---
title: "Get Open Interest"
method: GET
path: "/api/market/open-interest"
tags: ["Market Data"]
---

# Get Open Interest

`GET /api/market/open-interest`

## Request

- Base URL: `https://api.zerogex.io` (the document declares no server; this is the origin it was published from)
- URL: `https://api.zerogex.io/api/market/open-interest`
- Auth: HTTP bearer

Get current open interest for each option contract for the underlying.

Returns one record per (strike, expiration, option_type) from the most recent
option chain snapshot, ordered by expiration, strike, and option type. Outside
the options session (evenings, weekends, holidays and pre-market) the snapshot
is the final minute of the most recent regular session. Contracts that have
expired are omitted.

## Query parameters

- `underlying` string: Underlying symbol, e.g. SPY

## Response `200`

Successful Response

- OpenInterestResponse
  - `underlying` string, required
  - `spot_price` string, required
  - `contracts` OpenInterestRecord[], required
    - `timestamp` string, date-time, required
    - `underlying` string, required
    - `strike` string, required
    - `expiration` string, date, required
    - `option_type` string, required
    - `open_interest` integer, required
    - `exposure` string, required
    - `updated_at` string, date-time, nullable

## Other responses

- `422`: Validation Error

---

[API](https://skmtc.dev/zerogex/apis/zerogex-api.md) · [All operations](https://skmtc.dev/zerogex/apis/zerogex-api/llms.txt) · [OpenAPI document](https://skmtc.dev/zerogex/apis/zerogex-api/revisions/753b26bf0592?raw)