Implementation:Openai Openai python Tool Choice Allowed

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 tool choice configuration that constrains the model to a pre-defined set of allowed tools, provided by the openai-python SDK.

Description

ToolChoiceAllowed is a Pydantic model that constrains which tools the model is allowed to use during response generation. It has a mode field set to either "auto" (model may choose from allowed tools or generate a message) or "required" (model must call one or more of the allowed tools). The tools field is a list of tool definition dictionaries specifying which tools are permitted, and the type field is always "allowed_tools".

Usage

Import this type when you need to inspect or type-check a tool choice configuration that restricts the model to specific tools, as returned in API responses.

Code Reference

Source Location

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

Signature

class ToolChoiceAllowed(BaseModel):
    """Constrains the tools available to the model to a pre-defined set."""

    mode: Literal["auto", "required"]
    tools: List[Dict[str, object]]
    type: Literal["allowed_tools"]

Import

from openai.types.responses import ToolChoiceAllowed

I/O Contract

Fields

Name	Type	Required	Description
mode	Literal["auto", "required"]	Yes	auto allows the model to pick from allowed tools and generate a message. required requires the model to call one or more of the allowed tools.
tools	List[Dict[str, object]]	Yes	A list of tool definitions that the model is allowed to call. Each dict specifies tool type and identifying info (e.g., {"type": "function", "name": "get_weather"}).
type	Literal["allowed_tools"]	Yes	Allowed tool configuration type. Always allowed_tools.

Usage Examples

import openai

client = openai.OpenAI()

response = client.responses.create(
    model="gpt-4o",
    input="What is the weather in Paris?",
    tools=[
        {"type": "function", "name": "get_weather", "parameters": {
            "type": "object",
            "properties": {"location": {"type": "string"}},
            "required": ["location"],
        }},
        {"type": "web_search_preview"},
    ],
    tool_choice={
        "type": "allowed_tools",
        "mode": "auto",
        "tools": [
            {"type": "function", "name": "get_weather"},
        ],
    },
)

Related Pages

• Environment:Openai_Openai_python_Python_3_9_Plus