NSE India API Docs

import requests, time, threading

class NSESession:
    BASE = "https://www.nseindia.com"
    HEADERS = {
        "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36",
        "Accept":       "*/*",
        "Accept-Language": "en-US,en;q=0.9",
        "Referer":      "https://www.nseindia.com/",
        "sec-fetch-site": "same-origin",
        "sec-fetch-mode": "cors",
        "sec-fetch-dest": "empty",
    }

    def __init__(self):
        self.session = requests.Session()
        self.session.headers.update(self.HEADERS)
        self._seed()
        # auto re-seed every 4 minutes
        self._schedule_reseed()

    def _seed(self):
        self.session.get(self.BASE, timeout=15)
        time.sleep(1)

    def _schedule_reseed(self):
        t = threading.Timer(240, self._reseed_loop)
        t.daemon = True
        t.start()

    def _reseed_loop(self):
        self._seed()
        self._schedule_reseed()

    def get(self, path):
        url = self.BASE + path
        r = self.session.get(url, timeout=10)
        r.raise_for_status()
        return r.json()

# Usage
nse = NSESession()
market = nse.get("/api/market-status")
chain  = nse.get("/api/option-chain-indices?symbol=NIFTY")

const axios = require('axios');

const BASE = 'https://www.nseindia.com';
const HEADERS = {
  'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36',
  'Accept': '*/*',
  'Accept-Language': 'en-US,en;q=0.9',
  'Referer': 'https://www.nseindia.com/',
  'sec-fetch-site': 'same-origin',
  'sec-fetch-mode': 'cors',
};

let cookies = '';

async function seedCookie() {
  const res = await axios.get(BASE, { headers: HEADERS });
  cookies = (res.headers['set-cookie'] || [])
    .map(c => c.split(';')[0]).join('; ');
}

async function nseGet(path) {
  const res = await axios.get(BASE + path, {
    headers: { ...HEADERS, 'Cookie': cookies }
  });
  return res.data;
}

// Re-seed every 4 minutes
setInterval(seedCookie, 4 * 60 * 1000);

// Init and use
(async () => {
  await seedCookie();
  const status = await nseGet('/api/market-status');
  const chain  = await nseGet('/api/option-chain-indices?symbol=NIFTY');
  console.log(status, chain);
})();

# Step 1: seed cookie (run once, save the cookies.txt)
curl -c cookies.txt -b cookies.txt \
  -H "User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64)" \
  -H "Accept: */*" \
  -H "Referer: https://www.nseindia.com/" \
  https://www.nseindia.com

# Step 2: call any endpoint (reuse cookies.txt)
curl -c cookies.txt -b cookies.txt \
  -H "User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64)" \
  -H "Accept: */*" \
  -H "Referer: https://www.nseindia.com/" \
  "https://www.nseindia.com/api/option-chain-indices?symbol=NIFTY"

// GET /api/option-chain-indices?symbol=NIFTY
{
  "records": {
    "expiryDates": ["10-Apr-2025", "17-Apr-2025", ...],
    "data": [
      {
        "strikePrice": 22000,
        "expiryDate": "10-Apr-2025",
        "CE": {
          "strikePrice": 22000,
          "lastPrice": 145.5,        // LTP
          "openInterest": 125000,     // OI in lots
          "changeinOpenInterest": 2500,
          "impliedVolatility": 12.5,  // IV %
          "volume": 48000,
          "change": -12.5,
          "pChange": -7.9,
          "bidQty": 150, "bidprice": 145,
          "askQty": 75,  "askPrice": 146
        },
        "PE": {
          "strikePrice": 22000,
          "lastPrice": 78.2,
          "openInterest": 95000,
          "impliedVolatility": 13.1,
          "volume": 32000
        }
      }
    ],
    "underlyingValue": 22187.65   // Current NIFTY spot price
  },
  "filtered": {
    "data": [...],  // Only near ATM strikes
    "CE": { "totOI": 12500000, "totVol": 4800000 },
    "PE": { "totOI": 11200000, "totVol": 4100000 }
  }
}

// nse-proxy.js — Run on your server/VPS (NOT cloud providers)
const express = require('express');
const axios   = require('axios');
const app     = express();

const BASE    = 'https://www.nseindia.com';
const HEADERS = {
  'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36',
  'Accept': '*/*',
  'Referer': 'https://www.nseindia.com/',
};

let cookies = '';
let lastSeed = 0;

async function ensureCookie() {
  if (Date.now() - lastSeed > 240000) { // re-seed every 4 min
    const res = await axios.get(BASE, { headers: HEADERS });
    cookies = (res.headers['set-cookie'] || [])
      .map(c => c.split(';')[0]).join('; ');
    lastSeed = Date.now();
  }
}

async function nseGet(path) {
  await ensureCookie();
  const res = await axios.get(BASE + path, {
    headers: { ...HEADERS, 'Cookie': cookies },
    timeout: 10000,
  });
  return res.data;
}

// Proxy routes — your React/Next.js frontend calls these
app.get('/api/nse/market-status',  async (req, res) => res.json(await nseGet('/api/market-status')));
app.get('/api/nse/indices',        async (req, res) => res.json(await nseGet('/api/allIndices')));
app.get('/api/nse/option-chain',  async (req, res) => {
  const { symbol = 'NIFTY' } = req.query;
  res.json(await nseGet(`/api/option-chain-indices?symbol=${symbol}`));
});
app.get('/api/nse/quote',         async (req, res) => {
  const { symbol } = req.query;
  res.json(await nseGet(`/api/quote-equity?symbol=${symbol}`));
});
app.get('/api/nse/gainers',       async (req, res) =>
  res.json(await nseGet('/api/live-analysis-variations?index=gainers&trade_type=securities')));
app.get('/api/nse/losers',        async (req, res) =>
  res.json(await nseGet('/api/live-analysis-variations?index=losers&trade_type=securities')));
app.get('/api/nse/historical',   async (req, res) => {
  const { symbol, from, to } = req.query;
  res.json(await nseGet(`/api/historical/cm/equity?symbol=${symbol}&series=[%22EQ%22]&from=${from}&to=${to}`));
});

app.listen(4000, () => console.log('NSE Proxy running on :4000'));

// Recommended polling intervals for your backend
{
  "market-status":        "every 60 seconds",
  "allIndices":            "every 5 seconds",     // for live index ticker
  "option-chain-indices":  "every 10–15 seconds", // large payload, be careful
  "quote-equity":          "every 5 seconds",     // per-stock quote
  "gainers/losers":        "every 30 seconds",    // homepage widgets
  "historical":            "once per day (cache)",// no need to refresh often
  "corporate-actions":     "once per day (cache)"
}

// NSE rate limit: max 3 requests/second from same IP
// If polling 3+ endpoints every 5s → add 400ms delay between calls
// Cache results in Redis or in-memory to serve frontend without hammering NSE