Add "user" property from Reponses API for caching/tracking and abuse issues

[sarunas-zebra]

OpenAI docks state:

A stable identifier for your end-users. Used to boost cache hit rates by better bucketing similar requests and to help OpenAI detect and prevent abuse.

https://platform.openai.com/docs/api-reference/responses/object#responses/object-user
https://platform.openai.com/docs/guides/safety-best-practices#end-user-ids

[sibblegp]

Would love to have this

[seratch]

Hi @sarunas-zebra @sibblegp, thanks for writing in!

You can use ModelSettings#extra_args to pass the parameter as below:

import asyncio
from agents import Agent, Runner, ModelSettings

async def main():
    agent = Agent(
        name="Assistant",
        model="gpt-4.1",
        model_settings=ModelSettings(
            extra_args={
                # Pass optional parameters to Responses API
                "user": "user_123456",
            },
        ),
    )
    result = await Runner.run(agent, "Hey, can you tell me a joke?")
    print(result)

if __name__ == "__main__":
    asyncio.run(main())

Hope this helps! Also, I found that this is not mentioned in the document pages at all, so I will come up with a pull request to add the section to cover this.

[sibblegp]

Wait, shouldn't we be able to dynamically set the user object? I run a multi-user, multi-agent setup so this doesn't allow me to pass which user I need to the agent.

[sibblegp]

I would imagine it should be more like

Runner.run("What is the weather?", AGENT, context, user)