Next.js guide · Node.js SDK

Next.js rate limitingfor the API you sell.

Wrap a route handler with withReqKey. The caller’s key is checked, their credits are charged, and their plan’s rate limit is applied — on Vercel, Node, or anywhere else Next.js runs.

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  • Keys issued per customer
  • Credits that refill
  • Limits per plan, not per process

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API requests validated
100M+
Average key validation
<5ms
Average analytics ingest
<5ms
Check and log, end to end
<10ms

The usual Next.js rate limiter counts requests. It doesn’t know your customers.

Serverless functions can’t keep counts in memory, so most Next.js apps pair @upstash/ratelimit with an Upstash Redis database and call limit() at the top of each handler.

With Upstash Ratelimittoday
// route.ts — with @upstash/ratelimitimport { Ratelimit } from "@upstash/ratelimit";
import { Redis } from "@upstash/redis";

const ratelimit = new Ratelimit({
  redis: Redis.fromEnv(),
  limiter: Ratelimit.slidingWindow(10, "10 s"),
});

export async function POST(request: Request) {
  const key = request.headers.get("x-api-key") ?? "anonymous";
  const { success } = await ratelimit.limit(key);
  if (!success) return new Response("Too many requests", { status: 429 });
  return Response.json({ ok: true });
}
  • A Redis database to create, pay for, and keep in the same region
  • The identifier is whatever the header says — nothing validates the key
  • No API keys: issuing, hashing, scoping, and revoking them is still yours to build
  • No credit balance: a request can’t cost 5 on one route and 1 on another, or refill each month
  • One limit for everyone — no per-plan limits for Free, Pro, and Enterprise customers
  • No per-customer usage log to answer “why was I blocked?” or bill against
With ReqKey in Next.jsone middleware
  • API keys issued per customer, prefixed, hashed, and revocable from the dashboard
  • A credit balance per customer — price each route, refill every hour, day, week, or month
  • Rate limits set per plan, shared by all of a customer’s keys, from 1 second to 24 hours
  • The same count on every worker, instance, and region — no Redis to run
  • Over the limit? A 429 with Retry-After, and no credits charged
  • Every request logged per customer — status, latency, endpoint — in under 5ms
Inside the handler, getReqKey(request) returns the verdict — credits remaining, the consumer, and the request ID. See the code

Next.js in three steps, one of them code.

ReqKey runs inside your API, not in front of it. Your server asks one question per request and gets an answer in under 5ms.

  1. 1

    Install the SDK

    npm install reqkey

  2. 2

    Set your project key

    Copy it from the dashboard into REQKEY_PROJECT_KEY. It stays on your server.

  3. 3

    Add the Next.js middleware

    Every request is checked, charged, and logged before your handler runs.

app/api/payments/route.tsnpm install reqkey
// app/api/payments/route.ts
import { getReqKey, withReqKey } from "reqkey/next";
 
export const POST = withReqKey(
  async (request) => {
    const decision = getReqKey(request);
    return Response.json(
      { created: true, creditsRemaining: decision?.creditsRemaining },
      { status: 201 },
    );
  },
  {
    projectKey: process.env.REQKEY_PROJECT_KEY,
    apiId: "api_payments",
    mode: "both",
    keyName: "x-startup-key",
  },
);
Also in Node.js: Express, NestJS, Fastify, Hono, KoaFull Node.js reference

Every request gets one of these answers

  • 200Valid key, credits charged — your handler runs
  • 402Out of credits
  • 403Key disabled, or not allowed on this API
  • 429Over the rate limit — no credits charged

Where ReqKey sits

Your customer
Your APIReqKey, under 5ms
Your handler

Responses go straight back to your customer. ReqKey sees the key check and the log line, nothing else.

Credits

Charge each route what it costs you.

A lookup can cost 1 credit and a render 5, from the same balance. Excluded paths are never validated, charged, or recorded. In Node.js:

Per-route credits · Node.js
// Exact paths or trailing-* prefixes: never validated, charged, or recorded
excludePaths: ["/health", "/openapi.json", "/docs/*", "/cron/*"]
 
// Or decide per request with a sync or async resolver
shouldProtect: ({ path }) => path.startsWith("/api/")
 
// Charge different endpoints differently (non-negative integers)
credits: ({ method, path }) => {
  if (method === "POST" && path === "/images") return 5;
  if (path.startsWith("/reports/")) return 2;
  return 1;
}

Rate limits

Set limits on plans, not in code.

Your Next.js code never hard-codes a number. Each plan carries its credits, refill, and rate limit; moving a customer to Pro changes all three with no deploy.

PlanCreditsRate limit
Free1,000 / month5 req / s
Pro50,000 / month50 req / s
Scale1,000,000 / month500 req / s
429Over the limit, a call is answered with Retry-After and costs nothing — no credits and no quota.

Example plans. You name them and pick the numbers.

Notes for Next.js teams hit in production.

Per route handler

withReqKey wraps the exported POST, GET, or any other handler, so you choose exactly which routes are paid API and which stay public.

Serverless-safe by design

Nothing is kept in the function’s memory. Cold starts, scale-out, and multiple regions all share one balance per customer.

App Router route handlers

The example uses app/api/**/route.ts. The handler receives a standard Request and returns a standard Response.

Next.js rate limiting: the questions teams ask.

Something else? Ask the team or read the docs.

  • Not for customer limits. ReqKey keeps the counts and credit balances, so there is no database to provision for rate limiting.

  • The documented integration wraps route handlers with withReqKey, which gives each handler the verdict it needs. Use that for API routes; keep middleware.ts for redirects and auth on pages.

  • On their plan or on the customer (consumer) in ReqKey — a number of requests per window from 1 second to 24 hours, shared by all of that customer’s keys. Your Next.js code never hard-codes a limit, so upgrading a customer is a dashboard change, not a deploy.

  • A check averages under 5ms. ReqKey runs inside your app as middleware, not as a gateway in front of it, so responses go straight back to your customer.

  • You choose: fail closed and answer 503, or fail open and let requests through. Invalid keys are denied either way, and a validation is never retried, so no one is charged twice.

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