diff --git a/apps/api/internal/runner/param_processor.go b/apps/api/internal/runner/param_processor.go
index 621a574..3bf9550 100644
--- a/apps/api/internal/runner/param_processor.go
+++ b/apps/api/internal/runner/param_processor.go
@@ -1478,7 +1478,7 @@ func isVideoResolution(modelType string, value string) bool {
 }
 
 func isVideoModelType(modelType string) bool {
-	return modelType == "video_generate" || modelType == "text_to_video" || modelType == "image_to_video" || modelType == "video_edit" || modelType == "omni_video" || modelType == "omni"
+	return modelType == "video_generate" || modelType == "text_to_video" || modelType == "image_to_video" || modelType == "video_edit" || modelType == "video_reference" || modelType == "video_first_last_frame" || modelType == "omni_video" || modelType == "omni"
 }
 
 func cloneMap(values map[string]any) map[string]any {
diff --git a/apps/api/internal/runner/service.go b/apps/api/internal/runner/service.go
index 288e169..116da1a 100644
--- a/apps/api/internal/runner/service.go
+++ b/apps/api/internal/runner/service.go
@@ -687,7 +687,7 @@ func requestedModelTypeFromBody(body map[string]any) string {
 
 func isKnownModelType(value string) bool {
 	switch value {
-	case "text_generate", "image_generate", "image_edit", "video_generate", "image_to_video", "text_to_video", "video_edit", "omni_video", "omni":
+	case "text_generate", "image_generate", "image_edit", "video_generate", "image_to_video", "text_to_video", "video_edit", "video_reference", "video_first_last_frame", "omni_video", "omni":
 		return true
 	default:
 		return false
diff --git a/apps/web/src/api.ts b/apps/web/src/api.ts
index 74e8f8f..664ac20 100644
--- a/apps/web/src/api.ts
+++ b/apps/web/src/api.ts
@@ -668,8 +668,12 @@ export async function createVideoGenerationTask(
     audio?: boolean;
     audioUrl?: string | string[];
     audio_url?: string | string[];
+    capabilityType?: string;
     content?: Array<Record<string, unknown>>;
+    firstFrame?: string;
+    first_frame?: string;
     model: string;
+    model_type?: string;
     prompt: string;
     aspect_ratio?: string;
     count?: number;
@@ -681,6 +685,8 @@ export async function createVideoGenerationTask(
     image_url?: string | string[];
     imageUrls?: string[];
     image_urls?: string[];
+    lastFrame?: string;
+    last_frame?: string;
     n?: number;
     output_audio?: boolean;
     referenceAudio?: string | string[];
diff --git a/apps/web/src/pages/PlaygroundPage.tsx b/apps/web/src/pages/PlaygroundPage.tsx
index 0ab04b0..cd26a68 100644
--- a/apps/web/src/pages/PlaygroundPage.tsx
+++ b/apps/web/src/pages/PlaygroundPage.tsx
@@ -19,10 +19,15 @@ import { code } from '@streamdown/code';
 import { math } from '@streamdown/math';
 import { mermaid } from '@streamdown/mermaid';
 import type { GatewayApiKey, GatewayTask, PlatformModel } from '@easyai-ai-gateway/contracts';
-import { Bot, ChevronDown, FileText, Image as ImageIcon, LoaderCircle, MessageSquarePlus, Music2, Paperclip, Send, Sparkles, Video, X } from 'lucide-react';
+import { Bot, ChevronDown, FileText, Image as ImageIcon, LoaderCircle, MessageSquarePlus, Music2, Paperclip, Plus, Repeat2, Send, Sparkles, Video, X } from 'lucide-react';
 import { Badge, Button, Select, Textarea } from '../components/ui';
 import { GatewayApiError, createImageEditTask, createImageGenerationTask, createVideoGenerationTask, pollTaskUntilSettled, streamChatCompletionText, taskIsPending, uploadFileToStorage } from '../api';
 import type { PlaygroundMode } from '../types';
+import {
+  PlaygroundPromptMentionInput,
+  removeInvalidPlaygroundResourceTokens,
+  replacePlaygroundResourceTokens,
+} from './playground-prompt-mention';
 import {
   defaultMediaGenerationSettings,
   deriveMediaModelCapabilities,
@@ -59,6 +64,7 @@ interface ModelOption {
 }
 
 type PlaygroundUploadKind = 'audio' | 'file' | 'image' | 'video';
+type PlaygroundUploadRole = 'first_frame' | 'last_frame';
 
 interface PlaygroundUpload {
   contentType: string;
@@ -66,6 +72,7 @@ interface PlaygroundUpload {
   kind: PlaygroundUploadKind;
   name: string;
   raw: Record<string, unknown>;
+  role?: PlaygroundUploadRole;
   size: number;
   url: string;
 }
@@ -95,6 +102,7 @@ const quickPrompts: Record<PlaygroundMode, string[]> = {
 };
 
 const mediaUploadAccept = 'image/*,video/*,audio/*';
+const imageOnlyUploadAccept = 'image/*';
 const chatUploadAccept = [
   mediaUploadAccept,
   '.csv',
@@ -167,7 +175,9 @@ export function PlaygroundPage(props: {
   const pendingMediaModelRef = useRef('');
   const resumedTaskIdsRef = useRef(new Set<string>());
   const activeMode = useMemo(() => modeOptions.find((item) => item.value === props.mode) ?? modeOptions[0], [props.mode]);
+  const mediaUploadAcceptValue = mediaUploadAcceptForMode(props.mode, videoMode);
   const effectiveImageHasReference = imageHasReference || (props.mode === 'image' && mediaUploads.some((item) => item.kind === 'image'));
+  const mediaUploadSignature = useMemo(() => mediaUploads.map((item) => `${item.id}:${item.kind}:${item.role ?? ''}`).join('|'), [mediaUploads]);
   const modelOptions = useMemo(
     () => buildModelOptions(filterModelsForMode(props.models, props.mode, effectiveImageHasReference, videoMode)),
     [effectiveImageHasReference, props.mode, props.models, videoMode],
@@ -215,7 +225,31 @@ export function PlaygroundPage(props: {
     writeStoredMediaRuns(mediaRuns);
   }, [mediaRuns]);
 
-  async function uploadMediaFiles(files: File[]) {
+  useEffect(() => {
+    if (props.mode === 'chat') return;
+    setPrompt((current) => removeInvalidPlaygroundResourceTokens(current, mediaUploads));
+  }, [mediaUploadSignature, props.mode]);
+
+  useEffect(() => {
+    if (props.mode === 'image') {
+      setMediaUploads((current) => current.some((item) => item.kind !== 'image') ? current.filter((item) => item.kind === 'image') : current);
+      return;
+    }
+    if (props.mode === 'video' && videoMode === 'first_last_frame') {
+      setMediaUploads((current) => normalizeFirstLastFrameUploads(current));
+    }
+  }, [props.mode, videoMode]);
+
+  useEffect(() => {
+    if (props.mode !== 'video') return;
+    setVideoMode((current) => {
+      if (mediaUploads.length > 0 && current === 'text_to_video') return 'omni_reference';
+      if (mediaUploads.length === 0 && current === 'omni_reference') return 'text_to_video';
+      return current;
+    });
+  }, [mediaUploads.length, props.mode]);
+
+  async function uploadMediaFiles(files: File[], targetRole?: PlaygroundUploadRole) {
     if (!files.length) return;
     const credential = activeApiKeySecret || props.token;
     if (!props.token) {
@@ -231,15 +265,19 @@ export function PlaygroundPage(props: {
     try {
       const { items, warnings } = await uploadPlaygroundFiles(credential, files, {
         allowFiles: false,
+        allowedKinds: allowedMediaUploadKinds(props.mode, videoMode),
         source: `ai-gateway-playground-${props.mode}`,
       });
       if (items.length) {
-        setMediaUploads((current) => [...current, ...items]);
+        setMediaUploads((current) => mergeMediaUploadsForMode(current, items, props.mode, videoMode, targetRole));
         if (props.mode === 'image' && items.some((item) => item.kind === 'image')) {
           setImageHasReference(true);
         }
+        if (props.mode === 'video' && videoMode === 'text_to_video') {
+          setVideoMode('omni_reference');
+        }
       }
-      setMediaUploadMessage(warnings[0] ?? (items.length ? `已上传 ${items.length} 个参考素材。` : ''));
+      setMediaUploadMessage(warnings[0] ?? '');
     } catch (err) {
       setMediaUploadMessage(err instanceof Error ? err.message : '文件上传失败');
     } finally {
@@ -305,7 +343,8 @@ export function PlaygroundPage(props: {
 
     const localId = newLocalId();
