Enhance story item management with trimming, splitting, and duplication features

- Updated StoryTrackEditor and StoryContent components to support trimming and splitting of story items.
- Introduced new API endpoints for trimming, splitting, and duplicating story items, enhancing item management capabilities.
- Refactored related hooks and state management to accommodate new functionalities.
- Improved data models to include trim start and end times for better audio playback control.
- Enhanced UI interactions for selecting and managing story items within the track editor.

app/src/components/StoriesTab/StoryContent.tsx

@@ -131,13 +131,13 @@ export function StoryContent() {
     }
   }, [isPlaying]);
 
-  const handleRemoveItem = (generationId: string) => {
+  const handleRemoveItem = (itemId: string) => {
     if (!story) return;
 
     removeItem.mutate(
       {
         storyId: story.id,
-        generationId,
+        itemId,
       },
       {
         onError: (error) => {
@@ -360,7 +360,7 @@ export function StoryContent() {
                       item={item}
                       storyId={story.id}
                       index={index}
-                      onRemove={() => handleRemoveItem(item.generation_id)}
+                      onRemove={() => handleRemoveItem(item.id)}
                       currentTimeMs={currentTimeMs}
                       isPlaying={isPlaying && playbackStoryId === story.id}
                     />

app/src/components/StoriesTab/StoryTrackEditor.tsx

@@ -1,21 +1,45 @@
-import { GripHorizontal, Minus, Pause, Play, Plus, Square } from 'lucide-react';
+import { Copy, GripHorizontal, Minus, Pause, Play, Plus, Scissors, Square, Trash2 } from 'lucide-react';
 import { useCallback, useEffect, useMemo, useRef, useState } from 'react';
 import WaveSurfer from 'wavesurfer.js';
 import { Button } from '@/components/ui/button';
 import { useToast } from '@/components/ui/use-toast';
 import { apiClient } from '@/lib/api/client';
-import { useMoveStoryItem } from '@/lib/hooks/useStories';
+import { useMoveStoryItem, useTrimStoryItem, useSplitStoryItem, useDuplicateStoryItem, useRemoveStoryItem } from '@/lib/hooks/useStories';
 import { useStoryStore } from '@/stores/storyStore';
 import type { StoryItemDetail } from '@/lib/api/types';
 import { cn } from '@/lib/utils/cn';
 
-// Clip waveform component
-function ClipWaveform({ generationId, width }: { generationId: string; width: number }) {
-  const containerRef = useRef<HTMLDivElement>(null);
+// Clip waveform component with trim support
+function ClipWaveform({ 
+  generationId, 
+  width, 
+  trimStartMs, 
+  trimEndMs, 
+  duration 
+}: { 
+  generationId: string; 
+  width: number;
+  trimStartMs: number;
+  trimEndMs: number;
+  duration: number;
+}) {
+  const waveformRef = useRef<HTMLDivElement>(null);
   const wavesurferRef = useRef<WaveSurfer | null>(null);
 
+  // Calculate the full waveform width based on the original duration
+  // The visible portion (width) represents the effective duration after trimming
+  const effectiveDurationMs = (duration * 1000) - trimStartMs - trimEndMs;
+  const fullWaveformWidth = effectiveDurationMs > 0 
+    ? (width / effectiveDurationMs) * (duration * 1000) 
+    : width;
+  
+  // Calculate how much to offset the waveform to hide the trimmed start
+  const offsetX = effectiveDurationMs > 0 
+    ? (trimStartMs / (duration * 1000)) * fullWaveformWidth 
+    : 0;
+
   useEffect(() => {
-    if (!containerRef.current || width < 20) return;
+    if (!waveformRef.current || fullWaveformWidth < 20) return;
 
     // Get CSS colors
     const root = document.documentElement;
@@ -27,7 +51,7 @@ function ClipWaveform({ generationId, width }: { generationId: string; width: nu
     const waveColor = getCSSVar('--accent-foreground');
 
     const wavesurfer = WaveSurfer.create({
-      container: containerRef.current,
+      container: waveformRef.current,
       waveColor,
       progressColor: waveColor,
       cursorWidth: 0,
@@ -50,9 +74,21 @@ function ClipWaveform({ generationId, width }: { generationId: string; width: nu
       wavesurfer.destroy();
       wavesurferRef.current = null;
     };
-  }, [generationId, width]);
+  }, [generationId, fullWaveformWidth]);
 
-  return <div ref={containerRef} className="w-full h-full opacity-60" />;
+  return (
+    <div className="w-full h-full opacity-60 overflow-hidden">
+      {/* Inner container that holds the full waveform, offset to show only visible portion */}
+      <div 
+        ref={waveformRef}
+        style={{ 
+          width: `${fullWaveformWidth}px`,
+          transform: `translateX(-${offsetX}px)`,
+        }}
+        className="h-full"
+      />
+    </div>
+  );
 }
 
 interface StoryTrackEditorProps {
@@ -80,7 +116,21 @@ export function StoryTrackEditor({ storyId, items }: StoryTrackEditorProps) {
   const resizeStartY = useRef(0);
   const resizeStartHeight = useRef(0);
   const moveItem = useMoveStoryItem();
+  const trimItem = useTrimStoryItem();
+  const splitItem = useSplitStoryItem();
+  const duplicateItem = useDuplicateStoryItem();
+  const removeItem = useRemoveStoryItem();
   const { toast } = useToast();
+  
+  // Selection state
+  const selectedClipId = useStoryStore((state) => state.selectedClipId);
+  const setSelectedClipId = useStoryStore((state) => state.setSelectedClipId);
+  
+  // Trim state
+  const [trimmingItem, setTrimmingItem] = useState<string | null>(null);
+  const [trimSide, setTrimSide] = useState<'start' | 'end' | null>(null);
+  const [trimStartX, setTrimStartX] = useState(0);
+  const [tempTrimValues, setTempTrimValues] = useState<{ trim_start_ms: number; trim_end_ms: number } | null>(null);
 
   // Track editor height from store (shared with FloatingGenerateBox)
   const editorHeight = useStoryStore((state) => state.trackEditorHeight);
@@ -140,11 +190,16 @@ export function StoryTrackEditor({ storyId, items }: StoryTrackEditorProps) {
     return () => observer.disconnect();
   }, []);
 
-  // Calculate total duration
+  // Calculate effective duration (accounting for trims)
+  const getEffectiveDuration = (item: StoryItemDetail) => {
+    return item.duration * 1000 - (item.trim_start_ms || 0) - (item.trim_end_ms || 0);
+  };
+
+  // Calculate total duration (using effective durations)
   const totalDurationMs = useMemo(() => {
     if (items.length === 0) return 10000; // Default 10 seconds
     return Math.max(
-      ...items.map((item) => item.start_time_ms + item.duration * 1000),
+      ...items.map((item) => item.start_time_ms + getEffectiveDuration(item)),
       10000
     );
   }, [items]);
@@ -228,13 +283,246 @@ export function StoryTrackEditor({ storyId, items }: StoryTrackEditorProps) {
   }, [isResizing, handleResizeMove, handleResizeEnd]);
 
   const handleTimelineClick = (e: React.MouseEvent<HTMLDivElement>) => {
-    if (!tracksRef.current || draggingItem) return;
+    if (!tracksRef.current || draggingItem || trimmingItem) return;
     const rect = tracksRef.current.getBoundingClientRect();
     const x = e.clientX - rect.left + tracksRef.current.scrollLeft;
     const timeMs = Math.max(0, pixelsToMs(x));
     seek(timeMs);
+    // Deselect clip when clicking on timeline
+    setSelectedClipId(null);
   };
 
