Hello @smrtsaravanan , Apologies for the delayed response. We have introduced OI Data for Nifty and Banknifty via Market Data API and Websocket Streaming 2.0. Please have a look. https://smartapi.angelbroking.com/docs/Historical https://smartapi.angelbroking.com/docs/WebSocket2 If you have any other issue, please share request and response on smartapi@angelbroking.com. Thank you. SmartAPI Team