     const runUploads = overrides ? [] : mediaUploads;
-    const modelLabel = modelOptions.find((item) => item.value === runModel)?.label ?? runModel;
+    const runModelOption = modelOptions.find((item) => item.value === runModel);
+    const modelLabel = runModelOption?.label ?? runModel;
     const run: MediaGenerationRun = {
       createdAt: new Date().toISOString(),
       localId,
@@ -320,11 +359,13 @@ export function PlaygroundPage(props: {
     setMediaRuns((current) => [...current, run]);
     setMediaMessage('');
     try {
-      const uploadPayload = mediaUploadRequestPayload(runUploads, runMode);
+      const requestPrompt = replacePlaygroundResourceTokens(trimmedPrompt, runUploads, runMode);
+      const uploadPayload = mediaUploadRequestPayload(runUploads, runMode, videoMode);
       const requestPayload = {
         model: runModel,
-        prompt: promptWithUploadSummary(trimmedPrompt, runUploads),
+        prompt: requestPrompt,
         ...mediaRequestPayload(runSettings, runMode),
+        ...videoModeRequestPayload(runMode, videoMode, runUploads, runModelOption),
         ...uploadPayload,
       };
       const response = runMode === 'video'
@@ -415,7 +456,7 @@ export function PlaygroundPage(props: {
       imageHasReference={effectiveImageHasReference}
       mediaSettings={mediaSettings}
       mediaCapabilities={mediaCapabilities}
-      uploadAccept={mediaUploadAccept}
+      uploadAccept={mediaUploadAcceptValue}
       uploadMessage={mediaUploadMessage}
       uploads={mediaUploads}
       uploading={mediaUploading}
@@ -434,8 +475,9 @@ export function PlaygroundPage(props: {
         }
         return next;
       })}
+      onSwapFrameUploads={() => setMediaUploads((current) => swapFirstLastFrameUploads(current))}
       onSubmit={() => void submitMediaTask()}
-      onUploadFiles={(files) => void uploadMediaFiles(files)}
+      onUploadFiles={(files, targetRole) => void uploadMediaFiles(files, targetRole)}
       onVideoModeChange={setVideoMode}
     />
   );
@@ -1120,34 +1162,64 @@ function Composer(props: {
   onModelChange: (value: string) => void;
   onPromptChange: (value: string) => void;
   onRemoveUpload?: (id: string) => void;
+  onSwapFrameUploads?: () => void;
   onSubmit?: () => void;
-  onUploadFiles?: (files: File[]) => void;
+  onUploadFiles?: (files: File[], targetRole?: PlaygroundUploadRole) => void;
   onVideoModeChange?: (value: VideoCreateMode) => void;
 }) {
   const quickItems = quickPrompts[props.mode];
   const apiKeyNotice = props.apiKeys && props.apiKeySecretsById ? apiKeyNoticeText(props.apiKeys, props.apiKeySecretsById) : '';
+  const hasMediaReferencePicker = props.mode !== 'chat' && Boolean(props.onUploadFiles);
+  const mediaReferenceMessage = hasMediaReferencePicker
+    ? props.uploadMessage || mediaUploadSummaryMessage(props.uploads ?? [], props.mode, props.videoMode ?? 'text_to_video')
+    : props.uploadMessage;
   return (
     <div className={props.compact ? 'playgroundComposer compact' : 'playgroundComposer'}>
-      <div className="composerBody">
-        <ComposerUploadButton
-          accept={props.uploadAccept ?? mediaUploadAccept}
-          active={Boolean(props.uploads?.length) || props.imageHasReference === true}
-          disabled={!props.onUploadFiles}
-          uploading={props.uploading}
-          onFiles={props.onUploadFiles}
-        />
-        <div className="composerInputStack">
-          <Textarea
-            size={props.compact ? 'sm' : 'md'}
-            value={props.prompt}
-            placeholder={placeholderByMode[props.mode]}
-            onChange={(event) => props.onPromptChange(event.target.value)}
-          />
-          <UploadAttachmentList
-            message={props.uploadMessage}
+      <div className={hasMediaReferencePicker ? 'composerBody composerBodyWithReferences' : 'composerBody'} data-frame-mode={props.mode === 'video' && props.videoMode === 'first_last_frame'}>
+        {hasMediaReferencePicker ? (
+          <MediaReferencePicker
+            accept={props.uploadAccept ?? mediaUploadAccept}
+            mode={props.mode as Exclude<PlaygroundMode, 'chat'>}
             uploads={props.uploads ?? []}
+            uploading={props.uploading}
+            videoMode={props.videoMode ?? 'text_to_video'}
+            onFiles={props.onUploadFiles}
             onRemove={props.onRemoveUpload}
+            onSwapFrames={props.onSwapFrameUploads}
           />
+        ) : (
+          <ComposerUploadButton
+            accept={props.uploadAccept ?? mediaUploadAccept}
+            active={Boolean(props.uploads?.length) || props.imageHasReference === true}
+            disabled={!props.onUploadFiles}
+            uploading={props.uploading}
+            onFiles={props.onUploadFiles}
+          />
+        )}
+        <div className="composerInputStack">
+          {hasMediaReferencePicker ? (
+            <PlaygroundPromptMentionInput
+              value={props.prompt}
+              placeholder={mediaPromptPlaceholder(props.mode)}
+              uploads={props.uploads ?? []}
+              onChange={props.onPromptChange}
+            />
+          ) : (
+            <Textarea
+              size={props.compact ? 'sm' : 'md'}
+              value={props.prompt}
+              placeholder={placeholderByMode[props.mode]}
+              onChange={(event) => props.onPromptChange(event.target.value)}
+            />
+          )}
+          {!hasMediaReferencePicker && (
+            <UploadAttachmentList
+              message={props.uploadMessage}
+              uploads={props.uploads ?? []}
+              onRemove={props.onRemoveUpload}
+            />
+          )}
+          {hasMediaReferencePicker && mediaReferenceMessage && <div className="composerUploadMessage">{mediaReferenceMessage}</div>}
         </div>
       </div>
       <div className="composerFooter">
@@ -1235,6 +1307,260 @@ function ComposerUploadButton(props: {
   );
 }
 
+function MediaReferencePicker(props: {
+  accept: string;
+  mode: Exclude<PlaygroundMode, 'chat'>;
+  uploads: PlaygroundUpload[];
+  uploading?: boolean;
+  videoMode: VideoCreateMode;
+  onFiles?: (files: File[], targetRole?: PlaygroundUploadRole) => void;
+  onRemove?: (id: string) => void;
+  onSwapFrames?: () => void;
+}) {
+  if (props.mode === 'video' && props.videoMode === 'first_last_frame') {
+    return (
+      <FirstLastFramePicker
+        accept={props.accept}
+        uploads={props.uploads}
+        uploading={props.uploading}
+        onFiles={props.onFiles}
+        onRemove={props.onRemove}
+        onSwapFrames={props.onSwapFrames}
+      />
+    );
+  }
+  return (
+    <StackedReferencePicker
+      accept={props.accept}
+      uploads={props.uploads}
+      uploading={props.uploading}
+      onFiles={props.onFiles}
+      onRemove={props.onRemove}
+    />
+  );
+}
+
+function StackedReferencePicker(props: {
+  accept: string;
+  uploads: PlaygroundUpload[];
+  uploading?: boolean;
+  onFiles?: (files: File[]) => void;
+  onRemove?: (id: string) => void;
+}) {
+  const inputRef = useRef<HTMLInputElement>(null);
+  const [hoveredId, setHoveredId] = useState('');
+  const [expanded, setExpanded] = useState(false);
+  const hoveredUpload = props.uploads.find((item) => item.id === hoveredId);
+  const disabled = props.uploading || !props.onFiles;
+  const uploadCardIndex = props.uploads.length;
+
+  return (
+    <div
+      className="mediaReferenceStack"
+      data-expanded={expanded}
+      onMouseLeave={() => {
+        setExpanded(false);
+        setHoveredId('');
+      }}
+    >
+      {hoveredUpload && <div className="mediaReferenceTooltip">{hoveredUpload.name}</div>}
+      <div
+        className="mediaReferenceStackCards"
+        data-empty={!props.uploads.length}
+        style={{ '--reference-count': Math.max(1, props.uploads.length + 1) } as React.CSSProperties}
