diff --git a/litellm/__init__.py b/litellm/__init__.py
index 0db5d365a6..d6ddf8db2a 100644
--- a/litellm/__init__.py
+++ b/litellm/__init__.py
@@ -27,8 +27,8 @@ input_callback: List[Union[str, Callable]] = []
 success_callback: List[Union[str, Callable]] = []
 failure_callback: List[Union[str, Callable]] = []
 service_callback: List[Union[str, Callable]] = []
-callbacks: List[Callable] = []
-_custom_logger_compatible_callbacks: list = ["openmeter"]
+_custom_logger_compatible_callbacks_literal = Literal["lago"]
+callbacks: List[Union[Callable, _custom_logger_compatible_callbacks_literal]] = []
 _langfuse_default_tags: Optional[
     List[
         Literal[
diff --git a/litellm/integrations/lago.py b/litellm/integrations/lago.py
new file mode 100644
index 0000000000..cf2f604754
--- /dev/null
+++ b/litellm/integrations/lago.py
@@ -0,0 +1,153 @@
+# What is this?
+## On Success events log cost to Lago - https://github.com/BerriAI/litellm/issues/3639
+
+import dotenv, os, json
+import litellm
+import traceback, httpx
+from litellm.integrations.custom_logger import CustomLogger
+from litellm.llms.custom_httpx.http_handler import AsyncHTTPHandler, HTTPHandler
+import uuid
+from typing import Optional
+
+
+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 LagoLogger(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
+        LAGO_API_BASE,
+        LAGO_API_KEY,
+
+        in the environment
+        """
+        missing_keys = []
+        if os.getenv("LAGO_API_KEY", None) is None:
+            missing_keys.append("LAGO_API_KEY")
+
+        if os.getenv("LAGO_API_BASE", None) is None:
+            missing_keys.append("LAGO_API_BASE")
+
+        if os.getenv("LAGO_API_EVENT_CODE", None) is None:
+            missing_keys.append("LAGO_API_EVENT_CODE")
+
+        if len(missing_keys) > 0:
+            raise Exception("Missing keys={} in environment.".format(missing_keys))
+
+    def _common_logic(self, kwargs: dict, response_obj) -> dict:
+        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"),
+            }
+
+        litellm_params = kwargs.get("litellm_params", {}) or {}
+        proxy_server_request = litellm_params.get("proxy_server_request") or {}
+        end_user_id = proxy_server_request.get("body", {}).get("user", None)
+        user_id = litellm_params["metadata"].get("user_api_key_user_id", None)
+        team_id = litellm_params["metadata"].get("user_api_key_team_id", None)
+        org_id = litellm_params["metadata"].get("user_api_key_org_id", None)
+
+        if end_user_id is None:
+            raise Exception("LAGO: user is required")
+
+        return {
+            "event": {
+                "transaction_id": str(uuid.uuid4()),
+                "external_customer_id": end_user_id,
+                "code": os.getenv("LAGO_API_EVENT_CODE"),
+                "properties": {"model": model, "response_cost": 10000, **usage},
+            }
+        }
+
+    def log_success_event(self, kwargs, response_obj, start_time, end_time):
+        _url = os.getenv("LAGO_API_BASE")
+        assert _url is not None and isinstance(
+            _url, str
+        ), "LAGO_API_BASE missing or not set correctly. LAGO_API_BASE={}".format(_url)
+        if _url.endswith("/"):
+            _url += "api/v1/events"
+        else:
+            _url += "/api/v1/events"
+
+        api_key = os.getenv("LAGO_API_KEY")
+
+        _data = self._common_logic(kwargs=kwargs, response_obj=response_obj)
+        _headers = {
+            "Content-Type": "application/json",
+            "Authorization": "Bearer {}".format(api_key),
+        }
+
+        try:
+            response = self.sync_http_handler.post(
+                url=_url,
+                data=json.dumps(_data),
+                headers=_headers,
+            )
+
+            response.raise_for_status()
+        except Exception as e:
+            if hasattr(response, "text"):
+                litellm.print_verbose(f"\nError Message: {response.text}")
+            raise e
+
+    async def async_log_success_event(self, kwargs, response_obj, start_time, end_time):
+        try:
+            _url = os.getenv("LAGO_API_BASE")
