diff --git a/backend/open_webui/utils/context_compaction.py b/backend/open_webui/utils/context_compaction.py
index 1a9b5e9f96..1fc5296c56 100644
--- a/backend/open_webui/utils/context_compaction.py
+++ b/backend/open_webui/utils/context_compaction.py
@@ -260,9 +260,14 @@ async def get_chat_context_usage(chat: Any, model_id: str | None = None) -> dict
 
     for idx in range(len(messages) - 1, -1, -1):
         usage = messages[idx].get('usage') or (messages[idx].get('info') or {}).get('usage')
-        input_tokens = (usage or {}).get('input_tokens') or (usage or {}).get('prompt_tokens')
+        input_tokens = (
+            (usage or {}).get('prompt_tokens')
+            or (usage or {}).get('input_tokens')
+        )
         if isinstance(usage, dict) and input_tokens:
-            tokens = int(input_tokens or 0) + int(usage.get('output_tokens') or usage.get('completion_tokens') or 0)
+            tokens = int(input_tokens or 0) + int(
+                usage.get('completion_tokens') or usage.get('output_tokens') or 0
+            )
             tokens += _estimate_messages_tokens(messages[idx + 1 :])
             return _build_context_usage(tokens, threshold)
 
@@ -301,8 +306,10 @@ def _exceeds_token_threshold(messages: list[dict], system_prompt: str, summary:
 
     for idx in range(len(messages) - 1, -1, -1):
         usage = messages[idx].get('usage') or (messages[idx].get('info') or {}).get('usage')
-        if isinstance(usage, dict) and usage.get('input_tokens'):
-            total = int(usage.get('input_tokens') or 0) + int(usage.get('output_tokens') or 0)
+        if isinstance(usage, dict) and (usage.get('prompt_tokens') or usage.get('input_tokens')):
+            total = int(usage.get('prompt_tokens') or usage.get('input_tokens') or 0) + int(
+                usage.get('completion_tokens') or usage.get('output_tokens') or 0
+            )
             return total + _estimate_messages_tokens(messages[idx + 1 :]) > threshold
 
     estimated = _estimate_tokens(system_prompt) + _estimate_tokens(summary or '') + _estimate_messages_tokens(messages)
diff --git a/backend/open_webui/utils/response.py b/backend/open_webui/utils/response.py
index de3ede0a07..8b0214f6c8 100644
--- a/backend/open_webui/utils/response.py
+++ b/backend/open_webui/utils/response.py
@@ -55,8 +55,6 @@ USAGE_TOKEN_KEYS = {
     'input_tokens',
     'output_tokens',
     'total_tokens',
-    'prompt_tokens',
-    'completion_tokens',
 }
 
 USAGE_COST_KEYS = {
@@ -105,7 +103,7 @@ def merge_usage(current: dict | None, incoming: dict | None) -> dict:
     """
     Merge usage payloads from multiple model calls into one cumulative usage dict.
 
-    Token fields are additive; non-numeric metadata keeps the latest provider value.
+    Canonical token fields are additive; provider aliases keep the latest value.
     """
     current_usage = normalize_usage(current or {}) if current else {}
     incoming_usage = normalize_usage(incoming or {}) if incoming else {}
@@ -133,6 +131,17 @@ def merge_usage(current: dict | None, incoming: dict | None) -> dict:
                 incoming_usage.get(key) if isinstance(incoming_usage.get(key), dict) else {},
             )
 
+    result['prompt_tokens'] = (
+        incoming_usage.get('prompt_tokens')
+        or incoming_usage.get('input_tokens')
+        or current_usage.get('prompt_tokens', 0)
+    )
+    result['completion_tokens'] = (
+        incoming_usage.get('completion_tokens')
+        or incoming_usage.get('output_tokens')
+        or current_usage.get('completion_tokens', 0)
+    )
+
     return result