+      >
+        {props.uploads.map((item, index) => (
+          <div
+            className="mediaReferenceCard"
+            data-hovered={hoveredId === item.id}
+            data-kind={item.kind}
+            key={item.id}
+            style={referenceCardStyle(index)}
+            title={item.name}
+            onMouseEnter={() => {
+              setExpanded(true);
+              setHoveredId(item.id);
+            }}
+          >
+            <ReferencePreview item={item} />
+            {item.kind === 'video' && <span className="mediaReferenceDuration">视频</span>}
+            {props.onRemove && hoveredId === item.id && (
+              <button type="button" className="mediaReferenceRemove" aria-label={`删除 ${item.name}`} onClick={() => props.onRemove?.(item.id)}>
+                <X size={13} />
+              </button>
+            )}
+          </div>
+        ))}
+        <button
+          type="button"
+          className="mediaReferenceCard mediaReferenceUploadCard"
+          aria-label="追加参考资源"
+          data-has-uploads={props.uploads.length > 0}
+          data-uploading={Boolean(props.uploading)}
+          disabled={disabled}
+          style={referenceCardStyle(uploadCardIndex)}
+          title="追加参考资源"
+          onClick={() => inputRef.current?.click()}
+          onMouseEnter={() => setHoveredId('')}
+        >
+          {props.uploading ? <LoaderCircle className="composerUploadSpinner" size={18} /> : <Plus size={20} />}
+          <span>参考内容</span>
+        </button>
+        {props.uploads.length > 0 && (
+          <button
+            type="button"
+            className="mediaReferenceAdd"
+            aria-label="追加参考资源"
+            data-uploading={Boolean(props.uploading)}
+            disabled={disabled}
+            title="追加参考资源"
+            onClick={() => inputRef.current?.click()}
+            onMouseEnter={() => {
+              setExpanded(false);
+              setHoveredId('');
+            }}
+          >
+            {props.uploading ? <LoaderCircle className="composerUploadSpinner" size={15} /> : <Plus size={17} />}
+          </button>
+        )}
+      </div>
+      <input
+        ref={inputRef}
+        type="file"
+        multiple
+        hidden
+        accept={props.accept}
+        disabled={disabled}
+        onChange={(event) => {
+          const files = Array.from(event.currentTarget.files ?? []);
+          event.currentTarget.value = '';
+          props.onFiles?.(files);
+        }}
+      />
+    </div>
+  );
+}
+
+const referenceTiltValues = [-7, 6, -3, 8, -5, 4, -8, 5];
+const referenceXValues = [0, -5, 6, -3, 4, -6, 3, -4];
+const referenceYValues = [0, 3, -1, 4, 1, 5, 2, -2];
+
+function referenceCardStyle(index: number) {
+  const valueIndex = index % referenceTiltValues.length;
+  return {
+    '--reference-index': index,
+    '--reference-tilt': `${referenceTiltValues[valueIndex]}deg`,
+    '--reference-x': `${referenceXValues[valueIndex]}px`,
+    '--reference-y': `${referenceYValues[valueIndex]}px`,
+  } as React.CSSProperties;
+}
+
+function FirstLastFramePicker(props: {
+  accept: string;
+  uploads: PlaygroundUpload[];
+  uploading?: boolean;
+  onFiles?: (files: File[], targetRole?: PlaygroundUploadRole) => void;
+  onRemove?: (id: string) => void;
+  onSwapFrames?: () => void;
+}) {
+  const first = frameUploadByRole(props.uploads, 'first_frame');
+  const last = frameUploadByRole(props.uploads, 'last_frame');
+  const canSwap = Boolean(first && last);
+
+  return (
+    <div className="firstLastFramePicker">
+      <FrameSlot
+        accept={props.accept}
+        item={first}
+        label="首帧"
+        role="first_frame"
+        uploading={props.uploading}
+        onFiles={props.onFiles}
+        onRemove={props.onRemove}
+      />
+      <button type="button" className="frameSwapButton" aria-label="交换首尾帧" disabled={!canSwap} onClick={props.onSwapFrames}>
+        <Repeat2 size={19} />
+      </button>
+      <FrameSlot
+        accept={props.accept}
+        item={last}
+        label="尾帧"
+        role="last_frame"
+        uploading={props.uploading}
+        onFiles={props.onFiles}
+        onRemove={props.onRemove}
+      />
+    </div>
+  );
+}
+
+function FrameSlot(props: {
+  accept: string;
+  item?: PlaygroundUpload;
+  label: string;
+  role: PlaygroundUploadRole;
+  uploading?: boolean;
+  onFiles?: (files: File[], targetRole?: PlaygroundUploadRole) => void;
+  onRemove?: (id: string) => void;
+}) {
+  const inputRef = useRef<HTMLInputElement>(null);
+  const disabled = props.uploading || !props.onFiles;
+
+  return (
+    <div className="frameSlot">
+      <button
+        type="button"
+        className="frameSlotButton"
+        data-filled={Boolean(props.item)}
+        disabled={disabled}
+        title={props.item?.name ?? props.label}
+        onClick={() => inputRef.current?.click()}
+      >
+        {props.item ? <ReferencePreview item={props.item} /> : <Plus size={20} />}
+        <span>{props.label}</span>
+      </button>
+      {props.item && props.onRemove && (
+        <button type="button" className="frameSlotRemove" aria-label={`删除 ${props.label}`} onClick={() => props.onRemove?.(props.item!.id)}>
+          <X size={13} />
+        </button>
+      )}
+      <input
+        ref={inputRef}
+        type="file"
+        hidden
+        accept={props.accept}
+        disabled={disabled}
+        onChange={(event) => {
+          const files = Array.from(event.currentTarget.files ?? []);
+          event.currentTarget.value = '';
+          props.onFiles?.(files, props.role);
+        }}
+      />
+    </div>
+  );
+}
+
+function ReferencePreview(props: { item: PlaygroundUpload }) {
+  if (props.item.kind === 'image') {
+    return <img src={props.item.url} alt="" draggable={false} />;
+  }
+  if (props.item.kind === 'video') {
+    return <video src={props.item.url} muted playsInline preload="metadata" />;
+  }
+  if (props.item.kind === 'audio') {
+    return (
+      <span className="mediaReferencePlaceholder">
+        <Music2 size={18} />
+      </span>
+    );
+  }
+  return (
+    <span className="mediaReferencePlaceholder">
+      <FileText size={18} />
+    </span>
+  );
+}
+
 function UploadAttachmentList(props: {
   message?: string;
   uploads: PlaygroundUpload[];
@@ -1301,16 +1627,17 @@ function ApiKeySelect(props: {
 async function uploadPlaygroundFiles(
   token: string,
   files: File[],
-  options: { allowFiles: boolean; source: string },
+  options: { allowFiles: boolean; allowedKinds?: PlaygroundUploadKind[]; source: string },
 ): Promise<{ items: PlaygroundUpload[]; warnings: string[] }> {
+  const allowedKinds = options.allowedKinds ?? (options.allowFiles ? ['audio', 'file', 'image', 'video'] : ['audio', 'image', 'video']);
   const accepted: Array<{ file: File; kind: PlaygroundUploadKind }> = [];
   const warnings: string[] = [];
   files.forEach((file) => {
     const kind = acceptedUploadKind(file, options.allowFiles);
-    if (!kind) {
+    if (!kind || !allowedKinds.includes(kind)) {
       warnings.push(options.allowFiles
         ? `已跳过 ${file.name}，聊天仅支持图片、视频、音频和常见文档。`
-        : `已跳过 ${file.name}，当前场景仅支持图片、视频和音频。`);
+        : `已跳过 ${file.name}，当前场景仅支持${allowedUploadKindLabel(allowedKinds)}。`);
       return;
     }
     accepted.push({ file, kind });
@@ -1399,7 +1726,7 @@ function promptWithUploadSummary(prompt: string, uploads: PlaygroundUpload[]) {
   return `${prompt}\n\n参考附件：\n${lines.join('\n')}`;
 }
 
-function mediaUploadRequestPayload(uploads: PlaygroundUpload[], mode: Exclude<PlaygroundMode, 'chat'>) {
+function mediaUploadRequestPayload(uploads: PlaygroundUpload[], mode: Exclude<PlaygroundMode, 'chat'>, videoMode: VideoCreateMode) {
   const images = uploads.filter((item) => item.kind === 'image').map((item) => item.url);