+            assert _url is not None and isinstance(
+                _url, str
+            ), "LAGO_API_BASE missing or not set correctly. LAGO_API_BASE={}".format(
+                _url
+            )
+            if _url.endswith("/"):
+                _url += "api/v1/events"
+            else:
+                _url += "/api/v1/events"
+
+            api_key = os.getenv("LAGO_API_KEY")
+
+            _data = self._common_logic(kwargs=kwargs, response_obj=response_obj)
+            _headers = {
+                "Content-Type": "application/json",
+                "Authorization": "Bearer {}".format(api_key),
+            }
+        except Exception as e:
+            raise e
+
+        response: Optional[httpx.Response] = None
+        try:
+            response = await self.async_http_handler.post(
+                url=_url,
+                data=json.dumps(_data),
+                headers=_headers,
+            )
+
+            response.raise_for_status()
+        except Exception as e:
+            if response is not None and hasattr(response, "text"):
+                litellm.print_verbose(f"\nError Message: {response.text}")
+            raise e
diff --git a/litellm/proxy/_super_secret_config.yaml b/litellm/proxy/_super_secret_config.yaml
index 8d3e4f5e14..fb57510cd2 100644
--- a/litellm/proxy/_super_secret_config.yaml
+++ b/litellm/proxy/_super_secret_config.yaml
@@ -30,6 +30,7 @@ router_settings:
 
 litellm_settings:
   fallbacks: [{"gpt-3.5-turbo-012": ["azure-gpt-3.5-turbo"]}]
+  callbacks: ["lago"]
   # service_callback: ["prometheus_system"]
   # success_callback: ["prometheus"]
   # failure_callback: ["prometheus"]
diff --git a/litellm/proxy/proxy_server.py b/litellm/proxy/proxy_server.py
index 18d5916734..aacd383b4c 100644
--- a/litellm/proxy/proxy_server.py
+++ b/litellm/proxy/proxy_server.py
@@ -2,7 +2,7 @@ import sys, os, platform, time, copy, re, asyncio, inspect
 import threading, ast
 import shutil, random, traceback, requests
 from datetime import datetime, timedelta, timezone
-from typing import Optional, List, Callable
+from typing import Optional, List, Callable, get_args
 import secrets, subprocess
 import hashlib, uuid
 import warnings
@@ -2098,8 +2098,18 @@ class ProxyConfig:
                 elif key == "callbacks":
                     if isinstance(value, list):
                         imported_list: List[Any] = []
+                        known_compatible_callbacks = list(
+                            get_args(
+                                litellm._custom_logger_compatible_callbacks_literal
+                            )
+                        )
                         for callback in value:  # ["presidio", <my-custom-callback>]
-                            if isinstance(callback, str) and callback == "presidio":
+                            if (
+                                isinstance(callback, str)
+                                and callback in known_compatible_callbacks
+                            ):
+                                imported_list.append(callback)
+                            elif isinstance(callback, str) and callback == "presidio":
                                 from litellm.proxy.hooks.presidio_pii_masking import (
                                     _OPTIONAL_PresidioPIIMasking,
                                 )
diff --git a/litellm/proxy/utils.py b/litellm/proxy/utils.py
index d1210a504f..9939ab5943 100644
--- a/litellm/proxy/utils.py
+++ b/litellm/proxy/utils.py
@@ -140,6 +140,8 @@ class ProxyLogging:
             self.slack_alerting_instance.response_taking_too_long_callback
         )
         for callback in litellm.callbacks:
+            if isinstance(callback, str):
+                callback = litellm.utils._init_custom_logger_compatible_class(callback)
             if callback not in litellm.input_callback:
                 litellm.input_callback.append(callback)
             if callback not in litellm.success_callback:
diff --git a/litellm/utils.py b/litellm/utils.py
index 36f4ad481f..a21cee9296 100644
--- a/litellm/utils.py
+++ b/litellm/utils.py
@@ -76,6 +76,7 @@ from .integrations.weights_biases import WeightsBiasesLogger
