express-queue

0.0.13 verified Sat Apr 25 auth: no javascript

Express middleware that limits the number of simultaneously processed requests by queuing excess requests. Version 0.0.13, stable but low activity. Supports configurable active limit and queued limit with optional custom rejection handler. Uses MiniQueue internally. Differentiates from simple rate-limiters by queuing rather than dropping requests immediately.

Common errors

error Middleware is not a function ↓

cause Incorrect import (e.g., destructuring '{ queue }' from require)

fix

Use const queue = require('express-queue'); then use queue({...}) as middleware.

error Cannot find module 'express-queue' ↓

cause Package not installed or misspelled

fix

Run 'npm install express-queue' and check package.json for correct spelling.

error queue is not a function ↓

cause Using default import incorrectly in ESM or CommonJS

fix

In Node.js CJS: const queue = require('express-queue'); in ESM: import queue from 'express-queue';

Warnings

gotcha Setting queuedLimit to 0 causes all requests to be rejected immediately ↓

fix Set queuedLimit to -1 for unlimited queue, or a positive integer for limited queue.

gotcha Middleware must be used before routes that need queueing; otherwise requests bypass the queue ↓

fix Ensure app.use(queue(...)) is called before any route definitions.

gotcha activeLimit must be > 0; setting to 0 will cause all requests to be queued indefinitely ↓

fix Set activeLimit to at least 1 to allow processing.

Install

npm install express-queue

yarn add express-queue

pnpm add express-queue

Imports

default
wrong
```
const queue = require('express-queue')
```
correct
```
import queue from 'express-queue'
```
ESM default import works; CommonJS require works in Node >=6
default
wrong
```
const { queue } = require('express-queue')
```
correct
```
const queue = require('express-queue')
```
CommonJS pattern: package exports a single function, not a named export
default
```
const { default: queue } = require('express-queue')
```
For TypeScript with esModuleInterop false, use this destructuring

Quickstart

Sets up Express with queue middleware limiting concurrent requests to 2, queueing excess requests without rejection.

const express = require('express');
const queue = require('express-queue');
const app = express();

app.use(queue({ activeLimit: 2, queuedLimit: -1 }));

app.get('/', (req, res) => {
  res.send('Hello World!');
});

app.listen(3000, () => {
  console.log('Server running on port 3000');
});