Polygon.io

Polygon.io is the market-data API used in Brevvie Python + AI — Section 4: APIs, Postman & Calling the Web. It demonstrates a keyed API with terse field names and date-ranged financial data.

Role in the source

• fetches QQQ daily aggregate bars
• introduces compact field names like o, c, h, l, v, and t
• reinforces the need to read API docs because naming conventions vary