ko.io/ API Documentation

API Reference

SEC financial data API. Institutional holdings, insider trades, congress trading, and more.

Authentication

All API requests require a Bearer token in the Authorization header.

curl https://api.ko.io/api/v1/institutions \ -H "Authorization: Bearer ko_live_your_key"

Get your API key at Console → API Keys

Rate Limits

PlanRequests/DayPrice
Free100$0
Developer10,000$29/mo
Team100,000$99/mo
EnterpriseUnlimited$499+/mo

Response Format

Success

{ "data": { ... }, "meta": { "query_time_ms": 4.2, "total_count": 1847 } }

Error

{ "error": { "code": "RATE_LIMIT_EXCEEDED", "message": "..." } }

Endpoints

GET/api/v1/holdings/{cik}

Get institution holdings from 13F filings

GET/api/v1/institutions

List institutional investors

GET/api/v1/institutions/{cik}

Get institution details

GET/api/v1/insider-trades

List insider trades (Form 4)

GET/api/v1/executive-trades/{ticker}

Get executive trades for a stock

GET/api/v1/congress-trades

List congress member trades

GET/api/v1/congress-trades/{member}

Get trades for a specific member

GET/api/v1/stocks/{ticker}

Get stock info + top holders

GET/api/v1/stock-price/{ticker}

Get historical stock prices

POST/api/v1/query

Natural language to SQL query

All list endpoints support page and per_page query parameters for pagination (default: page=1, per_page=50, max 500).