Implementation:Openai Openai python Response Function Tool Call

Knowledge Sources	Openai_Openai_python OpenAI API Reference
Domains	API_Types, Responses_API
Last Updated	2026-02-15 00:00 GMT

Overview

Concrete type for representing a function tool call issued by the model during a Responses API interaction, provided by the openai-python SDK.

Description

ResponseFunctionToolCall is a Pydantic model that represents a tool call to run a function. It contains the arguments serialized as a JSON string, the call_id uniquely identifying the call on the model side, the name of the function to invoke, and an optional status indicating the progress of the call. The type field is always set to the literal value "function_call". See the function calling guide for more information.

Usage

Import this type when you need to inspect or type-check function tool call items returned in a Responses API response output, or when building typed event handlers for streaming responses.

Code Reference

Source Location

• Repository: openai-python
• File: src/openai/types/responses/response_function_tool_call.py

Signature

class ResponseFunctionToolCall(BaseModel):
    """A tool call to run a function."""

    arguments: str
    call_id: str
    name: str
    type: Literal["function_call"]
    id: Optional[str] = None
    status: Optional[Literal["in_progress", "completed", "incomplete"]] = None

Import

from openai.types.responses import ResponseFunctionToolCall

I/O Contract

Fields

Name	Type	Required	Description
arguments	str	Yes	A JSON string of the arguments to pass to the function.
call_id	str	Yes	The unique ID of the function tool call generated by the model.
name	str	Yes	The name of the function to run.
type	Literal["function_call"]	Yes	The type of the function tool call. Always function_call.
id	Optional[str]	No	The unique ID of the function tool call.
status	Optional[Literal["in_progress", "completed", "incomplete"]]	No	The status of the item. Populated when items are returned via API.

Usage Examples

import openai

client = openai.OpenAI()

response = client.responses.create(
    model="gpt-4o",
    input="What is the weather in Boston?",
    tools=[{
        "type": "function",
        "name": "get_weather",
        "description": "Get the current weather for a location.",
        "parameters": {
            "type": "object",
            "properties": {"location": {"type": "string"}},
            "required": ["location"],
        },
    }],
)

for item in response.output:
    if item.type == "function_call":
        print(item.name)        # "get_weather"
        print(item.arguments)   # '{"location": "Boston"}'
        print(item.call_id)

Related Pages

• Environment:Openai_Openai_python_Python_3_9_Plus