# Kraken Crypto Signals — x402 pay-per-call API
Machine-readable crypto market-state data for AI agents, paid per call in USDC on Base via x402. No accounts, no API keys. Every response is ECDSA-signed and verifiable.

Base: https://signals.nsgoods.org
Manifest: https://signals.nsgoods.org/.well-known/x402
OpenAPI: https://signals.nsgoods.org/openapi.json
Agent card (A2A): https://signals.nsgoods.org/.well-known/agent.json
MCP: npx -y nsgoods-mcp — unified server (Claude Desktop / Cursor). Previews free; paid tools need EVM_PRIVATE_KEY (small USDC on Base).
Quickstart (runnable demo agent, free preview + 402 challenge, ~5 min): https://github.com/Nikoble1926/kraken-crypto-signals/tree/main/examples/quickstart

Paid endpoints (USDC on Base):
- GET /signals?pair=BTC/USD   trading signal BUY/SELL/HOLD + confidence   $0.01
- GET /signals/top            market scan, strongest signals             $0.10
- GET /history?limit=20       revealed historical snapshots + hashes      $0.05
- GET /regime/changed?since=RISK_ON   market regime + change flag         $0.02
- GET /backtest?pair=BTC/USD  walk-forward win-rate + avg forward return  $0.25

Free:
- GET /signals/preview        sample BTC/USD direction
- GET /track-record           public commit-reveal hash chain

How to pay: call an endpoint; on HTTP 402, settle the x402 payment (USDC on Base) and retry. See https://x402.org. Not financial advice.