Balance Updates WebSocket

Pushes a fresh balance snapshot whenever any of your wallet balances change — typically after order placements, fills, cancellations, or deposits/withdrawals.

Type	Socket.IO v4
Base URL	wss://ws.coinswitch.co/
Handshake path	/pro/realtime-rates-socket/spot/balance-updates
Namespace	/balanceupdates
Event name	FETCH_BALANCE_UPDATES
Auth	API key on the subscribe payload.

Subscribe payload

Parameter	Type	Required	Description
event	string	Yes	Must be "subscribe" (case-sensitive).
apikey	string	Yes	Your CoinSwitch API key.

Subscribe

Python

import socketio

BASE_URL = "https://ws.coinswitch.co"
HANDSHAKE_PATH = "/pro/realtime-rates-socket/spot/balance-updates"
NAMESPACE = "/balanceupdates"

sio = socketio.Client()

@sio.event(namespace=NAMESPACE)
def connect():
    sio.emit(
        "FETCH_BALANCE_UPDATES",
        {"apikey": "<your api key>", "event": "subscribe"},
        namespace=NAMESPACE,
    )

@sio.on("FETCH_BALANCE_UPDATES", namespace=NAMESPACE)
def on_balance_update(data):
    print("Balance update:", data)

sio.connect(
    BASE_URL,
    namespaces=[NAMESPACE],
    socketio_path=HANDSHAKE_PATH.lstrip("/"),
)
sio.wait()

Java

import okhttp3.*;
import org.json.JSONObject;

OkHttpClient client = new OkHttpClient();
Request request = new Request.Builder()
    .url("wss://ws.coinswitch.co/pro/realtime-rates-socket/spot/balance-updates?EIO=4&transport=websocket")
    .build();

JSONObject subscribe = new JSONObject()
    .put("event", "subscribe")
    .put("apikey", "<your api key>");

String namespaceFrame = "40/balanceupdates,";
String subscribeFrame = "42/balanceupdates,[\"FETCH_BALANCE_UPDATES\"," + subscribe + "]";

WebSocket ws = client.newWebSocket(request, new WebSocketListener() { /* ... */ });
ws.send(namespaceFrame);
ws.send(subscribeFrame);

Go

import (
    "log"
    socketio "github.com/zishang520/socket.io-client-go/v2/client"
)

opts := socketio.DefaultOptions()
opts.SetTransports([]string{"websocket"})
opts.SetPath("/pro/realtime-rates-socket/spot/balance-updates")

sock := socketio.Connect("wss://ws.coinswitch.co/balanceupdates", opts)
defer sock.Close()

sock.On("connect", func(args ...any) {
    sock.Emit("FETCH_BALANCE_UPDATES", map[string]any{
        "apikey": "<your api key>",
        "event":  "subscribe",
    })
})

sock.On("FETCH_BALANCE_UPDATES", func(args ...any) {
    log.Println("update:", args)
})

select {}

Node.js

// npm install socket.io-client@^4
const { io } = require('socket.io-client');

const sock = io('wss://ws.coinswitch.co/balanceupdates', {
  path: '/pro/realtime-rates-socket/spot/balance-updates',
  transports: ['websocket'],
});

sock.on('connect', () => {
  sock.emit('FETCH_BALANCE_UPDATES', {
    apikey: '<your api key>',
    event:  'subscribe',
  });
});

sock.on('FETCH_BALANCE_UPDATES', (data) => {
  console.log('update:', data);
});

Update payload

A flat object keyed by lowercase coin code, with one entry per asset that you hold:

{
  "btc": {
    "free_balance": 0.0001154,
    "locked_balance": 0
  },
  "inr": {
    "free_balance": 5003.373751312903,
    "locked_balance": 705
  }
}

Field	Type	Description
<coin>.free_balance	number	Available balance — what you can spend on a new order.
<coin>.locked_balance	number	Reserved against open orders. Released back to free_balance when those orders fill or cancel.

Each push replaces your previous snapshot entirely — you don't need to merge updates.