hp24-idemkit-next

Idempotency for Next.js — wrappers for both the App Router and the Pages API. Part of idemkit.

npm install hp24-idemkit-next hp24-idemkit-core

App Router (app/api/*/route.ts)

import { MemoryStore } from 'hp24-idemkit-core';
import { withIdempotency } from 'hp24-idemkit-next';

const store = new MemoryStore(); // module scope — reuse across requests

export const POST = withIdempotency(async (req) => {
  const body = await req.json();
  return Response.json({ id: 'ch_123' }, { status: 201 });
}, { store });

Pages API (pages/api/*.ts)

import { MemoryStore } from 'hp24-idemkit-core';
import { withIdempotencyApi } from 'hp24-idemkit-next';

const store = new MemoryStore();

export default withIdempotencyApi((req, res) => {
  res.status(201).json({ id: 'ch_123' });
}, { store });

Behavior matches the rest of idemkit: replay on repeat (X-Idempotency-Replay: true), 422 on payload mismatch, 409 (or wait) on concurrent duplicates, 5xx not cached.

Use a module-scoped store, not one created per request — a fresh store per invocation can't deduplicate anything. In serverless, prefer hp24-idemkit-redis so the store is shared across instances and survives cold starts.

Options are the same as the Express adapter. License: MIT.