feat: Add Spend metrics in datadog

Author: mubashir1osmani

litellm/integrations/datadog/datadog_llm_obs.py

@@ -148,10 +148,27 @@ async def async_send_batch(self):
                     ),
                 ),
             }
-            verbose_logger.debug("payload %s", json.dumps(payload, indent=4))
+            # serialize datetime objects - for budget reset time in spend metrics
+            import json
+            from datetime import datetime, date
+            
+            def custom_json_encoder(obj):
+                if isinstance(obj, (datetime, date)):
+                    return obj.isoformat()
+                raise TypeError(f"Object of type {type(obj)} is not JSON serializable")
+            
+            # Serialize payload with custom encoder for debugging
+            try:
+                verbose_logger.debug("payload %s", json.dumps(payload, indent=4, default=custom_json_encoder))
+            except Exception as debug_error:
+                verbose_logger.debug("payload serialization failed: %s", str(debug_error))
+            
+            # Convert payload to JSON string with custom encoder for HTTP request
+            json_payload = json.dumps(payload, default=custom_json_encoder)
+            
             response = await self.async_client.post(
                 url=self.intake_url,
-                json=payload,
+                content=json_payload,
                 headers={
                     "DD-API-KEY": self.DD_API_KEY,
                     "Content-Type": "application/json",

litellm/types/integrations/datadog_llm_obs.py

@@ -85,5 +85,4 @@ class DDLLMObsLatencyMetrics(TypedDict, total=False):
 class DDLLMObsSpendMetrics(TypedDict, total=False):
     litellm_spend_metric: float
     litellm_api_key_max_budget_metric: float
-    litellm_remaining_api_key_budget_metric: float
-    litellm_api_key_budget_remaining_hours_metric: float
+    litellm_api_key_budget_remaining_hours_metric: float