Plug that makes POST and PATCH requests idempotent

Implement idempotent endpoints in Laravel à la Stripe

🛡️ Laravel Idempotency Middleware package to prevent duplicate requests

🚥 Idempotency Handler, for making sure incoming requests are idempotent. Useful for payments, "at least once delivery" systems and more.

Gem for supporting idempotency in your Grape APIs

makes any request idempotent across nodejs frameworks like nestjs, express, fastify

Interpret HTTP responses and handle failures in Swift.

Idempotent Package for Laravel

My vision of pretty good FastAPI project template to start with

IdempotentSharp allows you to develop idempotent endpoints.

Quickie is an open-source library to build APIs and backend services with idempotency and rate limiting QUICKLY in .NET

Deterministic idempotency keys and storage adapters for taming duplicate requests across Redis, SQL, MongoDB, and in-memory backends.

The idempotency-middleware library adds idempotency support to your Go API projects. It ensures that a client request is processed only once, regardless of how many times it is received. This middleware is especially useful for handling retry logic in distributed systems.

Sample implementation of draft-ietf-httpapi-idempotency-key-header in HTTP API on Rails

Make any mutating endpoint idepmotent

A Rack Middleware implementing the idempotency design principle using the Idempotency-Key HTTP header.

🔑 Manage idempotency for JSON payloads with steadykey. Generate stable keys, prevent duplicates, and ensure auditing with pluggable storage options.