Built into AlgoGP (data) Pro

How to get a Massive (Polygon.io) API key

Every Massive (Polygon.io) account gets a default API key at signup. It is a single string used as apiKey or a bearer token.

Open Massive (Polygon.io) Build with Massive (Polygon.io) data
About 5 minutes 4 steps Checked October 2026

Before you start

  • An email address (or a Google/GitHub login)

Create your Massive (Polygon.io) API key

  1. 1

    Create an account

    Go to massive.com (polygon.io redirects there) and click Sign up. Confirm your email.

  2. 2

    Open API Keys in the dashboard

    In the dashboard choose Keys (or API Keys) in the left menu. A Default key already exists.

  3. 3

    Copy or create a key

    Click the copy icon next to the default key, or New Key to create a separate one per project so you can revoke it independently.

  4. 4

    Pick a plan if you need more

    The free plan works immediately. Upgrade under Billing for real-time data, minute bars or no rate limit; the same key gains access.

Test the key

Before wiring the key into a strategy, make one request by hand. It separates “the key is wrong” from “my code is wrong”.

curl -s "https://api.massive.com/v2/aggs/ticker/AAPL/prev?adjusted=true&apiKey=$POLYGON_API_KEY"
"status":"OK" with a results bar means the key works. 401/403 means an invalid key or data your plan does not include.

Add the key to your AlgoGP project

  1. 1

    Open your project’s APIs & keys tab

    Open the strategy project, select APIs & keys, and under Platforms choose Massive (Polygon.io) (Pro).

  2. 2

    Paste each value

    Paste the values into POLYGON_API_KEY and click Save. Values are encrypted at rest, never shown again and never written into code or exports.

  3. 3

    Run locally with the same names

    Exported projects read the same names from .env (copy .env.example). Keep .env out of version control.

POLYGON_API_KEY=paste-your-value-here
.env for local runs

Troubleshooting

429 Too Many Requests
Over 5 calls per minute on the free plan. Wait and fetch larger ranges per call.
NOT_AUTHORIZED
The data (e.g. minute bars, real-time, options) is not in your plan.
Empty results
A wrong ticker prefix (X: crypto, C: forex) or a range outside your plan’s history.

Frequently asked questions

Can I have more than one Massive API key?

Yes. Create one per app in the dashboard and revoke them individually.

Should I send the key in the URL or a header?

Both work. A header (Authorization: Bearer) keeps it out of logs; the query parameter is easier for quick tests.

Turn Massive (Polygon.io) data into a tested strategy

Backtest an idea in the browser, then export Python whose live loop reads candles straight from Massive (Polygon.io) with your own key.

  • Generated Massive (Polygon.io) candle fetcher, closed bars only
  • An AI copilot that writes and revises the rules
  • Pair it with Alpaca, Binance, OANDA or another broker
Build with Massive (Polygon.io) dataCompare platforms

Free plan, no card required. Massive (Polygon.io) is included with Pro.

How the Massive (Polygon.io) API works

AlgoGP is not affiliated with Massive (Polygon.io). Menus get renamed from time to time; if a label differs, the official documentation has the current path.