OpenAI Responses API

Overview

OpenAI's Responses API is their new recommended API for inference, offering improved performance and features compared to Chat Completions.

Key features: - 3% better performance on reasoning tasks - 40-80% improved cache utilization - Built-in tools: web search, file search, code interpreter - Server-side conversation state via previous_response_id - Semantic streaming events

Inference feature compatibility: - tool calling (supported) - native JSON object response_format (supported) - native JSON schema response_format (recommended) - Instructor markdown-JSON fallback (fallback)

Example

<?php

use Cognesy\Messages\Messages;
use Cognesy\Polyglot\Inference\Inference;
use Cognesy\Utils\Str;

require 'examples/boot.php';

$answer = Inference::using('openai-responses')
    ->with(
        messages: Messages::fromString('What is the capital of France'),
        options: ['max_tokens' => 64]
    )
    ->get();

echo "USER: What is capital of France\n";
echo "ASSISTANT: $answer\n";
assert(Str::contains($answer, 'Paris'));
?>