Massive

What it covers

Massive offers REST request/response APIs, WebSocket streams, and bulk flat files across multiple asset classes. The REST quickstart uses dividends to demonstrate the common JSON response shape with status, results, and request_id fields.

Request shape

curl "https://api.massive.com/v3/reference/dividends" \
  -H "Authorization: Bearer $MASSIVE_API_KEY"

The query-string apiKey form also works, but authorization headers reduce accidental key leakage through logs and copied URLs.

Key endpoints

Endpoint	Description
GET /v2/aggs/ticker/{ticker}/range/{mult}/{ts}/{from}/{to}	OHLCV aggregates
GET /v2/aggs/grouped/locale/us/market/stocks/{date}	Grouped daily bars
GET /v1/open-close/{ticker}/{date}	Daily open/close
GET /v3/reference/tickers	Ticker reference data
GET /v3/reference/tickers/{ticker}	Ticker details
GET /v3/reference/dividends	Dividend data
GET /v3/reference/splits	Stock splits
GET /v2/last/trade/{ticker}	Last trade

Decision notes

Compare Massive plans on four axes: asset class, historical depth, feed latency, and usage rights. “Unlimited calls” does not by itself answer whether the data may be displayed or redistributed in a commercial product.

Python example: aggregates and ticker details

The aggregate helper below reads only the first results page. For a long range, use the response’s next_url or the SDK iterator and check the base-aggregate limit; see the Massive missing minute bars case before treating absent minutes as a data defect.

import httpx
from decimal import Decimal
from datetime import date

API_KEY = "your_massive_api_key"
BASE = "https://api.massive.com"

def get_aggs(ticker: str, from_: str, to: str, timespan: str = "day") -> list[dict]:
    """Get OHLCV aggregates. Response nests under 'results'."""
    resp = httpx.get(
        f"{BASE}/v2/aggs/ticker/{ticker}/range/1/{timespan}/{from_}/{to}",
        params={"apiKey": API_KEY},
        timeout=30,
    )
    resp.raise_for_status()
    data = resp.json()
    if data.get("status") != "OK":
        raise RuntimeError(f"Massive error: {data.get('status')}")
    return [
        {
            "date": date.fromtimestamp(r["t"] / 1000),
            "open": Decimal(str(r["o"])),
            "close": Decimal(str(r["c"])),
            "volume": r["v"],
        }
        for r in data.get("results", [])
    ]

def get_ticker_details(ticker: str) -> dict:
    resp = httpx.get(f"{BASE}/v3/reference/tickers/{ticker}", params={"apiKey": API_KEY}, timeout=30)
    resp.raise_for_status()
    return resp.json()["results"]

for bar in get_aggs("AAPL", "2024-01-02", "2024-01-05"):
    print(bar["date"], bar["close"])

Notes:

• Timestamps are milliseconds since epoch — divide by 1000
• Free tier is delayed 15 min and limited to 5 calls/min; paid plans unlock real-time
• The company rebranded from Polygon.io to Massive in 2025; old polygon.io hosts still work
• Dividends live under /v3/reference/dividends; splits under /v3/reference/splits