Idempotency Check

Analyze PHP code for idempotency violations that can cause duplicate writes, double charges, or inconsistent state on retries.

Detection Patterns

1. Missing Idempotency Key on POST/PUT Endpoints

<?php

declare(strict_types=1);

// BAD: POST endpoint creates resource without deduplication
final class CreateOrderAction
{
    public function __invoke(Request $request): Response
    {
        $order = $this->orderService->create($request->validated());