Announcing idempot-js: Idempotency Middleware for Node.js, Bun, and Deno

You click a payment button. You wait. You wonder if it worked. You click again—just to be safe. That moment of uncertainty represents one of distributed systems’ harder problems: ensuring operations happen exactly once, even when networks fail and clients retry. I’ve been working on idempot-js — IETF-compliant idempotency middleware for Express, Fastify, and Hono. ...

April 6, 2026 · 3 min