Skip priority token details when subtracting

Co-authored-by: Hassieb Pakzad <hassiebp@users.noreply.github.com>

Author: cursoragent

langfuse/langchain/CallbackHandler.py

@@ -1102,22 +1102,9 @@ def _flatten_comprehension(matrix: Any) -> Any:
     return [item for row in matrix for item in row]
 
 
-_TOKEN_DETAIL_SUBTRACT_KEYS = {
-    "audio",
-    "cache_read",
-    "cache_creation",
-    "reasoning",
-}
-
-
 def _should_subtract_token_detail(detail_key: str) -> bool:
     normalized_key = detail_key.lower()
-    for subtract_key in _TOKEN_DETAIL_SUBTRACT_KEYS:
-        if normalized_key == subtract_key or normalized_key.endswith(
-            f"_{subtract_key}"
-        ):
-            return True
-    return False
+    return not normalized_key.startswith("priority")
 
 
 def _parse_usage_model(usage: Union[pydantic.BaseModel, dict]) -> Any:

tests/test_langchain_usage.py

@@ -33,17 +33,21 @@ def test_parse_usage_model_subtracts_known_details():
         "input_token_details": {
             "cache_read": 20,
             "audio": 5,
+            "custom_detail": 3,
         },
         "output_token_details": {
             "reasoning": 10,
+            "custom_output": 2,
         },
     }
 
     parsed = _parse_usage_model(usage)
 
-    assert parsed["input"] == 75
-    assert parsed["output"] == 40
+    assert parsed["input"] == 72
+    assert parsed["output"] == 38
     assert parsed["input_cache_read"] == 20
     assert parsed["input_audio"] == 5
+    assert parsed["input_custom_detail"] == 3
     assert parsed["output_reasoning"] == 10
+    assert parsed["output_custom_output"] == 2
     assert parsed["total"] == 150