API Documentation

Guide

Overview

What this is

Bulk historical US stock data as compressed CSV files (day and minute aggregates). The API returns a short-lived presigned download URL — you download the file directly from storage, not through a long JSON body.

URLs to know

Portal (website)
https://financialdata.online — sign up, pricing, and account area.
REST API (Flat Files)
https://api.financialdata.online/api/v1/stocks/s3/ — day and minute aggregate paths under aggs/day/ and aggs/minute/.

Example: https://api.financialdata.online/api/v1/stocks/s3/aggs/day/2025/10/10/

Suggested flow

  1. Auth Read — same X-Request-Token as REST.
  2. Endpoint Pick day or minute aggregates in the sidebar and note the path parameters (year, month, day).
  3. Request GET the endpoint; the JSON response includes download_url, file_path, and expires_in.
  4. Download Fetch the file from download_url before it expires (typically about one hour).
Files are .csv.gz (gzip). See each operation for the exact path layout and fields.