+  const handleClipClick = (e: React.MouseEvent, item: StoryItemDetail) => {
+    e.stopPropagation();
+    if (draggingItem || trimmingItem) return;
+    setSelectedClipId(item.id);
+  };
+
+  const handleTrimStart = (e: React.MouseEvent, item: StoryItemDetail, side: 'start' | 'end') => {
+    e.stopPropagation();
+    if (!tracksRef.current) return;
+    setTrimmingItem(item.id);
+    setTrimSide(side);
+    setSelectedClipId(item.id);
+    setTrimStartX(e.clientX);
+    trimStartItemRef.current = {
+      item,
+      initialTrimStart: item.trim_start_ms || 0,
+      initialTrimEnd: item.trim_end_ms || 0,
+    };
+  };
+
+
+  const trimStartItemRef = useRef<{ item: StoryItemDetail; initialTrimStart: number; initialTrimEnd: number } | null>(null);
+
+  const handleTrimMove = useCallback(
+    (e: MouseEvent) => {
+      if (!trimmingItem || !trimSide || !trimStartItemRef.current) return;
+      
+      const deltaX = e.clientX - trimStartX;
+      const deltaMs = pixelsToMs(deltaX); // Signed delta in milliseconds
+      
+      const { item, initialTrimStart, initialTrimEnd } = trimStartItemRef.current;
+      const originalDurationMs = item.duration * 1000;
+      
+      let newTrimStart = initialTrimStart;
+      let newTrimEnd = initialTrimEnd;
+      
+      if (trimSide === 'start') {
+        // Moving right increases trim_start (trims more from start)
+        // Moving left decreases trim_start (restores from start)
+        newTrimStart = Math.round(Math.max(0, Math.min(initialTrimStart + deltaMs, originalDurationMs - initialTrimEnd - 100)));
+      } else {
+        // Moving right decreases trim_end (restores from end)
+        // Moving left increases trim_end (trims more from end)
+        newTrimEnd = Math.round(Math.max(0, Math.min(initialTrimEnd - deltaMs, originalDurationMs - initialTrimStart - 100)));
+      }
+      
+      // Validate that we don't exceed duration
+      if (newTrimStart + newTrimEnd >= originalDurationMs - 100) {
+        return; // Don't allow trimming to less than 100ms
+      }
+      
+      // Update temporary trim values for visual feedback
+      setTempTrimValues({
+        trim_start_ms: newTrimStart,
+        trim_end_ms: newTrimEnd,
+      });
+    },
+    [trimmingItem, trimSide, trimStartX, pixelsToMs]
+  );
+
+  const handleTrimEnd = useCallback(() => {
+    if (!trimmingItem || !trimSide || !trimStartItemRef.current) {
+      setTrimmingItem(null);
+      setTrimSide(null);
+      setTempTrimValues(null);
+      trimStartItemRef.current = null;
+      return;
+    }
+
+    const { initialTrimStart, initialTrimEnd } = trimStartItemRef.current;
+    
+    // Use temporary trim values if available, otherwise use initial values
+    // Ensure values are integers for the backend
+    const finalTrimStart = Math.round(tempTrimValues?.trim_start_ms ?? initialTrimStart);
+    const finalTrimEnd = Math.round(tempTrimValues?.trim_end_ms ?? initialTrimEnd);
+    
+    // Only update if values changed
+    if (finalTrimStart !== initialTrimStart || finalTrimEnd !== initialTrimEnd) {
+      trimItem.mutate(
+        {
+          storyId,
+          itemId: trimmingItem,
+          data: {
+            trim_start_ms: finalTrimStart,
+            trim_end_ms: finalTrimEnd,
+          },
+        },
+        {
+          onError: (error) => {
+            toast({
+              title: 'Failed to trim clip',
+              description: error instanceof Error ? error.message : String(error),
+              variant: 'destructive',
+            });
+          },
+        }
+      );
+    }
+    
+    setTrimmingItem(null);
+    setTrimSide(null);
+    setTempTrimValues(null);
+    trimStartItemRef.current = null;
+  }, [trimmingItem, trimSide, tempTrimValues, storyId, trimItem, toast]);
+
+  const handleSplit = useCallback(() => {
+    if (!selectedClipId) return;
+    
+    const item = items.find((i) => i.id === selectedClipId);
+    if (!item) return;
+
+    const splitTimeMs = currentTimeMs - item.start_time_ms;
+    const effectiveDuration = getEffectiveDuration(item);
+    
+    if (splitTimeMs <= 0 || splitTimeMs >= effectiveDuration) {
+      toast({
+        title: 'Invalid split point',
+        description: 'Playhead must be within the selected clip',
+        variant: 'destructive',
+      });
+      return;
+    }
+
+    splitItem.mutate(
+      {
+        storyId,
+        itemId: selectedClipId,
+        data: { split_time_ms: splitTimeMs },
+      },
+      {
+        onSuccess: () => {
+          setSelectedClipId(null);
+        },
+        onError: (error) => {
+          toast({
+            title: 'Failed to split clip',
+            description: error instanceof Error ? error.message : String(error),
+            variant: 'destructive',
+          });
+        },
+      }
+    );
+  }, [selectedClipId, items, currentTimeMs, getEffectiveDuration, storyId, splitItem, toast, setSelectedClipId]);
+
+  const handleDuplicate = useCallback(() => {
+    if (!selectedClipId) return;
+
+    duplicateItem.mutate(
+      {
+        storyId,
+        itemId: selectedClipId,
+      },
+      {
+        onError: (error) => {
+          toast({
+            title: 'Failed to duplicate clip',
+            description: error instanceof Error ? error.message : String(error),
+            variant: 'destructive',
+          });
+        },
+      }
+    );
+  }, [selectedClipId, storyId, duplicateItem, toast]);
+
+  const handleDelete = useCallback(() => {
+    if (!selectedClipId) return;
+
+    removeItem.mutate(
+      {
+        storyId,
+        itemId: selectedClipId,
+      },
+      {
+        onSuccess: () => {
+          setSelectedClipId(null);
+        },
+        onError: (error) => {
+          toast({
+            title: 'Failed to delete clip',
+            description: error instanceof Error ? error.message : String(error),
+            variant: 'destructive',
+          });
+        },
+      }
+    );
+  }, [selectedClipId, storyId, removeItem, toast, setSelectedClipId]);
+
+  // Keyboard shortcuts
+  useEffect(() => {
+    const handleKeyDown = (e: KeyboardEvent) => {
+      // Only handle shortcuts when editor is focused or no input is focused
+      if (e.target instanceof HTMLInputElement || e.target instanceof HTMLTextAreaElement) {
+        return;
+      }
+
+      if (e.key === 'Escape') {
+        setSelectedClipId(null);
+      } else if (e.key === 's' || e.key === 'S') {
+        if (selectedClipId) {
+          e.preventDefault();
+          handleSplit();
+        }
+      } else if (e.key === 'd' || e.key === 'D') {
+        if (selectedClipId && (e.metaKey || e.ctrlKey)) {
+          e.preventDefault();
+          handleDuplicate();
+        }
+      } else if (e.key === 'Delete' || e.key === 'Backspace') {
+        if (selectedClipId) {
+          e.preventDefault();
+          handleDelete();
+        }
+      }
+    };
+
+    window.addEventListener('keydown', handleKeyDown);
+    return () => window.removeEventListener('keydown', handleKeyDown);
+  }, [selectedClipId, handleSplit, handleDuplicate, handleDelete, setSelectedClipId]);
+
+  // Add global mouse listeners for trimming
+  useEffect(() => {
+    if (trimmingItem) {
+      window.addEventListener('mousemove', handleTrimMove);
+      window.addEventListener('mouseup', handleTrimEnd);
+      return () => {
+        window.removeEventListener('mousemove', handleTrimMove);
+        window.removeEventListener('mouseup', handleTrimEnd);
+      };
+    }
+  }, [trimmingItem, handleTrimMove, handleTrimEnd]);
+
   const handleDragStart = (
     e: React.MouseEvent,
     item: StoryItemDetail
@@ -251,7 +539,7 @@ export function StoryTrackEditor({ storyId, items }: StoryTrackEditorProps) {
       x: rect.left - tracksRef.current.getBoundingClientRect().left + tracksRef.current.scrollLeft,
       y: rect.top - tracksRef.current.getBoundingClientRect().top,
     });
-    setDraggingItem(item.generation_id);
+    setDraggingItem(item.id);
   };
 
   const handleDragMove = useCallback(
@@ -273,7 +561,7 @@ export function StoryTrackEditor({ storyId, items }: StoryTrackEditorProps) {
       return;
     }
 
