zodFunction helper rejects default() and min() Zod methods in validation schemas for function calling

[aleksa-codes]

Confirm this is a Node library issue and not an underlying OpenAI API issue

• This is an issue with the Node library

Describe the bug

When using the zodFunction helper found here, Zod schemas containing default() and min() methods are rejected with errors like 'default' is not permitted and 'minLength' is not permitted. These methods work fine when using the example zodFunction utility provided here, but not with the exported helper function. default() for enums seems to work in both cases, but not for other types of values.

To Reproduce

1. Working Example:

import { z, ZodSchema } from 'zod';
import { JSONSchema } from 'openai/lib/jsonschema';
import { zodToJsonSchema } from 'zod-to-json-schema';
import { RunnableToolFunctionWithParse } from 'openai/lib/RunnableFunction';

export const TimeParams = z.object({
  timeZone: z.string().describe('Time zone of the location').default('Europe/Belgrade'),
});
type TimeParams = z.input<typeof TimeParams>;

const getCurrentTime = async (params: TimeParams) => {
  try {
    const response = await fetch(`https://worldtimeapi.org/api/timezone/${params.timeZone}`);

    const data = await response.json();
    const importantTimeData = {
      abbreviation: data.abbreviation,
      datetime: new Date(data.datetime).toLocaleString('en-US', {
        weekday: 'long',
        year: 'numeric',
        month: 'long',
        day: 'numeric',
        hour: 'numeric',
        minute: 'numeric',
        timeZone: data.timezone,
        timeZoneName: 'short',
      }),
      timezone: data.timezone,
    };

    return {
      current_time: importantTimeData,
    };
  } catch (error) {
    return {
      error: getErrorMessage(error, 'Failed to fetch the current time'),
    };
  }
};

function zodFunction<T extends object>({
  function: fn,
  schema,
  description = '',
  name,
}: {
  function: (args: T) => Promise<object>;
  schema: ZodSchema<T>;
  description?: string;
  name?: string;
}): RunnableToolFunctionWithParse<T> {
  return {
    type: 'function',
    function: {
      function: fn,
      name: name ?? fn.name,
      description: description,
      parameters: zodToJsonSchema(schema) as JSONSchema,
      parse(input: string): T {
        const obj = JSON.parse(input);
        return schema.parse(obj);
      },
    },
  };
}

export const chatCompletionsTools = [
  zodFunction({
    function: getCurrentTime,
    name: 'getCurrentTime',
    schema: TimeParams,
    description: 'Get the current time in a given location',
  }),
];

2. Non-Working Example (Using the Official zodFunction Helper):

import { z } from 'zod';
import { zodFunction } from 'openai/helpers/zod';

export const TimeParams = z.object({
  timeZone: z.string().describe('Time zone of the location').default('Europe/Belgrade'),
});
type TimeParams = z.input<typeof TimeParams>;

const getCurrentTime = async (params: TimeParams) => {
  try {
    const response = await fetch(`https://worldtimeapi.org/api/timezone/${params.timeZone}`);

    const data = await response.json();
    const importantTimeData = {
      abbreviation: data.abbreviation,
      datetime: new Date(data.datetime).toLocaleString('en-US', {
        weekday: 'long',
        year: 'numeric',
        month: 'long',
        day: 'numeric',
        hour: 'numeric',
        minute: 'numeric',
        timeZone: data.timezone,
        timeZoneName: 'short',
      }),
      timezone: data.timezone,
    };

    return {
      current_time: importantTimeData,
    };
  } catch (error) {
    return {
      error: getErrorMessage(error, 'Failed to fetch the current time'),
    };
  }
};

export const chatCompletionsTools = [
  zodFunction({
    function: getCurrentTime,
    name: 'getCurrentTime',
    parameters: TimeParams, 
    description: 'Get the current time in a given location',
  }),
];

3. Both examples were tested with:

openai.beta.chat.completions.runTools()

Code snippets

No response

OS

Windows 11

Node version

v20.16.0

Library version

4.67.1

[OB42]

same issue here :(