feat(factory.py): option to add function details to prompt, if model doesn't support functions param

litellm/__init__.py

@@ -41,6 +41,7 @@ model_alias_map: Dict[str, str] = {}
 max_budget: float = 0.0 # set the max budget across all providers
 _current_cost = 0 # private variable, used if max budget is set 
 error_logs: Dict = {}
+add_function_to_prompt: bool = False # if function calling not supported by api, append function call details to system prompt
 #############################################
 
 def get_model_cost_map():

litellm/llms/prompt_templates/factory.py

@@ -200,6 +200,24 @@ def hf_chat_template(model: str, messages: list):
     except: 
         raise Exception("Error rendering template")
 
+# Function call template 
+def function_call_prompt(messages: list, functions: list):
+    function_prompt = "The following functions are available to you:"
+    for function in functions: 
+        function_prompt += f"""\n{function}\n"""
+    
+    function_added_to_prompt = False
+    for message in messages: 
+        if "system" in message["role"]: 
+            message['content'] += f"""{function_prompt}"""
+            function_added_to_prompt = True
+    
+    if function_added_to_prompt == False: 
+        messages.append({'role': 'system', 'content': f"""{function_prompt}"""})
+
+    return messages
+
+
 # Custom prompt template
 def custom_prompt(role_dict: dict, messages: list, initial_prompt_value: str="", final_prompt_value: str=""):
     prompt = initial_prompt_value
@@ -243,4 +261,5 @@ def prompt_factory(model: str, messages: list, custom_llm_provider: Optional[str
         else: 
             return hf_chat_template(original_model_name, messages)
     except:
-        return default_pt(messages=messages) # default that covers Bloom, T-5, any non-chat tuned model (e.g. base Llama2)
+        return default_pt(messages=messages) # default that covers Bloom, T-5, any non-chat tuned model (e.g. base Llama2)
+    

litellm/main.py

@@ -28,7 +28,7 @@ from litellm.utils import (
     completion_with_fallbacks,
     get_llm_provider,
     get_api_key,
-    mock_completion_streaming_obj,
+    mock_completion_streaming_obj
 )
 from .llms import (
     anthropic,
@@ -48,7 +48,7 @@ from .llms import (
     oobabooga,
     palm,
     vertex_ai)
-from .llms.prompt_templates.factory import prompt_factory, custom_prompt
+from .llms.prompt_templates.factory import prompt_factory, custom_prompt, function_call_prompt
 import tiktoken
 from concurrent.futures import ThreadPoolExecutor
 from typing import Callable, List, Optional, Dict
@@ -259,27 +259,33 @@ def completion(
             api_base = "https://proxy.litellm.ai"
             custom_llm_provider = "openai" 
             api_key = model_api_key
+        
         # check if user passed in any of the OpenAI optional params
         optional_params = get_optional_params(
-            functions=functions,
-            function_call=function_call,
-            temperature=temperature,
-            top_p=top_p,
-            n=n,
-            stream=stream,
-            stop=stop,
-            max_tokens=max_tokens,
-            presence_penalty=presence_penalty,
-            frequency_penalty=frequency_penalty,
-            logit_bias=logit_bias,
-            user=user,
-            request_timeout=request_timeout,
-            deployment_id=deployment_id,
-            # params to identify the model
-            model=model,
-            custom_llm_provider=custom_llm_provider,
-            **non_default_params 
-        )
+                functions=functions,
+                function_call=function_call,
+                temperature=temperature,
+                top_p=top_p,
+                n=n,
+                stream=stream,
+                stop=stop,
+                max_tokens=max_tokens,
+                presence_penalty=presence_penalty,
+                frequency_penalty=frequency_penalty,
+                logit_bias=logit_bias,
+                user=user,
+                request_timeout=request_timeout,
+                deployment_id=deployment_id,
+                # params to identify the model
+                model=model,
+                custom_llm_provider=custom_llm_provider,
+                **non_default_params 
+            )
+        
+        if litellm.add_function_to_prompt and optional_params.get("functions_unsupported_model", None):  # if user opts to add it to prompt, when API doesn't support function calling 
+            functions_unsupported_model = optional_params.pop("functions_unsupported_model")
+            messages = function_call_prompt(messages=messages, functions=functions_unsupported_model)
+
         # For logging - save the values of the litellm-specific params passed in
         litellm_params = get_litellm_params(
             return_async=return_async,

