Calibrated Similarity Search API

Gold402 Verified. Hand-reviewed and on the curated list — curation is the bar. The stamp means a human read this entry and the endpoint answered when we knocked. It is not a delivery test: we have not paid this service and graded what came back, so treat it as "reachable and speaks the protocol," never as "this is worth the money."

Stateless NMI + cosine fusion similarity search over pre-computed numeric vectors, with an entropy-calibrated blending weight (alpha) computed per request; vectors only, no server-side embedding. $0.01 USDC on Base Sepolia (testnet) via x402, no API key required. Example: `POST /similarity/search {"query":{"id":"q1","vector":[0.1,0.2,0.3]},"corpus":[{"id":"c1","vector":[0.1,0.2,0.3]}]}`. ([OpenAPI](https://similarity-search-api-production.up.railway.app/openapi.json)) ([Agent Card](https://similarity-search-api-production.up.railway.app/.well-known/agent-card.json)) ([GitHub](https://github.com/nexus-mcp-infra/similarity-search-api-sdk))