   const videos = uploads.filter((item) => item.kind === 'video').map((item) => item.url);
   const audios = uploads.filter((item) => item.kind === 'audio').map((item) => item.url);
@@ -1411,19 +1738,25 @@ function mediaUploadRequestPayload(uploads: PlaygroundUpload[], mode: Exclude<Pl
     }
     return payload;
   }
+  if (videoMode === 'first_last_frame') {
+    const first = frameUploadByRole(uploads, 'first_frame');
+    const last = frameUploadByRole(uploads, 'last_frame');
+    if (first) {
+      payload.first_frame = first.url;
+    }
+    if (last) {
+      payload.last_frame = last.url;
+    }
+    return payload;
+  }
   if (images.length) {
-    payload.image = singleOrMany(images);
-    payload.image_url = images[0];
-    payload.images = images;
     payload.reference_image = singleOrMany(images);
   }
   if (videos.length) {
     payload.reference_video = singleOrMany(videos);
-    payload.video_url = videos[0];
   }
   if (audios.length) {
     payload.reference_audio = singleOrMany(audios);
-    payload.audio_url = audios[0];
   }
   return payload;
 }
@@ -1439,6 +1772,11 @@ function uploadKindLabel(kind: PlaygroundUploadKind) {
   return '文件';
 }
 
+function allowedUploadKindLabel(kinds: PlaygroundUploadKind[]) {
+  const labels = kinds.map(uploadKindLabel);
+  return labels.length ? labels.join('、') : '当前文件类型';
+}
+
 function formatFileSize(size: number) {
   if (!Number.isFinite(size) || size <= 0) return '';
   if (size < 1024) return `${size} B`;
@@ -1446,6 +1784,155 @@ function formatFileSize(size: number) {
   return `${(size / 1024 / 1024).toFixed(1)} MB`;
 }
 
+function mediaPromptPlaceholder(mode: PlaygroundMode) {
+  if (mode === 'image') return '输入画面描述，可用 @ 快速引用图片资源，例如：让 @图像 1 保持人物一致...';
+  if (mode === 'video') return '输入镜头、运动和风格，可用 @ 引用图片、视频或音频资源...';
+  return placeholderByMode.chat;
+}
+
+function mediaUploadAcceptForMode(mode: PlaygroundMode, videoMode: VideoCreateMode) {
+  if (mode === 'image') return imageOnlyUploadAccept;
+  if (mode === 'video' && videoMode === 'first_last_frame') return imageOnlyUploadAccept;
+  return mediaUploadAccept;
+}
+
+function allowedMediaUploadKinds(mode: PlaygroundMode, videoMode: VideoCreateMode): PlaygroundUploadKind[] {
+  if (mode === 'image') return ['image'];
+  if (mode === 'video' && videoMode === 'first_last_frame') return ['image'];
+  if (mode === 'video') return ['audio', 'image', 'video'];
+  return ['audio', 'file', 'image', 'video'];
+}
+
+function mediaUploadSummaryMessage(uploads: PlaygroundUpload[], mode: PlaygroundMode, videoMode: VideoCreateMode) {
+  if (!uploads.length) return '';
+  const images = uploads.filter((item) => item.kind === 'image').length;
+  const videos = uploads.filter((item) => item.kind === 'video').length;
+  const audios = uploads.filter((item) => item.kind === 'audio').length;
+  const files = uploads.filter((item) => item.kind === 'file').length;
+  if (mode === 'image') {
+    return `已上传 ${images} 张参考图。`;
+  }
+  if (mode === 'video' && videoMode === 'first_last_frame') {
+    const first = frameUploadByRole(uploads, 'first_frame');
+    const last = frameUploadByRole(uploads, 'last_frame');
+    if (first && last) return '已上传首帧、尾帧参考图。';
+    if (first) return '已上传首帧参考图。';
+    if (last) return '已上传尾帧参考图。';
+    return `已上传 ${images} 张首尾帧参考图。`;
+  }
+  const parts = [
+    images ? `${images} 张图片` : '',
+    videos ? `${videos} 个视频` : '',
+    audios ? `${audios} 段音频` : '',
+    files ? `${files} 个文件` : '',
+  ].filter(Boolean);
+  return parts.length ? `已上传 ${parts.join('、')}。` : '';
+}
+
+function mergeMediaUploadsForMode(
+  current: PlaygroundUpload[],
+  items: PlaygroundUpload[],
+  mode: PlaygroundMode,
+  videoMode: VideoCreateMode,
+  targetRole?: PlaygroundUploadRole,
+) {
+  if (mode === 'image') {
+    return [...current.filter((item) => item.kind === 'image'), ...items.filter((item) => item.kind === 'image')];
+  }
+  if (mode === 'video' && videoMode === 'first_last_frame') {
+    return mergeFirstLastFrameUploads(current, items, targetRole);
+  }
+  return [...current, ...items.filter((item) => item.kind === 'image' || item.kind === 'video' || item.kind === 'audio')];
+}
+
+function normalizeFirstLastFrameUploads(uploads: PlaygroundUpload[]) {
+  const images = uploads.filter((item) => item.kind === 'image');
+  if (!images.length) return uploads.length ? [] : uploads;
+  const first = frameUploadByRole(images, 'first_frame') ?? images[0];
+  const last = frameUploadByRole(images, 'last_frame') ?? images.find((item) => item.id !== first?.id);
+  const next: PlaygroundUpload[] = [];
+  if (first) next.push({ ...first, role: 'first_frame' });
+  if (last) next.push({ ...last, role: 'last_frame' });
+  return uploadListsEqual(uploads, next) ? uploads : next;
+}
+
+function mergeFirstLastFrameUploads(current: PlaygroundUpload[], items: PlaygroundUpload[], targetRole?: PlaygroundUploadRole) {
+  const incoming = items.filter((item) => item.kind === 'image');
+  let next = normalizeFirstLastFrameUploads(current);
+  if (!incoming.length) return next;
+  const assignUpload = (item: PlaygroundUpload, role: PlaygroundUploadRole) => {
+    next = next.filter((upload) => upload.role !== role);
+    next.push({ ...item, role });
+  };
+  if (targetRole) {
+    assignUpload(incoming[0]!, targetRole);
+    const oppositeRole: PlaygroundUploadRole = targetRole === 'first_frame' ? 'last_frame' : 'first_frame';
+    incoming.slice(1).forEach((item) => {
+      if (!frameUploadByRole(next, oppositeRole)) assignUpload(item, oppositeRole);
+    });
+    return sortFrameUploads(next);
+  }
+  incoming.forEach((item) => {
+    if (!frameUploadByRole(next, 'first_frame')) {
+      assignUpload(item, 'first_frame');
+    } else if (!frameUploadByRole(next, 'last_frame')) {
+      assignUpload(item, 'last_frame');
+    }
+  });
+  return sortFrameUploads(next);
+}
+
+function swapFirstLastFrameUploads(uploads: PlaygroundUpload[]) {
+  return sortFrameUploads(uploads.map((item) => {
+    if (item.role === 'first_frame') return { ...item, role: 'last_frame' as const };
+    if (item.role === 'last_frame') return { ...item, role: 'first_frame' as const };
+    return item;
+  }));
+}
+
+function sortFrameUploads(uploads: PlaygroundUpload[]) {
+  const first = frameUploadByRole(uploads, 'first_frame');
+  const last = frameUploadByRole(uploads, 'last_frame');
+  return [first, last].filter((item): item is PlaygroundUpload => Boolean(item));
+}
+
+function frameUploadByRole(uploads: PlaygroundUpload[], role: PlaygroundUploadRole) {
+  return uploads.find((item) => item.role === role);
+}
+
+function uploadListsEqual(left: PlaygroundUpload[], right: PlaygroundUpload[]) {
+  if (left.length !== right.length) return false;
+  return left.every((item, index) => {
+    const next = right[index];
+    return next && item.id === next.id && item.role === next.role && item.kind === next.kind;
+  });
+}
+
+function videoModeRequestPayload(
+  mode: Exclude<PlaygroundMode, 'chat'>,
+  videoMode: VideoCreateMode,
+  uploads: PlaygroundUpload[],
+  modelOption?: ModelOption,
+) {
+  if (mode !== 'video') return {};
+  const modelTypes = new Set(modelOption?.models.flatMap((model) => model.modelType) ?? []);
+  if (videoMode === 'first_last_frame') {
+    const modelType = modelTypes.has('video_first_last_frame') ? 'video_first_last_frame' : 'image_to_video';
+    return { capabilityType: modelType, model_type: modelType };
+  }
+  if (videoMode === 'omni_reference' || uploads.length > 0) {
+    const modelType = modelTypes.has('omni_video')
+      ? 'omni_video'
+      : modelTypes.has('video_reference')
+        ? 'video_reference'
+        : modelTypes.has('image_to_video')
+          ? 'image_to_video'
+          : 'video_generate';
+    return { capabilityType: modelType, model_type: modelType };
