How to use Polygon.io — a practical guide

If you're here, you probably want working code in five minutes. That's exactly what this guide does.

Five steps to get started

  1. 1
    Register at polygon.io for an API key.
  2. 2
    Call /v2/aggs/ticker/{ticker}/prev.

Shortest snippet that will actually run

curl "https://api.polygon.io/v2/aggs/ticker/AAPL/prev?apiKey=YOUR_KEY"

Common mistakes (the honest list)

For historical storage — /v2/aggs/ticker/.../range/... returns daily history.