x402 Protocol — Episode 7: Zero Services Offered Korean Crypto Sentiment. So I Built One.
I counted how many services in the world offer Korean-language crypto sentiment analysis as an API. Santiment — English only, $49–349/month. LunarCrush — English only, $49–299/month. The Tie — English only, institutional pricing. Messari — English only, x402 pay-per-request. Sentiment402 — English only, $0.10/call. Korean? Zero. Not one service where an AI agent can call an API and get "here's what Korean retail investors are feeling right now" in a structured JSON response. And there's an academic paper from April 2026 that says Korean news sentiment is the only one that predicts global crypto returns. Not US sentiment. Not Chinese. Korean. So I built it. What This Post Covers Building a Korean crypto sentiment analysis endpoint from scratch — the market research that confirmed zero competition exists, a data source that turned out to be useless, the realization that exchange data I was already collecting was the real sentiment signal all along, and gett...