-    const item = items.find((i) => i.generation_id === draggingItem);
+    const item = items.find((i) => i.id === draggingItem);
     if (!item) {
       setDraggingItem(null);
       return;
@@ -292,7 +580,7 @@ export function StoryTrackEditor({ storyId, items }: StoryTrackEditorProps) {
       moveItem.mutate(
         {
           storyId,
-          generationId: item.generation_id,
+          itemId: item.id,
           data: {
             start_time_ms: newTimeMs,
             track: newTrack,
@@ -302,7 +590,7 @@ export function StoryTrackEditor({ storyId, items }: StoryTrackEditorProps) {
           onError: (error) => {
             toast({
               title: 'Failed to move item',
-              description: error.message,
+              description: error instanceof Error ? error.message : String(error),
               variant: 'destructive',
             });
           },
@@ -318,9 +606,10 @@ export function StoryTrackEditor({ storyId, items }: StoryTrackEditorProps) {
 
   // Calculate clip position and dimensions
   const getClipStyle = (item: StoryItemDetail) => {
-    const isDragging = draggingItem === item.generation_id;
+    const isDragging = draggingItem === item.id;
     const trackIndex = getTrackIndex(item.track);
-    const width = msToPixels(item.duration * 1000);
+    const effectiveDuration = getEffectiveDuration(item);
+    const width = msToPixels(effectiveDuration);
     const left = isDragging ? dragPosition.x : msToPixels(item.start_time_ms);
     const top = isDragging ? dragPosition.y : trackIndex * TRACK_HEIGHT;
 
@@ -375,6 +664,39 @@ export function StoryTrackEditor({ storyId, items }: StoryTrackEditorProps) {
           </span>
         </div>
 
+        {/* Clip editing controls - center */}
+        {selectedClipId && (
+          <div className="flex items-center gap-1">
+            <Button
+              variant="ghost"
+              size="icon"
+              className="h-7 w-7"
+              onClick={handleSplit}
+              title="Split at playhead (S)"
+            >
+              <Scissors className="h-4 w-4" />
+            </Button>
+            <Button
+              variant="ghost"
+              size="icon"
+              className="h-7 w-7"
+              onClick={handleDuplicate}
+              title="Duplicate (Cmd/Ctrl+D)"
+            >
+              <Copy className="h-4 w-4" />
+            </Button>
+            <Button
+              variant="ghost"
+              size="icon"
+              className="h-7 w-7"
+              onClick={handleDelete}
+              title="Delete (Delete/Backspace)"
+            >
+              <Trash2 className="h-4 w-4" />
+            </Button>
+          </div>
+        )}
+
         {/* Zoom controls - right side */}
         <div className="flex items-center gap-2">
           <span className="text-xs text-muted-foreground">Zoom:</span>
@@ -421,15 +743,18 @@ export function StoryTrackEditor({ storyId, items }: StoryTrackEditorProps) {
           onMouseUp={draggingItem ? handleDragEnd : undefined}
           onMouseLeave={draggingItem ? handleDragEnd : undefined}
         >
-          {/* Time ruler */}
-          <div
-            className="h-6 border-b bg-muted/20 sticky top-0 z-10"
+          {/* Time ruler - clickable to seek */}
+          <button
+            type="button"
+            className="h-6 border-b bg-muted/20 sticky top-0 z-10 cursor-pointer text-left"
             style={{ width: `${timelineWidth}px` }}
+            onClick={handleTimelineClick}
+            aria-label="Seek timeline"
           >
             {timeMarkers.map((ms) => (
               <div
                 key={ms}
-                className="absolute top-0 h-full flex flex-col justify-end"
+                className="absolute top-0 h-full flex flex-col justify-end pointer-events-none"
                 style={{ left: `${msToPixels(ms)}px` }}
               >
                 <div className="h-2 w-px bg-border" />
@@ -438,19 +763,19 @@ export function StoryTrackEditor({ storyId, items }: StoryTrackEditorProps) {
                 </span>
               </div>
             ))}
-          </div>
+          </button>
 
           {/* Tracks area */}
           <div
             className="relative"
             style={{ width: `${timelineWidth}px`, height: `${tracksAreaHeight}px` }}
           >
-            {/* Track backgrounds */}
+            {/* Track backgrounds - pointer-events-none to allow clicks to pass through */}
             {tracks.map((trackNumber, index) => (
               <div
                 key={trackNumber}
                 className={cn(
-                  'absolute left-0 right-0 border-b',
+                  'absolute left-0 right-0 border-b pointer-events-none',
                   index % 2 === 0 ? 'bg-background' : 'bg-muted/10'
                 )}
                 style={{
@@ -470,35 +795,83 @@ export function StoryTrackEditor({ storyId, items }: StoryTrackEditorProps) {
 
           {/* Audio clips */}
           {items.map((item) => {
-            const isDragging = draggingItem === item.generation_id;
-            const style = getClipStyle(item);
-            const clipWidth = msToPixels(item.duration * 1000);
+            const isDragging = draggingItem === item.id;
+            const isSelected = selectedClipId === item.id;
+            const isTrimming = trimmingItem === item.id;
+            
+            // Use temporary trim values during trimming for visual feedback
+            const displayTrimStart = isTrimming && tempTrimValues ? tempTrimValues.trim_start_ms : (item.trim_start_ms || 0);
+            const displayTrimEnd = isTrimming && tempTrimValues ? tempTrimValues.trim_end_ms : (item.trim_end_ms || 0);
+            const effectiveDuration = (item.duration * 1000) - displayTrimStart - displayTrimEnd;
+            
+            const style = getClipStyle({ ...item, trim_start_ms: displayTrimStart, trim_end_ms: displayTrimEnd });
+            const clipWidth = msToPixels(effectiveDuration);
 