+  }
+  return {};
+}
+
 function filterModelsForMode(models: PlatformModel[], mode: PlaygroundMode, hasReference: boolean, videoMode: VideoCreateMode) {
   if (mode === 'chat') {
     return filterWithFallback(models, ['text_generate', 'chat', 'responses', 'text']);
@@ -1455,7 +1942,7 @@ function filterModelsForMode(models: PlatformModel[], mode: PlaygroundMode, hasR
     return filterWithFallback(models, [...preferredTypes, 'image']);
   }
   const videoTypesByMode: Record<VideoCreateMode, string[]> = {
-    first_last_frame: ['image_to_video', 'video_first_last_frame', 'video_generate'],
+    first_last_frame: ['video_first_last_frame', 'image_to_video', 'video_generate'],
     omni_reference: ['omni_video', 'video_reference', 'video_generate'],
     text_to_video: ['text_to_video', 'video_generate'],
   };
diff --git a/apps/web/src/pages/playground-prompt-mention.tsx b/apps/web/src/pages/playground-prompt-mention.tsx
new file mode 100644
index 0000000..9e022d5
--- /dev/null
+++ b/apps/web/src/pages/playground-prompt-mention.tsx
@@ -0,0 +1,554 @@
+import { useCallback, useEffect, useMemo, useRef, useState, type KeyboardEvent as ReactKeyboardEvent } from 'react';
+import { FileText, Music2, Video } from 'lucide-react';
+
+export type PlaygroundMentionUploadKind = 'audio' | 'file' | 'image' | 'video';
+
+export interface PlaygroundMentionUpload {
+  id: string;
+  kind: PlaygroundMentionUploadKind;
+  name: string;
+  url: string;
+}
+
+const resourceTokenPrefix = '<<<playground-resource:';
+const resourceTokenSuffix = '>>>';
+const resourceTokenPattern = /<<<playground-resource:([^>]+)>>>/g;
+const resourceTokenWithSpacePattern = /<<<playground-resource:([^>]+)>>>\s?/g;
+
+export function buildPlaygroundResourceToken(id: string) {
+  return `${resourceTokenPrefix}${id}${resourceTokenSuffix}`;
+}
+
+export function removeInvalidPlaygroundResourceTokens(raw: string, uploads: PlaygroundMentionUpload[]) {
+  if (!raw.includes(resourceTokenPrefix)) return raw;
+  const validIds = new Set(uploads.map((item) => item.id));
+  return raw.replace(resourceTokenWithSpacePattern, (full, id: string) => validIds.has(id) ? full : '');
+}
+
+export function replacePlaygroundResourceTokens(
+  raw: string,
+  uploads: PlaygroundMentionUpload[],
+  mode: 'image' | 'video',
+) {
+  if (!raw.includes(resourceTokenPrefix)) return raw;
+  const byId = new Map(uploads.map((item) => [item.id, item]));
+  return raw.replace(resourceTokenPattern, (full, id: string) => {
+    const item = byId.get(id);
+    if (!item) return '';
+    return resourcePromptLabel(item, uploads, mode);
+  });
+}
+
+export function PlaygroundPromptMentionInput(props: {
+  disabled?: boolean;
+  placeholder: string;
+  uploads: PlaygroundMentionUpload[];
+  value: string;
+  onChange: (value: string) => void;
+}) {
+  const editableRef = useRef<HTMLDivElement>(null);
+  const dropdownRef = useRef<HTMLDivElement>(null);
+  const blurTimerRef = useRef<number | undefined>(undefined);
+  const [text, setText] = useState(props.value);
+  const [focused, setFocused] = useState(false);
+  const [isComposing, setIsComposing] = useState(false);
+  const [mentionOpen, setMentionOpen] = useState(false);
+  const [mentionAtIndex, setMentionAtIndex] = useState(-1);
+  const [mentionSearch, setMentionSearch] = useState('');
+  const [highlightIndex, setHighlightIndex] = useState(0);
+  const [dropdownPosition, setDropdownPosition] = useState({ top: 0, left: 0, placement: 'bottom' as 'bottom' | 'top' });
+  const showPlaceholder = text.trim().length === 0;
+
+  const uploadSignature = useMemo(
+    () => props.uploads.map((item) => `${item.id}:${item.kind}:${item.name}:${item.url}`).join('|'),
+    [props.uploads],
+  );
+
+  const mentionItems = useMemo(() => props.uploads.map((item, index) => ({
+    item,
+    label: mentionDisplayLabel(item, props.uploads),
+    searchText: `${item.name} ${mentionDisplayLabel(item, props.uploads)} ${uploadKindChinese(item.kind)} ${index + 1}`.toLowerCase(),
+    token: buildPlaygroundResourceToken(item.id),
+  })), [props.uploads]);
+
+  const filteredMentionItems = useMemo(() => {
+    const keyword = mentionSearch.trim().toLowerCase();
+    if (!keyword) return mentionItems;
+    return mentionItems.filter((item) => item.searchText.includes(keyword));
+  }, [mentionItems, mentionSearch]);
+
+  useEffect(() => {
+    if (props.value === text) return;
+    setText(props.value);
+    if (!focused) {
+      requestAnimationFrame(() => renderToEditable(props.value));
+    }
+  }, [focused, props.value, text]);
+
+  useEffect(() => {
+    const cleaned = removeInvalidPlaygroundResourceTokens(text, props.uploads);
+    if (cleaned !== text) {
+      setText(cleaned);
+      props.onChange(cleaned);
+      requestAnimationFrame(() => renderToEditable(cleaned));
+      return;
+    }
+    if (!focused) {
+      requestAnimationFrame(() => renderToEditable(text));
+    }
+  }, [uploadSignature]);
+
+  useEffect(() => {
+    requestAnimationFrame(() => renderToEditable(text));
+    return () => {
+      if (blurTimerRef.current) window.clearTimeout(blurTimerRef.current);
+    };
+  }, []);
+
+  const updateMentionDropdownPosition = useCallback(() => {
+    const editable = editableRef.current;
+    const root = editable?.parentElement;
+    if (!editable || !root) return;
+    const rootRect = root.getBoundingClientRect();
+    const caretRect = getCaretClientRect(editable) ?? editable.getBoundingClientRect();
+    const dropdown = dropdownRef.current;
+    const viewportPadding = 8;
+    const gap = 6;
+    const dropdownWidth = Math.min(dropdown?.offsetWidth ?? 320, Math.max(180, window.innerWidth - viewportPadding * 2));
+    const dropdownHeight = Math.min(dropdown?.offsetHeight ?? 220, Math.max(120, window.innerHeight - viewportPadding * 2));
+    const minLeft = viewportPadding - rootRect.left;
+    const maxLeft = window.innerWidth - viewportPadding - dropdownWidth - rootRect.left;
+    const left = clamp(caretRect.left - rootRect.left, minLeft, Math.max(minLeft, maxLeft));
+    const belowTop = caretRect.bottom + gap;
+    const aboveTop = caretRect.top - dropdownHeight - gap;
+    const shouldOpenAbove = belowTop + dropdownHeight > window.innerHeight - viewportPadding && aboveTop >= viewportPadding;
+    const viewportTop = shouldOpenAbove
+      ? Math.max(viewportPadding, aboveTop)
+      : Math.min(belowTop, window.innerHeight - viewportPadding - dropdownHeight);
+    setDropdownPosition({
+      top: viewportTop - rootRect.top,
+      left,
+      placement: shouldOpenAbove ? 'top' : 'bottom',
+    });
+  }, []);
+
+  useEffect(() => {
+    if (!mentionOpen) return;
+    const frame = window.requestAnimationFrame(updateMentionDropdownPosition);
+    const handleViewportChange = () => updateMentionDropdownPosition();
+    window.addEventListener('resize', handleViewportChange);
+    window.addEventListener('scroll', handleViewportChange, true);
+    return () => {
+      window.cancelAnimationFrame(frame);
+      window.removeEventListener('resize', handleViewportChange);
+      window.removeEventListener('scroll', handleViewportChange, true);
+    };
+  }, [filteredMentionItems.length, mentionOpen, mentionSearch, updateMentionDropdownPosition]);
+
+  function renderToEditable(nextText = text, caret?: number) {
+    const editable = editableRef.current;
+    if (!editable) return;
+    editable.innerHTML = textToHtml(nextText, props.uploads);
+    if (typeof caret === 'number') {
+      editable.focus();
+      setCaretOffset(editable, caret);
+    }
+  }
+
+  function commitFromEditable(shouldInspectMention: boolean, event?: InputEvent) {
+    const editable = editableRef.current;
+    if (!editable || props.disabled || isComposing) return;
+    const nextText = serializeEditableToPlainText(editable);
