[Responses API] Structured output

[Wauplin]

Built on top of #1576.

Based on https://platform.openai.com/docs/guides/structured-outputs

Works both with and without streaming.

Non-stream

Run

pnpm run example structured_output

(which core logic is:)

(...)
const response = await openai.responses.parse({
	model: "Qwen/Qwen2.5-VL-72B-Instruct",
	provider: "nebius",
	input: [
		{
			role: "system",
			content: "You are a helpful math tutor. Guide the user through the solution step by step.",
		},
		{ role: "user", content: "how can I solve 8x + 7 = -23" },
	],
	text: {
		format: zodTextFormat(MathReasoning, "math_reasoning"),
	},
});
(...)

Output:

{
  steps: [
    {
      explanation: 'To solve for x, we need to isolate it on one side of the equation. We start by subtracting 7 from both sides of the equation.',
      output: '8x + 7 - 7 = -23 - 7'
    },
    {
      explanation: 'Simplify the equation after performing the subtraction.',
      output: '8x = -30'
    },
    {
      explanation: 'Now that we have isolated the term with x, we divide both sides by 8 to get x by itself.',
      output: '8x / 8 = -30 / 8'
    },
    {
      explanation: 'Perform the division to find the value of x.',
      output: 'x = -30 / 8'
    },
    {
      explanation: 'Simplify the fraction if possible.',
      output: 'x = -15 / 4'
    }
  ],
  final_answer: 'The solution is x = -15/4 or x = -3.75.'
}

Stream

Run

pnpm run example structured_output_streaming

(which core logic is:)

const stream = openai.responses
	.stream({
		model: "Qwen/Qwen2.5-VL-72B-Instruct",
		provider: "nebius",
		instructions: "Extract the event information.",
		input: "Alice and Bob are going to a science fair on Friday.",
		text: {
			format: zodTextFormat(CalendarEvent, "calendar_event"),
		},
	})
	.on("response.refusal.delta", (event) => {
		process.stdout.write(event.delta);
	})
	.on("response.output_text.delta", (event) => {
		process.stdout.write(event.delta);
	})
	.on("response.output_text.done", () => {
		process.stdout.write("\n");
	})
	.on("response.error", (event) => {
		console.error(event.error);
	});

const result = await stream.finalResponse();
console.log(result.output_parsed);

Output:

{
  "name": "Science Fair",
  "date": "Friday",
  "participants": ["Alice", "Bob"]
}
{
  name: 'Science Fair',
  date: 'Friday',
  participants: [ 'Alice', 'Bob' ]
}