direction: column; gap: 4px; }
+.msg-image-preview { max-width: 320px; max-height: 200px; border-radius: 6px; border: 1px solid var(--border); margin-top: 4px; object-fit: contain; display: block; }
+
+/* ── reactions ── */
+.message-wrapper { display: flex; flex-direction: column; padding: 0; }
+.message-wrapper .message { padding: 2px 16px; }
+.reaction-add { background: none; color: var(--muted); font-size: 13px; padding: 0 4px; line-height: 1; opacity: 0; transition: opacity 0.1s; margin-left: 4px; flex-shrink: 0; }
+.message-wrapper:hover .reaction-add { opacity: 1; }
+.reaction-add:hover { color: var(--accent); background: none; }
+.reaction-picker { display: flex; gap: 4px; padding: 4px 16px 2px; }
+.reaction-picker-btn { background: var(--surface); border: 1px solid var(--border); border-radius: 6px; font-size: 18px; padding: 2px 6px; line-height: 1.4; cursor: pointer; }
+.reaction-picker-btn:hover { border-color: var(--accent); background: rgba(124,106,247,0.12); }
+.reaction-bar { display: flex; flex-wrap: wrap; gap: 4px; padding: 2px 16px 4px; }
+.reaction-chip { background: var(--surface); border: 1px solid var(--border); border-radius: 12px; font-size: 13px; padding: 1px 8px; cursor: pointer; color: var(--text); }
+.reaction-chip:hover { border-color: var(--accent); background: rgba(124,106,247,0.1); }
+.reaction-chip.mine { border-color: var(--accent); background: rgba(124,106,247,0.18); }
+
 /* ── mobile hamburger / close buttons ── */
 .menu-btn-mobile { display: none; background: none; color: var(--muted); font-size: 18px; padding: 0 8px 0 0; line-height: 1; }
 .menu-btn-mobile:hover { color: var(--text); background: none; }

web/src/components/MessagePane.tsx

@@ -12,20 +12,48 @@ function formatTs(ts: number): string {
   return d.toLocaleDateString([], { month: 'short', day: 'numeric' }) + ' ' + time
 }
 
+const URL_RE = /https?:\/\/[^\s<>"']+/g
+const IMAGE_EXT_RE = /\.(jpe?g|png|gif|webp|svg)(\?[^\s]*)?$/i
+
+function renderText(text: string): React.ReactNode {
+  const parts: React.ReactNode[] = []
+  let last = 0
+  let m: RegExpExecArray | null
+  URL_RE.lastIndex = 0
+  while ((m = URL_RE.exec(text)) !== null) {
+    if (m.index > last) parts.push(text.slice(last, m.index))
+    const url = m[0]
+    const isImage = IMAGE_EXT_RE.test(url) || url.startsWith('blob:') || url.startsWith('data:image')
+    parts.push(
+      <a key={m.index} href={url} target="_blank" rel="noopener noreferrer" className="msg-link">
+        {url}
+      </a>
+    )
+    if (isImage) {
+      parts.push(
+        <img key={`img-${m.index}`} src={url} alt="" className="msg-image-preview" loading="lazy" />
+      )
+    }
+    last = m.index + url.length
+  }
+  if (last < text.length) parts.push(text.slice(last))
+  return parts.length > 1 ? <>{parts}</> : text
+}
+
+const EMOJI_SET = ['👍', '❤️', '😂', '😮', '😢', '🙏']
+
 export function MessagePane({ onMenuClick }: { onMenuClick: () => void }) {
-  const { messages, historyCutoff, activeRoom, activeNetworkId, localPeer, connectedPeers, knownPeers, send } = useWaste()
+  const { messages, historyCutoff, activeRoom, activeNetworkId, localPeer, connectedPeers, knownPeers, reactions, sendReaction, send } = useWaste()
   const [draft, setDraft] = useState('')
+  const [pickerMid, setPickerMid] = useState<string | null>(null)
   const bottomRef = useRef<HTMLDivElement>(null)
   const msgKey = activeNetworkId ? `${activeNetworkId}:${activeRoom}` : activeRoom
   const roomMessages = messages[msgKey] ?? []
   const cutoff = historyCutoff[msgKey] ?? 0
 
-  // Find the index of the first live message (ts > cutoff).
-  // The divider appears just before this index, or at the top if all are history.
   const firstLiveIdx = cutoff > 0
     ? roomMessages.findIndex(m => m.ts > cutoff)
     : -1
-  // If all messages are history (no live yet), put divider at the start.
   const dividerIdx = cutoff > 0
     ? (firstLiveIdx === -1 ? 0 : firstLiveIdx)
     : -1
@@ -34,6 +62,14 @@ export function MessagePane({ onMenuClick }: { onMenuClick: () => void }) {
     bottomRef.current?.scrollIntoView({ behavior: 'smooth' })
   }, [roomMessages.length])
 
+  // Close picker when clicking outside
+  useEffect(() => {
+    if (!pickerMid) return
+    const handler = () => setPickerMid(null)
+    document.addEventListener('click', handler)
+    return () => document.removeEventListener('click', handler)
+  }, [pickerMid])
+
   function submit(e: React.FormEvent) {
     e.preventDefault()
     const text = draft.trim()
@@ -58,6 +94,18 @@ export function MessagePane({ onMenuClick }: { onMenuClick: () => void }) {
       ?? fromId.slice(0, 8)
   }
 
