# nsgoods — the verifiable trust layer for AI agents

> The verifiable trust layer for AI agents: pay-per-call oracles on Base (USDC) whose every paid
> response is ECDSA-signed and appended to a public, tamper-evident hash chain (OpenTimestamps-
> anchored) — so an agent can verify authenticity before trusting it. Free preview on every service.
> This hub is a directory only — it does not take payments. Pay per call at each service's own endpoint.

## Services
- Kraken Crypto Signals (markets) — https://signals.nsgoods.org — Signed & provable market signals — BUY/SELL/HOLD + confidence for Kraken pairs. Paid $0.01/call.
    - manifest: https://signals.nsgoods.org/.well-known/x402 · free preview + /health · signed + hash-chain proof
- Agent Trust Oracle (agent-infra) — https://trust.nsgoods.org — Verify any agent — ERC-8004 reputation / trust scores (0-100), signed, for agent-to-agent decisions. Paid $0.005/call.
    - manifest: https://trust.nsgoods.org/.well-known/x402 · free preview + /health · signed + hash-chain proof
- CMC Regime Skill (markets) — https://regime.nsgoods.org — Deterministic, signed market regime (TREND_UP/DOWN/CHOP/RISK_OFF) + strategy spec. Paid $0.01/call.
    - manifest: https://regime.nsgoods.org/.well-known/x402 · free preview + /health · signed + hash-chain proof
- Extractability Oracle (web/GEO) — https://schema.nsgoods.org — Verifiable web / GEO trust score (0-100) for any page: can AI answer engines quote it? Paid $0.01/call.
    - manifest: https://schema.nsgoods.org/.well-known/x402 · free preview + /health · signed + hash-chain proof
- Solar Legality Oracle (open-data) — https://solar.nsgoods.org — Signed reference data — US 50-state plug-in / balcony solar legality (CC BY 4.0). Paid $0.005/call.
    - manifest: https://solar.nsgoods.org/.well-known/x402 · free preview + /health · signed + hash-chain proof

## Hub endpoints
- GET / — catalog landing (human + JSON-LD Organization/ItemList)
- GET /health — live up/down of all five services
- GET /.well-known/x402 — aggregated discovery index (points to per-service manifests)
- GET /openapi.json — hub API description
- GET /llms.txt — this document
- GET /ai/summary.json — machine-readable hub summary for AI agents
- GET /.well-known/ai.txt — AI crawler policy

## Payment
All services use the x402 protocol on Base mainnet, settled in USDC. An agent calls a paid
endpoint, receives HTTP 402 with price + instructions, submits a signed USDC payment, and retries.

## How to pay (for agents)
Every service is free to preview first: hit /health or the /*/preview (or /.well-known/x402)
route to see shape and price at no cost, then pay only the signed endpoint.
The 402 payment requirements are provided in BOTH places, so any x402 client works:
  - the base64 PAYMENT-REQUIRED response header (x402 v2 clients), and
  - the JSON response body's `accepts[]` array (v1-compatible clients, e.g. x402-fetch),
    which additionally carries a `maxAmountRequired` alias of `amount`.
Minimal client (Node, x402-fetch + a viem wallet):
    import { wrapFetchWithPayment } from "x402-fetch";
    const pay = wrapFetchWithPayment(fetch, wallet);   // wallet = viem account/signer
    const res = await pay("https://trust.nsgoods.org/agent-trust?agent=25975");