             return (
-              <button
-                type="button"
-                key={item.generation_id}
+              <div
+                key={item.id}
                 className={cn(
-                  'absolute rounded cursor-move select-none overflow-hidden z-10',
-                  'bg-accent/80 hover:bg-accent border border-accent-foreground/20',
-                  'flex flex-col justify-center',
-                  isDragging && 'opacity-80 shadow-lg z-20',
-                  !isDragging && 'transition-all duration-100'
+                  'absolute rounded select-none overflow-visible z-10',
+                  isSelected && 'ring-2 ring-primary ring-offset-1',
+                  isTrimming && 'ring-2 ring-accent'
                 )}
                 style={style}
-                onMouseDown={(e) => handleDragStart(e, item)}
               >
-                {/* Clip label */}
-                <div className="absolute top-0 left-1 right-1 z-10">
-                  <p className="text-[9px] font-medium text-accent-foreground truncate">
-                    {item.profile_name}
-                  </p>
-                </div>
-                {/* Waveform */}
-                <div className="absolute inset-0 top-3">
-                  <ClipWaveform generationId={item.generation_id} width={clipWidth} />
-                </div>
-              </button>
+                <button
+                  type="button"
+                  className={cn(
+                    'w-full h-full rounded cursor-move overflow-hidden',
+                    'bg-accent/80 hover:bg-accent border border-accent-foreground/20',
+                    'flex flex-col justify-center',
+                    isDragging && 'opacity-80 shadow-lg z-20',
+                    !isDragging && 'transition-all duration-100'
+                  )}
+                  onClick={(e) => handleClipClick(e, item)}
+                  onMouseDown={(e) => {
+                    // Only start drag if not clicking on trim handles
+                    if (!(e.target as HTMLElement).closest('.trim-handle')) {
+                      handleDragStart(e, item);
+                    }
+                  }}
+                >
+                  {/* Clip label */}
+                  <div className="absolute top-0 left-1 right-1 z-10">
+                    <p className="text-[9px] font-medium text-accent-foreground truncate">
+                      {item.profile_name}
+                    </p>
+                  </div>
+                  {/* Waveform */}
+                  <div className="absolute inset-0 top-3">
+                    <ClipWaveform 
+                      generationId={item.generation_id} 
+                      width={clipWidth}
+                      trimStartMs={displayTrimStart}
+                      trimEndMs={displayTrimEnd}
+                      duration={item.duration}
+                    />
+                  </div>
+                </button>
+                
+                {/* Trim handles */}
+                {isSelected && (
+                  <>
+                    {/* Left trim handle */}
+                    <button
+                      type="button"
+                      className="trim-handle absolute left-0 top-0 bottom-0 w-2 cursor-ew-resize hover:bg-primary/30 bg-primary/20 z-30 rounded-l"
+                      onMouseDown={(e) => handleTrimStart(e, item, 'start')}
+                      aria-label="Trim start"
+                    />
+                    {/* Right trim handle */}
+                    <button
+                      type="button"
+                      className="trim-handle absolute right-0 top-0 bottom-0 w-2 cursor-ew-resize hover:bg-primary/30 bg-primary/20 z-30 rounded-r"
+                      onMouseDown={(e) => handleTrimStart(e, item, 'end')}
+                      aria-label="Trim end"
+                    />
+                  </>
+                )}
+              </div>
             );
           })}
 

app/src/lib/api/client.ts

@@ -21,6 +21,8 @@ import type {
   StoryItemBatchUpdate,
   StoryItemReorder,
   StoryItemMove,
+  StoryItemTrim,
+  StoryItemSplit,
 } from './types';
 
 class ApiClient {
@@ -406,8 +408,8 @@ class ApiClient {
     });
   }
 
-  async removeStoryItem(storyId: string, generationId: string): Promise<void> {
-    await this.request<void>(`/stories/${storyId}/items/${generationId}`, {
+  async removeStoryItem(storyId: string, itemId: string): Promise<void> {
+    await this.request<void>(`/stories/${storyId}/items/${itemId}`, {
       method: 'DELETE',
     });
   }
@@ -426,13 +428,33 @@ class ApiClient {
     });
   }
 
-  async moveStoryItem(storyId: string, generationId: string, data: StoryItemMove): Promise<StoryItemDetail> {
-    return this.request<StoryItemDetail>(`/stories/${storyId}/items/${generationId}/move`, {
+  async moveStoryItem(storyId: string, itemId: string, data: StoryItemMove): Promise<StoryItemDetail> {
+    return this.request<StoryItemDetail>(`/stories/${storyId}/items/${itemId}/move`, {
       method: 'PUT',
       body: JSON.stringify(data),
     });
   }
 
+  async trimStoryItem(storyId: string, itemId: string, data: StoryItemTrim): Promise<StoryItemDetail> {
+    return this.request<StoryItemDetail>(`/stories/${storyId}/items/${itemId}/trim`, {
+      method: 'PUT',
+      body: JSON.stringify(data),
+    });
+  }
+
+  async splitStoryItem(storyId: string, itemId: string, data: StoryItemSplit): Promise<StoryItemDetail[]> {
+    return this.request<StoryItemDetail[]>(`/stories/${storyId}/items/${itemId}/split`, {
+      method: 'POST',
+      body: JSON.stringify(data),
+    });
+  }
+
+  async duplicateStoryItem(storyId: string, itemId: string): Promise<StoryItemDetail> {
+    return this.request<StoryItemDetail>(`/stories/${storyId}/items/${itemId}/duplicate`, {
+      method: 'POST',
+    });
+  }
+
   async exportStoryAudio(storyId: string): Promise<Blob> {
     const url = `${this.getBaseUrl()}/stories/${storyId}/export-audio`;
     const response = await fetch(url);

app/src/lib/api/types.ts

@@ -144,6 +144,8 @@ export interface StoryItemDetail {
   generation_id: string;
   start_time_ms: number;
   track: number;
+  trim_start_ms: number;
+  trim_end_ms: number;
   created_at: string;
   profile_id: string;
   profile_name: string;
@@ -188,3 +190,12 @@ export interface StoryItemMove {
   start_time_ms: number;
   track: number;
 }
+
+export interface StoryItemTrim {
+  trim_start_ms: number;
+  trim_end_ms: number;
+}
+
+export interface StoryItemSplit {
+  split_time_ms: number;
+}

app/src/lib/hooks/useStories.ts

@@ -1,6 +1,6 @@
 import { useMutation, useQuery, useQueryClient } from '@tanstack/react-query';
 import { apiClient } from '@/lib/api/client';
-import type { StoryCreate, StoryItemCreate, StoryItemBatchUpdate, StoryItemReorder, StoryItemMove } from '@/lib/api/types';
+import type { StoryCreate, StoryItemCreate, StoryItemBatchUpdate, StoryItemReorder, StoryItemMove, StoryItemTrim, StoryItemSplit } from '@/lib/api/types';
 import { isTauri } from '@/lib/tauri';
 
 export function useStories() {
@@ -70,8 +70,8 @@ export function useRemoveStoryItem() {
   const queryClient = useQueryClient();
 
   return useMutation({
-    mutationFn: ({ storyId, generationId }: { storyId: string; generationId: string }) =>
-      apiClient.removeStoryItem(storyId, generationId),
+    mutationFn: ({ storyId, itemId }: { storyId: string; itemId: string }) =>
+      apiClient.removeStoryItem(storyId, itemId),
     onSuccess: (_, variables) => {
       queryClient.invalidateQueries({ queryKey: ['stories'] });
       queryClient.invalidateQueries({ queryKey: ['stories', variables.storyId] });
@@ -109,8 +109,47 @@ export function useMoveStoryItem() {
   const queryClient = useQueryClient();
 
