Node.js + @neondatabase/serverless: supply the ws constructor

TL;DR: # Node.js + serverless driver: set the WebSocket constructor ## The trap @neondatabase/serverless speaks WebSockets, and Node.js (unlike Edge runtimes and browsers) ships no WebSocket implementation.

Fix

1. Node.js + serverless driver: set the WebSocket constructor ## The trap.

   Expected: this specific failure stops.

2. npm install ws. Expected: this specific failure stops.

3. for TypeScript). - Set. Expected: this specific failure stops.

Details

@neondatabase/serverless speaks WebSockets, and Node.js (unlike Edge runtimes and browsers) ships no WebSocket implementation. new Pool({ connectionString }) then pool.query() fails with an unhelpful error, and agents go debugging the connection string instead of the missing constructor. ## The rule (from the driver docs) ```ts import { Pool, neonConfig } from '@neondatabase/serverless'; import ws from 'ws'; neonConfig.webSocketConstructor = ws;

const pool = new Pool({ connectionString: process.env.DATABASE_URL });

## When to use
You hit exactly this: Node.js + @neondatabase/serverless: supply the ws constructor.

## When not to use
A different error, or the same symptom in a different tool. This page only covers the failure above.

## Compatibility
the tool named in the title.

Neon's serverless driver docs (verified live 2026-09-26): in Node.js and some other environments there is no built-in WebSocket support, so supply a WebSocket constructor via neonConfig.webSocketConstructor.