Support JSON Schema in responseFormat

[hi019]

It would be great if Token.js could support type: "json_schema" in response_format:

import { TokenJS } from "token.js";

const t = new TokenJS();

await o.chat.completions.create({
  provider: "openai",
  model: "gpt-4o-mini",
  messages: [
    {
      role: "user",
      content: "Extract the name from the following text: 'John Doe'",
    },
  ],
  response_format: {
    type: "json_schema",
    json_schema: {
      name: "test",
      schema: {
        type: "object",
        properties: {
          name: {
            type: "string",
            description: "The name of the person",
          },
        },
      },
    },
  },
});

This works with the native client:

import { OpenAI} from "openai"

const o = new OpenAI()

await o.chat.completions.create({
  model: "gpt-4o-mini",
  messages: [
    {
      role: "user",
      content: "Extract the name from the following text: 'John Doe'",
    },
  ],
  response_format: {
    type: "json_schema", // Error, can only be "json_object" or "text"
    json_schema: {
      name: "test",
      schema: {
        type: "object",
        properties: {
          name: {
            type: "string",
            description: "The name of the person",
          },
        },
      },
    },
  },
});

Docs: https://platform.openai.com/docs/guides/structured-outputs?lang=javascript

It looks like the json_schema type doesn't exist on the currently depended on openai version (4.52.2), so we probably need to update to the latest (4.82.2)

[Hamnivore]

Structured response seems to be working on openai now, but not on gemini models

const tokenjs = new TokenJS();

async function test_structured_response(provider, model) {
  const response = await tokenjs.chat.completions.create({
    provider: provider,
    model: model,
    messages: [
      {
        role: "user",
        content: "Extract the name from the following text: 'John Doe'",
      },
    ],
    response_format: {
      type: "json_schema",
      json_schema: {
        name: "test",
        schema: {
          type: "object",
          properties: {
            name: {
              type: "string",
              description: "The name of the person",
            },
          },
        },
      },
    },
  });

  console.log(
    provider, 
    model,
    `\nresponse: ${response.choices[0].message.content}`
  );
}

test_structured_response("openai", "gpt-4o-mini"); // outputs {"name":"John Doe"}
test_structured_response("gemini", "gemini-2.0-flash-001"); // outputs  John Doe