# Stock Options Chain API
> Live (15-minute delayed) US equity and index options chains, served from CBOE's public delayed-quotes feed. For any optionable ticker the summary endpoint returns the underlying quote — current price, day change, open/high/low/close, volume, bid/ask and the 30-day implied volatility (IV30) with its change. The expirations endpoint lists every available expiration date with its call and put contract counts. The chain endpoint returns the option contracts themselves: for each strike and expiry it gives the call/put bid, ask, last, implied volatility, open interest, volume and the full greeks — delta, gamma, theta and vega — and can be filtered by expiration date and by call or put. US index options are addressed with an underscore prefix (_SPX, _VIX). This is the single-name equity and index options surface — strikes, expiries, IV and greeks — distinct from the options-pricing calculators, the crypto-options and the FX/rate APIs in the catalogue. Live, no key on the upstream, nothing stored.

## Authentication
All requests require your oanor API key in the `x-oanor-key` header. Get one at https://www.oanor.com/developer/keys.

```bash
curl -H "x-oanor-key: oanor_live_…" "https://api.oanor.com/optionschain-api/..."
```

## Pricing
- **Free** (Free) — 18,000 calls/Mo, 3 req/s
- **Starter** ($9/Mo) — 210,000 calls/Mo, 10 req/s
- **Pro** ($27/Mo) — 920,000 calls/Mo, 30 req/s
- **Scale** ($64/Mo) — 3,300,000 calls/Mo, 80 req/s

## Endpoints

### Options

#### `GET /v1/chain` — Option contracts with IV, OI, volume & greeks

**Parameters:**
- `symbol` (query, required, string) — US ticker Example: `AAPL`
- `expiry` (query, optional, string) — Expiration date YYYY-MM-DD (defaults to nearest) Example: `2026-06-12`
- `type` (query, optional, string) — call or put (omit for both) Example: `call`
- `limit` (query, optional, string) — Max contracts (max 500) Example: `100`

**Example:**
```bash
curl -H "x-oanor-key: $KEY" \
  "https://api.oanor.com/optionschain-api/v1/chain?symbol=AAPL&expiry=2026-06-12&type=call&limit=100"
```

#### `GET /v1/expirations` — Available expiration dates with counts

**Parameters:**
- `symbol` (query, required, string) — US ticker Example: `AAPL`

**Example:**
```bash
curl -H "x-oanor-key: $KEY" \
  "https://api.oanor.com/optionschain-api/v1/expirations?symbol=AAPL"
```

#### `GET /v1/summary` — Underlying quote + IV30 for a symbol

**Parameters:**
- `symbol` (query, required, string) — US ticker; index uses underscore prefix Example: `AAPL`

**Example:**
```bash
curl -H "x-oanor-key: $KEY" \
  "https://api.oanor.com/optionschain-api/v1/summary?symbol=AAPL"
```

### Meta

#### `GET /v1/meta` — Spec

**Example:**
```bash
curl -H "x-oanor-key: $KEY" \
  "https://api.oanor.com/optionschain-api/v1/meta"
```


---
Marketplace page: https://www.oanor.com/api/optionschain-api
OpenAPI spec: https://www.oanor.com/api/optionschain-api/openapi.json