+    setText(nextText);
+    props.onChange(nextText);
+    if (!shouldInspectMention) return;
+    inspectMentionTrigger(nextText, getCaretOffset(editable), event);
+  }
+
+  function inspectMentionTrigger(nextText: string, caret: number, event?: InputEvent) {
+    const beforeCaret = nextText.slice(0, caret);
+    const atIndex = Math.max(beforeCaret.lastIndexOf('@'), beforeCaret.lastIndexOf('＠'));
+    if (atIndex < 0) {
+      closeMention();
+      return;
+    }
+    const search = beforeCaret.slice(atIndex + 1);
+    if (/\s/.test(search)) {
+      closeMention();
+      return;
+    }
+    const inputData = event?.data ?? '';
+    if (!mentionOpen && search.length > 0 && inputData !== '@' && inputData !== '＠') {
+      closeMention();
+      return;
+    }
+    setMentionAtIndex(atIndex);
+    setMentionSearch(search);
+    setMentionOpen(true);
+    setHighlightIndex(0);
+    requestAnimationFrame(updateMentionDropdownPosition);
+  }
+
+  function closeMention() {
+    setMentionOpen(false);
+    setMentionSearch('');
+    setMentionAtIndex(-1);
+    setHighlightIndex(0);
+  }
+
+  function applyMention(token: string) {
+    const editable = editableRef.current;
+    if (!editable || mentionAtIndex < 0) return;
+    const currentText = serializeEditableToPlainText(editable);
+    const replaceEnd = Math.max(mentionAtIndex + 1, mentionAtIndex + 1 + mentionSearch.length);
+    const before = currentText.slice(0, mentionAtIndex);
+    const after = currentText.slice(replaceEnd);
+    const nextText = `${before}${token} ${after}`;
+    const nextCaret = before.length + token.length + 1;
+    setText(nextText);
+    props.onChange(nextText);
+    closeMention();
+    requestAnimationFrame(() => renderToEditable(nextText, nextCaret));
+  }
+
+  function handleKeyDown(event: ReactKeyboardEvent<HTMLDivElement>) {
+    if (props.disabled) {
+      event.preventDefault();
+      return;
+    }
+    if (!mentionOpen || !filteredMentionItems.length) return;
+    if (event.key === 'ArrowDown') {
+      event.preventDefault();
+      setHighlightIndex((current) => (current + 1) % filteredMentionItems.length);
+      return;
+    }
+    if (event.key === 'ArrowUp') {
+      event.preventDefault();
+      setHighlightIndex((current) => (current - 1 + filteredMentionItems.length) % filteredMentionItems.length);
+      return;
+    }
+    if (event.key === 'Enter') {
+      event.preventDefault();
+      const item = filteredMentionItems[Math.min(highlightIndex, filteredMentionItems.length - 1)];
+      if (item) applyMention(item.token);
+      return;
+    }
+    if (event.key === 'Escape') {
+      event.preventDefault();
+      closeMention();
+    }
+  }
+
+  return (
+    <div className="promptMentionInput">
+      <div
+        ref={editableRef}
+        className="promptMentionEditable"
+        contentEditable={!props.disabled}
+        role="textbox"
+        aria-label={props.placeholder}
+        aria-multiline="true"
+        suppressContentEditableWarning
+        onBlur={() => {
+          blurTimerRef.current = window.setTimeout(() => {
+            setFocused(false);
+            closeMention();
+            commitFromEditable(false);
+          }, 120);
+        }}
+        onCompositionEnd={() => {
+          setIsComposing(false);
+          requestAnimationFrame(() => commitFromEditable(true));
+        }}
+        onCompositionStart={() => setIsComposing(true)}
+        onFocus={() => {
+          setFocused(true);
+          if (blurTimerRef.current) window.clearTimeout(blurTimerRef.current);
+        }}
+        onInput={(event) => commitFromEditable(true, event.nativeEvent instanceof InputEvent ? event.nativeEvent : undefined)}
+        onKeyDown={handleKeyDown}
+        onPaste={(event) => {
+          if (props.disabled) return;
+          event.preventDefault();
+          const plainText = event.clipboardData.getData('text/plain');
+          document.execCommand('insertText', false, plainText);
+        }}
+      />
+      {showPlaceholder && <div className="promptMentionPlaceholder" aria-hidden="true">{props.placeholder}</div>}
+      {mentionOpen && (
+        <div
+          ref={dropdownRef}
+          className="promptMentionDropdown"
+          data-placement={dropdownPosition.placement}
+          style={{ left: dropdownPosition.left, top: dropdownPosition.top }}
+          onMouseDown={(event) => event.preventDefault()}
+        >
+          {filteredMentionItems.length ? (
+            filteredMentionItems.map((candidate, index) => (
+              <button
+                type="button"
+                className="promptMentionItem"
+                data-active={index === highlightIndex}
+                key={candidate.item.id}
+                onMouseEnter={() => setHighlightIndex(index)}
+                onMouseDown={(event) => {
+                  event.preventDefault();
+                  applyMention(candidate.token);
+                }}
+              >
+                <MentionThumb item={candidate.item} />
+                <span>
+                  <strong>{candidate.label}</strong>
+                  <small>{candidate.item.name}</small>
+                </span>
+                <em>{uploadKindChinese(candidate.item.kind)}</em>
+              </button>
+            ))
+          ) : (
+            <div className="promptMentionEmpty">暂无可引用资源</div>
+          )}
+        </div>
+      )}
+    </div>
+  );
+}
+
+function MentionThumb(props: { item: PlaygroundMentionUpload }) {
+  if (props.item.kind === 'image') {
+    return <img className="promptMentionThumb" src={props.item.url} alt="" draggable={false} />;
+  }
+  if (props.item.kind === 'video') {
+    return <video className="promptMentionThumb" src={props.item.url} muted playsInline preload="metadata" />;
+  }
+  if (props.item.kind === 'audio') {
+    return <Music2 className="promptMentionThumbIcon" size={16} />;
+  }
+  return <FileText className="promptMentionThumbIcon" size={16} />;
+}
+
+function textToHtml(raw: string, uploads: PlaygroundMentionUpload[]) {
+  const uploadById = new Map(uploads.map((item) => [item.id, item]));
+  const parts: string[] = [];
+  let lastIndex = 0;
+  let match: RegExpExecArray | null;
+  const re = new RegExp(resourceTokenPattern);
+  while ((match = re.exec(raw)) !== null) {
+    if (match.index > lastIndex) {
+      parts.push(escapeHtml(raw.slice(lastIndex, match.index)));
+    }
+    const token = match[0] ?? '';
+    const id = match[1] ?? '';
+    const item = uploadById.get(id);
+    parts.push(item ? mentionChipHtml(token, item, uploads) : '');
+    lastIndex = match.index + token.length;
+  }
+  if (lastIndex < raw.length) {
+    parts.push(escapeHtml(raw.slice(lastIndex)));
+  }
+  return parts.join('').replace(/\n/g, '<br>');
+}
+
+function mentionChipHtml(token: string, item: PlaygroundMentionUpload, uploads: PlaygroundMentionUpload[]) {
+  const label = mentionDisplayLabel(item, uploads);
+  const thumb = item.kind === 'image'
+    ? `<img class="promptMentionChipThumb" src="${escapeAttr(item.url)}" alt="" draggable="false">`
+    : item.kind === 'video'
+      ? `<video class="promptMentionChipThumb" src="${escapeAttr(item.url)}" muted preload="metadata" playsinline></video>`
+      : `<span class="promptMentionChipThumb promptMentionChipThumbPlaceholder">${escapeHtml(uploadKindShort(item.kind))}</span>`;
+  return `<span contenteditable="false" class="promptMentionChip" data-token="${escapeAttr(token)}">${thumb}<span>${escapeHtml(label)}</span></span>`;
+}
+
+function getCaretClientRect(editable: HTMLElement) {
+  const selection = document.getSelection();
+  if (!selection || selection.rangeCount === 0) return null;
+  const originalRange = selection.getRangeAt(0);
+  if (!editable.contains(originalRange.startContainer)) return null;