   return useMutation({
-    mutationFn: ({ storyId, generationId, data }: { storyId: string; generationId: string; data: StoryItemMove }) =>
-      apiClient.moveStoryItem(storyId, generationId, data),
+    mutationFn: ({ storyId, itemId, data }: { storyId: string; itemId: string; data: StoryItemMove }) =>
+      apiClient.moveStoryItem(storyId, itemId, data),
+    onSuccess: (_, variables) => {
+      queryClient.invalidateQueries({ queryKey: ['stories'] });
+      queryClient.invalidateQueries({ queryKey: ['stories', variables.storyId] });
+    },
+  });
+}
+
+export function useTrimStoryItem() {
+  const queryClient = useQueryClient();
+
+  return useMutation({
+    mutationFn: ({ storyId, itemId, data }: { storyId: string; itemId: string; data: StoryItemTrim }) =>
+      apiClient.trimStoryItem(storyId, itemId, data),
+    onSuccess: (_, variables) => {
+      queryClient.invalidateQueries({ queryKey: ['stories'] });
+      queryClient.invalidateQueries({ queryKey: ['stories', variables.storyId] });
+    },
+  });
+}
+
+export function useSplitStoryItem() {
+  const queryClient = useQueryClient();
+
+  return useMutation({
+    mutationFn: ({ storyId, itemId, data }: { storyId: string; itemId: string; data: StoryItemSplit }) =>
+      apiClient.splitStoryItem(storyId, itemId, data),
+    onSuccess: (_, variables) => {
+      queryClient.invalidateQueries({ queryKey: ['stories'] });
+      queryClient.invalidateQueries({ queryKey: ['stories', variables.storyId] });
+    },
+  });
+}
+
+export function useDuplicateStoryItem() {
+  const queryClient = useQueryClient();
+
+  return useMutation({
+    mutationFn: ({ storyId, itemId }: { storyId: string; itemId: string }) =>
+      apiClient.duplicateStoryItem(storyId, itemId),
     onSuccess: (_, variables) => {
       queryClient.invalidateQueries({ queryKey: ['stories'] });
       queryClient.invalidateQueries({ queryKey: ['stories', variables.storyId] });

app/src/lib/hooks/useStoryPlayback.ts

@@ -5,6 +5,7 @@ import { useStoryStore } from '@/stores/storyStore';
 
 interface ActiveSource {
   source: AudioBufferSourceNode;
+  itemId: string;
   generationId: string;
   startTimeMs: number;
   endTimeMs: number;
@@ -26,9 +27,9 @@ export function useStoryPlayback(items: StoryItemDetail[] | undefined) {
   const audioContextRef = useRef<AudioContext | null>(null);
   // Master gain for volume control
   const masterGainRef = useRef<GainNode | null>(null);
-  // Preloaded AudioBuffers by generation_id
+  // Preloaded AudioBuffers by generation_id (audio file is shared between split clips)
   const audioBuffersRef = useRef<Map<string, AudioBuffer>>(new Map());
-  // Currently playing AudioBufferSourceNodes by generation_id
+  // Currently playing AudioBufferSourceNodes by item.id (unique per clip)
   const activeSourcesRef = useRef<Map<string, ActiveSource>>(new Map());
   // Animation frame for syncing visual playhead
   const animationFrameRef = useRef<number | null>(null);
@@ -56,16 +57,16 @@ export function useStoryPlayback(items: StoryItemDetail[] | undefined) {
     return audioContextRef.current;
   }, []);
 
-  // Stop a source
-  const stopSource = useCallback((generationId: string) => {
-    const activeSource = activeSourcesRef.current.get(generationId);
+  // Stop a source by item id
+  const stopSource = useCallback((itemId: string) => {
+    const activeSource = activeSourcesRef.current.get(itemId);
     if (activeSource) {
       try {
         activeSource.source.stop();
       } catch {
         // Source may have already stopped
       }
-      activeSourcesRef.current.delete(generationId);
+      activeSourcesRef.current.delete(itemId);
     }
   }, []);
 
@@ -123,8 +124,8 @@ export function useStoryPlayback(items: StoryItemDetail[] | undefined) {
   useEffect(() => {
     return () => {
       // Stop all sources
-      for (const [generationId] of activeSourcesRef.current) {
-        stopSource(generationId);
+      for (const [itemId] of activeSourcesRef.current) {
+        stopSource(itemId);
       }
       activeSourcesRef.current.clear();
 
@@ -151,7 +152,11 @@ export function useStoryPlayback(items: StoryItemDetail[] | undefined) {
     (storyTimeMs: number, itemList: StoryItemDetail[]): StoryItemDetail[] => {
       return itemList.filter((item) => {
         const itemStart = item.start_time_ms;
-        const itemEnd = item.start_time_ms + item.duration * 1000;
+        // Use effective duration (accounting for trims)
+        const trimStartMs = item.trim_start_ms || 0;
+        const trimEndMs = item.trim_end_ms || 0;
+        const effectiveDurationMs = item.duration * 1000 - trimStartMs - trimEndMs;
+        const itemEnd = item.start_time_ms + effectiveDurationMs;
         return storyTimeMs >= itemStart && storyTimeMs < itemEnd;
       });
     },
@@ -185,8 +190,8 @@ export function useStoryPlayback(items: StoryItemDetail[] | undefined) {
   // Stop all sources
   const stopAllSources = useCallback(() => {
     console.log('[StoryPlayback] Stopping all sources');
-    for (const [generationId] of activeSourcesRef.current) {
-      stopSource(generationId);
+    for (const [itemId] of activeSourcesRef.current) {
+      stopSource(itemId);
     }
     activeSourcesRef.current.clear();
   }, [stopSource]);
@@ -199,18 +204,18 @@ export function useStoryPlayback(items: StoryItemDetail[] | undefined) {
 
       // Find all items that should be playing
       const shouldBePlaying = findActiveItems(storyTimeMs, itemList);
-      const shouldBePlayingIds = new Set(shouldBePlaying.map((item) => item.generation_id));
+      const shouldBePlayingIds = new Set(shouldBePlaying.map((item) => item.id));
 
       // Stop sources that shouldn't be playing anymore
-      for (const [generationId] of activeSourcesRef.current) {
-        if (!shouldBePlayingIds.has(generationId)) {
-          stopSource(generationId);
+      for (const [itemId] of activeSourcesRef.current) {
+        if (!shouldBePlayingIds.has(itemId)) {
+          stopSource(itemId);
         }
       }
 
       // Schedule new sources for items that should be playing
       for (const item of shouldBePlaying) {
-        if (!activeSourcesRef.current.has(item.generation_id)) {
+        if (!activeSourcesRef.current.has(item.id)) {
           const buffer = audioBuffersRef.current.get(item.generation_id);
           if (!buffer) {
             console.warn('[StoryPlayback] Buffer not loaded for:', item.generation_id);
@@ -219,16 +224,24 @@ export function useStoryPlayback(items: StoryItemDetail[] | undefined) {
 
           // Calculate when this item should start in AudioContext time
           const itemStartContextTime = storyTimeToContextTime(item.start_time_ms);
-          const itemEndStoryTime = item.start_time_ms + item.duration * 1000;
+          
+          // Calculate effective duration and trim offsets
+          const trimStartSec = (item.trim_start_ms || 0) / 1000;
+          const trimEndSec = (item.trim_end_ms || 0) / 1000;
+          const effectiveDuration = item.duration - trimStartSec - trimEndSec;
+          const itemEndStoryTime = item.start_time_ms + effectiveDuration * 1000;
 
           // Calculate offset into the buffer (if seeking mid-way)
-          const offsetIntoBuffer = Math.max(0, (storyTimeMs - item.start_time_ms) / 1000);
-          const duration = item.duration - offsetIntoBuffer;
+          // Offset is relative to the trimmed start of the clip
+          const offsetIntoEffectiveClip = Math.max(0, (storyTimeMs - item.start_time_ms) / 1000);
+          const offsetIntoBuffer = trimStartSec + offsetIntoEffectiveClip;
+          const duration = effectiveDuration - offsetIntoEffectiveClip;
 
