feat: implemented class using InputTokenDetails, will revert for comp…

…letions compatibility

src/agents/usage.py

@@ -1,4 +1,17 @@
 from dataclasses import dataclass
+from typing import TypeVar
+
+from openai.types.responses.response_usage import InputTokensDetails, OutputTokensDetails
+
+T = TypeVar("T", bound="InputTokensDetails | OutputTokensDetails")
+
+
+def add_numeric_fields(current: T, other: T) -> None:
+    for field in current.__dataclass_fields__:
+        v1 = getattr(current, field, 0)
+        v2 = getattr(other, field, 0)
+        if isinstance(v1, (int, float)) and isinstance(v2, (int, float)):
+            setattr(current, field, (v1 or 0) + (v2 or 0))
 
 
 @dataclass
@@ -9,9 +22,13 @@ class Usage:
     input_tokens: int = 0
     """Total input tokens sent, across all requests."""
 
+    input_tokens_details: InputTokensDetails = InputTokensDetails(cached_tokens=0)
+
     output_tokens: int = 0
     """Total output tokens received, across all requests."""
 
+    output_tokens_details: OutputTokensDetails = OutputTokensDetails(reasoning_tokens=0)
+
     total_tokens: int = 0
     """Total tokens sent and received, across all requests."""
 
@@ -20,3 +37,5 @@ def add(self, other: "Usage") -> None:
         self.input_tokens += other.input_tokens if other.input_tokens else 0
         self.output_tokens += other.output_tokens if other.output_tokens else 0
         self.total_tokens += other.total_tokens if other.total_tokens else 0
+        add_numeric_fields(self.input_tokens_details, other.input_tokens_details)
+        add_numeric_fields(self.output_tokens_details, other.output_tokens_details)