Implementation:Googleapis Python genai AutomaticFunctionCallingConfig Setup

Knowledge Sources	googleapis/python-genai Google Gen AI Python SDK
Domains	Function_Calling, Tool_Use
Last Updated	2026-02-15 00:00 GMT

Overview

Concrete tool for configuring automatic function calling behavior and tool invocation modes provided by the google-genai types module.

Description

AutomaticFunctionCallingConfig controls whether the SDK automatically executes function calls and feeds results back to the model. When enabled (default), the SDK handles the multi-turn function calling loop transparently. ToolConfig with FunctionCallingConfig controls the model's function calling mode (AUTO, ANY, NONE) and can restrict which functions are allowed. These configurations are set in GenerateContentConfig.

Usage

Set automatic_function_calling_config in the GenerateContentConfig to control the AFC loop. Disable AFC by setting disable=True when you want manual control over function execution. Set maximum_remote_calls to limit the number of automatic invocations (default: 10). Use ToolConfig to control whether the model must, may, or cannot call functions.

Code Reference

Source Location

• Repository: googleapis/python-genai
• File: google/genai/types.py
• Lines: L4606 (AutomaticFunctionCallingConfig), L4424 (ToolConfig)

Signature

class AutomaticFunctionCallingConfig(_common.BaseModel):
    """Configuration for automatic function calling."""
    disable: Optional[bool] = None  # If True, disable AFC
    maximum_remote_calls: Optional[int] = 10  # Max auto calls
    ignore_call_history: Optional[bool] = None

class ToolConfig(_common.BaseModel):
    """Tool configuration shared for all tools."""
    function_calling_config: Optional[FunctionCallingConfig] = None
    retrieval_config: Optional[RetrievalConfig] = None

class FunctionCallingConfig(_common.BaseModel):
    """Config for function calling."""
    mode: Optional[FunctionCallingConfigMode] = None  # AUTO, ANY, NONE
    allowed_function_names: Optional[list[str]] = None

Import

from google.genai import types

I/O Contract

Inputs

Name	Type	Required	Description
disable	Optional[bool]	No	If True, disable automatic function calling
maximum_remote_calls	Optional[int]	No	Max number of automatic calls (default 10)
mode	Optional[FunctionCallingConfigMode]	No	AUTO, ANY, or NONE
allowed_function_names	Optional[list[str]]	No	Restrict which functions model can call

Outputs

Name	Type	Description
AutomaticFunctionCallingConfig	AutomaticFunctionCallingConfig	AFC configuration for GenerateContentConfig
ToolConfig	ToolConfig	Tool behavior configuration for GenerateContentConfig

Usage Examples

Disable Automatic Function Calling

from google import genai
from google.genai import types

client = genai.Client(api_key="YOUR_API_KEY")

response = client.models.generate_content(
    model="gemini-2.0-flash",
    contents="What's the weather?",
    config=types.GenerateContentConfig(
        tools=[get_weather],
        automatic_function_calling_config=types.AutomaticFunctionCallingConfig(
            disable=True
        ),
    ),
)
# response.function_calls will contain the call to execute manually

Force Function Calling

response = client.models.generate_content(
    model="gemini-2.0-flash",
    contents="Tell me about the weather.",
    config=types.GenerateContentConfig(
        tools=[get_weather],
        tool_config=types.ToolConfig(
            function_calling_config=types.FunctionCallingConfig(
                mode="ANY"  # Force model to call a function
            )
        ),
    ),
)

Limit Automatic Calls

response = client.models.generate_content(
    model="gemini-2.0-flash",
    contents="Plan a trip to Paris.",
    config=types.GenerateContentConfig(
        tools=[get_weather, get_flights, get_hotels],
        automatic_function_calling_config=types.AutomaticFunctionCallingConfig(
            maximum_remote_calls=5  # Limit loop iterations
        ),
    ),
)

Related Pages

Implements Principle

• Principle:Googleapis_Python_genai_Tool_Configuration