# 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
- Agent Screening (agent-infra): https://trust.nsgoods.org. Signed OFAC sanctions + malicious-address screening for any EVM or Solana address, negative-evidence risk signals for counterparty / payment decisions. Paid $0.005/call.
    - manifest: https://trust.nsgoods.org/.well-known/x402 · free preview + /health · signed + hash-chain proof
- Sanctions Screening Oracle (agent-infra): https://sanctions.nsgoods.org. Signed multi-chain OFAC SDN exact-address screening (live counts: sanctions.nsgoods.org/health). Free signed preview. Settles on Solana in USDC (not Base). Paid $0.005/call.
    - manifest: https://sanctions.nsgoods.org/.well-known/x402 · free preview + /health · signed + hash-chain proof
- x402 Payability Check (agent-infra): https://payable.nsgoods.org. Checks whether an x402 endpoint can actually settle: reachable, well-formed 402, and (for Solana/SPL) whether the destination token account (ATA) exists on-chain. Signed verdict, free preview. Paid $0.005/call.
    - manifest: https://payable.nsgoods.org/.well-known/x402 · free preview + /health · signed + hash-chain proof
- Solana Settlement Verification (agent-infra): https://x402.nsgoods.org/settle. Signed Solana settlement verification: did this transaction credit that amount to that payee? Finalized-mainnet verdict (VERIFIED / REFUTED / UNCONFIRMED / NOT_FOUND) with a per-field breakdown. Free signed preview. Paid $0.01/call.
    - manifest: https://x402.nsgoods.org/settle/schema/settle_v1.schema.json · free preview + /health · signed + hash-chain proof
- Preflight Composite (agent-infra): https://x402.nsgoods.org/preflight. One signed call, three independent checks of one address: payability, OFAC sanctions, and ERC-8004 trust, each its own signed sub-result with no aggregate score. Composite envelope, free signed preview. Paid $0.015/call.
    - manifest: https://x402.nsgoods.org/preflight/schema/preflight_v3.schema.json · free preview + /health · signed + hash-chain proof
- Watchdog (agent-infra): https://x402.nsgoods.org/watchdog. Signed monitoring of any x402 endpoint: EIP-191-signed alerts when it goes unreachable, its payability verdict degrades, or its declared payTo / networks / asset changes. One paid call is a 30-day subscription for one endpoint at $5; free tier is one endpoint per verified channel (email or webhook). Paid $5.00/call.
    - manifest: https://x402.nsgoods.org/watchdog/schema/watchdog_v1.schema.json · free preview + /health · signed + hash-chain proof
- Multi-List Sanctions Screening (agent-infra): https://sanctions.nsgoods.org/screen-multi. Signed four-list sanctions screening (OFAC, UN, EU, UK Sanctions List (FCDO)), per-list matched/clear + that list's version date in one signed verdict, with explicit list_health (a stale or unavailable feed is reported, never a silent clear). Dual-rail USDC on Base or Solana. Free signed preview. Paid $0.01/call.
    - manifest: https://sanctions.nsgoods.org/screen-multi/preview · free preview + /health · signed + hash-chain proof
    - Sanctions check before you pay: https://sanctions.nsgoods.org/screen-url, same screening, but you give the x402 endpoint URL instead of an address: reads its own 402 quote and screens every payTo on every network against OFAC, UN, EU and UK; signed verdict per payee and overall; $0.01 USDC on Base or Solana; never charged for an error; free preview at /screen-url/preview.

## MCP server
- MCP server (read only, free, 8 tools): https://mcp.nsgoods.org/mcp. Connect from Claude via Settings > Connectors > Add custom connector. Details: https://x402.nsgoods.org/#mcp

## Case study
- Walpulse runs our multi list sanctions screening inside its product: https://x402.nsgoods.org/proof/case-studies/walpulse.html

## Independently observed
- Third party public records that reference nsgoods, none written or paid for by us: https://x402.nsgoods.org/proof/observed.html
- ExactZK (independent zkML provenance project) independently verified the nsgoods signing construction by counter test, recomputed the JCS digests of specific published attestations and matched them to the values we publish, and checked that our signed manifest is the authority scoping the signing key. September 2026. This verification covers those signatures and our manifest only, not our services.

## Independent reproductions
- We rebuild third party deployed artifacts on a clean disposable host and publish signed attestations. Six signed attestation records are in our signed manifest https://x402.nsgoods.org/proof/index.json, covering four independent reproductions of the ExactZK bundle, including the first signed reproduction of the solo circuit's verifying key, now filed on chain; four of the records are also published in the upstream bundle: https://github.com/achemperety/exactzk-mnistmlp-provenance-demo

## Operator
- nsgoods is built and operated by Nikolaos Dimitriadis, an independent developer based in Liverpool, United Kingdom, working as a UK registered sole trader.
- Operator identity links: X https://x.com/nickbuildsai · npm profile https://www.npmjs.com/~nikosble1926 · npm package https://www.npmjs.com/package/nsgoods-mcp · LinkedIn https://www.linkedin.com/in/nikos-dimitriadis-ai
- About: https://x402.nsgoods.org/about · Terms: https://x402.nsgoods.org/terms · Privacy: https://x402.nsgoods.org/privacy · Basescan: https://basescan.org/address/0xc87a06DEE4c0E85912296002617120BBfd5EF990

## Hub endpoints
- GET /: catalog landing (human + JSON-LD Organization/ItemList)
- GET /health: live up/down of all twelve 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
- POST /feedback: structured feedback from agents, free

## 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");