feat(openmeter.py): add support for user billing

open-meter supports user based billing. Closes https://github.com/BerriAI/litellm/issues/1268

litellm/integrations/openmeter.py

@@ -0,0 +1,122 @@
+# What is this?
+## On Success events log cost to OpenMeter - https://github.com/BerriAI/litellm/issues/1268
+
+import dotenv, os, json
+import requests
+import litellm
+
+dotenv.load_dotenv()  # Loading env variables using dotenv
+import traceback
+from litellm.integrations.custom_logger import CustomLogger
+from litellm.llms.custom_httpx.http_handler import AsyncHTTPHandler, HTTPHandler
+import uuid
+
+
+def get_utc_datetime():
+    import datetime as dt
+    from datetime import datetime
+
+    if hasattr(dt, "UTC"):
+        return datetime.now(dt.UTC)  # type: ignore
+    else:
+        return datetime.utcnow()  # type: ignore
+
+
+class OpenMeterLogger(CustomLogger):
+    def __init__(self) -> None:
+        super().__init__()
+        self.validate_environment()
+        self.async_http_handler = AsyncHTTPHandler()
+        self.sync_http_handler = HTTPHandler()
+
+    def validate_environment(self):
+        """
+        Expects
+        OPENMETER_API_ENDPOINT,
+        OPENMETER_API_KEY,
+
+        in the environment
+        """
+        missing_keys = []
+        if litellm.get_secret("OPENMETER_API_ENDPOINT", None) is None:
+            missing_keys.append("OPENMETER_API_ENDPOINT")
+
+        if litellm.get_secret("OPENMETER_API_KEY", None) is None:
+            missing_keys.append("OPENMETER_API_KEY")
+
+        if len(missing_keys) > 0:
+            raise Exception("Missing keys={} in environment.".format(missing_keys))
+
+    def _common_logic(self, kwargs: dict, response_obj):
+        call_id = response_obj.get("id", kwargs.get("litellm_call_id"))
+        dt = get_utc_datetime().isoformat()
+        cost = kwargs.get("response_cost", None)
+        model = kwargs.get("model")
+        usage = {}
+        if (
+            isinstance(response_obj, litellm.ModelResponse)
+            or isinstance(response_obj, litellm.EmbeddingResponse)
+        ) and hasattr(response_obj, "usage"):
+            usage = {
+                "prompt_tokens": response_obj["usage"].get("prompt_tokens", 0),
+                "completion_tokens": response_obj["usage"].get("completion_tokens", 0),
+                "total_tokens": response_obj["usage"].get("total_tokens"),
+            }
+
+        return {
+            "specversion": "1.0",
+            "type": os.getenv("OPENMETER_EVENT_TYPE", "litellm_tokens"),
+            "id": call_id,
+            "time": dt,
+            "subject": kwargs.get("user", ""),  # end-user passed in via 'user' param
+            "source": "litellm-proxy",
+            "data": {"model": model, "cost": cost, **usage},
+        }
+
+    def log_success_event(self, kwargs, response_obj, start_time, end_time):
+        _url = litellm.get_secret("OPENMETER_API_ENDPOINT")
+        if _url.endswith("/"):
+            _url += "api/v1/events"
+        else:
+            _url += "/api/v1/events"
+
+        api_key = litellm.get_secret("OPENMETER_API_KEY")
+
+        _data = self._common_logic(kwargs=kwargs, response_obj=response_obj)
+        self.sync_http_handler.post(
+            url=_url,
+            data=_data,
+            headers={
+                "Content-Type": "application/cloudevents+json",
+                "Authorization": "Bearer {}".format(api_key),
+            },
+        )
+
+    async def async_log_success_event(self, kwargs, response_obj, start_time, end_time):
+        _url = litellm.get_secret("OPENMETER_API_ENDPOINT")
+        if _url.endswith("/"):
+            _url += "api/v1/events"
+        else:
+            _url += "/api/v1/events"
+
+        api_key = litellm.get_secret("OPENMETER_API_KEY")
+
+        _data = self._common_logic(kwargs=kwargs, response_obj=response_obj)
+        _headers = {
+            "Content-Type": "application/cloudevents+json",
+            "Authorization": "Bearer {}".format(api_key),
+        }
+
+        try:
+            response = await self.async_http_handler.post(
+                url=_url,
+                data=json.dumps(_data),
+                headers=_headers,
+            )
+
+            response.raise_for_status()
+        except Exception as e:
+            print(f"\nAn Exception Occurred - {str(e)}")
+            if hasattr(response, "text"):
+                print(f"\nError Message: {response.text}")
+            raise e