google-genai[patch]: match function call interface

libs/partners/google-genai/langchain_google_genai/_function_utils.py

@@ -0,0 +1,135 @@
+from __future__ import annotations
+
+from typing import (
+    Dict,
+    List,
+    Type,
+    Union,
+)
+
+from langchain_core.pydantic_v1 import BaseModel
+from langchain_core.tools import BaseTool
+from langchain_core.utils.json_schema import dereference_refs
+
+FunctionCallType = Union[BaseTool, Type[BaseModel], Dict]
+
+TYPE_ENUM = {
+    "string": 1,
+    "number": 2,
+    "integer": 3,
+    "boolean": 4,
+    "array": 5,
+    "object": 6,
+}
+
+
+def convert_to_genai_function_declarations(
+    function_calls: List[FunctionCallType],
+) -> Dict:
+    function_declarations = []
+    for fc in function_calls:
+        function_declarations.append(_convert_to_genai_function(fc))
+    return {
+        "function_declarations": function_declarations,
+    }
+
+
+def _convert_to_genai_function(fc: FunctionCallType) -> Dict:
+    """
+        Produce
+
+        {
+      "name": "get_weather",
+      "description": "Determine weather in my location",
+      "parameters": {
+        "properties": {
+          "location": {
+            "description": "The city and state e.g. San Francisco, CA",
+            "type_": 1
+          },
+          "unit": { "enum": ["c", "f"], "type_": 1 }
+        },
+        "required": ["location"],
+        "type_": 6
+      }
+    }
+
+    """
+    if isinstance(fc, BaseTool):
+        return _convert_tool_to_genai_function(fc)
+    elif isinstance(fc, type) and issubclass(fc, BaseModel):
+        return _convert_pydantic_to_genai_function(fc)
+    elif isinstance(fc, dict):
+        return {
+            **fc,
+            "parameters": {
+                "properties": {
+                    k: {
+                        "type_": TYPE_ENUM[v["type"]],
+                        "description": v.get("description"),
+                    }
+                    for k, v in fc["parameters"]["properties"].items()
+                },
+                "required": fc["parameters"].get("required", []),
+                "type_": TYPE_ENUM[fc["parameters"]["type"]],
+            },
+        }
+    else:
+        raise ValueError(f"Unsupported function call type {fc}")
+
+
+def _convert_tool_to_genai_function(tool: BaseTool) -> Dict:
+    if tool.args_schema:
+        schema = dereference_refs(tool.args_schema.schema())
+        schema.pop("definitions", None)
+
+        return {
+            "name": tool.name or schema["title"],
+            "description": tool.description or schema["description"],
+            "parameters": {
+                "properties": {
+                    k: {
+                        "type_": TYPE_ENUM[v["type"]],
+                        "description": v.get("description"),
+                    }
+                    for k, v in schema["properties"].items()
+                },
+                "required": schema["required"],
+                "type_": TYPE_ENUM[schema["type"]],
+            },
+        }
+    else:
+        return {
+            "name": tool.name,
+            "description": tool.description,
+            "parameters": {
+                "properties": {
+                    "__arg1": {"type": "string"},
+                },
+                "required": ["__arg1"],
+                "type_": TYPE_ENUM["object"],
+            },
+        }
+
+
+def _convert_pydantic_to_genai_function(
+    pydantic_model: Type[BaseModel],
+) -> Dict:
+    schema = dereference_refs(pydantic_model.schema())
+    schema.pop("definitions", None)
+
+    return {
+        "name": schema["title"],
+        "description": schema.get("description", ""),
+        "parameters": {
+            "properties": {
+                k: {
+                    "type_": TYPE_ENUM[v["type"]],
+                    "description": v.get("description"),
+                }
+                for k, v in schema["properties"].items()
+            },
+            "required": schema["required"],
+            "type_": TYPE_ENUM[schema["type"]],
+        },
+    }

libs/partners/google-genai/langchain_google_genai/chat_models.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 import base64
+import json
 import logging
 import os
 from io import BytesIO
@@ -54,6 +55,9 @@
 )
 
 from langchain_google_genai._common import GoogleGenerativeAIError
+from langchain_google_genai._function_utils import (
+    convert_to_genai_function_declarations,
+)
 from langchain_google_genai.llms import GoogleModelFamily, _BaseGoogleGenerativeAI
 
 IMAGE_TYPES: Tuple = ()
@@ -351,69 +355,14 @@ def _retrieve_function_call_response(
             return {
                 "function_call": {
                     "name": fc.name,
-                    "arguments": dict(fc.args.items()),
+                    "arguments": json.dumps(
+                        dict(fc.args.items())
+                    ),  # dump to match other function calling llms for now
                 }
             }
     return None
 
