diff --git a/src/renderer/src/services/messageStreaming/StreamingService.ts b/src/renderer/src/services/messageStreaming/StreamingService.ts
index 8707b18a0c..674e5fbace 100644
--- a/src/renderer/src/services/messageStreaming/StreamingService.ts
+++ b/src/renderer/src/services/messageStreaming/StreamingService.ts
@@ -282,18 +282,23 @@ class StreamingService {
     // Register block mapping
     this.blockToMessageMap.set(block.id, messageId)
 
-    // Add to session
-    session.blocks[block.id] = block
-
-    // Update message block references
-    if (!session.message.blocks.includes(block.id)) {
-      session.message.blocks = [...session.message.blocks, block.id]
+    // Create new message with updated blocks (immutable update for cache notification)
+    const newMessage: Message = {
+      ...session.message,
+      blocks: session.message.blocks.includes(block.id) ? session.message.blocks : [...session.message.blocks, block.id]
     }
 
-    // Update caches
-    cacheService.set(getSessionKey(messageId), session, SESSION_TTL)
+    // Create new session with updated blocks and message (immutable update for cache notification)
+    const newSession: StreamingSession = {
+      ...session,
+      blocks: { ...session.blocks, [block.id]: block },
+      message: newMessage
+    }
+
+    // Update caches with new references to trigger notifications
+    cacheService.set(getSessionKey(messageId), newSession, SESSION_TTL)
     cacheService.set(getBlockKey(block.id), block, SESSION_TTL)
-    cacheService.set(getMessageKey(messageId), session.message, SESSION_TTL)
+    cacheService.set(getMessageKey(messageId), newMessage, SESSION_TTL)
 
     logger.debug('Added block to session', { messageId, blockId: block.id, blockType: block.type })
   }
@@ -329,10 +334,15 @@ class StreamingService {
 
     // Merge changes - use type assertion since we're updating the same block type
     const updatedBlock = { ...existingBlock, ...changes } as MessageBlock
-    session.blocks[blockId] = updatedBlock
 
-    // Update caches
-    cacheService.set(getSessionKey(messageId), session, SESSION_TTL)
+    // Create new session with updated block (immutable update for cache notification)
+    const newSession: StreamingSession = {
+      ...session,
+      blocks: { ...session.blocks, [blockId]: updatedBlock }
+    }
+
+    // Update caches with new references to trigger notifications
+    cacheService.set(getSessionKey(messageId), newSession, SESSION_TTL)
     cacheService.set(getBlockKey(blockId), updatedBlock, SESSION_TTL)
   }
 
@@ -362,12 +372,18 @@ class StreamingService {
       return
     }
 
-    // Merge updates
-    session.message = { ...session.message, ...updates }
+    // Create new message with updates (immutable update for cache notification)
+    const newMessage = { ...session.message, ...updates }
 
-    // Update caches
-    cacheService.set(getSessionKey(messageId), session, SESSION_TTL)
-    cacheService.set(getMessageKey(messageId), session.message, SESSION_TTL)
+    // Create new session with updated message (immutable update for cache notification)
+    const newSession: StreamingSession = {
+      ...session,
+      message: newMessage
+    }
+
+    // Update caches with new references to trigger notifications
+    cacheService.set(getSessionKey(messageId), newSession, SESSION_TTL)
+    cacheService.set(getMessageKey(messageId), newMessage, SESSION_TTL)
   }
 
   /**