# Wintergreen x402 Trust Check

> Wintergreen x402 Trust Check is a paid API for AI agents from x402.wintergreen.uk, paid per call via x402, $0.002/call, status down (last checked 2026-10-13).

Verifies whether a given URL is a legitimate, verified x402 payment-gated endpoint by checking its trust score and P2D badge status.

## Facts

- Endpoint: GET https://x402.wintergreen.uk/api/v1/trust/check?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: down
- Last checked: 2026-10-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/wintergreen-x402-trust-check-03f6a738
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_aK9hnagVmHQMH0doQdWFd

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability wintergreen-x402-trust-check-03f6a738
```

Example prompt: Can you check whether https://api.someservice.xyz/crypto/signals is a legitimate, verified x402 endpoint before I authorize any USDC payments to it?

## When to prefer this

Use this endpoint when an AI agent needs to vet an unknown x402 payment-gated API before committing USDC funds — especially useful in automated agent pipelines where arbitrary x402 URLs may be encountered and must be screened for legitimacy before payment. Prefer this over manual inspection when operating at scale or when the agent cannot otherwise verify P2D badge status.

## Known failure modes

- URL not found in any trust registry — returns low or zero trust score
- Malformed or non-HTTP URL input causes validation error
- Endpoint not yet indexed by x402scan or probe sources — result may be stale or absent
- Payment of $0.002 USDC required; missing or invalid X-PAYMENT header returns HTTP 402
- Network timeout reaching the Wintergreen trust service

## How this service works

Payment-gated crypto trading intelligence for AI agents.
    
## Categories
- **Hyperliquid Signals**: Real-time funding divergence, lead-lag correlation, liquidation clusters, session volume area levels
- **Quant Methodology**: Backtesting walk-forward validation, strategy generation with kill battery (19 rules), risk management with Kelly sizing, regime detection, execution frameworks, agent orchestration
- **Market Insights**: 22 crypto microstructure observations — funding, liquidation, orderbook, regime, flow, anomaly
- **Power Markets**: ERCOT field guide, merit-order model, duck curve analysis
- **Career Guides**: Firefighter oral board prep, medical coding, ATSA, contractor estimating
- **Trust Scoring**: x402 endpoint verification, P2D badges

## Payment
All paid endpoints return HTTP 402 with USDC on Base (eip155:8453). 
Sign EIP-712 TransferWithAuthorization and retry with X-PAYMENT header.
PayTo: 0xAe9834d71F1Bd989A0dc17593451af823E31CeeD

## Output

Returns a trust assessment for the submitted URL, including a verification status indicating whether the endpoint is a recognized x402 provider, any P2D (Proved-to-Deliver) badge status, and a trust score derived from crawl sources such as x402scan and Coinbase-curated GitHub listings.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "url": {
   "type": "string"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/wintergreen-x402-trust-check-03f6a738/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402.wintergreen.uk](https://www.zero.xyz/host/x402.wintergreen.uk/llms.txt)