What are the built-in tools available in the OpenAI Responses API?

The Responses API ships with several built-in tools that the model can invoke automatically without you writing wrapper code. These tools connect the model to the real world and the developer's environment.

# Using web_search in the Responses API:
from openai import OpenAI
client = OpenAI()

response = client.responses.create(
    model="gpt-5.5",
    tools=[{"type": "web_search_preview"}],
    input="What are the latest changes to Python's asyncio in 3.12?",
)
print(response.output_text)

# Using multiple tools together:
response = client.responses.create(
    model="gpt-5.5",
    tools=[
        {"type": "web_search_preview"},
        {"type": "file_search", "vector_store_ids": ["vs_abc123"]}
    ],
    input="Summarise our internal Q3 report and compare it with industry trends.",
)

Tools can be combined in a single request. The model decides when and how to invoke them - the developer does not need to manually manage tool invocation loops as with function calling in Chat Completions.

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