feat(web): add message edit, retry, and copy actions

internal/session/session.go

@@ -266,6 +266,97 @@ func (r *Recorder) RecordCompact(summary string, compactedN int) {
 	_ = r.writeEntry(Entry{Type: EntryCompact, Summary: summary, CompactedN: compactedN})
 }
 
+// TruncateAtUserMessage rewrites the session file keeping only entries that
+// appear before the (beforeCount)th user message (0-indexed).
+// If beforeCount == 0, the file is truncated to the session_start header only.
+// The recorder is reset to append mode on the (now shorter) file.
+// This preserves the session UUID and index entry — no new session is created.
+func (r *Recorder) TruncateAtUserMessage(beforeCount int) error {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+
+	if r.agentID != "" {
+		return fmt.Errorf("TruncateAtUserMessage not supported for teammate recorders")
+	}
+
+	// Close current file handle before rewriting.
+	if r.file != nil {
+		_ = r.file.Close()
+		r.file = nil
+	}
+
+	dir, err := config.SessionsDir()
+	if err != nil {
+		return err
+	}
+	filePath := filepath.Join(dir, r.uuid+".json")
+
+	// Load existing entries.
+	data, err := os.ReadFile(filePath)
+	if err != nil {
+		if os.IsNotExist(err) {
+			// Nothing to truncate.
+			return nil
+		}
+		return fmt.Errorf("read session file: %w", err)
+	}
+
+	// Collect entries to keep: session_start always, then everything before
+	// the beforeCount-th user entry. When beforeCount == 0 we keep nothing
+	// except the session_start header.
+	var keep []string
+	userCount := 0
+	for _, line := range strings.Split(string(data), "\n") {
+		line = strings.TrimSpace(line)
+		if line == "" {
+			continue
+		}
+		var e Entry
+		if err := json.Unmarshal([]byte(line), &e); err != nil {
+			continue
+		}
+		// Always keep the session_start header.
+		if e.Type == EntrySessionStart {
+			keep = append(keep, line)
+			continue
+		}
+		// Stop as soon as we reach the Nth user message.
+		if e.Type == EntryUser {
+			if userCount >= beforeCount {
+				break
+			}
+			userCount++
+		}
+		// For beforeCount == 0 we must not keep any non-session_start entry.
+		if beforeCount == 0 {
+			break
+		}
+		keep = append(keep, line)
+	}
+
+	// Atomically rewrite the file.
+	tmpPath := filePath + ".tmp"
+	content := strings.Join(keep, "\n")
+	if len(keep) > 0 {
+		content += "\n"
+	}
+	if err := os.WriteFile(tmpPath, []byte(content), 0644); err != nil {
+		return fmt.Errorf("write truncated session: %w", err)
+	}
+	if err := os.Rename(tmpPath, filePath); err != nil {
+		return fmt.Errorf("rename truncated session: %w", err)
+	}
+
+	// Reopen for append so subsequent writes go to the correct file.
+	f, err := os.OpenFile(filePath, os.O_APPEND|os.O_WRONLY, 0644)
+	if err != nil {
+		return fmt.Errorf("reopen session for append: %w", err)
+	}
+	r.file = f
+	r.resuming = true
+	return nil
+}
+
 // Close flushes and closes the underlying file.  Safe to call multiple times.
 // If no messages were ever recorded the file is never created.
 func (r *Recorder) Close() {

internal/web/server.go

@@ -250,6 +250,9 @@ func (s *Server) Start(ctx context.Context) error {
 	mux.HandleFunc("POST /api/providers", s.handleAddProvider)
 	mux.HandleFunc("DELETE /api/providers/{id}", s.handleDeleteProvider)
 
+	// History management.
+	mux.HandleFunc("POST /api/history/truncate", s.handleTruncateHistory)
+
 	// Model state API — favorites & recent.
 	mux.HandleFunc("GET /api/model-state", s.handleGetModelState)
 	mux.HandleFunc("POST /api/model-state/favorite", s.handleToggleFavorite)
@@ -621,6 +624,72 @@ func (s *Server) handleDeleteSession(w http.ResponseWriter, r *http.Request) {
 	writeJSON(w, http.StatusOK, map[string]string{"status": "ok"})
 }
 
