Registry / messaging / socket.io-adapter-postgres

socket.io-adapter-postgres

library1.2.1jsnpmunverified

PostgreSQL-based adapter for Socket.IO enabling horizontal scaling by broadcasting and emitting events across multiple Socket.IO instances. Version 1.2.1 is the latest stable release, with infrequent updates (no recent commits). Unlike Redis-based adapters, it uses PostgreSQL's LISTEN/NOTIFY for pub/sub, making it suitable for teams already running PostgreSQL. Supports remote join, leave, and disconnect across nodes.

messaging

npm install socket.io-adapter-postgres

github ↗package ↗homepage ↗

INSTALL

IMPORT

SIG · SOCKET.IO-ADAPTER-

socket.io-adapter-postgres

messagingjavascriptv1.2.1

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.

default

✓ import adapter from 'socket.io-adapter-postgres'

✗ const adapter = require('socket.io-adapter-postgres').default

Default export is the adapter factory function. ESM usage requires named import as shown.

PostgresAdapter

✓ import { PostgresAdapter } from 'socket.io-adapter-postgres'

✗ const { PostgresAdapter } = require('socket.io-adapter-postgres')

Named export for the class itself; CommonJS require works but named import is preferred for TypeScript.

require

✓ const adapter = require('socket.io-adapter-postgres')

CommonJS style: adapter is a function. This is the legacy pattern.

Connects Socket.IO to PostgreSQL for multi-process broadcasting using the postgres adapter.

const io = require('socket.io')(3000); const postgresAdapter = require('socket.io-adapter-postgres'); const adapter = postgresAdapter({ host: 'localhost', port: 5432 }); io.adapter(adapter); io.on('connection', (socket) => { console.log('Client connected'); socket.emit('message', 'Hello from server'); });

Debug

Known issues

gotchaThe adapter requires PostgreSQL's LISTEN/NOTIFY feature; ensure your PostgreSQL user has permission to use LISTEN and NOTIFY.

fix

Grant the user the ability to execute LISTEN/NOTIFY, or use a superuser for development.

affects: >=1.0.0

gotchaIf you supply custom pubClient and subClient, they must be from the 'pg' library with compatible APIs; using different PostgreSQL clients may break.

fix

Use the 'pg' package and ensure pubClient is a Pool, subClient is a Client.

affects: >=1.0.0

gotchaThis package is derived from socket.io-redis but not actively maintained; latest release is 1.2.1 from 2019. No support for Socket.IO v4 or newer.

fix

Consider using socket.io-redis or a maintained adapter for Socket.IO v4+ compatibility.

affects: >=1.0.0

gotchaThe adapter uses a single LISTEN/NOTIFY channel; if many instances publish heavily, performance may degrade due to PostgreSQL limitations.

fix

Limit the number of Socket.IO instances or use Redis for high-throughput scenarios.

affects: >=1.0.0

Errors

Common errors & fixes

Error: listen EADDRINUSE :::5432

PostgreSQL port already in use by another process or adapter configuration.

fix

Ensure PostgreSQL is running on the specified port, or change the port in the adapter options.

TypeError: io.adapter is not a function

Using an older version of Socket.IO (<1.0) where adapter method is not available.

fix

Upgrade Socket.IO to version 1.0 or later.

Unhandled rejection Error: sorry, too many clients already

PostgreSQL connection pool exhausted; too many Socket.IO instances or high concurrency.

fix

Increase max connections in PostgreSQL configuration or limit pool size in adapter options (not directly supported).

Upgrade

Version history

1.2.1latest on npm

Audit

Dependencies

pgrequiredPostgreSQL client required for pool and client instances

socket.io-adapterrequiredBase adapter class from Socket.IO

Agent activity

11 hits · last 30 days

node

OpenAI (training)

Resources

githubhttps://github.com/BenLubar/socket.io-adapter-postgres ↗

packagesocket.io-adapter-postgres ↗

homepagehttps://github.com/BenLubar/socket.io-adapter-postgres#readme ↗