+  function toggleReaction(mid: string, emoji: string, e: React.MouseEvent) {
+    e.stopPropagation()
+    if (!activeNetworkId || !mid) return
+    sendReaction(activeNetworkId, mid, emoji)
+    setPickerMid(null)
+  }
+
+  function openPicker(mid: string, e: React.MouseEvent) {
+    e.stopPropagation()
+    setPickerMid(prev => prev === mid ? null : mid)
+  }
+
   const roomLabel = activeRoom.startsWith('dm:')
     ? `@ ${activeRoom.slice(3, 11)}…`
     : `# ${activeRoom}`
@@ -77,16 +125,54 @@ export function MessagePane({ onMenuClick }: { onMenuClick: () => void }) {
           const mine = msg.from === localPeer?.id
           const alias = aliasFor(String(msg.from))
           const ts = formatTs(msg.ts)
+          const mid = msg.mid ?? ''
+          const msgReactions = mid ? reactions[mid] : undefined
+          const hasReactions = msgReactions && Object.keys(msgReactions).length > 0
           return (
-            <div key={msg.mid ?? i}>
+            <div key={mid || i} className="message-wrapper">
               {i === dividerIdx && dividerIdx > 0 && (
                 <div className="history-divider"><span>earlier messages</span></div>
               )}
               <div className={`message ${mine ? 'mine' : ''}`}>
                 <span className="message-ts">{ts}</span>
                 <span className="message-alias">{alias}</span>
-                <span className="message-text">{msg.text}</span>
+                <span className="message-text">
+                  {renderText(msg.text)}
+                </span>
+                {mid && (
+                  <button
+                    className="reaction-add"
+                    onClick={e => openPicker(mid, e)}
+                    title="React"
+                  >+</button>
+                )}
               </div>
+              {pickerMid === mid && (
+                <div className="reaction-picker" onClick={e => e.stopPropagation()}>
+                  {EMOJI_SET.map(emoji => (
+                    <button key={emoji} className="reaction-picker-btn" onClick={e => toggleReaction(mid, emoji, e)}>
+                      {emoji}
+                    </button>
+                  ))}
+                </div>
+              )}
+              {hasReactions && (
+                <div className="reaction-bar">
+                  {Object.entries(msgReactions!).map(([emoji, fromIds]) => {
+                    const iMine = fromIds.includes(localPeer?.id ?? '')
+                    return (
+                      <button
+                        key={emoji}
+                        className={`reaction-chip ${iMine ? 'mine' : ''}`}
+                        onClick={e => toggleReaction(mid, emoji, e)}
+                        title={fromIds.map(aliasFor).join(', ')}
+                      >
+                        {emoji} {fromIds.length}
+                      </button>
+                    )
+                  })}
+                </div>
+              )}
             </div>
           )
         })}

web/src/store/index.ts

@@ -58,6 +58,8 @@ interface WasteState {
   fileProgress: Record<string, { peerId: string; name: string; received: number; total: number }>
   // partial downloads found on daemon startup: sha256 → info
   resumableFiles: Record<string, { name: string; from: string; size: number; offset: number }>
+  // reactions: mid → emoji → [fromId, ...]
+  reactions: Record<string, Record<string, string[]>>
 
   // actions
   connect: (url: string) => void
@@ -74,6 +76,7 @@ interface WasteState {
   rejectOffer: (peerId: string, xid: string) => void
   cancelTransfer: (peerId: string, xid: string, direction: 'recv' | 'send') => void
   createRoom: (name: string) => void
+  sendReaction: (networkId: string, mid: string, emoji: string) => void
   logout: (clearIdentity: boolean) => void
   handleEvent: (msg: IpcMessage) => void
 }
@@ -101,6 +104,7 @@ export const useWaste = create<WasteState>((set, get) => ({
   pendingOffers: {},
   fileProgress: {},
   resumableFiles: {},
+  reactions: {},
 
   connect(url: string) {
     const adapter = new DaemonAdapter(url)
@@ -189,6 +193,10 @@ export const useWaste = create<WasteState>((set, get) => ({
     window.location.reload()
   },
 
+  sendReaction(networkId, mid, emoji) {
+    get().send({ type: 'send_reaction', network_id: networkId, reaction_mid: mid, reaction_emoji: emoji })
+  },
+
   createRoom(name) {
     const netId = get().activeNetworkId
     if (!netId || !name.trim()) return
@@ -374,6 +382,19 @@ export const useWaste = create<WasteState>((set, get) => ({
         set(s => ({ resumableFiles: { ...s.resumableFiles, ...byHash } }))
         break
       }
+      case 'reaction': {
+        const mid = msg.reaction_mid
+        const emoji = msg.reaction_emoji
+        const from = msg.peer_id
+        if (!mid || !emoji || !from) break
+        set(s => {
+          const byEmoji = { ...(s.reactions[mid] ?? {}) }
+          const existing = byEmoji[emoji] ?? []
+          if (existing.includes(from)) return s
+          return { reactions: { ...s.reactions, [mid]: { ...byEmoji, [emoji]: [...existing, from] } } }
+        })
+        break
+      }
       case 'history_loaded': {
         const room = msg.room
         const incoming = (msg.messages ?? []) as ChatMessage[]

web/src/types.ts

@@ -86,6 +86,8 @@ export type IpcMsgType =
   | 'room_created'
   | 'create_room'
   | 'resumable_transfers'
+  | 'send_reaction'
+  | 'reaction'
 
 export interface IpcMessage {
   type: IpcMsgType
@@ -133,4 +135,7 @@ export interface IpcMessage {
   messages?: ChatMessage[]
   // resumable_transfers
   resumable_files?: Array<{ name: string; sha256: string; from: string; size: number; offset: number }>
+  // reaction
+  reaction_mid?: string
+  reaction_emoji?: string
 }