diff --git a/components/canvas/CanvasChatPanel.tsx b/components/canvas/CanvasChatPanel.tsx
index 144ec0b58..5afef8612 100644
--- a/components/canvas/CanvasChatPanel.tsx
+++ b/components/canvas/CanvasChatPanel.tsx
@@ -2066,6 +2066,7 @@ export function CanvasChatPanel({
   const detailModeSwitchRef = useRef(false);
   const hiddenPromptRef = useRef<string | null>(null);
   const autoContextRef = useRef<string | null>(null);
+  const contextPayloadRef = useRef<any>(null);
   const lastWorkflowAutofillSignatureRef = useRef<string | null>(null);
   const lastWorkflowAutofillUrlsRef = useRef<string[]>([]);
   const pendingLaunchRef = useRef<CanvasLaunchPayload | null>(null);
@@ -4561,25 +4562,27 @@ export function CanvasChatPanel({
           ? request.id.replace('canvas-', '') 
           : request.id;
         
+        const capturedContextPayload = contextPayloadRef.current ?? buildContextPayload();
         console.log("[CanvasChat] Preparing request:", {
           id: rawId,
           modelId: currentModelIdRef.current,
           composerMode: activeComposerModeRef.current,
           agentEntryMode: agentEntryModeRef.current,
           imageParams: imageParamsRef.current,
-          contextPayload: buildContextPayload(),
+          contextPayload: capturedContextPayload,
           lastMessage: request.messages.at(-1),
         });
         const effectiveComposerMode = activeComposerModeRef.current || activeComposerMode;
         const effectiveAgentEntryMode = agentEntryModeRef.current;
         const hiddenPrompt = hiddenPromptRef.current || undefined;
         const autoContext = autoContextRef.current || undefined;
-        const contextPayload = buildContextPayload();
+        const contextPayload = capturedContextPayload;
         const requestModel = allModels.find((model) => model.id === currentModelIdRef.current);
         const requestIsVideoModel = isCanvasVideoModel(requestModel);
         const requestIsConversationModel = isCanvasConversationOnlyModel(requestModel);
         hiddenPromptRef.current = null;
         autoContextRef.current = null;
+        contextPayloadRef.current = null;
         return {
           body: {
             id: rawId,
@@ -8284,6 +8287,7 @@ export function CanvasChatPanel({
     const autoContext = buildAutoContext();
     autoContextRef.current =
       clampChatRequestText(autoContext, MAX_CHAT_AUTO_CONTEXT_LENGTH) || null;
+    contextPayloadRef.current = buildContextPayload() || null;
     
     if (textContent) {
       parts.push({ type: "text" as const, text: textContent });
@@ -8328,6 +8332,7 @@ export function CanvasChatPanel({
       });
     } catch (error) {
       releaseSendGuard(activeChatId);
+      contextPayloadRef.current = null;
       console.error("[CanvasChat] sendMessage failed:", error);
       toast.error("发送失败，请重试");
       return;