Live Market Data Feed — Integration Guide

Real-time streaming market data over Server-Sent Events (SSE). Drop-in JavaScript client, works in any modern browser, no WebSocket handshake needed.

1. What you'll get from us

Before you can integrate, we'll send you three things:

Important: the token only works from origins we've whitelisted for you. Tell us every domain/subdomain (prod + staging) where your pages will run. CORS preflight will block any other origin with a 403 Forbidden.

2. Quickest integration (drop-in script, ~10 lines of HTML)

<script src="https://mkt-ticker-data-production.up.railway.app/velora-feed-client.js"></script>
<script>
  const feed = new VeloraFeed({
    endpoint: 'https://mkt-ticker-data-production.up.railway.app',
    token:    'YOUR_TOKEN_HERE',
    subs: [
      [19, 2101],  // BTC/USD
      [19, 2102],  // ETH/USD
      [3, 2],      // EUR/USD
      [2, 26000],  // NIFTY 50
      [1, 2885],   // RELIANCE (NSE)
    ],
  });

  feed.on('tick', (t) => {
    console.log(t.symbol, t.ltp, `${t.changePct.toFixed(2)}%`);
    // Example: update a DOM element
    document.getElementById('price-' + t.key)?.replaceChildren(t.ltp.toFixed(t.priceDecimals));
  });

  feed.on('status', (s) => console.log('connection:', s.status));
  feed.start();
</script>

That's it. You'll start getting live ticks within a second of feed.start().

Live demo page you can inspect for reference: https://mkt-ticker-data-production.up.railway.app/demo.html

3. Subscribe format

Every subscription is a [exchangeId, instrumentToken] pair.

Exchange IDs

Common instrument tokens

Crypto (Exchange 19)

Forex (Exchange 3)

US Stocks (Exchange 3)

Global Indices (Exchange 3)

NSE Stocks (Exchange 1)

NSE F&O + Indices (Exchange 2)

For the full list, query the instruments API (see section 5).

4. Tick payload

Each tick you receive looks like this:

{
  "key": "19_2101",
  "exchange": 19,
  "token": 2101,
  "symbol": "BTCUSD",
  "category": "CRYPTO",
  "ltp": 77539.9,
  "change": 512.3,
  "changePct": 0.66,
  "bid": 77538.5,
  "ask": 77541.2,
  "high": 77800.0,
  "low": 76500.0,
  "ltq": 0.12,
  "openInterest": 0,
  "ltt": 1745324500,
  "priceDecimals": 1,
  "ts": 1745324512345
}

5. Discovering instruments programmatically

GET https://mkt-ticker-data-production.up.railway.app/api/public/instruments
    ?token=YOUR_TOKEN
    &category=CRYPTO          (optional — filter by segment)
    &q=BTC                    (optional — substring match on symbol/name)
    &limit=200                (optional — default 500)

Response:

{
  "total": 10,
  "categories": ["CRYPTO", "FOREX", "USSTOCK", ...],
  "items": [
    {
      "token": 2101,
      "exchange": 19,
      "symbol": "BTCUSD",
      "name": "Bitcoin / USD",
      "category": "CRYPTO",
      "priceDecimals": 2,
      "qtyDecimals": 2
    },
    ...
  ]
}

The categories array lists only segments your token is allowed to access.

6. Events emitted by the client

feed.on('hello', (info) => {
  // Sent once on connect. Tells you which subs were accepted/denied.
  console.log(info);
  // { client: "Your Name", allowedSegments: [...], subscribed: 5, denied: [] }
});

feed.on('status', (s) => {
  // Upstream connection state: "open", "closed", "connecting"
  console.log(s.status);
});

feed.on('snapshot', (ticks) => {
  // Bulk payload sent on connect with the last known value for every instrument
  // you subscribed to. Useful to populate your UI immediately.
  ticks.forEach(updateRow);
});

feed.on('tick', (tick) => {
  // Streamed continuously as prices change.
  updateRow(tick);
});

feed.on('error', (err) => {
  // Connection error or server-side message.
  console.error(err);
});

7. Using without the SDK (plain EventSource)

If you prefer native browser APIs:

const url = new URL('https://mkt-ticker-data-production.up.railway.app/api/public/stream');
url.searchParams.set('token', 'YOUR_TOKEN');
url.searchParams.set('subs', '19:2101,19:2102,3:2,2:26000');

const es = new EventSource(url);
es.addEventListener('tick', (msg) => {
  const tick = JSON.parse(msg.data);
  console.log(tick.symbol, tick.ltp);
});

8. Framework examples

React (hook)

import { useEffect, useState } from 'react';

function useLiveTicker(subs, token) {
  const [ticks, setTicks] = useState({});
  useEffect(() => {
    const feed = new VeloraFeed({
      endpoint: 'https://mkt-ticker-data-production.up.railway.app',
      token,
      subs,
    });
    feed.on('snapshot', (list) => {
      setTicks((cur) => ({ ...cur, ...Object.fromEntries(list.map(t => [t.key, t])) }));
    });
    feed.on('tick', (t) => setTicks((cur) => ({ ...cur, [t.key]: t })));
    feed.start();
    return () => feed.stop();
  }, [JSON.stringify(subs), token]);
  return ticks;
}

// usage:
const ticks = useLiveTicker([[19,2101],[2,26000]], 'YOUR_TOKEN');
return <div>BTC: {ticks['19_2101']?.ltp}</div>;

Vue 3

<script setup>
import { ref, onMounted, onUnmounted } from 'vue';
const ticks = ref({});
let feed;
onMounted(() => {
  feed = new VeloraFeed({
    endpoint: 'https://mkt-ticker-data-production.up.railway.app',
    token: 'YOUR_TOKEN',
    subs: [[19,2101],[19,2102]],
  });
  feed.on('tick', (t) => (ticks.value = { ...ticks.value, [t.key]: t }));
  feed.start();
});
onUnmounted(() => feed?.stop());
</script>

<template>
  <div v-for="t in ticks" :key="t.key">{{ t.symbol }}: {{ t.ltp }}</div>
</template>

9. Rate limits & policies

10. Troubleshooting

11. Browser compatibility

Works in all modern browsers (Chrome, Edge, Firefox, Safari). SSE is supported natively; no polyfill needed. IE 11 is not supported.

12. Contact

• Endpoint: https://mkt-ticker-data-production.up.railway.app
• Demo: https://mkt-ticker-data-production.up.railway.app/demo.html
• Issues / new origins / limit increases: contact your account manager

Happy trading!