The SEC EDGAR API is one of the best-kept secrets in financial data engineering: every mandatory disclosure filed by every U.S. public company, available as clean JSON, for free, with no API key. If you've ever paid for a "fundamentals" data vendor or scraped a brokerage page for a balance sheet, you've been working harder than you need to. The raw, authoritative source — quarterly revenue, insider trades, institutional holdings, 8-K event filings — is sitting on data.sec.gov waiting for an HTTP GET.
The catch is small but absolute, and it trips up almost everyone on their first request. Let's walk through how the API actually works, write a correct, runnable Python example, and cover the one rule that will get your IP blocked if you ignore it.
What "the SEC EDGAR API" actually is
There isn't a single endpoint. "The SEC EDGAR API" is really three free public services that work together:
The structured data API (data.sec.gov) — JSON endpoints for company submissions and XBRL financial facts.
