postman-ws

library7.4.5-postman.1jsnpmunverified

Postman's fork of the ws WebSocket library for Node.js. Version 7.4.5-postman.1 provides a simple to use, blazing fast, and thoroughly tested WebSocket client and server implementation. It passes the Autobahn test suite and supports HyBi drafts 07-17, permessage-deflate compression, and binary data. Notable differences from the original ws: maintained by Postman for internal use, includes potential patches or compatibility fixes. Release cadence follows upstream ws development. Key differentiator: same API as ws but with Postman-specific modifications. Requires Node.js >=8.3.0, optional dependencies bufferutil and utf-8-validate for performance.

messaging

npm install postman-ws

github ↗package ↗homepage ↗

INSTALL

IMPORT

SIG · POSTMAN-WS

postman-ws

messagingjavascriptv7.4.5-postman.1

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

WebSocket

✓ import WebSocket from 'ws'

✗ const WebSocket = require('ws').WebSocket

Default export is the WebSocket class. CommonJS users can do const WebSocket = require('ws');

WebSocketServer

✓ import { WebSocketServer } from 'ws'

✗ import WebSocketServer from 'ws'

Named export, not default. Also accessible via WebSocket.Server.

WebSocket (type)

✓ import type { WebSocket } from 'ws'

✗ import { WebSocket } from 'ws'

When using TypeScript, use 'import type' for type-only imports to avoid runtime overhead.

Shows how to create a WebSocket server and client using the ws library, with event handling for connection, open, and message.

import WebSocket from 'ws'; import { WebSocketServer } from 'ws'; const wss = new WebSocketServer({ port: 8080 }); wss.on('connection', function connection(ws) { ws.on('message', function incoming(data) { console.log('received: %s', data); }); ws.send('something'); }); const ws = new WebSocket('ws://localhost:8080'); ws.on('open', function open() { ws.send('Hello, server!'); }); ws.on('message', function incoming(data) { console.log('received from server: %s', data); });

Debug

Known issues

gotchaThis package is a Postman-specific fork of ws. It may contain changes not present in the original ws package.

fix

Use the original ws package unless you need Postman-specific modifications.

affects: >=7.4.5-postman.1

breakingThe module does not work in the browser. The client API is for Node.js.

fix

Use native WebSocket API or isomorphic-ws for browser/Node.js compatibility.

affects: all

deprecatedThe 'WebSocketServer' constructor is the recommended way, not 'WebSocket.Server'.

fix

Use import { WebSocketServer } from 'ws' instead of WebSocket.Server.

affects: >=7

gotchaPer message deflate compression is disabled by default on the server, enabled by default on the client.

fix

Explicitly configure perMessageDeflate option if needed.

affects: >=7

breakingThe 'close' event does not expose the close reason in the event object.

fix

Access 'code' and 'reason' from the WebSocket 'close' event's first argument.

affects: <7

Errors

Common errors & fixes

Error: getaddrinfo ENOTFOUND <host>

DNS resolution failure when connecting to WebSocket server.

fix

Ensure the hostname is correct and DNS is configured properly.

WebSocket connection to 'ws://...' failed: Error: Unexpected server response: 401

Server returned unauthorized response due to missing or invalid authentication.

fix

Set headers on the WebSocket constructor, e.g., new WebSocket('ws://...', { headers: { Authorization: 'Bearer token' } })

Error: read ECONNRESET

Connection abruptly closed by the remote end.

fix

Handle the 'error' and 'close' events properly to detect and reconnect.

Upgrade

Version history

7.4.5-postman.1latest on npm

Audit

Dependencies

bufferutiloptionalOptional addon for efficient masking/unmasking of WebSocket frames

utf-8-validateoptionalOptional addon for efficient UTF-8 validation

Agent activity

15 hits · last 30 days

node

OpenAI (training)

Resources

githubhttps://github.com/postmanlabs/postman-ws ↗

packagepostman-ws ↗

homepagehttps://github.com/postmanlabs/postman-ws ↗