           // If the item should have already started, schedule it to start immediately
           const startAtContextTime = Math.max(currentContextTime, itemStartContextTime);
 
           console.log('[StoryPlayback] Scheduling source:', {
+            itemId: item.id,
             generationId: item.generation_id,
             storyTimeMs,
             itemStart: item.start_time_ms,
@@ -243,20 +256,21 @@ export function useStoryPlayback(items: StoryItemDetail[] | undefined) {
 
           const activeSource: ActiveSource = {
             source,
+            itemId: item.id,
             generationId: item.generation_id,
             startTimeMs: item.start_time_ms,
             endTimeMs: itemEndStoryTime,
           };
 
-          activeSourcesRef.current.set(item.generation_id, activeSource);
+          activeSourcesRef.current.set(item.id, activeSource);
 
           // Schedule playback
           source.start(startAtContextTime, offsetIntoBuffer, duration);
 
           // Clean up when source ends
           source.onended = () => {
-            console.log('[StoryPlayback] Source ended:', item.generation_id);
-            activeSourcesRef.current.delete(item.generation_id);
+            console.log('[StoryPlayback] Source ended:', item.id);
+            activeSourcesRef.current.delete(item.id);
           };
         }
       }

app/src/stores/storyStore.ts

@@ -5,6 +5,8 @@ interface StoryPlaybackState {
   // Selection
   selectedStoryId: string | null;
   setSelectedStoryId: (id: string | null) => void;
+  selectedClipId: string | null;
+  setSelectedClipId: (id: string | null) => void;
 
   // Track editor UI state
   trackEditorHeight: number;
@@ -34,6 +36,8 @@ export const useStoryStore = create<StoryPlaybackState>((set, get) => ({
   // Selection
   selectedStoryId: null,
   setSelectedStoryId: (id) => set({ selectedStoryId: id }),
+  selectedClipId: null,
+  setSelectedClipId: (id) => set({ selectedClipId: id }),
 
   // Track editor UI state
   trackEditorHeight: DEFAULT_TRACK_EDITOR_HEIGHT,

backend/database.py

@@ -71,6 +71,8 @@ class StoryItem(Base):
     generation_id = Column(String, ForeignKey("generations.id"), nullable=False)
     start_time_ms = Column(Integer, nullable=False, default=0)  # Milliseconds from story start
     track = Column(Integer, nullable=False, default=0)  # Track number (0 = main track)
+    trim_start_ms = Column(Integer, nullable=False, default=0)  # Milliseconds trimmed from start
+    trim_end_ms = Column(Integer, nullable=False, default=0)  # Milliseconds trimmed from end
     created_at = Column(DateTime, default=datetime.utcnow)
 
 
@@ -256,6 +258,24 @@ def _run_migrations(engine):
             conn.execute(text("ALTER TABLE story_items ADD COLUMN track INTEGER NOT NULL DEFAULT 0"))
             conn.commit()
             print("Added track column to story_items")
+    
+    # Migration: Add trim columns if they don't exist
+    # Re-check columns after potential track migration
+    columns = {col['name'] for col in inspector.get_columns('story_items')}
+    if 'trim_start_ms' not in columns:
+        print("Migrating story_items: adding trim_start_ms column")
+        with engine.connect() as conn:
+            conn.execute(text("ALTER TABLE story_items ADD COLUMN trim_start_ms INTEGER NOT NULL DEFAULT 0"))
+            conn.commit()
+            print("Added trim_start_ms column to story_items")
+    
+    columns = {col['name'] for col in inspector.get_columns('story_items')}
+    if 'trim_end_ms' not in columns:
+        print("Migrating story_items: adding trim_end_ms column")
+        with engine.connect() as conn:
+            conn.execute(text("ALTER TABLE story_items ADD COLUMN trim_end_ms INTEGER NOT NULL DEFAULT 0"))
+            conn.commit()
+            print("Added trim_end_ms column to story_items")
 
 
 def get_db():

backend/main.py

@@ -770,14 +770,14 @@ async def add_story_item(
     return item
 
 
-@app.delete("/stories/{story_id}/items/{generation_id}")
+@app.delete("/stories/{story_id}/items/{item_id}")
 async def remove_story_item(
     story_id: str,
-    generation_id: str,
+    item_id: str,
     db: Session = Depends(get_db),
 ):
-    """Remove a generation from a story."""
-    success = await stories.remove_item_from_story(story_id, generation_id, db)
+    """Remove a story item from a story."""
+    success = await stories.remove_item_from_story(story_id, item_id, db)
     if not success:
         raise HTTPException(status_code=404, detail="Story item not found")
     return {"message": "Item removed successfully"}
@@ -809,15 +809,56 @@ async def reorder_story_items(
     return items
 
 
-@app.put("/stories/{story_id}/items/{generation_id}/move", response_model=models.StoryItemDetail)
+@app.put("/stories/{story_id}/items/{item_id}/move", response_model=models.StoryItemDetail)
 async def move_story_item(
     story_id: str,
-    generation_id: str,
+    item_id: str,
     data: models.StoryItemMove,
     db: Session = Depends(get_db),
 ):
     """Move a story item (update position and/or track)."""
-    item = await stories.move_story_item(story_id, generation_id, data, db)
+    item = await stories.move_story_item(story_id, item_id, data, db)
+    if item is None:
+        raise HTTPException(status_code=404, detail="Story item not found")
+    return item
+
+
+@app.put("/stories/{story_id}/items/{item_id}/trim", response_model=models.StoryItemDetail)
+async def trim_story_item(
+    story_id: str,
+    item_id: str,
+    data: models.StoryItemTrim,
+    db: Session = Depends(get_db),
+):
+    """Trim a story item (update trim_start_ms and trim_end_ms)."""
+    item = await stories.trim_story_item(story_id, item_id, data, db)
+    if item is None:
+        raise HTTPException(status_code=404, detail="Story item not found or invalid trim values")
+    return item
+
+
+@app.post("/stories/{story_id}/items/{item_id}/split", response_model=List[models.StoryItemDetail])
+async def split_story_item(
+    story_id: str,
+    item_id: str,
+    data: models.StoryItemSplit,
+    db: Session = Depends(get_db),
+):
+    """Split a story item at a given time, creating two clips."""
+    items = await stories.split_story_item(story_id, item_id, data, db)
+    if items is None:
+        raise HTTPException(status_code=404, detail="Story item not found or invalid split point")
+    return items
+
+
+@app.post("/stories/{story_id}/items/{item_id}/duplicate", response_model=models.StoryItemDetail)
+async def duplicate_story_item(
+    story_id: str,
+    item_id: str,
+    db: Session = Depends(get_db),
+):
+    """Duplicate a story item, creating a copy with all properties."""
+    item = await stories.duplicate_story_item(story_id, item_id, db)
     if item is None:
         raise HTTPException(status_code=404, detail="Story item not found")
     return item

backend/models.py

@@ -221,6 +221,8 @@ class StoryItemDetail(BaseModel):
     generation_id: str
     start_time_ms: int
     track: int = 0
+    trim_start_ms: int = 0
+    trim_end_ms: int = 0
     created_at: datetime
     # Generation details
     profile_id: str
@@ -277,3 +279,14 @@ class StoryItemMove(BaseModel):
     """Request model for moving a story item (position and/or track)."""
     start_time_ms: int = Field(..., ge=0)
     track: int = 0
+
+
+class StoryItemTrim(BaseModel):
+    """Request model for trimming a story item."""
+    trim_start_ms: int = Field(..., ge=0)
+    trim_end_ms: int = Field(..., ge=0)
+
+
+class StoryItemSplit(BaseModel):
+    """Request model for splitting a story item."""
+    split_time_ms: int = Field(..., ge=0)  # Time within the clip to split at (relative to clip start)

