Free Crypto Options API

Endpoints

Examples

curl https://xoomar.com/api/markets/options/BTC

import requests

r = requests.get("https://xoomar.com/api/markets/options/BTC")
data = r.json()["data"]
print(f"BTC Total OI: {data['totalOI']}")
for exp in data["expiries"][:3]:
    print(f"  {exp['expiry']}: max pain ${exp['maxPain']}")

Main features

• BTC and ETH options data from Deribit, where most crypto options open interest trades, updated every 15 minutes.
• Max pain per expiry: the strike at which the total payout to option holders at expiry would be smallest.
• Put/call open interest ratio overall and per expiry, plus the DVOL implied volatility index with hourly history.

Example

Request

curl "https://xoomar.com/api/markets/options/btc"

Response, live at 2026-10-15 17:12 UTC, trimmed

{
  "data": {
    "currency": "BTC",
    "underlyingPrice": 82915.05,
    "totalOI": 400805.2,
    "pcRatio": 0.614,
    "dvol": 39.04,
    "expiries": [
      {
        "expiry": "2026-10-16",
        "maxPain": 83000,
        "totalOI": 17992.3,
        "pcRatio": 1.299
      },
      {
        "expiry": "2026-10-17",
        "maxPain": 82000,
        "totalOI": 1961.9,
        "pcRatio": 2.743
      }
    ],
    "updatedAt": "2026-10-15T17:00:00.000Z"
  },
  "updatedAt": "2026-10-15T17:12:54.970Z",
  "source": "xoomar.com",
  "docs": "https://xoomar.com/markets/api",
  "license": "https://xoomar.com/terms",
  "attribution": "Credit XOOMAR with a link to the dataset page on xoomar.com when you republish this data",
  "meta": {
    "source": "Deribit",
    "sourceAttribution": "Options data: Deribit.",
    "notice": "10 requests a minute without a key, 30 with a free key. Get a free key at https://xoomar.com/signup?utm_source=api, register your app at https://xoomar.com/developers/register?utm_source=api, and credit the data as \"Data: XOOMAR\" together with the sourceAttribution line."
  }
}

expiries arrives nearest first. The dvol field is the latest hourly close; the full candles are at /api/markets/options/{currency}/dvol.

What people build with it

Response shape

Every endpoint returns the same JSON envelope: { data, updatedAt, source, docs, license, attribution, meta }. In meta, source names who publishes the data and sourceAttribution is the credit line to show with it. The data field is an object with these fields:

The summary refreshes every 15 minutes, from Deribit.

Numeric fields typed string in the table carry exact decimals; parse them with your language's decimal type. No key needed to start: 10 requests a minute per IP without a key and 30 a minute with a free account key, with at least six months of history. A 429 response carries a Retry-After header in seconds. Credit XOOMAR with a link to the dataset page when you republish the data; the data terms are on the terms page.

A free account key raises the limit; send it in an X-API-Key header.