express-ruid

1.1.5 verified Sat Apr 25 auth: no javascript

Express.js middleware for generating unique request IDs with prefixes (pid, hostname) and sequence numbers. v1.1.5, stable. Uses built-in crypto. Supports HTTP header inheritance, configurable attribute names, and optional express-http-context integration. Lighter than express-request-id, no external dependencies.

Common errors

error TypeError: ruid is not a function ↓

cause Using ES import with require or wrong default export import.

fix

Use import ruid from 'express-ruid' or const ruid = require('express-ruid').default if using ESM require.

error Cannot read properties of undefined (reading 'ruid') ↓

cause Accessing req.ruid before the middleware runs or missing ruid() call.

fix

Ensure app.use(ruid()) is placed before route handlers.

error express-http-context middleware not used ↓

cause setInContext true but httpContext.middleware not added.

fix

Add app.use(httpContext.middleware) before ruid.

error Property 'ruid' does not exist on type 'Request' ↓

cause TypeScript lacks declaration; package ships types but not augmented correctly.

fix

Install @types/express and ensure tsconfig includes express-ruid types.

Warnings

breaking v1.1.0 removed app.locals support and introduced express-http-context dependency for context storage. ↓

fix Use setInContext option and add httpContext.middleware if you need context access. For app.locals, use setInLocals: true (added back in v1.2.0?) – check docs.

deprecated setInLocals option deprecated in v1.1.0, but restored in v1.2.0? Actually not, stay on v1.0.x if you rely on app.locals. ↓

fix Upgrade to v1.2.0+ or use setInContext with express-http-context.

gotcha Forgetting to add httpContext.middleware before ruid when setInContext:true leads to context loss. ↓

fix Place app.use(httpContext.middleware) BEFORE app.use(ruid({ setInContext: true })).

gotcha Request ID attribute name changed from 'rid' to 'ruid' in v1.x? Check default: it's 'ruid' in latest. ↓

fix Access req.ruid instead of req.rid.

gotcha Middleware resets sequence counter on server restart? Prefix uses random unique part, but sequence may repeat. ↓

fix Use header-based ID propagation across microservices to ensure uniqueness.

Install

npm install express-ruid

yarn add express-ruid

pnpm add express-ruid

Imports

default
wrong
```
const ruid = require('express-ruid')
```
correct
```
import ruid from 'express-ruid'
```
Package is ESM-only since v1.1.0? Actually older versions used CJS, but current typings support default import

ruid

wrong

import { ruid } from 'express-ruid'

correct

const ruid = require('express-ruid')

CommonJS require is still supported for Node.js environments

HttpContext

wrong

import { httpContext } from 'express-http-context'

correct

import httpContext from 'express-http-context'

Optional peer dependency; only needed when setInContext: true

Request
```
import type { Request } from 'express'
```
Express augmentation: req.ruid added; TypeScript types included

Quickstart

Basic usage: generates unique request ID and attaches to req.ruid.

import express, { Request, Response } from 'express';
import ruid from 'express-ruid';

const app = express();

// Add request ID middleware
app.use(ruid());

app.get('/', (req: Request, res: Response) => {
  console.log(`Request ID: ${req.ruid}`);
  res.json({ ruid: req.ruid });
});

app.listen(3000);
// Output: Request ID: 1234@hostname/abc123-0000000000000001