litellm/tests/test_add_function_to_prompt.py

@@ -0,0 +1,75 @@
+#### What this tests ####
+#  Allow the user to map the function to the prompt, if the model doesn't support function calling
+
+import sys, os, pytest
+import traceback
+
+sys.path.insert(
+    0, os.path.abspath("../..")
+)  # Adds the parent directory to the system path
+import litellm
+
+## case 1: set_function_to_prompt not set 
+def test_function_call_non_openai_model():
+    try: 
+        model = "claude-instant-1"
+        messages=[{"role": "user", "content": "what's the weather in sf?"}]
+        functions = [
+            {
+            "name": "get_current_weather",
+            "description": "Get the current weather in a given location",
+            "parameters": {
+                "type": "object",
+                "properties": {
+                "location": {
+                    "type": "string",
+                    "description": "The city and state, e.g. San Francisco, CA"
+                },
+                "unit": {
+                    "type": "string",
+                    "enum": ["celsius", "fahrenheit"]
+                }
+                },
+                "required": ["location"]
+            }
+            }
+        ]
+        response = litellm.completion(model=model, messages=messages, functions=functions)
+        pytest.fail(f'An error occurred')
+    except Exception as e: 
+        pass
+
+test_function_call_non_openai_model()
+
+## case 2: add_function_to_prompt set 
+def test_function_call_non_openai_model_litellm_mod_set():
+    litellm.add_function_to_prompt = True
+    try: 
+        model = "claude-instant-1"
+        messages=[{"role": "user", "content": "what's the weather in sf?"}]
+        functions = [
+            {
+            "name": "get_current_weather",
+            "description": "Get the current weather in a given location",
+            "parameters": {
+                "type": "object",
+                "properties": {
+                "location": {
+                    "type": "string",
+                    "description": "The city and state, e.g. San Francisco, CA"
+                },
+                "unit": {
+                    "type": "string",
+                    "enum": ["celsius", "fahrenheit"]
+                }
+                },
+                "required": ["location"]
+            }
+            }
+        ]
+        response = litellm.completion(model=model, messages=messages, functions=functions)
+        print(f'response: {response}')
+    except Exception as e: 
+        pytest.fail(f'An error occurred {e}')
+
+# test_function_call_non_openai_model_litellm_mod_set()

litellm/utils.py

@@ -1001,17 +1001,20 @@ def get_optional_params(  # use the openai defaults
     }
     # filter out those parameters that were passed with non-default values
     non_default_params = {k: v for k, v in passed_params.items() if (k != "model" and k != "custom_llm_provider" and k in default_params and v != default_params[k])}
-
+    optional_params = {}
     ## raise exception if function calling passed in for a provider that doesn't support it
     if "functions" in non_default_params or "function_call" in non_default_params:
         if custom_llm_provider != "openai" and custom_llm_provider != "text-completion-openai" and custom_llm_provider != "azure": 
-            raise ValueError("LiteLLM.Exception: Function calling is not supported by this provider")
+            if litellm.add_function_to_prompt: # if user opts to add it to prompt instead
+                optional_params["functions_unsupported_model"] = non_default_params.pop("functions")
+            else: 
+                raise ValueError("LiteLLM.Exception: Function calling is not supported by this provider")
 
     def _check_valid_arg(supported_params): 
         print_verbose(f"checking params for {model}")
         print_verbose(f"params passed in {passed_params}")
         print_verbose(f"non-default params passed in {non_default_params}")
-        unsupported_params = []
+        unsupported_params = {}
         for k in non_default_params.keys():
             if k not in supported_params:
                 if k == "n" and n == 1: # langchain sends n=1 as a default value
@@ -1020,12 +1023,11 @@ def get_optional_params(  # use the openai defaults
                 elif k == "request_timeout": # litellm handles request time outs
                     pass
                 else: 
-                    unsupported_params.append(k)
+                    unsupported_params[k] = non_default_params[k]
         if unsupported_params and not litellm.drop_params:
             raise ValueError("LiteLLM.Exception: Unsupported parameters passed: {}".format(', '.join(unsupported_params)))
 
     ## raise exception if provider doesn't support passed in param 
-    optional_params = {}
     if custom_llm_provider == "anthropic":
         ## check if unsupported param passed in 
         supported_params = ["stream", "stop", "temperature", "top_p", "max_tokens"]