CrossFin is a financial router for AI agents, designed to solve the problem of AI agents having difficulty accessing Asian (especially South Korean) cryptocurrency markets. South Korean exchanges typically have language barriers, IP restrictions, real-name verification account requirements, and a lack of English documentation. CrossFin opens access to these markets for agents through a unified routing and payment layer.
Main capabilities:
- Routing engine: Given a source (exchange + currency) and destination, evaluate all possible paths, taking into account trading fees (0.10–0.25%), withdrawal fees (fixed by coin), order book slippage, transfer time, and routing spread direction, supporting bidirectional routing from South Korea to the world and from the world to South Korea. Use 13 bridge coins (BTC, ETH, XRP, SOL, DOGE, ADA, DOT, LINK, AVAX, TRX, KAIA, SUI, APT) across 14 exchanges to find the optimal path.
- Kimchi premium and price comparison: Real-time query of the price spread between South Korean and global exchanges, as well as the price comparison between Bithumb KRW and Binance USD.
- Asian premium index: Cryptocurrency premium analysis covering four countries: South Korea, Japan, Indonesia, and Thailand. Data sources include bitbank.cc (Japan), Indodax (Indonesia), Bitkub (Thailand), Bithumb (South Korea), and Binance (global).
- x402 payments: Support pay-per-call API access via the x402 protocol with USDC (on the Base network), with no API keys, subscriptions, or invoices required. Currently, all endpoints are free during the public beta.
- MCP tools: Provide 16 MCP tools, including find_optimal_route, get_kimchi_premium, compare_exchange_prices, call_paid_service, etc.
How to use: Add the CrossFin MCP server to the MCP client configuration, restart the client, and then the 16 tools can be used. Currently, all API endpoints are free and require no API key, and an EVM wallet is optional (for testing the x402 payment process). Developers can use the npm package crossfin-mcp.
Use cases: AI agents need to access Asian cryptocurrency market data, find the optimal path for cross-exchange fund transfers, monitor price spreads between South Korean and global markets, perform Asian premium analysis, etc.
Limitations and notes: Currently, all endpoints are in an open public beta phase and are all free; the x402 payment infrastructure is ready and waiting to be enabled in the future. An EVM wallet is optional for testing the payment process. The project was built by a non-developer within 1 week through AI collaboration, with zero programming experience background. The links provided include live.crossfin.dev (demo), crossfin.dev (online), Agent Guide, OpenAPI Spec, Docs, etc.