+  const collapsedRange = originalRange.cloneRange();
+  collapsedRange.collapse(true);
+  let rect = collapsedRange.getBoundingClientRect();
+  if (rect.width || rect.height) return rect;
+  const marker = document.createElement('span');
+  marker.textContent = '\u200b';
+  const restoreRange = originalRange.cloneRange();
+  collapsedRange.insertNode(marker);
+  rect = marker.getBoundingClientRect();
+  marker.remove();
+  selection.removeAllRanges();
+  selection.addRange(restoreRange);
+  return rect.width || rect.height ? rect : null;
+}
+
+function serializeEditableToPlainText(editable: HTMLElement) {
+  const parts: string[] = [];
+  const walk = (node: Node) => {
+    if (node.nodeType === Node.TEXT_NODE) {
+      parts.push(node.textContent ?? '');
+      return;
+    }
+    if (node.nodeType !== Node.ELEMENT_NODE) return;
+    const element = node as HTMLElement;
+    const token = element.getAttribute('data-token');
+    if (token) {
+      parts.push(token);
+      return;
+    }
+    if (element.tagName === 'BR') {
+      parts.push('\n');
+      return;
+    }
+    if (element.tagName === 'DIV' && parts.length && !parts[parts.length - 1]?.endsWith('\n')) {
+      parts.push('\n');
+    }
+    element.childNodes.forEach(walk);
+  };
+  editable.childNodes.forEach(walk);
+  return parts.join('');
+}
+
+function getCaretOffset(editable: HTMLElement) {
+  const selection = document.getSelection();
+  if (!selection || selection.rangeCount === 0) return 0;
+  const range = selection.getRangeAt(0);
+  let offset = 0;
+  const walk = (node: Node): boolean => {
+    if (node.nodeType === Node.TEXT_NODE) {
+      const textLength = (node.textContent ?? '').length;
+      if (node === range.startContainer) {
+        offset += range.startOffset;
+        return true;
+      }
+      offset += textLength;
+      return false;
+    }
+    if (node.nodeType !== Node.ELEMENT_NODE) return false;
+    const element = node as HTMLElement;
+    const token = element.getAttribute('data-token');
+    if (token) {
+      if (node === range.startContainer || element.contains(range.startContainer)) {
+        offset += range.startOffset > 0 ? token.length : 0;
+        return true;
+      }
+      offset += token.length;
+      return false;
+    }
+    if (element.tagName === 'BR') {
+      offset += 1;
+      return false;
+    }
+    for (const child of Array.from(element.childNodes)) {
+      if (walk(child)) return true;
+    }
+    return false;
+  };
+  for (const child of Array.from(editable.childNodes)) {
+    if (walk(child)) break;
+  }
+  return offset;
+}
+
+function setCaretOffset(editable: HTMLElement, targetOffset: number) {
+  const selection = document.getSelection();
+  if (!selection) return;
+  let offset = 0;
+  let targetNode: Node | null = null;
+  let targetNodeOffset = 0;
+  const walk = (node: Node): boolean => {
+    if (node.nodeType === Node.TEXT_NODE) {
+      const textLength = (node.textContent ?? '').length;
+      if (offset + textLength >= targetOffset) {
+        targetNode = node;
+        targetNodeOffset = Math.max(0, targetOffset - offset);
+        return true;
+      }
+      offset += textLength;
+      return false;
+    }
+    if (node.nodeType !== Node.ELEMENT_NODE) return false;
+    const element = node as HTMLElement;
+    const token = element.getAttribute('data-token');
+    if (token) {
+      if (offset + token.length >= targetOffset) {
+        targetNode = node;
+        targetNodeOffset = targetOffset <= offset ? 0 : 1;
+        return true;
+      }
+      offset += token.length;
+      return false;
+    }
+    if (element.tagName === 'BR') {
+      if (offset + 1 >= targetOffset) {
+        targetNode = node;
+        targetNodeOffset = 0;
+        return true;
+      }
+      offset += 1;
+      return false;
+    }
+    for (const child of Array.from(element.childNodes)) {
+      if (walk(child)) return true;
+    }
+    return false;
+  };
+  for (const child of Array.from(editable.childNodes)) {
+    if (walk(child)) break;
+  }
+  if (!targetNode) {
+    targetNode = editable;
+    targetNodeOffset = editable.childNodes.length;
+  }
+  const range = document.createRange();
+  range.setStart(targetNode, targetNode.nodeType === Node.TEXT_NODE ? targetNodeOffset : Math.min(targetNodeOffset, targetNode.childNodes.length));
+  range.collapse(true);
+  selection.removeAllRanges();
+  selection.addRange(range);
+}
+
+function mentionDisplayLabel(item: PlaygroundMentionUpload, uploads: PlaygroundMentionUpload[]) {
+  return `@${uploadKindChinese(item.kind)} ${uploadKindIndex(item, uploads)}`;
+}
+
+function resourcePromptLabel(item: PlaygroundMentionUpload, uploads: PlaygroundMentionUpload[], mode: 'image' | 'video') {
+  const kind = mode === 'image' ? 'image' : uploadKindEnglish(item.kind);
+  return `${kind} ${uploadKindIndex(item, uploads)}`;
+}
+
+function uploadKindIndex(item: PlaygroundMentionUpload, uploads: PlaygroundMentionUpload[]) {
+  const sameKind = uploads.filter((upload) => upload.kind === item.kind);
+  return Math.max(1, sameKind.findIndex((upload) => upload.id === item.id) + 1);
+}
+
+function uploadKindChinese(kind: PlaygroundMentionUploadKind) {
+  if (kind === 'image') return '图像';
+  if (kind === 'video') return '视频';
+  if (kind === 'audio') return '音频';
+  return '文件';
+}
+
+function uploadKindEnglish(kind: PlaygroundMentionUploadKind) {
+  if (kind === 'image') return 'image';
+  if (kind === 'video') return 'video';
+  if (kind === 'audio') return 'audio';
+  return 'file';
+}
+
+function uploadKindShort(kind: PlaygroundMentionUploadKind) {
+  if (kind === 'image') return '图';
+  if (kind === 'video') return '视';
+  if (kind === 'audio') return '音';
+  return '文';
+}
+
+function clamp(value: number, min: number, max: number) {
+  return Math.min(max, Math.max(min, value));
+}
+
+function escapeHtml(value: string) {
+  return value
+    .replace(/&/g, '&amp;')
+    .replace(/</g, '&lt;')
+    .replace(/>/g, '&gt;');
+}
+
+function escapeAttr(value: string) {
+  return escapeHtml(value).replace(/"/g, '&quot;');
+}
diff --git a/apps/web/src/styles/playground.css b/apps/web/src/styles/playground.css
index 03fc268..9f39262 100644
--- a/apps/web/src/styles/playground.css
+++ b/apps/web/src/styles/playground.css
@@ -139,6 +139,442 @@
   line-height: var(--line-height-relaxed);
 }
 
+.composerBodyWithReferences {
+  grid-template-columns: 120px minmax(0, 1fr);
+  align-items: start;
+}
+
+.composerBodyWithReferences[data-frame-mode="true"] {
+  grid-template-columns: 250px minmax(0, 1fr);
+}
+
+.mediaReferenceStack {
+  position: relative;
+  width: 108px;
+  min-height: 106px;
+  overflow: visible;
+}
+
+.mediaReferenceStack[data-expanded="true"] {
+  z-index: 12;
+}
+
+.mediaReferenceTooltip {
+  position: absolute;
+  z-index: 14;
+  top: -42px;
+  left: 0;
+  max-width: min(640px, 54vw);
+  overflow: hidden;
+  padding: 10px 14px;
+  border-radius: 12px;
+  background: #20252b;
+  color: #fff;
+  font-size: var(--font-size-sm);
+  line-height: 1.2;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+  box-shadow: 0 12px 32px rgba(24, 24, 27, 0.22);
+}
+
+.mediaReferenceStackCards {
+  position: relative;
+  width: 108px;
+  min-height: 104px;
+  transition: width 160ms ease;
+}
+
+.mediaReferenceStack[data-expanded="true"] .mediaReferenceStackCards {
+  width: min(calc(var(--reference-count) * 52px + 18px), calc(100vw - 96px));
+}
+
+.mediaReferenceCard {
+  position: absolute;
+  display: grid;
+  width: 58px;
+  height: 76px;
+  place-items: center;
+  overflow: visible;
+  border: 1px solid var(--border);
+  border-radius: 8px;
+  background: var(--surface-muted);
+  color: var(--text-soft);
+  box-shadow: 0 10px 24px rgba(24, 24, 27, 0.12);
+}
+
+.mediaReferenceCard {
+  left: calc(24px + var(--reference-x, 0px));