 
-def _convert_function_call_req(function_calls: Union[Dict, List[Dict]]) -> Dict:
-    function_declarations = []
-    if isinstance(function_calls, dict):
-        function_declarations.append(_convert_fc_type(function_calls))
-    else:
-        for fc in function_calls:
-            function_declarations.append(_convert_fc_type(fc))
-    return {
-        "function_declarations": function_declarations,
-    }
-
-
-def _convert_fc_type(fc: Dict) -> Dict:
-    # type_: "Type"
-    # format_: str
-    # description: str
-    # nullable: bool
-    # enum: MutableSequence[str]
-    # items: "Schema"
-    # properties: MutableMapping[str, "Schema"]
-    # required: MutableSequence[str]
-    if "parameters" in fc:
-        fc["parameters"] = _convert_fc_type(fc["parameters"])
-    if "properties" in fc:
-        for k, v in fc["properties"].items():
-            fc["properties"][k] = _convert_fc_type(v)
-    if "type" in fc:
-        # STRING = 1
-        # NUMBER = 2
-        # INTEGER = 3
-        # BOOLEAN = 4
-        # ARRAY = 5
-        # OBJECT = 6
-        if fc["type"] == "string":
-            fc["type_"] = 1
-        elif fc["type"] == "number":
-            fc["type_"] = 2
-        elif fc["type"] == "integer":
-            fc["type_"] = 3
-        elif fc["type"] == "boolean":
-            fc["type_"] = 4
-        elif fc["type"] == "array":
-            fc["type_"] = 5
-        elif fc["type"] == "object":
-            fc["type_"] = 6
-        del fc["type"]
-    if "format" in fc:
-        fc["format_"] = fc["format"]
-        del fc["format"]
-
-    for k, v in fc.items():
-        if isinstance(v, dict):
-            fc[k] = _convert_fc_type(v)
-
-    return fc
-
-
 def _parts_to_content(
     parts: List[genai.types.PartType],
 ) -> Tuple[Union[str, List[Union[Dict[Any, Any], str]]], Optional[Dict]]:
@@ -708,19 +657,19 @@ def _prepare_chat(
         stop: Optional[List[str]] = None,
         **kwargs: Any,
     ) -> Tuple[Dict[str, Any], genai.ChatSession, genai.types.ContentDict]:
-        cli = self.client
+        client = self.client
         functions = kwargs.pop("functions", None)
         if functions:
-            tools = _convert_function_call_req(functions)
-            cli = genai.GenerativeModel(model_name=self.model, tools=tools)
+            tools = convert_to_genai_function_declarations(functions)
+            client = genai.GenerativeModel(model_name=self.model, tools=tools)
 
         params = self._prepare_params(stop, **kwargs)
         history = _parse_chat_history(
             messages,
             convert_system_message_to_human=self.convert_system_message_to_human,
         )
         message = history.pop()
-        chat = cli.start_chat(history=history)
+        chat = client.start_chat(history=history)
         return params, chat, message
 
     def get_num_tokens(self, text: str) -> int:

libs/partners/google-genai/tests/integration_tests/test_function_call.py

@@ -1,5 +1,11 @@
 """Test ChatGoogleGenerativeAI function call."""
 
+import json
+
+from langchain_core.messages import AIMessage
+from langchain_core.pydantic_v1 import BaseModel
+from langchain_core.tools import tool
+
 from langchain_google_genai.chat_models import (
     ChatGoogleGenerativeAI,
 )
@@ -29,6 +35,50 @@ def test_function_call() -> None:
     assert res.additional_kwargs
     assert "function_call" in res.additional_kwargs
     assert "get_weather" == res.additional_kwargs["function_call"]["name"]
-    arguments = res.additional_kwargs["function_call"]["arguments"]
-    assert isinstance(arguments, dict)
+    arguments_str = res.additional_kwargs["function_call"]["arguments"]
+    assert isinstance(arguments_str, str)
+    arguments = json.loads(arguments_str)
     assert "location" in arguments
+
+
+def test_tool_call() -> None:
+    @tool
+    def search_tool(query: str) -> str:
+        """Searches the web for `query` and returns the result."""
+        raise NotImplementedError
+
+    llm = ChatGoogleGenerativeAI(model="gemini-pro").bind(functions=[search_tool])
+    response = llm.invoke("weather in san francisco")
+    assert isinstance(response, AIMessage)
+    assert isinstance(response.content, str)
+    assert response.content == ""
+    function_call = response.additional_kwargs.get("function_call")
+    assert function_call
+    assert function_call["name"] == "search_tool"
+    arguments_str = function_call.get("arguments")
+    assert arguments_str
+    arguments = json.loads(arguments_str)
+    assert "query" in arguments
+
+
+class MyModel(BaseModel):
+    name: str
+    age: int
+
+
+def test_pydantic_call() -> None:
+    llm = ChatGoogleGenerativeAI(model="gemini-pro").bind(functions=[MyModel])
+    response = llm.invoke("my name is Erick and I am 27 years old")
+    assert isinstance(response, AIMessage)
+    assert isinstance(response.content, str)
+    assert response.content == ""
+    function_call = response.additional_kwargs.get("function_call")
+    assert function_call
+    assert function_call["name"] == "MyModel"
+    arguments_str = function_call.get("arguments")
+    assert arguments_str
+    arguments = json.loads(arguments_str)
+    assert arguments == {
+        "name": "Erick",
+        "age": 27.0,
+    }