Models are told the user is in the USA when using the web tool

I’m not sure what you’re saying here.

I’m saying that the string “The user is in an estimated location of United States” is injected into the prompt when tools=[{"type": "web_search"}]is passed to client.responses.create.

I’m not talking about what happens when a location is passed in the web search definition, or how the model infers location from language, or the scope of search results, or anything else.

I think you’re confusing the issue by bringing other languages into it, but just to be clear: if you pass tools=[{"type": "web_search"}] and ask the model where you are in Japanese it will say that you are in the United States (in Japanese) because the string “The user is in an estimated location of United States” is injected into the prompt.

BTW @sps since this is the expected behaviour, but in my opinion, not a sensible default, I’ve logged this as an issue with the SDK folks so hopefully the USA-string-injection can be avoided or at least have the behaviour explained in the docs and have the workaround explained.