Go realtime with Deepstream

// Client B: Delivery driver's smartphone feeds position into record
const driver = client.record.getRecord('driver/jack')
navigator.geolocation.watchPosition(position => {
  driver.set('coords', position.coords)
})

// Client A: Hungry customer sees pizza delivery approach on map
const driver = client.record.getRecord('driver/jack')
driver.subscribe('coords', updateMapPointer)

client.rpc.provide( 'add-two-numbers', ( data, response ) => {
    response.send( data.numA + data.numB );
});

client.rpc.make( 'add-two-numbers', { numA: 7, numB: 13 }, ( err, result ) => {
    // result == 20;
});

//Limiting to 50 simultanious image resize tasks at a time
var inProgress = 0;
client.rpc.provide( 'resize-image', ( url, response ) => {
    inProgress++;

    if( inProgress > 50 ) {
        response.reject();
    } else {
        resizeImage( url ).then(() => {
            inProgress--;
            response.send( 'done' );
        });
    }
});

// Client B
client.event.emit('news/sports', 'football is happening')

//Subscribing to an event
client.event.subscribe('news/sports', tweetThis)

function tweetThis(data) {
    //callback for incoming events
}

# reading users and passwords from a file
auth:
 type: file
 options:
   path: ./users.yml # Path to the user file. Can be json, js or yml
   hash: 'md5' # the name of a HMAC digest algorithm
   iterations: 100 # the number of times the algorithm should be applied
   keyLength: 32 # the length of the resulting key

badri:
  password: "GPO+dr/0MoA1HAhIYREDc13zSK1/ywsRv2Wwo3gQ1TE=Mh62TJsaGBRORPtorRbyTw=="
  data:
    role: developer
lakshmi:
  password: "GPO+dr/0MoA1HAhIYREDc13zSK1/ywsRv2Wwo3gQ1TE=Mh62TJsaGBRORPtorRbyTw=="
  data:
   role: scrum-master

type: http
options:
  endpointUrl: https://someurl.com/auth-user
  permittedStatusCodes: [ 200 ]
  requestTimeout: 2000

record:
    #an auctioned item
    auction/item/$sellerId/$itemId:

        #everyone can see the item and its price
        read: true

        #only users with canBid flag in their authData can bid
        #and bids can only be higher than the current price
        write: "user.data.canBid && data.price > oldData.price"

        #only the seller can delete the item
        delete: "user.id == $sellerId"