 from .integrations.custom_logger import CustomLogger
 from .integrations.langfuse import LangFuseLogger
 from .integrations.openmeter import OpenMeterLogger
+from .integrations.lago import LagoLogger
 from .integrations.datadog import DataDogLogger
 from .integrations.prometheus import PrometheusLogger
 from .integrations.prometheus_services import PrometheusServicesLogger
@@ -123,6 +124,7 @@ from typing import (
     BinaryIO,
     Iterable,
     Tuple,
+    Callable,
 )
 from .caching import Cache
 from concurrent.futures import ThreadPoolExecutor
@@ -147,6 +149,7 @@ weightsBiasesLogger = None
 customLogger = None
 langFuseLogger = None
 openMeterLogger = None
+lagoLogger = None
 dataDogLogger = None
 prometheusLogger = None
 dynamoLogger = None
@@ -2111,7 +2114,7 @@ class Logging:
         """
         Implementing async callbacks, to handle asyncio event loop issues when custom integrations need to use async functions.
         """
-        print_verbose(f"Logging Details LiteLLM-Async Success Call: {cache_hit}")
+        print_verbose(f"Logging Details LiteLLM-Async Success Call")
         start_time, end_time, result = self._success_handler_helper_fn(
             start_time=start_time, end_time=end_time, result=result, cache_hit=cache_hit
         )
@@ -2333,8 +2336,8 @@ class Logging:
                             end_time=end_time,
                             print_verbose=print_verbose,
                         )
-            except:
-                print_verbose(
+            except Exception as e:
+                verbose_logger.error(
                     f"LiteLLM.LoggingError: [Non-Blocking] Exception occurred while success logging {traceback.format_exc()}"
                 )
                 pass
@@ -2692,6 +2695,15 @@ class Rules:
         return True
 
 
+def _init_custom_logger_compatible_class(
+    logging_integration: litellm._custom_logger_compatible_callbacks_literal,
+) -> Callable:
+    if logging_integration == "lago":
+        return LagoLogger()  # type: ignore
+    elif logging_integration == "openmeter":
+        return OpenMeterLogger()  # type: ignore
+
+
 ####### CLIENT ###################
 # make it easy to log if completion/embedding runs succeeded or failed + see what happened | Non-Blocking
 def function_setup(
@@ -2702,16 +2714,24 @@ def function_setup(
         function_id = kwargs["id"] if "id" in kwargs else None
         if len(litellm.callbacks) > 0:
             for callback in litellm.callbacks:
+                # check if callback is a string - e.g. "lago", "openmeter"
+                if isinstance(callback, str):
+                    callback = _init_custom_logger_compatible_class(callback)
+                    if any(
+                        isinstance(cb, type(callback))
+                        for cb in litellm._async_success_callback
+                    ):  # don't double add a callback
+                        continue
                 if callback not in litellm.input_callback:
-                    litellm.input_callback.append(callback)
+                    litellm.input_callback.append(callback)  # type: ignore
                 if callback not in litellm.success_callback:
-                    litellm.success_callback.append(callback)
+                    litellm.success_callback.append(callback)  # type: ignore
                 if callback not in litellm.failure_callback:
-                    litellm.failure_callback.append(callback)
+                    litellm.failure_callback.append(callback)  # type: ignore
                 if callback not in litellm._async_success_callback:
-                    litellm._async_success_callback.append(callback)
+                    litellm._async_success_callback.append(callback)  # type: ignore
                 if callback not in litellm._async_failure_callback:
-                    litellm._async_failure_callback.append(callback)
+                    litellm._async_failure_callback.append(callback)  # type: ignore
             print_verbose(
                 f"Initialized litellm callbacks, Async Success Callbacks: {litellm._async_success_callback}"
             )