K-Data x402

Korean market data for AI agents — kimchi premium on a tradeable USDT basis, premium history and percentiles, Korean news translated to English, Upbit KRW quotes. Pay per request with USDC via x402. No account, no API key.

x402USDC on Baseno API keyagent-first

Why this service

Dual-basis kimchi premium: the official USD/KRW figure everyone quotes, plus the Upbit KRW/USDT basis that an arbitrageur can actually realize. The two often disagree in sign — official can read negative while the tradeable basis is positive.
Premium history and percentile context, continuously archived. No free source and no competing x402 seller offers this; it cannot be reconstructed after the fact.
Korean headlines translated to English, so a non-Korean agent can actually use them.

How to pay (for agents)

GET any paid endpoint → you receive HTTP 402 with payment requirements.
Pay with any x402 client (@x402/fetch, x402 MCP tools, Apify, etc.).
Retry with the payment header → data is returned and payment settles on-chain.

For agents: openapi.json · catalog · llms.txt

Endpoints & pricing

Endpoint	Price	Description
`GET /api/kimchi-premium`	$0.03	Kimchi premium on two bases: premium_official_pct (official USD/KRW rate — the quoted figure) and premium_usdt_pct (Upbit KRW/USDT rate — the margin actually realizable, since the KRW exit leg goes through USDT rather than banks). The two frequently disagree in sign. Optional ?symbols=BTC,ETH (max 10).
`GET /api/kimchi-premium/stats`	$0.12	Where the current kimchi premium sits inside its own recent distribution: percentile, mean, stdev, z-score, min/max/median, and a plain-language read. Answers 'is this premium unusual right now?' in one call. Built from a continuous archive that cannot be reconstructed from any free source. Params: ?symbol=BTC &window=1h\|6h\|24h\|7d\|30d\|90d &basis=usdt\|official.
`GET /api/kimchi-premium/history`	$0.08	Time series of the kimchi premium from the continuous archive, both bases, newest-last. Params: ?symbol=BTC &window=1h\|6h\|24h\|7d\|30d\|90d &points=500 (max 2000). Archive depth is reported as first_recorded.
`GET /api/news/headlines/en`	$0.05	Latest Korean headlines with English translations attached (title_en), from Yonhap, Maeil Business and Hankyung — deduplicated, newest first. Use this instead of the Korean-only route when the consuming agent does not read Korean. Optional ?category=top\|economy\|tech\|politics and ?limit=20 (max 50).
`GET /api/korea/market-snapshot`	$0.08	One-call Korea briefing: dual-basis kimchi premium + top Upbit KRW markets + USD/KRW + latest economy headlines translated to English. Everything needed for a Korea market read in a single paid request.
`GET /api/crypto/krw/markets`	$0.01	Snapshot of all Upbit KRW crypto markets: top by 24h traded value, top gainers, top losers. Optional ?limit=30 (max 100) for the volume ranking.
`GET /api/news/headlines`	$0.01	Latest Korean headlines from Yonhap, Maeil Business and Hankyung, deduplicated and newest-first. Titles stay in Korean — use /api/news/headlines/en for English. Optional ?category=top\|economy\|tech\|politics and ?limit=30 (max 100).
`GET /api/crypto/krw/:ticker`	$0.005	Live quote for one Upbit KRW market by ticker symbol (e.g. BTC, ETH, XRP): price, 24h change, 24h high/low, 24h traded value in KRW.
`GET /api/fx/usdkrw`	$0.005	Current USD/KRW exchange rate (ECB reference via Frankfurter, fallback open.er-api.com).