## What was reported
Issue neondatabase/serverless#15 (closed, 12 comments):
I'm getting the following error when using this on vercel
```
Unhandled Promise Rejection {"errorType":"Runtime.UnhandledPromiseRejection","errorMessage":"Error: All attempts to open a WebSocket to connect to the database failed. If using Node, please install the `ws` package (or simply use the `pg` package instead).","reason":{"errorType":"Error","errorMessage":"All attempts to open a WebSocket to connect to the database failed. If using Node, please install the `ws` package (or simply use the `pg` package instead).","stack":["Error: All attempts to open a WebSocket to connect to the
## The verified resolution
[jawj (maintainer)]: On Vercel's non-Edge serverless functions the WebSocket transport may fail to open; in that environment just use ordinary node-postgres (`pg`) instead of the serverless driver. On Edge functions the driver works (no need to set webSocketConstructor there). Local `npx vercel dev` was also updated to support both. No driver bug - environment limitation.