diff --git a/api/server/routes/memories.js b/api/server/routes/memories.js
index fe520de000..a136bc8e61 100644
--- a/api/server/routes/memories.js
+++ b/api/server/routes/memories.js
@@ -172,40 +172,68 @@ router.patch('/preferences', checkMemoryOptOut, async (req, res) => {
 /**
  * PATCH /memories/:key
  * Updates the value of an existing memory entry for the authenticated user.
- * Body: { value: string }
+ * Body: { key?: string, value: string }
  * Returns 200 and { updated: true, memory: <updatedDoc> } when successful.
  */
 router.patch('/:key', checkMemoryUpdate, async (req, res) => {
-  const { key } = req.params;
-  const { value } = req.body || {};
+  const { key: urlKey } = req.params;
+  const { key: bodyKey, value } = req.body || {};
 
   if (typeof value !== 'string' || value.trim() === '') {
     return res.status(400).json({ error: 'Value is required and must be a non-empty string.' });
   }
 
+  // Use the key from the body if provided, otherwise use the key from the URL
+  const newKey = bodyKey || urlKey;
+
   try {
     const tokenCount = Tokenizer.getTokenCount(value, 'o200k_base');
 
     const memories = await getAllUserMemories(req.user.id);
-    const existingMemory = memories.find((m) => m.key === key);
+    const existingMemory = memories.find((m) => m.key === urlKey);
 
     if (!existingMemory) {
       return res.status(404).json({ error: 'Memory not found.' });
     }
 
-    const result = await setMemory({
-      userId: req.user.id,
-      key,
-      value,
-      tokenCount,
-    });
+    // If the key is changing, we need to handle it specially
+    if (newKey !== urlKey) {
+      const keyExists = memories.find((m) => m.key === newKey);
+      if (keyExists) {
+        return res.status(409).json({ error: 'Memory with this key already exists.' });
+      }
 
-    if (!result.ok) {
-      return res.status(500).json({ error: 'Failed to update memory.' });
+      const createResult = await createMemory({
+        userId: req.user.id,
+        key: newKey,
+        value,
+        tokenCount,
+      });
+
+      if (!createResult.ok) {
+        return res.status(500).json({ error: 'Failed to create new memory.' });
+      }
+
+      const deleteResult = await deleteMemory({ userId: req.user.id, key: urlKey });
+      if (!deleteResult.ok) {
+        return res.status(500).json({ error: 'Failed to delete old memory.' });
+      }
+    } else {
+      // Key is not changing, just update the value
+      const result = await setMemory({
+        userId: req.user.id,
+        key: newKey,
+        value,
+        tokenCount,
+      });
+
+      if (!result.ok) {
+        return res.status(500).json({ error: 'Failed to update memory.' });
+      }
     }
 
     const updatedMemories = await getAllUserMemories(req.user.id);
-    const updatedMemory = updatedMemories.find((m) => m.key === key);
+    const updatedMemory = updatedMemories.find((m) => m.key === newKey);
 
     res.json({ updated: true, memory: updatedMemory });
   } catch (error) {
diff --git a/client/src/components/SidePanel/Memories/MemoryCreateDialog.tsx b/client/src/components/SidePanel/Memories/MemoryCreateDialog.tsx
index 1670ba6f60..3f916872cb 100644
--- a/client/src/components/SidePanel/Memories/MemoryCreateDialog.tsx
+++ b/client/src/components/SidePanel/Memories/MemoryCreateDialog.tsx
@@ -52,6 +52,10 @@ export default function MemoryCreateDialog({
           if (axiosError.response?.status === 409 || errorMessage.includes('already exists')) {
             errorMessage = localize('com_ui_memory_key_exists');
           }
+          // Check for key validation error (lowercase and underscores only)
+          else if (errorMessage.includes('lowercase letters and underscores')) {
+            errorMessage = localize('com_ui_memory_key_validation');
+          }
         }
       } else if (error.message) {
         errorMessage = error.message;
diff --git a/client/src/components/SidePanel/Memories/MemoryEditDialog.tsx b/client/src/components/SidePanel/Memories/MemoryEditDialog.tsx
index db6a0ab68e..6793bf3d6b 100644
--- a/client/src/components/SidePanel/Memories/MemoryEditDialog.tsx
+++ b/client/src/components/SidePanel/Memories/MemoryEditDialog.tsx
@@ -44,9 +44,29 @@ export default function MemoryEditDialog({
         status: 'success',
       });
     },
-    onError: () => {
+    onError: (error: Error) => {
+      let errorMessage = localize('com_ui_error');
+
+      if (error && typeof error === 'object' && 'response' in error) {
+        const axiosError = error as any;
+        if (axiosError.response?.data?.error) {
+          errorMessage = axiosError.response.data.error;
+
+          // Check for duplicate key error
+          if (axiosError.response?.status === 409 || errorMessage.includes('already exists')) {
+            errorMessage = localize('com_ui_memory_key_exists');
+          }
+          // Check for key validation error (lowercase and underscores only)
+          else if (errorMessage.includes('lowercase letters and underscores')) {
+            errorMessage = localize('com_ui_memory_key_validation');
+          }
+        }
+      } else if (error.message) {
+        errorMessage = error.message;
+      }
+
       showToast({
-        message: localize('com_ui_error'),
+        message: errorMessage,
         status: 'error',
       });
     },
diff --git a/client/src/locales/en/translation.json b/client/src/locales/en/translation.json
index de3721c779..0288678e05 100644
--- a/client/src/locales/en/translation.json
+++ b/client/src/locales/en/translation.json
@@ -856,6 +856,7 @@
   "com_ui_memory_deleted": "Memory deleted",
   "com_ui_memory_deleted_items": "Deleted Memories",
   "com_ui_memory_key_exists": "A memory with this key already exists. Please use a different key.",
+  "com_ui_memory_key_validation": "Memory key must only contain lowercase letters and underscores.",
   "com_ui_memory_updated": "Updated saved memory",
   "com_ui_memory_updated_items": "Updated Memories",
   "com_ui_mention": "Mention an endpoint, assistant, or preset to quickly switch to it",