backend/stories.py

@@ -18,6 +18,8 @@ from .models import (
     StoryItemCreate,
     StoryItemBatchUpdate,
     StoryItemMove,
+    StoryItemTrim,
+    StoryItemSplit,
 )
 from .database import Story as DBStory, StoryItem as DBStoryItem, Generation as DBGeneration, VoiceProfile as DBVoiceProfile
 from .utils.audio import load_audio, save_audio
@@ -129,6 +131,8 @@ async def get_story(
             generation_id=item.generation_id,
             start_time_ms=item.start_time_ms,
             track=item.track,
+            trim_start_ms=getattr(item, 'trim_start_ms', 0),
+            trim_end_ms=getattr(item, 'trim_end_ms', 0),
             created_at=item.created_at,
             profile_id=generation.profile_id,
             profile_name=profile_name,
@@ -252,6 +256,8 @@ async def add_item_to_story(
             generation_id=existing.generation_id,
             start_time_ms=existing.start_time_ms,
             track=existing.track,
+            trim_start_ms=getattr(existing, 'trim_start_ms', 0),
+            trim_end_ms=getattr(existing, 'trim_end_ms', 0),
             created_at=existing.created_at,
             profile_id=generation.profile_id,
             profile_name=profile.name if profile else "Unknown",
@@ -321,6 +327,8 @@ async def add_item_to_story(
         generation_id=item.generation_id,
         start_time_ms=item.start_time_ms,
         track=item.track,
+        trim_start_ms=getattr(item, 'trim_start_ms', 0),
+        trim_end_ms=getattr(item, 'trim_end_ms', 0),
         created_at=item.created_at,
         profile_id=generation.profile_id,
         profile_name=profile.name if profile else "Unknown",
@@ -336,7 +344,7 @@ async def add_item_to_story(
 
 async def move_story_item(
     story_id: str,
-    generation_id: str,
+    item_id: str,
     data: StoryItemMove,
     db: Session,
 ) -> Optional[StoryItemDetail]:
@@ -345,7 +353,7 @@ async def move_story_item(
 
     Args:
         story_id: Story ID
-        generation_id: Generation ID of the item to move
+        item_id: Story item ID
         data: New position and track data
         db: Database session
 
@@ -354,14 +362,14 @@ async def move_story_item(
     """
     # Get the item
     item = db.query(DBStoryItem).filter_by(
+        id=item_id,
         story_id=story_id,
-        generation_id=generation_id
     ).first()
     if not item:
         return None
 
     # Get the generation
-    generation = db.query(DBGeneration).filter_by(id=generation_id).first()
+    generation = db.query(DBGeneration).filter_by(id=item.generation_id).first()
     if not generation:
         return None
 
@@ -386,6 +394,8 @@ async def move_story_item(
         generation_id=item.generation_id,
         start_time_ms=item.start_time_ms,
         track=item.track,
+        trim_start_ms=getattr(item, 'trim_start_ms', 0),
+        trim_end_ms=getattr(item, 'trim_end_ms', 0),
         created_at=item.created_at,
         profile_id=generation.profile_id,
         profile_name=profile.name if profile else "Unknown",
@@ -401,23 +411,23 @@ async def move_story_item(
 
 async def remove_item_from_story(
     story_id: str,
-    generation_id: str,
+    item_id: str,
     db: Session,
 ) -> bool:
     """
-    Remove a generation from a story.
+    Remove a story item from a story.
 
     Args:
         story_id: Story ID
-        generation_id: Generation ID to remove
+        item_id: Story item ID to remove
         db: Database session
 
     Returns:
         True if removed, False if not found
     """
     item = db.query(DBStoryItem).filter_by(
+        id=item_id,
         story_id=story_id,
-        generation_id=generation_id
     ).first()
     if not item:
         return False
@@ -434,6 +444,277 @@ async def remove_item_from_story(
     return True
 
