Zero-DTE Hedge Flow API

Endpoint

GET /v1/flow/zero-dte/hedge-flow/{symbol}

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

Parameters

Name	In	Required	Default	Description
`symbol`	path	yes	-	Underlying symbol. Trimmed and upper-cased.
`side`	query	no	`all`	Which leg to project. Allowed: `all`, `calls`, `puts`. Anything else returns 400 invalid_side.
`bar`	query	no	`30s`	Bar size. Allowed: `30s`, `1m`, `5m`, `15m`. Anything else returns 400 invalid_bar.
`minutes`	query	no	`60`	Lookback window in minutes. Clamped to 1-390.

curl -H "X-Api-Key: YOUR_API_KEY" \
  "https://lab.flashalpha.com/v1/flow/zero-dte/hedge-flow/SPY?side=calls&bar=5m&minutes=180"

import requests

resp = requests.get(
    "https://lab.flashalpha.com/v1/flow/zero-dte/hedge-flow/SPY",
    params={"side": "calls", "bar": "5m", "minutes": 180},
    headers={"X-Api-Key": "YOUR_API_KEY"}
)
data = resp.json()
print(len(data["bars"]))

const resp = await fetch(
  "https://lab.flashalpha.com/v1/flow/zero-dte/hedge-flow/SPY?side=calls&bar=5m&minutes=180",
  { headers: { "X-Api-Key": "YOUR_API_KEY" } }
);
const data = await resp.json();
console.log(data.bars.length);

API Key

Response

{
  "symbol": "SPY",
  "expiration": "2026-06-05",          // today (ET)
  "as_of": "2026-06-05T18:45:12Z",     // UTC
  "side": "calls",                     // echoes the requested side (all | calls | puts)
  "bar_size": "5m",                    // echoes the requested bar
  "bars": [
    {
      "t": "2026-06-05T18:40:00Z",     // bar timestamp (UTC)
      "bar": 1240000,                  // per-bar signed delta-dollars in this bucket
      "cumulative": 18432000           // running sum since session open (for `side`)
    }
    // ... ascending by t
  ]
}

For side=all, bar and cumulative are the sum of the call and put legs; for calls / puts they are that single leg. There is no no_zero_dte / session_closed envelope - no samples returns 200 with the normal wrapper and an empty bars array.

Key Response Fields

Field	Type	Description
`expiration`	string	Today's 0DTE expiry (ET)
`as_of`	string	Server time the response was built (UTC)
`side`	string	Echoes the requested side (`all` \| `calls` \| `puts`)
`bar_size`	string	Echoes the requested bar size
`bars[].t`	string	Bar timestamp (UTC)
`bars[].bar`	number	Per-bar signed delta-dollars in this bucket
`bars[].cumulative`	number	Running sum since session open (for the requested `side`)

Errors

Status	Description
`400`	`invalid_side` - `side` was not all / calls / puts
`400`	`invalid_bar` - `bar` was not one of 30s / 1m / 5m / 15m
`403`	`tier_restricted` - caller is below the Growth plan

About

The hedge-flow endpoint returns the estimated dealer hedge-flow time series for today's 0DTE chain - the signed delta-dollars dealers are inferred to be buying or selling to stay hedged - as both per-bar increments and a running cumulative since session open.

It is projectable to calls only, puts only, or the combined total via side, without re-scanning trades (the raw tier stores both legs). It uses the same windowing and last-in-bucket downsampling as the series endpoint.

Common Use Cases

Plot cumulative dealer hedging pressure across today's session to see net delta-dollars dealers have bought or sold since the open
Split the flow into call versus put legs with side=calls and side=puts to attribute the pressure and spot one-sided hedging
Spot bursts of dealer buying or selling via the per-bar bar increments, flagging the bars where hedging is most likely to move spot
Overlay cumulative on price to judge whether dealers are chasing the move (amplifying) or fading it (dampening) and trade accordingly
Watch for a sign change in bar as the moment dealer hedging flips direction, often coinciding with a gamma-flip cross
Choose bar_size to match your horizon - fine 30s/1m bars for scalps, 5m/15m for a cleaner session-level pressure read

Complementary endpoints

Zero-DTE Flow Snapshot - the live 0DTE regime this hedging acts on
Dealer Risk - the settled-versus-live exposure shift behind the hedge flow
Flow GEX - the live gamma surface that determines hedging direction