+func (s *Server) handleTruncateHistory(w http.ResponseWriter, r *http.Request) {
+	if s.running.Load() {
+		writeJSON(w, http.StatusConflict, map[string]string{"error": "agent is currently running"})
+		return
+	}
+
+	var req struct {
+		// BeforeUserMessage: keep all history entries that come before the
+		// Nth user message (0-indexed). Everything from that user message
+		// onward is discarded. Pass 0 to clear everything.
+		BeforeUserMessage int `json:"before_user_message"`
+	}
+	if err := json.NewDecoder(io.LimitReader(r.Body, 1<<16)).Decode(&req); err != nil {
+		writeJSON(w, http.StatusBadRequest, map[string]string{"error": "invalid request"})
+		return
+	}
+
+	// Capture the recorder reference under the lock but do file I/O outside
+	// so we don't block other goroutines.
+	s.mu.Lock()
+	rec := s.recorder
+	sessionID := ""
+	if rec != nil {
+		sessionID = rec.UUID()
+	}
+	s.mu.Unlock()
+
+	// Persist first — if the file rewrite fails we abort without touching
+	// the in-memory history so state never diverges.
+	if rec != nil {
+		if err := rec.TruncateAtUserMessage(req.BeforeUserMessage); err != nil {
+			config.Logger().Printf("[truncate] rewrite session file failed: %v", err)
+			writeJSON(w, http.StatusInternalServerError, map[string]string{"error": "failed to truncate session file"})
+			return
+		}
+	}
+
+	// Now truncate in-memory history.
+	s.mu.Lock()
+	truncAt := 0
+	if req.BeforeUserMessage > 0 {
+		userCount := 0
+		truncAt = len(s.history) // default: keep all
+		for i, msg := range s.history {
+			if msg.Role == schema.User {
+				if userCount == req.BeforeUserMessage {
+					truncAt = i
+					break
+				}
+				userCount++
+			}
+		}
+	}
+	if truncAt == 0 {
+		s.history = nil
+	} else {
+		s.history = s.history[:truncAt]
+	}
+	s.mu.Unlock()
+
+	writeJSON(w, http.StatusOK, map[string]any{
+		"status":     "ok",
+		"session_id": sessionID,
+	})
+}
+
 func (s *Server) handleNewSession(w http.ResponseWriter, r *http.Request) {
 	// Parse optional request body for resume session ID.
 	var req struct {

web/src/App.vue

@@ -301,7 +301,15 @@ function startResize(e: MouseEvent) {
           <!-- Timeline -->
           <div v-else class="max-w-3xl mx-auto px-5 py-6 space-y-0.5">
             <template v-for="item in store.timeline" :key="item.seq">
-              <ChatMessageVue v-if="item.kind === 'message'" :message="item.data" class="animate-fade-up" />
+              <ChatMessageVue
+                v-if="item.kind === 'message'"
+                :message="item.data"
+                :can-retry="item.data.role === 'assistant' && !store.isRunning"
+                :can-edit="item.data.role === 'user' && !store.isRunning"
+                class="animate-fade-up"
+                @retry="store.retryFromMessage(item.data.id)"
+                @edit="(text) => store.editAndResend(item.data.id, text)"
+              />
               <ToolCallCard v-else-if="item.kind === 'tool'" :tool="item.data" class="animate-fade-up" />
               <ApprovalBanner v-else-if="item.kind === 'approval'" :approval="item.data" class="animate-fade-up" />
             </template>

web/src/components/ChatMessage.vue

@@ -1,15 +1,68 @@
 <script setup lang="ts">
 import { renderMarkdown } from '@/composables/markdown'
 import type { ChatMessage } from '@/types/api'
+import { ref, nextTick } from 'vue'
 
-defineProps<{
+const props = defineProps<{
   message: ChatMessage
+  canRetry?: boolean
+  canEdit?: boolean
 }>()
+
+const emit = defineEmits<{
+  retry: []
+  edit: [newText: string]
+}>()
+
+const copied = ref(false)
+const editing = ref(false)
+const editText = ref('')
+const editTextarea = ref<HTMLTextAreaElement | null>(null)
+
+function copyContent() {
+  navigator.clipboard.writeText(props.message.content).then(() => {
+    copied.value = true
+    setTimeout(() => { copied.value = false }, 1500)
+  }).catch((err) => {
+    console.error('Failed to copy:', err)
+  })
+}
+
+function startEdit() {
+  editText.value = props.message.content
+  editing.value = true
+  nextTick(() => {
+    editTextarea.value?.focus()
+  })
+}
+
+function confirmEdit() {
+  const text = editText.value.trim()
+  if (text) {
+    emit('edit', text)
+  }
+  editing.value = false
+}
+
+function cancelEdit() {
+  editing.value = false
+}
+
+function handleEditKeyDown(e: KeyboardEvent) {
+  if (e.key === 'Enter' && !e.shiftKey) {
+    e.preventDefault()
+    confirmEdit()
+  }
+  if (e.key === 'Escape') {
+    e.preventDefault()
+    cancelEdit()
+  }
+}
 </script>
 
