idempot-js

Fastify ​

Installation ​

bash
npm install @idempot/fastify-middleware @idempot/sqlite-store

Usage ​

javascript
import Fastify from "fastify";
import { idempotency } from "@idempot/fastify-middleware";
import { SqliteIdempotencyStore } from "@idempot/sqlite-store";

const fastify = Fastify();
const store = new SqliteIdempotencyStore({ path: ":memory:" });

fastify.post(
  "/orders",
  { preHandler: idempotency({ store }) },
  async (request, reply) => {
    const orderId = crypto.randomUUID();
    return { id: orderId, ...request.body };
  }
);

fastify.listen({ port: 3000 });

API ​

idempotency(options) ​

Creates Fastify preHandler hook for idempotency.

Options:

  • store (required): Storage backend implementing IdempotencyStore
  • required: Whether idempotency key is required (default: true)
  • ttlMs: Time-to-live for idempotency records in milliseconds
  • excludeFields: Fields to exclude from fingerprint calculation
  • resilience: Circuit breaker and retry options

Returns: Fastify preHandler hook function with circuit property for monitoring.