litellm-mirror/docs/my-website/docs/proxy/call_hooks.md

Modify / Reject Incoming Requests

Modify data just before making litellm completion calls call on proxy

See a complete example with our parallel request rate limiter

Quick Start

1. In your Custom Handler add a new async_pre_call_hook function

This function is called just before a litellm completion call is made, and allows you to modify the data going into the litellm call See Code

from litellm.integrations.custom_logger import CustomLogger
import litellm

# This file includes the custom callbacks for LiteLLM Proxy
# Once defined, these can be passed in proxy_config.yaml
class MyCustomHandler(CustomLogger): # https://docs.litellm.ai/docs/observability/custom_callback#callback-class
    # Class variables or attributes
    def __init__(self):
        pass

    #### ASYNC #### 
    
    async def async_log_stream_event(self, kwargs, response_obj, start_time, end_time):
        pass

    async def async_log_pre_api_call(self, model, messages, kwargs):
        pass

    async def async_log_success_event(self, kwargs, response_obj, start_time, end_time):
        pass

    async def async_log_failure_event(self, kwargs, response_obj, start_time, end_time):
        pass

    #### CALL HOOKS - proxy only #### 

    async def async_pre_call_hook(self, user_api_key_dict: UserAPIKeyAuth, cache: DualCache, data: dict, call_type: Literal["completion", "embeddings"]):
        data["model"] = "my-new-model"
        return data 

proxy_handler_instance = MyCustomHandler()

2. Add this file to your proxy config

model_list:
  - model_name: gpt-3.5-turbo
    litellm_params:
      model: gpt-3.5-turbo

litellm_settings:
  callbacks: custom_callbacks.proxy_handler_instance # sets litellm.callbacks = [proxy_handler_instance]

3. Start the server + test the request

$ litellm /path/to/config.yaml

curl --location 'http://0.0.0.0:8000/chat/completions' \
    --data ' {
    "model": "gpt-3.5-turbo",
    "messages": [
        {
        "role": "user",
        "content": "good morning good sir"
        }
    ],
    "user": "ishaan-app",
    "temperature": 0.2
    }'