Korea Financial Supervisory Service (FSS) DART
5% large-holdings reports (Capital Markets Act art. 147) for the KR listed universe - exact holding ratios per report, plus the corpCode master (118,712 registrants with Hangul + English names and KRX codes)
Source
Feed (what to expect)
Registered open API (free key): corpCode.xml master zip, then majorstock.json per listed corp_code. 20,000 requests/day on the free tier.
Quirks
Key in .env as STRATA_OPENDART_API_KEY (SecretStr, never logged). Issuers minted kr_dart:<corp_code>; English names + KRX codes ride as bridge evidence.
Reconciliation
Schema
Feeds (axes)
Record kinds
Identifier schemes