market:options:open_interests [ENT]

Make sure you're connected to this subscription: wss://ws.web3api.io.

{
  "jsonrpc" : "2.0",
  "id"      : 1,
  "method"  : "subscribe",
  "params"  : [ "market:options:open_interests", { "instrument": "ETH-17DEC21-4100-C", "exchange": "deribit" } ]
}

Param	Type	Description
instrument	`string`	The asset instrument. (OPTIONAL)
exchange	`string`	The exchange for which to retrieve asset instruments. (OPTIONAL)

Response

"result":{
            "exchange": "deribit",
            "instrument": "ETH-17DEC21-4100-C",
            "timestamp": 1638939825,
            "value": 1550,
}

Field	Type	Description
exchange	`string`	The exchange.
instrument	`string`	The asset pair
timestamp	`number`	The time at which the trade took place.
value	`number`	The open interest value

Example

const WebSocket = require('ws');
const ws = new WebSocket('wss://ws.web3api.io/', {headers: {x-api-key:'<api_key>'}});

ws.on('open', () => {
  ws.send(JSON.stringify({
      jsonrpc: '2.0',
      method: 'subscribe',
      params: ['market:options:open_interests'],
      id: 1,
    }));
});

ws.on('message', data => {
  console.log(JSON.stringify(JSON.parse(data), null, 2));
});