Side-by-side comparison of two Model Context Protocol servers — install paths, tools, quality signals, and directory engagement so you can pick the right one for Claude, Cursor, and other MCP clients.
PayPerByte — per-byte data marketplace for AI agents on Arbitrum. Discover publishers, evaluate on-chain Proof-of-Quality Score (PQS), subscribe + pay per request in USDC via x402 gateway. 15 tools, zero API keys.
LLM-agent-native backtest framework for SHFE daily futures research. 23 MCP tools (strategy validation, scaffolding, indicator catalog, error-code lookup), 22 in-package skills, 32 catalogued error codes, working strategy templates. pip install echolon then claude mcp add -s user echolon -- echolon-mcp.