Elysia Connect Middleware

0.0.6 verified Sat Apr 25 auth: no javascript

A plugin for the Elysia web framework that allows using Express/Connect middleware directly. Version 0.0.6, active development with frequent releases. It bridges Elysia's request/response objects to the Connect interface, enabling reuse of middleware like passport, cors, compression, and session. Key differentiators: lightweight, preserves Elysia's performance, and supports seamless integration without modifying existing middleware. Requires Elysia ^1.3.1.

Common errors

error Error: connectMiddleware is not a function ↓

cause Incorrect import or using CommonJS require style.

fix

Use ESM import: import { connectMiddleware } from 'elysia-connect-middleware'

error TypeError: Cannot read properties of undefined (reading 'query') ↓

cause Middleware expects req.query from Express, but plugin hasn't parsed URL params.

fix

Ensure you use .use(connectMiddleware()) before any middleware that relies on query parsing.

error Error: Elysia: unknown plugin 'connectMiddleware' ↓

cause Plugin not properly installed or imported.

fix

Run npm install elysia-connect-middleware, and import correctly.

Warnings

gotcha Some Express middleware that relies on Node.js-specific features (e.g., streaming, raw body parsing) may not work correctly. ↓

fix Test middleware compatibility; prefer middleware that works with standard request/response objects.

gotcha The plugin modifies the request object to include Express-style properties (e.g., req.query, req.body). Ensure no conflicts with Elysia's native handling. ↓

fix Access Express properties via the request object, but be aware of potential overrides.

deprecated Early versions (pre-0.0.2) used a different import pattern; deprecated. ↓

fix Update to latest version and use the current import syntax.

gotcha Multiple middleware must be wrapped in an array or chained; single function passed directly may not be detected correctly. ↓

fix Always pass middleware functions wrapped in an array: .use(connectMiddleware([cors(), compression()]))

Install

npm install elysia-connect-middleware

yarn add elysia-connect-middleware

pnpm add elysia-connect-middleware

Imports

connectMiddleware

wrong

const connectMiddleware = require('elysia-connect-middleware')

correct

import { connectMiddleware } from 'elysia-connect-middleware'

ESM-only package; CommonJS require will not work.

default

wrong

const connectMiddleware = require('elysia-connect-middleware').default

correct

import connectMiddleware from 'elysia-connect-middleware'

Default export also available; works for named and default import interchangeably.

types

import type { ConnectMiddlewareOptions } from 'elysia-connect-middleware'

TypeScript users can import types for configuration options.

Quickstart

Shows basic setup: import Elysia and the plugin, apply middleware, and start server.

import { Elysia } from 'elysia';
import { connectMiddleware } from 'elysia-connect-middleware';

const app = new Elysia()
  .use(connectMiddleware())
  .get('/', () => 'Hello from Elysia!')
  .listen(3000);

console.log('Server running on http://localhost:3000');