Removes optional cache metric

Author: Workshop Participant

src/strands/telemetry/tracer.py

@@ -492,8 +492,8 @@ def end_agent_span(
                         "gen_ai.usage.input_tokens": accumulated_usage["inputTokens"],
                         "gen_ai.usage.output_tokens": accumulated_usage["outputTokens"],
                         "gen_ai.usage.total_tokens": accumulated_usage["totalTokens"],
-                        "gen_ai.usage.cache_read_input_tokens": accumulated_usage["cacheReadInputTokens"],
-                        "gen_ai.usage.cache_write_input_tokens": accumulated_usage["cacheWriteInputTokens"],
+                        "gen_ai.usage.cache_read_input_tokens": accumulated_usage.get("cacheReadInputTokens", 0),
+                        "gen_ai.usage.cache_write_input_tokens": accumulated_usage.get("cacheWriteInputTokens", 0),
                     }
                 )
 

src/strands/types/event_loop.py

@@ -1,6 +1,6 @@
 """Event loop-related type definitions for the SDK."""
 
-from typing import Literal, Optional
+from typing import Literal
 
 from typing_extensions import TypedDict
 
@@ -19,8 +19,8 @@ class Usage(TypedDict, total=False):
     inputTokens: int
     outputTokens: int
     totalTokens: int
-    cacheReadInputTokens: Optional[int]
-    cacheWriteInputTokens: Optional[int]
+    cacheReadInputTokens: int
+    cacheWriteInputTokens: int
 
 
 class Metrics(TypedDict):