+  top: calc(7px + var(--reference-y, 0px));
+  transform: rotate(var(--reference-tilt, -6deg));
+  transition: left 160ms ease, top 160ms ease, transform 160ms ease, z-index 150ms ease, box-shadow 150ms ease;
+}
+
+.mediaReferenceStack[data-expanded="true"] .mediaReferenceCard {
+  left: calc(2px + var(--reference-index) * 52px);
+  top: 8px;
+  transform: rotate(var(--reference-tilt, -4deg));
+}
+
+.mediaReferenceCard[data-hovered="true"] {
+  z-index: 6;
+  transform: translateY(-8px) scale(1.04) rotate(0deg);
+  box-shadow: 0 16px 36px rgba(24, 24, 27, 0.18);
+}
+
+.mediaReferenceCard img,
+.mediaReferenceCard video,
+.frameSlotButton video,
+.frameSlotButton img {
+  width: 100%;
+  height: 100%;
+  overflow: hidden;
+  border-radius: inherit;
+  object-fit: cover;
+}
+
+.mediaReferencePlaceholder {
+  display: grid;
+  width: 100%;
+  height: 100%;
+  place-items: center;
+  overflow: hidden;
+  border-radius: inherit;
+  background: var(--surface-muted);
+  color: var(--primary);
+}
+
+.mediaReferenceDuration {
+  position: absolute;
+  left: 6px;
+  bottom: 6px;
+  padding: 1px 5px;
+  border-radius: 999px;
+  background: rgba(24, 24, 27, 0.66);
+  color: #fff;
+  font-size: var(--font-size-xs);
+  line-height: 1.35;
+}
+
+.mediaReferenceRemove,
+.frameSlotRemove {
+  position: absolute;
+  z-index: 7;
+  display: grid;
+  width: 24px;
+  height: 24px;
+  place-items: center;
+  border: 0;
+  border-radius: 999px;
+  background: #20252b;
+  color: #fff;
+  padding: 0;
+  box-shadow: 0 6px 16px rgba(24, 24, 27, 0.18);
+}
+
+.mediaReferenceRemove {
+  top: -13px;
+  right: -13px;
+}
+
+.mediaReferenceUploadCard {
+  border-style: dashed;
+  box-shadow: none;
+}
+
+.mediaReferenceUploadCard span {
+  position: absolute;
+  bottom: 10px;
+  color: inherit;
+  font-size: var(--font-size-xs);
+  font-weight: var(--font-weight-medium);
+}
+
+.mediaReferenceStack:not([data-expanded="true"]) .mediaReferenceUploadCard[data-has-uploads="true"] {
+  opacity: 0;
+  pointer-events: none;
+}
+
+.mediaReferenceStack[data-expanded="true"] .mediaReferenceUploadCard,
+.mediaReferenceUploadCard[data-has-uploads="false"] {
+  opacity: 1;
+  pointer-events: auto;
+}
+
+.mediaReferenceUploadCard:not(:disabled):hover {
+  color: var(--text-normal);
+  background: var(--surface);
+}
+
+.mediaReferenceUploadCard:disabled {
+  cursor: not-allowed;
+  opacity: 0.64;
+}
+
+.mediaReferenceStack:not([data-expanded="true"]) .mediaReferenceUploadCard[data-has-uploads="true"]:disabled {
+  opacity: 0;
+}
+
+.mediaReferenceAdd {
+  position: absolute;
+  left: 74px;
+  top: 61px;
+  z-index: 12;
+  display: grid;
+  width: 32px;
+  height: 32px;
+  place-items: center;
+  border: 1px solid var(--border);
+  border-radius: 999px;
+  background: var(--surface-muted);
+  color: var(--text-normal);
+  padding: 0;
+  box-shadow: 0 8px 20px rgba(24, 24, 27, 0.12);
+}
+
+.mediaReferenceStack[data-expanded="true"] .mediaReferenceAdd {
+  opacity: 0;
+  pointer-events: none;
+  transform: scale(0.86);
+}
+
+.mediaReferenceAdd:not(:disabled):hover {
+  background: var(--surface);
+  color: var(--primary);
+}
+
+.mediaReferenceAdd:disabled {
+  cursor: not-allowed;
+  opacity: 0.64;
+}
+
+.firstLastFramePicker {
+  display: grid;
+  grid-template-columns: 86px 34px 86px;
+  align-items: center;
+  gap: 10px;
+  min-height: 118px;
+}
+
+.frameSlot {
+  position: relative;
+}
+
+.frameSlotButton {
+  display: grid;
+  width: 78px;
+  height: 104px;
+  place-items: center;
+  overflow: hidden;
+  border: 1px dashed var(--border);
+  border-radius: 8px;
+  background: var(--surface-muted);
+  color: var(--text-soft);
+  transform: rotate(-7deg);
+}
+
+.frameSlot:nth-child(3) .frameSlotButton {
+  transform: rotate(6deg);
+}
+
+.frameSlotButton[data-filled="true"] {
+  border-style: solid;
+}
+
+.frameSlotButton span {
+  position: absolute;
+  bottom: 10px;
+  color: inherit;
+  font-size: var(--font-size-xs);
+  font-weight: var(--font-weight-medium);
+}
+
+.frameSlotButton[data-filled="true"] span {
+  padding: 1px 6px;
+  border-radius: 999px;
+  background: rgba(24, 24, 27, 0.62);
+  color: #fff;
+}
+
+.frameSlotRemove {
+  top: -8px;
+  right: 0;
+}
+
+.frameSwapButton {
+  display: grid;
+  width: 34px;
+  height: 34px;
+  place-items: center;
+  border: 0;
+  border-radius: 999px;
+  background: transparent;
+  color: var(--text-soft);
+}
+
+.frameSwapButton:not(:disabled):hover {
+  background: var(--surface-muted);
+  color: var(--text-normal);
+}
+
+.frameSwapButton:disabled {
+  opacity: 0.42;
+}
+
+.promptMentionInput {
+  position: relative;
+  min-width: 0;
+}
+
+.promptMentionEditable {
+  position: relative;
+  z-index: 1;
+  min-height: 88px;
+  max-height: 190px;
+  overflow-y: auto;
+  border: 0;
+  outline: 0;
+  background: transparent;
+  color: var(--text-normal);
+  font: inherit;
+  font-size: var(--font-size-sm);
+  line-height: var(--line-height-relaxed);
+  overflow-wrap: anywhere;
+  white-space: pre-wrap;
+}
+
+.promptMentionPlaceholder {
+  position: absolute;
+  z-index: 0;
+  top: 0;
+  left: 0;
+  right: 0;
+  overflow: hidden;
+  color: var(--muted-foreground);
+  font: inherit;
+  font-size: var(--font-size-sm);
+  line-height: var(--line-height-relaxed);
+  pointer-events: none;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+}
+
+.playgroundComposer.compact .promptMentionEditable {
+  min-height: 104px;
+}
+
+.promptMentionChip {
+  display: inline-flex;
+  max-width: min(260px, 80%);
+  align-items: center;
+  gap: 5px;
+  margin: 0 4px 2px 0;
+  padding: 2px 6px 2px 2px;
+  border-radius: 7px;
+  background: var(--primary);
+  color: var(--primary-foreground);
+  font-size: var(--font-size-xs);
+  line-height: 1.55;
+  vertical-align: middle;
+}
+
+.promptMentionChipThumb {
+  display: inline-grid;
+  width: 22px;
+  height: 22px;
+  min-width: 22px;
+  place-items: center;
+  overflow: hidden;
+  border-radius: 5px;
+  object-fit: cover;
+  background: rgba(255, 255, 255, 0.18);
+}
+
+.promptMentionChipThumbPlaceholder {
+  font-weight: var(--font-weight-semibold);
+}
+
+.promptMentionDropdown {
+  position: absolute;
+  z-index: 20;
+  width: min(320px, calc(100vw - 24px));
+  max-height: 286px;
+  overflow-y: auto;
+  border: 1px solid var(--border);
+  border-radius: 10px;
+  background: var(--surface);
+  box-shadow: 0 18px 42px rgba(24, 24, 27, 0.16);
+}
+
+.promptMentionItem {
+  display: grid;
+  grid-template-columns: 36px minmax(0, 1fr) auto;
+  width: 100%;
+  align-items: center;
+  gap: 10px;
+  min-height: 54px;
+  padding: 8px 10px;
+  border: 0;
+  background: transparent;
+  color: var(--text-normal);
+  text-align: left;
+}
+
+.promptMentionItem:hover,
+.promptMentionItem[data-active="true"] {
+  background: var(--surface-muted);
+}
+
+.promptMentionThumb,
+.promptMentionThumbIcon {
+  display: grid;
+  width: 36px;
+  height: 36px;
+  place-items: center;
+  border-radius: 8px;
+  background: var(--surface-muted);
+  color: var(--primary);
+  object-fit: cover;
+}
+
+.promptMentionItem span {
+  display: grid;
+  min-width: 0;
+  gap: 2px;
+}
+
+.promptMentionItem strong,
+.promptMentionItem small {
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+}
+
+.promptMentionItem strong {
+  color: var(--text-strong);
+  font-size: var(--font-size-sm);
+  font-weight: var(--font-weight-semibold);
+}
+
+.promptMentionItem small {
+  color: var(--muted-foreground);
+  font-size: var(--font-size-xs);
+}
+
+.promptMentionItem em {
+  padding: 2px 6px;
+  border-radius: 999px;
+  background: var(--surface-muted);
+  color: var(--text-soft);
+  font-size: var(--font-size-xs);
+  font-style: normal;
+}
+
+.promptMentionEmpty {
+  padding: 12px;
+  color: var(--muted-foreground);
+  font-size: var(--font-size-sm);
+}
+
 @keyframes composer-upload-spin {
   to {
     transform: rotate(360deg);