 <template>
-  <div class="py-3 animate-fade-in">
-    <!-- Role label -->
+  <div class="py-3 animate-fade-in group/msg">
+    <!-- Role label + action buttons -->
     <div class="flex items-center gap-2 mb-2">
       <div
         class="w-5 h-5 rounded flex items-center justify-center text-[9px] font-bold shrink-0"
@@ -38,7 +91,52 @@ defineProps<{
       >
         {{ message.role === 'user' ? (message.source === 'wechat' ? 'WeChat' : 'You') : message.role === 'assistant' ? '[J]CODE' : 'System' }}
       </span>
+
+      <!-- Action buttons: visible on hover or keyboard focus-within -->
+      <div class="flex items-center gap-0.5 ml-1 opacity-0 group-hover/msg:opacity-100 group-focus-within/msg:opacity-100 transition-opacity duration-150">
+        <!-- Copy button -->
+        <button
+          class="w-5 h-5 flex items-center justify-center rounded text-zinc-400 hover:text-zinc-600 dark:hover:text-zinc-300 hover:bg-zinc-100 dark:hover:bg-zinc-800 transition-colors cursor-pointer"
+          :title="copied ? 'Copied!' : 'Copy'"
+          @click="copyContent"
+        >
+          <svg v-if="!copied" class="w-3 h-3" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+            <rect x="9" y="9" width="13" height="13" rx="2" />
+            <path d="M5 15H4a2 2 0 0 1-2-2V4a2 2 0 0 1 2-2h9a2 2 0 0 1 2 2v1" />
+          </svg>
+          <svg v-else class="w-3 h-3 text-emerald-500" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2.5" stroke-linecap="round" stroke-linejoin="round">
+            <polyline points="20 6 9 17 4 12" />
+          </svg>
+        </button>
+
+        <!-- Retry button (assistant messages) -->
+        <button
+          v-if="canRetry"
+          class="w-5 h-5 flex items-center justify-center rounded text-zinc-400 hover:text-amber-500 dark:hover:text-amber-400 hover:bg-zinc-100 dark:hover:bg-zinc-800 transition-colors cursor-pointer"
+          title="Retry"
+          @click="emit('retry')"
+        >
+          <svg class="w-3 h-3" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+            <path d="M3 12a9 9 0 1 0 9-9 9.75 9.75 0 0 0-6.74 2.74L3 8" />
+            <path d="M3 3v5h5" />
+          </svg>
+        </button>
+
+        <!-- Edit button (user messages) -->
+        <button
+          v-if="canEdit && !editing"
+          class="w-5 h-5 flex items-center justify-center rounded text-zinc-400 hover:text-zinc-600 dark:hover:text-zinc-300 hover:bg-zinc-100 dark:hover:bg-zinc-800 transition-colors cursor-pointer"
+          title="Edit"
+          @click="startEdit"
+        >
+          <svg class="w-3 h-3" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+            <path d="M11 4H4a2 2 0 0 0-2 2v14a2 2 0 0 0 2 2h14a2 2 0 0 0 2-2v-7" />
+            <path d="M18.5 2.5a2.121 2.121 0 0 1 3 3L12 15l-4 1 1-4Z" />
+          </svg>
+        </button>
+      </div>
     </div>
+
     <!-- Images -->
     <div v-if="message.images && message.images.length > 0" class="pl-7 mb-2 flex flex-wrap gap-2">
       <img
@@ -49,10 +147,33 @@ defineProps<{
         @click="($event.target as HTMLImageElement).classList.toggle('max-w-64'); ($event.target as HTMLImageElement).classList.toggle('max-w-full')"
       />
     </div>
-    <!-- Content -->
-    <div
-      class="prose-chat pl-7"
-      v-html="renderMarkdown(message.content)"
-    />
+
+    <!-- Content or Edit mode -->
+    <div v-if="!editing" class="prose-chat pl-7" v-html="renderMarkdown(message.content)" />
+
+    <!-- Inline edit mode -->
+    <div v-else class="pl-7">
+      <textarea
+        ref="editTextarea"
+        v-model="editText"
+        class="w-full min-h-20 max-h-80 resize-y rounded-lg border border-zinc-300 dark:border-zinc-600 bg-white dark:bg-zinc-800 text-sm text-zinc-800 dark:text-zinc-200 px-3 py-2 focus:outline-none focus:ring-2 focus:ring-emerald-500/40 focus:border-emerald-500 dark:focus:border-emerald-400 transition-colors"
+        @keydown="handleEditKeyDown"
+      />
+      <div class="flex items-center gap-2 mt-2">
+        <button
+          class="px-3 py-1 text-xs font-medium rounded bg-emerald-500 hover:bg-emerald-600 text-white transition-colors cursor-pointer"
+          @click="confirmEdit"
+        >
+          Send
+        </button>
+        <button
+          class="px-3 py-1 text-xs font-medium rounded bg-zinc-100 hover:bg-zinc-200 dark:bg-zinc-700 dark:hover:bg-zinc-600 text-zinc-600 dark:text-zinc-300 transition-colors cursor-pointer"
+          @click="cancelEdit"
+        >
+          Cancel
+        </button>
+        <span class="text-[10px] text-zinc-400">Enter to send · Shift+Enter for newline · Esc to cancel</span>
+      </div>
+    </div>
   </div>
 </template>

web/src/composables/api.ts

@@ -19,6 +19,11 @@ async function request<T>(path: string, options?: RequestInit): Promise<T> {
 }
 
 export const api = {
+  truncateHistory: (beforeUserMessage: number) =>
+    request<{ status: string; session_id: string }>('/api/history/truncate', {
+      method: 'POST',
+      body: JSON.stringify({ before_user_message: beforeUserMessage }),
+    }),
   health: () =>
     request<{ status: string; version: string; pwd: string; provider: string; model: string; mode: string; session_id: string; running: boolean; image_support?: boolean }>(
       '/api/health',