---
title: "Idempotency: What, Why and How"
url: https://daily.dev/posts/idempotency-what-why-and-how-qrypjmflf
source_url: https://wendelladriel.com/blog/idempotency-what-why-and-how
type: article
source: "W endell Adriel"
author: "Wendell Adriel"
published: 2026-04-27T14:22:03.228Z
updated: 2026-07-16T02:12:44.043Z
tags: ["architecture", "laravel", "php"]
reading_time: 16
upvotes: 54
comments: 3
language: en
---

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# Idempotency: What, Why and How

**[W endell Adriel](https://daily.dev/sources/wendelladriel)** · [@wendell_adriel](https://daily.dev/wendell_adriel) · 16 min read · 54 upvotes · 3 comments

## Summary

A deep dive into idempotency for HTTP APIs, covering the theory and a practical Laravel implementation using the `wendelladriel/laravel-idempotency` package. Explains idempotency keys, request fingerprinting, cached response replay, atomic locks for concurrent requests, and key scoping (user/IP/global). Shows how to apply idempotency via route middleware or PHP attributes, customize per-endpoint settings, design idempotent controllers with proper domain invariants, handle failure status codes (400/409/422), use Artisan commands for observability, and write feature tests for retry contracts. Also covers common mistakes like reusing keys across operations or neglecting shared cache infrastructure.

## Full article

daily.dev links to this article rather than hosting it. Read it at the original source: <https://wendelladriel.com/blog/idempotency-what-why-and-how>

## Community discussion

Top comments from developers on daily.dev.

**@mahadihassanshakil** · 2 upvotes

> Great explanation—highlighting idempotency as “safe to retry” really captures why it’s essential for preventing duplicate actions in real-world distributed systems.

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---

Tags: [#architecture](https://daily.dev/tags/architecture), [#laravel](https://daily.dev/tags/laravel), [#php](https://daily.dev/tags/php)

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