Nefariously Programmed Mecha

    TypeScript icon, indicating that this package has built-in type declarations

    4.4.0 • Public • Published


    Build Status npm version npm downloads

    Socket.IO module for Angular


    npm install ngx-socket-io


    Make sure you're using the proper corresponding version of on the server.

    Package Version Socket-io Server Version Angular version
    v3.4.0 v2.2.0
    v4.1.0 v4.0.0 12.x
    v4.2.0 v4.0.0 13.x
    v4.3.0 v4.5.1 14.x
    v4.4.0 v4.5.1 15.x

    How to use

    Import and configure SocketIoModule

    import { SocketIoModule, SocketIoConfig } from 'ngx-socket-io';
    const config: SocketIoConfig = { url: 'http://localhost:8988', options: {} };
      declarations: [AppComponent],
      imports: [BrowserModule, SocketIoModule.forRoot(config)],
      providers: [],
      bootstrap: [AppComponent],
    export class AppModule {}

    We need to configure SocketIoModule module using the object config of type SocketIoConfig, this object accepts two optional properties they are the same used here io(url[, options]).

    Now we pass the configuration to the static method forRoot of SocketIoModule

    Using your socket Instance

    The SocketIoModule provides now a configured Socket service that can be injected anywhere inside the AppModule.

    import { Injectable } from '@angular/core';
    import { Socket } from 'ngx-socket-io';
    import { map } from 'rxjs/operators';
    export class ChatService {
      constructor(private socket: Socket) {}
      sendMessage(msg: string) {
        this.socket.emit('message', msg);
      getMessage() {
        return this.socket.fromEvent('message').pipe(map((data) => data.msg));

    Using multiple sockets with different end points

    In this case we do not configure the SocketIoModule directly using forRoot. What we have to do is: extend the Socket service, and call super() with the SocketIoConfig object type (passing url & options if any).

    import { Injectable, NgModule } from '@angular/core';
    import { Socket } from 'ngx-socket-io';
    export class SocketOne extends Socket {
      constructor() {
        super({ url: 'http://url_one:portOne', options: {} });
    export class SocketTwo extends Socket {
      constructor() {
        super({ url: 'http://url_two:portTwo', options: {} });
      declarations: [
      imports: [
      providers: [SocketOne, SocketTwo],
      bootstrap: [
        /** AppComponent **/
    export class AppModule {}

    Now you can inject SocketOne, SocketTwo in any other services and / or components.


    Most of the functionalities here you are already familiar with.

    The only addition is the fromEvent method, which returns an Observable that you can subscribe to.

    socket.of(namespace: string)

    Takes an namespace. Works the same as in Socket.IO.

    socket.on(eventName: string, callback: Function)

    Takes an event name and callback. Works the same as in Socket.IO.

    socket.removeListener(eventName: string, callback?: Function)

    Takes an event name and callback. Works the same as in Socket.IO.

    socket.removeAllListeners(eventName?: string)

    Takes an event name. Works the same as in Socket.IO.

    socket.emit(eventName:string, ...args: any[])

    Sends a message to the server. Works the same as in Socket.IO.

    socket.fromEvent<T>(eventName: string): Observable<T>

    Takes an event name and returns an Observable that you can subscribe to.

    socket.fromOneTimeEvent<T>(eventName: string): Promise<T>

    Creates a Promise for a one-time event.

    You should keep a reference to the Observable subscription and unsubscribe when you're done with it. This prevents memory leaks as the event listener attached will be removed (using socket.removeListener) ONLY and when/if you unsubscribe.

    If you have multiple subscriptions to an Observable only the last unsubscription will remove the listener.

    Know Issue

    For error TS2345 you need to add this to your tsconfig.json.

      "compilerOptions": {
        "paths": {
          "rxjs": ["node_modules/rxjs"]

    Related projects




    npm i ngx-socket-io

    DownloadsWeekly Downloads






    Unpacked Size

    57.9 kB

    Total Files


    Last publish


    • rodgc