 
+async def trim_story_item(
+    story_id: str,
+    item_id: str,
+    data: StoryItemTrim,
+    db: Session,
+) -> Optional[StoryItemDetail]:
+    """
+    Trim a story item (update trim_start_ms and trim_end_ms).
+
+    Args:
+        story_id: Story ID
+        item_id: Story item ID
+        data: Trim data (trim_start_ms, trim_end_ms)
+        db: Database session
+
+    Returns:
+        Updated item detail or None if not found
+    """
+    # Get the item
+    item = db.query(DBStoryItem).filter_by(
+        id=item_id,
+        story_id=story_id,
+    ).first()
+    if not item:
+        return None
+
+    # Get the generation
+    generation = db.query(DBGeneration).filter_by(id=item.generation_id).first()
+    if not generation:
+        return None
+
+    # Validate trim values don't exceed duration
+    max_duration_ms = int(generation.duration * 1000)
+    if data.trim_start_ms + data.trim_end_ms >= max_duration_ms:
+        return None  # Invalid trim - would result in zero or negative duration
+
+    # Update trim values
+    item.trim_start_ms = data.trim_start_ms
+    item.trim_end_ms = data.trim_end_ms
+
+    # Update story updated_at
+    story = db.query(DBStory).filter_by(id=story_id).first()
+    if story:
+        story.updated_at = datetime.utcnow()
+
+    db.commit()
+    db.refresh(item)
+
+    # Get profile name
+    profile = db.query(DBVoiceProfile).filter_by(id=generation.profile_id).first()
+
+    return StoryItemDetail(
+        id=item.id,
+        story_id=item.story_id,
+        generation_id=item.generation_id,
+        start_time_ms=item.start_time_ms,
+        track=item.track,
+        trim_start_ms=item.trim_start_ms,
+        trim_end_ms=item.trim_end_ms,
+        created_at=item.created_at,
+        profile_id=generation.profile_id,
+        profile_name=profile.name if profile else "Unknown",
+        text=generation.text,
+        language=generation.language,
+        audio_path=generation.audio_path,
+        duration=generation.duration,
+        seed=generation.seed,
+        instruct=generation.instruct,
+        generation_created_at=generation.created_at,
+    )
+
+
+async def split_story_item(
+    story_id: str,
+    item_id: str,
+    data: StoryItemSplit,
+    db: Session,
+) -> Optional[List[StoryItemDetail]]:
+    """
+    Split a story item at a given time, creating two clips.
+
+    Args:
+        story_id: Story ID
+        item_id: Story item ID to split
+        data: Split data (split_time_ms - time within clip to split at)
+        db: Database session
+
+    Returns:
+        List of two updated item details (original and new) or None if not found/invalid
+    """
+    # Get the item
+    item = db.query(DBStoryItem).filter_by(
+        id=item_id,
+        story_id=story_id,
+    ).first()
+    if not item:
+        return None
+
+    # Get the generation
+    generation = db.query(DBGeneration).filter_by(id=item.generation_id).first()
+    if not generation:
+        return None
+
+    # Calculate effective duration and validate split point
+    current_trim_start = getattr(item, 'trim_start_ms', 0)
+    current_trim_end = getattr(item, 'trim_end_ms', 0)
+    original_duration_ms = int(generation.duration * 1000)
+    effective_duration_ms = original_duration_ms - current_trim_start - current_trim_end
+
+    # Validate split_time_ms is within the effective duration
+    if data.split_time_ms <= 0 or data.split_time_ms >= effective_duration_ms:
+        return None  # Invalid split point
+
+    # Calculate the absolute time in the original audio where we're splitting
+    absolute_split_ms = current_trim_start + data.split_time_ms
+
+    # Update original clip: trim from the end
+    item.trim_end_ms = original_duration_ms - absolute_split_ms
+
+    # Create new clip: starts after the split, trimmed from the start
+    new_item = DBStoryItem(
+        id=str(uuid.uuid4()),
+        story_id=story_id,
+        generation_id=item.generation_id,  # Same generation, different trim
+        start_time_ms=item.start_time_ms + data.split_time_ms,
+        track=item.track,
+        trim_start_ms=absolute_split_ms,
+        trim_end_ms=current_trim_end,
+        created_at=datetime.utcnow(),
+    )
+
+    db.add(new_item)
+
+    # Update story updated_at
+    story = db.query(DBStory).filter_by(id=story_id).first()
+    if story:
+        story.updated_at = datetime.utcnow()
+
+    db.commit()
+    db.refresh(item)
+    db.refresh(new_item)
+
+    # Get profile name
+    profile = db.query(DBVoiceProfile).filter_by(id=generation.profile_id).first()
+    profile_name = profile.name if profile else "Unknown"
+
+    # Build response items
+    original_item_detail = StoryItemDetail(
+        id=item.id,
+        story_id=item.story_id,
+        generation_id=item.generation_id,
+        start_time_ms=item.start_time_ms,
+        track=item.track,
+        trim_start_ms=item.trim_start_ms,
+        trim_end_ms=item.trim_end_ms,
+        created_at=item.created_at,
+        profile_id=generation.profile_id,
+        profile_name=profile_name,
+        text=generation.text,
+        language=generation.language,
+        audio_path=generation.audio_path,
+        duration=generation.duration,
+        seed=generation.seed,
+        instruct=generation.instruct,
+        generation_created_at=generation.created_at,
+    )
+
+    new_item_detail = StoryItemDetail(
+        id=new_item.id,
+        story_id=new_item.story_id,
+        generation_id=new_item.generation_id,
+        start_time_ms=new_item.start_time_ms,
+        track=new_item.track,
+        trim_start_ms=new_item.trim_start_ms,
+        trim_end_ms=new_item.trim_end_ms,
+        created_at=new_item.created_at,
+        profile_id=generation.profile_id,
+        profile_name=profile_name,
+        text=generation.text,
+        language=generation.language,
+        audio_path=generation.audio_path,
+        duration=generation.duration,
+        seed=generation.seed,
+        instruct=generation.instruct,
+        generation_created_at=generation.created_at,
+    )
+
+    return [original_item_detail, new_item_detail]
+
+
+async def duplicate_story_item(
+    story_id: str,
+    item_id: str,
+    db: Session,
+) -> Optional[StoryItemDetail]:
+    """
+    Duplicate a story item, creating a copy with all properties.
+
+    Args:
+        story_id: Story ID
+        item_id: Story item ID to duplicate
+        db: Database session
+
+    Returns:
+        New item detail or None if not found
+    """
+    # Get the original item
+    original_item = db.query(DBStoryItem).filter_by(
+        id=item_id,
+        story_id=story_id,
+    ).first()
+    if not original_item:
+        return None
+
+    # Get the generation
+    generation = db.query(DBGeneration).filter_by(id=original_item.generation_id).first()
+    if not generation:
+        return None
+
+    # Calculate effective duration
+    current_trim_start = getattr(original_item, 'trim_start_ms', 0)
+    current_trim_end = getattr(original_item, 'trim_end_ms', 0)
+    original_duration_ms = int(generation.duration * 1000)
+    effective_duration_ms = original_duration_ms - current_trim_start - current_trim_end
+
+    # Create duplicate item - place it right after the original
+    new_item = DBStoryItem(
+        id=str(uuid.uuid4()),
+        story_id=story_id,
+        generation_id=original_item.generation_id,  # Same generation as original
+        start_time_ms=original_item.start_time_ms + effective_duration_ms + 200,  # 200ms gap
+        track=original_item.track,
+        trim_start_ms=current_trim_start,
+        trim_end_ms=current_trim_end,
+        created_at=datetime.utcnow(),
+    )
+
+    db.add(new_item)
+
+    # Update story updated_at
+    story = db.query(DBStory).filter_by(id=story_id).first()
+    if story:
+        story.updated_at = datetime.utcnow()
+
+    db.commit()
+    db.refresh(new_item)
+
+    # Get profile name
+    profile = db.query(DBVoiceProfile).filter_by(id=generation.profile_id).first()
+
+    return StoryItemDetail(
+        id=new_item.id,
+        story_id=new_item.story_id,
+        generation_id=new_item.generation_id,
+        start_time_ms=new_item.start_time_ms,
+        track=new_item.track,
+        trim_start_ms=new_item.trim_start_ms,
+        trim_end_ms=new_item.trim_end_ms,
+        created_at=new_item.created_at,
+        profile_id=generation.profile_id,
+        profile_name=profile.name if profile else "Unknown",
+        text=generation.text,
+        language=generation.language,
+        audio_path=generation.audio_path,
+        duration=generation.duration,
+        seed=generation.seed,
+        instruct=generation.instruct,
+        generation_created_at=generation.created_at,
+    )
+
+
 async def update_story_item_times(
     story_id: str,
     data: StoryItemBatchUpdate,
@@ -538,6 +819,8 @@ async def reorder_story_items(
             generation_id=item.generation_id,
             start_time_ms=item.start_time_ms,
             track=item.track,
+            trim_start_ms=getattr(item, 'trim_start_ms', 0),
+            trim_end_ms=getattr(item, 'trim_end_ms', 0),
             created_at=item.created_at,
             profile_id=generation.profile_id,
             profile_name=profile_name,
@@ -602,14 +885,31 @@ async def export_story_audio(
             audio, sr = load_audio(str(audio_path), sample_rate=sample_rate)
             sample_rate = sr  # Use actual sample rate from first file
             
+            # Get trim values
+            trim_start_ms = getattr(item, 'trim_start_ms', 0)
+            trim_end_ms = getattr(item, 'trim_end_ms', 0)
+            
+            # Calculate effective duration
+            original_duration_ms = int(generation.duration * 1000)
+            effective_duration_ms = original_duration_ms - trim_start_ms - trim_end_ms
+            
+            # Slice audio based on trim values
+            trim_start_sample = int((trim_start_ms / 1000.0) * sample_rate)
+            trim_end_sample = int((trim_end_ms / 1000.0) * sample_rate)
+            
+            # Extract the trimmed portion
+            if trim_end_ms > 0:
+                trimmed_audio = audio[trim_start_sample:-trim_end_sample] if trim_end_sample > 0 else audio[trim_start_sample:]
+            else:
+                trimmed_audio = audio[trim_start_sample:]
+            
             # Store audio with its timecode info
             start_time_ms = item.start_time_ms
-            duration_ms = int(generation.duration * 1000)
             
             audio_data.append({
-                'audio': audio,
+                'audio': trimmed_audio,
                 'start_time_ms': start_time_ms,
-                'duration_ms': duration_ms,
+                'duration_ms': effective_duration_ms,
             })
         except Exception:
             # Skip files that can't be loaded

tauri/src-tauri/Cargo.lock

@@ -4840,7 +4840,7 @@ checksum = "0b928f33d975fc6ad9f86c8f283853ad26bdd5b10b7f1542aa2fa15e2289105a"
 
 [[package]]
 name = "voicebox"
-version = "0.1.5"
+version = "0.1.6"
 dependencies = [
  "base64 0.22.1",
  "core-foundation-sys",