docs: Quickstart example throws multiple errors

[gonzochic]

Checklist

• I added a very descriptive title to this issue.
• I included a link to the documentation page I am referring to (if applicable).

Issue with current documentation:

I tried to follow the Quickstart examples for Typescript. Do only adaption I did, i used gpt-4o instead of the Sonnet models (altough I don't think this is the issues)

Multiple issues occured:

1. Typescript error: The "getUserLocation" Tool code creates a typescript error.

2. When running the full example code, it fails with a ``ìnvalid_request_error```.

error: 400 Invalid schema for response_format 'extract': In context=(), 'required' is required to be supplied and to be an array including every key in properties. Missing 'weather_conditions'.

I am using:

• Bun v1.3
• langchain v1.0.4
• @langchain/core v1.0.4
• @langchain/openai v1.1.0
• MacOS 15.6.1

Idea or request for content:

No response

[MilanMeurrens]

It seems like this is an OpenAI specific problem. Anthropic handles the optional fields in the scheme Zod generates better.

What you can do to make it work with OpenAi is use a union with the type and null instead of using optional.

name: z.union([z.string(), z.null()])

Edit: I just discovered using nullable also works: name: z.nullable(z.string())