Options Flow Summary API

Endpoint

GET /v1/flow/options/{symbol}/summary

Auth required (X-Api-Key) Rate Limited: Yes Alpha plan+

Parameters

Name	In	Required	Default	Description
`symbol`	path	yes	-	Underlying symbol
`expiry`	query	no	-	Filter to a single expiration cycle, `YYYY-MM-DD`. Aggregates only contracts on that expiry.

curl -H "X-Api-Key: YOUR_API_KEY" \
  "https://lab.flashalpha.com/v1/flow/options/SPY/summary"

import requests

resp = requests.get(
    "https://lab.flashalpha.com/v1/flow/options/SPY/summary",
    headers={"X-Api-Key": "YOUR_API_KEY"}
)
data = resp.json()
print(f"Net volume: {data['netVolume']:,}")

const resp = await fetch(
  "https://lab.flashalpha.com/v1/flow/options/SPY/summary",
  { headers: { "X-Api-Key": "YOUR_API_KEY" } }
);
const data = await resp.json();
console.log("Net volume: " + data.netVolume.toLocaleString());

API Key

Response

{
  "symbol": "SPY",
  "contractsWithTrades": 1820,
  "totalTrades": 482310,
  "buyVolume": 1245200,
  "sellVolume": 1118450,
  "midVolume": 84720,
  "netVolume": 126750,
  "biggestSingleTrade": 4800,
  "lastTradeUtc": "2026-05-12T18:42:09.812Z"
}

Key Response Fields

Field	Type	Description
`symbol`	string	Uppercase underlying symbol
`contractsWithTrades`	integer	Option contracts with at least one buffered trade
`totalTrades`	integer	Total buffered option trades
`buyVolume`	integer	Buy-classified contract volume
`sellVolume`	integer	Sell-classified contract volume
`midVolume`	integer	Mid/unknown-side contract volume
`netVolume`	integer	`buyVolume - sellVolume`
`biggestSingleTrade`	integer	Largest single option trade size
`lastTradeUtc`	string/null	Latest trade timestamp

Errors

Status	Description
`403`	Requires Alpha plan or higher
`502`	Upstream flow data source unavailable

About

Returns aggregated option trade-flow totals across every contract on the underlying. Volumes are in contract units. netVolume is the signed buy-minus-sell directional pressure and is the headline number most flow dashboards anchor on.

Common Use Cases

Headline directional pressure - surface signed netVolume (buyVolume - sellVolume) as the lead number on a per-symbol flow dashboard
Rank a watchlist by flow - sort names by absolute netVolume or totalTrades to spot where today's option activity is concentrated
Detect stale or quiet tapes - compare lastTradeUtc against now to flag symbols that have gone inactive before trusting the totals
Measure conviction with the buy/sell split - weigh buyVolume versus sellVolume (and discount midVolume) to judge how one-sided the tape really is
Spot outsized single tickets - scale biggestSingleTrade against typical size to know whether one block is skewing the aggregate
Gauge breadth of participation - read contractsWithTrades to tell broad-based flow from activity crowded into a handful of strikes

Complementary endpoints

Options Recent - drill from the aggregate into the individual prints behind it
Options Blocks - see the large prints driving biggestSingleTrade
Options Leaderboard - rank the most-active contracts inside the totals
Flow Signals - scored unusual-activity layer built on this flow